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2018 | Buch

Advanced Functional Materials

Proceedings of Chinese Materials Conference 2017

herausgegeben von: Prof. Yafang Han

Verlag: Springer Singapore

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Über dieses Buch

This proceedings volume gathers selected papers presented at the Chinese Materials Conference 2017 (CMC2017), held in Yinchuan City, Ningxia, China, on July 06-12, 2017.

This book covers a wide range of metamaterials and multifunctional composites, multiferroic materials, amorphous and high-entropy alloys, advanced glass materials and devices, advanced optoelectronic and microelectronic materials, biomaterials, deformation behavior and flow units in metastable materials, advanced fibers and nano-composites, polymer materials, and nanoporous metal materials.

The Chinese Materials Conference (CMC) is the most important serial conference of the Chinese Materials Research Society (C-MRS) and has been held each year since the early 1990s. The 2017 installment included 37 Symposia covering four fields: Advances in energy and environmental materials; High performance structural materials; Fundamental research on materials; and Advanced functional materials. More than 5500 participants attended the congress, and the organizers received more than 700 technical papers. Based on the recommendations of symposium organizers and after peer reviewing, 490 papers have been included in the present proceedings, which showcase the latest original research results in the field of materials, achieved by more than 300 research groups at various universities and research institutes.

Inhaltsverzeichnis

Frontmatter
The Stress and Morphology Evolution of CZO Films Under Different Growth Temperature

Zn1−xCoxO (x = 0.05, CZO) thin films are deposited on Si(111) and glass substrates at different substrate temperatures from 350 to 500 °C. All the CZO films on glass substrates exhibit compressive stress, but for the films deposited on Si substrates, the change from compressive to tensile one is observed. The increase of Ts is favorable for the reduction of stress in the films. Roughness exponent α, RMS roughness w and autocorrelation length ξ are calculated. At lower temperature, for both substrates, α is less than 0.65, indicating lower temperature could not provide sufficient energy for the free migration and diffusion of the deposited atoms. The ratio of w/ξ increases with the increase of Ts from 350 to 450 °C, suggesting that the upward growth of the CZO film depends much more on growth temperature than the lateral one. When the temperature increases further, w/ξ decreases, but the morphology of CZO films shows the same evolution feature in spite of the type of substrate, indicating that Ts plays a dominate role rather than substrates in the ratio of w/ξ CZO films.

Dong Zhao, Yunyan Liu, Shutao Li, Rendong Wang, Junshan Xiu, Gongxiang Wei, Meiling Sun, Mengzhen Song, Shenggui Fu
Tunable Dielectric Property of Fe3O4/SiO2 Meta-composite Fabricated by Magnetic-Field Assisted Self-assembly

In this paper, SiO2 microsphere self-assembly process and heat treatment were combined to prepare Fe3O4/SiO2 meta-composites. XRD, SEM and Precision Impedance Analyzer were used to study the phase composition, microstructure, and dielectric properties of the composites at MHz frequency range. The results show that SiO2 microsphere matrix forms a hexagonal close packing structure and nano-Fe3O4 magnetic particles fill the gap between the close-packed SiO2 microspheres. The results indicate that, in a certain frequency range (1–3 MHz), the dielectric properties of the composites can be tuned by using applied magnetic field to change the distribution of the magnetic particles. But in the other test frequency range, the dielectric properties of the composites show no difference, whether to use magnetic field to control the distribution of the magnetic particles or not.

Muyu Wang, Wenjin Zhang, Yang Huang, Chongpu Wang, Ruoyu Shi, Zhetong Liu, Yangfan Su, Zidong Zhang
Synthesis, Magnetic and Electrochemical Properties of NiFe2O4-rGO Nanohybrids

In this paper, nickel ferrite (NiFe2O4)-reduced graphene oxide (rGO) nanohybrids were synthesized via a hydrothermal strategy successfully. The morphology and phase composition of as-prepared products were analyzed by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results show that the well-crystalized NiFe2O4 nano octahedrons with edge of 100 nm grew on the surface of rGO successfully. The magnetic property of the synthesized nanohybrids at room temperature was characterized by a vibrating sample magnetometer (VSM). The result shows that the nanohybrids have high saturation magnetization of 76.8 emu‧g−1 and present a superparamagnetic property. The electrochemical property of the obtained nanohybrids was characterized by an Eight-channel battery tester through using the nanohybrids as the lithium-ion battery cathode material. It is found that the obtained nanohybrids have an initial discharge capacity and charge capacity of 1469 and 652 mA h·g−1 respectively when the discharge—charge rate is 0.1 C.

Gongqin Yan, Qiang He, Dongyan Yu
Insulating Technology Control of Soft Magnetic Composites

In this paper, fabrication procedures were adjusted and investigated in soft magnetic composite (SMCs) when the micro-scale iron powder was served as matrix with amorphous silica as the insulating coating layer. The coating situations were alternated by transforming the TEOS (tetraethoxysilane) hydrolysis parameters such as temperature, PH value, and TEOS reagent dosage. It was found that the silica deposited on raw iron particles which is produced by the hydrolysis reaction from the increasing addition of TEOS reagent would make the coating layer too thick. Over-high pH value would has a great negative influence on the silica coating layers, over-high temperature would speed the hydrolysis reaction up, while silica derived from hydrolysis reaction were self-assembled to silica particles and the deposition amounts on iron particles were less. Moreover, the circumstances of insulation coating layer were characterized by introducing low frequency complex dielectric parameters as indirect assessments. The magnetic properties including saturation flux density (Bs), hysteresis loss were investigated. SEM images were presented to directly exhibit the morphology of coated iron particles. The thorough investigation of coated particles’ fabrication procedures greatly facilitates the applications of soft magnetic materials.

Jiaqi Chen, Yunpeng Qu, Ciqun Xu, Huan Ren, Yao Liu
Dielectric Properties of Cu/Epoxy Random Composites at Radio-Frequency Range

Cu/epoxy composites with the different volume fraction of Cu were prepared through hot press process. The conductivity and dielectric properties of the Cu/epoxy composite were investigated. The analyze of the results indicated that the real part of permittivity $$ \varepsilon _{r}^{{\prime }} $$ of Cu/epoxy composites increased when copper content increased, which is caused by the increasing interface connect between Cu fillers and epoxy partials. The frequency dispersions of ac conductivity follow the power law and thus indicates the hopping conduction behavior in composites.

Ciqun Xu, Peitao Xie, Yunpeng Qu, Yulin Wu, Jiaqi Chen, Huan Ren, Yao Liu
Preparation and Photoelectric Property of Poly-3-Methylthiophene/Nano-TiO2 Composite

A poly 3-methylthiophene/nano-TiO2 composite was prepared by in situ oxidative polymerization technique. We explored properties of the composite when nano-TiO2 was modified and unmodified, researched the representation of the composite with different molar ratios of 3-methylthiophene and anhydrous FeCl3, different mass ratios of 3-methylthiophene and nano-TiO2. The results show that the photoelectric property of poly-3-methylthiophene/modified nano-TiO2 composite is better than that of unmodified nano-TiO2 composite. When the molar ratio of 3-methylthiophene and anhydrous FeCl3 is 1:2, the mass ratio of 3-methylthiophene and nano-TiO2 is 2:1, the composite material has good optical properties.

Li Gao, Xiaowei Yan, Xin Yang, Wulin Ma, Haiying Du
Preparation of Nickel and Manganese Oxides Composite via Co-precipitation Method and Its Electrochemical Properties

A simple co-precipitation using Na2CO3 as precipitation was used to get Nickel and manganese oxides (Ni–Mn oxides). After that process, there is a mixture of nickel oxide, manganese oxide and its solid solution. XRD and SEM were used to get the phase and morphology of the products. In 6 mol/L KOH aqueous electrolyte, electrochemical capacitance characterization were tested by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrical impedance spectroscopy (EIS) measurements. The results show that When the Ni/Mn ratio is 3/1, Mn2O3 appears, and at this point the compounds are NiO and Mn2O3 complexes. And the electrochemical performance of this composite is better than that of single-phase NiO.

Huan Ren, Zhong-yang Wang, Qian-qian Li, Yao Liu
Synthesis and Properties Research of Coin-Like α-Fe2O3 Nanoparticles

In this paper, coin-like α-Fe2O3 nanoparticles were synthesized successfully through a hydrothermal method in EG/DEG mixed solution with PVP as surfactant and NaOAc as alkali source. The phase composition and morphology of as-prepared products were analyzed. It was found that the EG/DEG ratio in the mixed solution plays a key role in the formation of coin-like α-Fe2O3 nanoparticles. The magnetic property of the synthesized coin-like α-Fe2O3 nanoparticles at room temperature was also characterized. The result shows that the coin-like α-Fe2O3 nanoparticles have a saturation magnetization of 7.678 emug−1 and present a superparamagnetic property. The electrochemical property of the obtained coin-like α-Fe2O3 nanoparticles was characterized through using the coin-like α-Fe2O3 nanoparticles as the cathode material of a lithium-ion battery. It is found that the obtained coin-like nanoparticles have an initial discharge capacity of 393 mAh·g−1 and a charge capacity of 236 mAh·g−1 when the charge-discharge rate is 0.1 C.

Gongqin Yan, Qiang He, Dongyan Yu
Preparation and Optical Properties of Self-assembled ZnO Lyche-like Aggregates

The self-assembled lyche-like aggregates with ZnO nanoparticles were prepared via the hydrothermal method assisted by solvent (isopropanol)-evaporation in the present of the additives. The evaporation of the solvent was demonstrated to play a critical role on the formation of lyche-like aggregates of ZnO. The structures, morphologies and optical properties of as-prepared products were investigated by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscope (FESEM), Fourier Transformation Infrared spectra (FT-IR), Ultraviolet visible absorption spectra (UV-vis) and Photoluminescence spectra (PL). The results show that the increased steric effect among the ZnO nanoparticles constructs the lyche-like aggregates ultimately with the decreases of the solvent in the reaction system. The infrared emissivity value in 8–14 μm of ZnO nanoparticles is 0.922. Contrastively the emissivity value of the lyche-like ZnO aggregates slightly decreases to 0.915. It can be expected as an effective method for the formation of near-spherical structure of metal oxides nanoparticles aggregates. It may be used as an unique pigment in the field of low infrared emissivity coatings or other functional materials.

Xiaoyun Ye, Wei Li, Yongnan Lin, Shuguang Cai, Yan Lin
Effects of Microwave Irradiation on Electricity of Graphene Oxide Films

In this study, thermally pre-reduced graphene oxide films were prepared, with respect to different microwave irradiation time and the electrical properties of those films were investigated. The interaction of GO films under intense microwave irradiation was also examined. It was found that the response of GO films to microwave irradiation was not obvious, while significant reduction could be observed for thermally pre-reduced GO films during microwave treatment. The reduction by microwave irradiation of pre-reduced GO films was confirmed through X-ray photoelectron spectroscopy (XPS) and raman spectroscopy. Compared with that of GO films, electrical conductivity of thermally pre-reduced GO films, under microwave irradiation for 5 min, was increased by three orders of magnitude approximately. The results indicated that pre-reduced GO films were effective microwave absorbent, with conversing microwave energy to heat, thus contributing to the restoration of graphite lattice and enhancing connectivity of existing graphite domains.

Shaofeng Lin, Sai Yuan, Jianwei Zhang, Dazhi Jiang
Microwave Absorbing Performance on Polymer-Derived SiCN Ceramics Doped with Rare Earth Oxides

This study investigated the compositions, dielectric properties, magnetic properties and microwave absorbing properties of polymer-derived SiCN ceramics doped with Dy2O3, Eu2O3, Sm2O3, Y2O3 and Gd2O3 respectively. The complex permittivity and complex permeability were measured at the frequency range of 2–18 GHz. The reflectivity of polymer-derived SiCN ceramics doped with Eu2O3 reaches to the lowest value of −35 dB at 16.4 GHz. While the electromagnetic damping coefficient reaches the maximum value of 653 at 16.1 GHz, which clearly demonstrates that by doping Eu2O3 the wave absorbing performance of polymer-derived SiCN can be enhanced more pointedly than the other samples.

Yu Liu, Yurun Feng, Hongyu Gong, Xue Guo, Adil Saleem, Xiao Lin, Bingying Xie, Yujun Zhang
Preparation and Properties of Pressureless-Sintered Porous Si3N4 Ceramics

In this paper, the effect of benzoic acid on the porosity, dielectrical and mechanical properties of porous Si3N4 ceramics prepared by pressureless sintering was investigated. The results showed that the addition of benzoic acid improved the porosity and dielectrical properties of Si3N4 remarkably by pressureless sintering at 1700 ℃ for 60 min. The porosity of sample reached 40.79% with 50 wt% benzoic acid addition and the reflectivity of the sample reached −45 dB at around 12 GHz.

Xiao Lin, Jinming Shi, Hongyu Gong, Yujun Zhang, Yurun Feng, Xue Guo, Bingying Xie, Yu Liu, Jiajun Wei
In Situ Synthesis of ZrB2–SiC Composite Powders by Carbothermal Reduction Method

ZrB2–SiC composite powders were synthesized in situ via carbothermal reduction using ZrO2, HBO2 and carbon black as the starting materials. The influences of HBO2 contents (40.6–45.5 wt%), boron sources (HBO2, H3BO3 and B2O3) and carbon sources (black carbon, activated carbon, graphite and petroleum coke) on phase composition and morphology of ZrB2–SiC composite powders were analyzed. The obtained samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Results showed that when the HBO2 content was 43.2 wt%, impurity-free ZrB2–SiC composite powders could be successfully produced at 1600 °C for 90 min in argon atmosphere. Meanwhile, columnar ZrB2 and granular SiC particles were combined interactively. Compared with control groups, products fabricated via black carbon revealed the better crystallinity and finer particle size.

Bingying Xie, Jincheng Yu, Yujun Zhang, Hongyu Gong, Xiao Lin, Yu Liu
Facile Synthesis of Mn3O4 Nanoparticles Decorated Graphene as Enhanced Performance Electrode for Supercapacitor

Graphene was prepared by using the plant stem as a biotemplate through high temperature carbonization and Mn3O4/graphene composites were then prepared via a simple hydrothermal process. The surface morphology and structure of the Mn3O4/graphene hybrids were characterized by X-ray diffraction spectroscopy (XRD), Raman spectra, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrogram (XPS), N2 adsorption–desorption isotherms and electrochemical test. The results showed that the metal oxide nanoparticles were uniformly supported on the surface of graphene. Judging from the XRD, XPS and Raman, we could acquire that the Mn3O4 nanoparticle was in the crystal form while the average crystallite size was about 21 nm. The composites exhibited excellent specific capacitance as high as 196 F/g and the capacitance of the composites was 88% retained after 1000 cycles in 1 M Na2SO4 electrolyte at a charging rate of 2 A/g. The superior electrochemical properties could be due to the improved accessible area for ions in electrolytes and enhanced conductivities. The present study provides a facile way to design a high-performance Mn3O4/graphene based supercapacitor electrode and the concept is extendable to other pseudo capacitive electrodes.

Hui Sun, Chengbao Liu, Junchao Qian, Feng Chen, Zhengying Wu, Zhigang Chen
Preparation and Properties of Interconnected NiS Nanoparticle Network with Amphiphilic Polymers

Low-dimensional functional nanocomposite with visible light activity is one of hot-spots fields in chemistry, physics and materials according to the demands of new energy and environmental fields. To simulate the process of photosynthesis of nanomaterials, in this study, NiS nanomaterials were synthesized with amphiphilic polymers as soft template. The nanocomposite with integrated multi-functionalities were characterized with several approaches. The photoconductive responses to weak visible light and 808 nm NIR (near infrared) were studied based on interdigital electrodes of Au on flexible PET (polyethylene terephthalate) film substrate with casting method. The results indicated that the resulting NiS nanocomposite is core/shell structure, showing interconnected network, looks like honeycomb, and the nanocomposite with integrated multi-functionalities exhibited photo-switching behaviors, the ratio of On/Off was 2–3 orders of magnitudes, the response and recovery were very rapidly. It would be developed the intelligent nanocomposites with external stimuli responses, light detector to NIR, biomimetic materials, nano-machine controlled by light, environmental fields, and so on.

Shizhen Wang, Lin Bian, Jianxun Qiu, Wei Du, Xintao Zhang, Xiaochun He, Mingjun Gao, Xiangming Li, Xingfa Ma, Guang Li
Crystal Structure and Magnetic Properties of FePd/Si3N4 Composite Films

The ferromagnetic FePd/Si3N4 composite films were prepared by magnetron sputtering and then annealed at 500, 550, 600 and 700 °C for 3 h. The results show that the Si3N4 top layer can effectively inhibit the growth of FePd particles and refine the grain of FePd thin films. The crystallization of FePd/Si3N4 films increase with the rise of heat treatment temperature, and the fcc-fct phase transition process of the film increases further. When the annealing temperature rises to 700 °C, the diffraction peaks of the ordered phase are degraded instead. The reason is that the high annealing temperature disrupts the ordered arrangement of Fe and Pd, resulting in an increase in the composition of the disorder phase in the sample. The results of magnetic properties show the performance of the film was the best when the heat treatment was carried out at 550 °C for 3 h.

Lei Ma, Xin Zhou, Tao Liu
Preparation of Low-Dimensional Carbon Nanomaterials and Its Improvement of Visible Light Activity

ZnO and its nanocomposites have been received good progresses in new energy, photocatalysts, environmental fields. However, to enhance the visible light activity of ZnO is still a great challenge. Among so many methods of modifying ZnO, carbon-doping or nanocomposite with carbon nanomaterials are simple and effective approaches. In this study, low-dimensional carbon nanomaterials were synthesized with biomass waste (such as com straw) referring to the method of chemical synthesis of graphene oxide. ZnO nanosheets/carbon nanocomposites were prepared utilizing the interaction between surface chemical groups of ZnO nanosheets and low-dimensional carbon nanomaterials produced with biomass waste. A series of characterizations were carried out. The results indicated that the band edge of nanocomposite was extended to the whole visible light and NIR. The photoconductive response to weak visible light and 808 nm NIR (near infrared) were studied based on interdigital electrodes of Au on flexible polymer film substrate with casting method. The results indicated that the ZnO/carbon nanocomposite holded photo-switching behavior, the response and recovery were very rapidly. This illustrated that the resulting nanocomposites showed good activities to weak visible light and NIR. Photocatalytic efficiency was examined by selecting typical organic pollutants, some good results were also obtained. It would be potential applications in photocatalysts, self-cleaning films, NIR detector, coatings, and organic pollutants treatment of environmental fields. It would be low-cost, effective, general method to treat the surface of several metal oxides.

Shisheng Lv, Lin Bian, Jianxun Qiu, Wei Du, Xintao Zhang, Xiaochun He, Mingjun Gao, Xiangming Li, Xingfa Ma, Guang Li
Corrosion Resistance of Fe-Based Stainless Steel Composite Layer Prepared by TWIAW

In this study, Fe-based stainless steel composite layer was prepared by Twin-Wire Indirect Arc Welding (TWIAW). Weld penetration increased with the increasing of the welding current and the amount of CO2 in Ar+CO2 protective gas. However, the CO2 content exceeded 20% led to serious welding spatters. The phase of the surfacing layer was austenite plus ferrite. As no sensitization or slight sensitization occurred, the composite layers show better intergranular corrosion resistance, which can be attributed to the low heat input in TWIAW. The pitting corrosion resistance depends on the point defects formed on the surface of the layers, which is relevant to the stability of the process and the oxidation of the protective gas.

Dongting Wu, Yong Zou, Cong Hu, Chuanwei Shi
Influence of Sintering Process on the Properties of Porous Ti2AlC

Ti2AlC belongs to the so-called “MAX” phases ternary carbides material group, which possess a useful combination of both metallic and ceramic properties. Its excellent oxidation and corrosion resistance indicate that porous Ti2AlC has remarkable application prospects in LHP (loop heat pipe) wicks. In this study, Ti+Al+TiC and Ti+Al+C powder mixtures are employed as starting powders respectively and effects of different volume fraction of pore former on properties of porous Ti2AlC were studied. The experimental results indicate that the reaction process of Ti+Al+TiC system is more stable than that of Ti+Al+C system. The porosity of the porous Ti2AlC through sintering Ti+Al+C powder mixtures are relatively large, which is easy to form through holes, increases capillary pressure and improves the pumping capacity of the wick.

Yingwen Cao, Chunsheng Guo, Yong Zou
Influences of La on Optical and Electric Properties of BiFeO3 Thin Films

Bismuth ferrite (BiFeO3, short for BFO) is an important room-temperature single phase multiferroic materials. To further improve electric properties of BFO, La3+ was introduced. Bi1−xLa x FeO3 (x = 0–0.12) thin films were fabricated by sol-gel method. The microstructure, optical and electric properties of Bi1−xLa x FeO3 thin films have been investigated. XRD results show that Bi1−xLa x FeO3 thin films is rhombohedral distortion perovskite structure and the addition of La3+ can inhibit the formation of impure phase. The substitution of La3+ for Bi3+ on A sites can restrain the growth of grain and improve the roughness of thin films. The band gap of Bi1−xLa x FeO3 thin films is less than that of BFO thin films, and its band gap decreases first and then increases as the content of La3+ increases, which results from both Burstein-Moss effect and impurity level. A larger amount of La3+ (x = 0.12) can make leakage current of BFO thin films obviously decrease. Moreover, the remnant polarization and coercive electric field of Bi1−xLa x FeO3 thin films increase with the increasing of La3+ content. It results from the decrease of oxygen vacancy and effects of grain size.

Wei Cai, Kaihua Liu, Rongli Gao, Xiaoling Deng, Gang Chen, Chunlin Fu
Effect of Mn-Doping on the Structure, Magnetic Properties of Fe17Gd2 Compound

The (Fe1−xMnx)17Gd2 (x = 0.0–0.4) compounds were prepared by arc melting method, then annealed at 700 °C for two weeks. The effect of Mn-doping on the structure and magentic properties were studied by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The crystal structure of (Fe1−xMnx)17Gd2 maintains the Th2Znl7-type rhombohedral structure, and the unit cell volume and lattice parameter a, b and c of (Fe1−xMnx)17Gd2 increase with the addition of Mn content. With the increase of Mn-doping, the magnetic-type of (Fe1−xMnx)17Gd2 compounds obviously transform from ferromagnetism to antiferromagnetism, and the saturation magnetization (Ms) can be tuned continuously from 80 Am2/kg at x = 0.0 to ~0 Am2/kg at x = 0.4. At the same time, the Curie temperature (TC) of compounds reduced to room temperature. It indicates that Mn doping can effectively tune the structure, magnetic-type and TC of Fe17Gd2 compound.

Yongbin Guo, Mufen He, Lei Ma, Dao Wang, Xin Zhou
Microstructure and Electric Properties of (Sr1−xCa x )3Sn2O7 Ceramics with Ruddlesden-Popper Structure

(Sr1−xCa x )3Sn2O7 (x = 0, 0.1 and 0.2) ceramics were prepared by conventional solid solution method. The microstructure, dielectric and ferroelectric properties of (Sr1−xCa x )3Sn2O7 ceramics have been investigated systematically. The XRD results show that (Sr1−xCa x )3Sn2O7 ceramics is orthorhombic structure and the lattice constants decrease as Ca2+ content increases. The grain size of (Sr1−xCa x )3Sn2O7 ceramics decreases with the increasing of Ca2+ content, which results in the decrease of dielectric constant and dielectric loss. The compactness of (Sr1−xCa x )3Sn2O7 ceramics deteriorates as Ca2+ content increases, which causes the increase of leakage current density. Moreover, the introduction of Ca2+ in (Sr1−xCa x )3Sn2O7 ceramics leads to the increase of the remnant polarization. But the remnant polarization changes a little with Ca2+ content when x is above 0.1. The coercive field increases with the increasing of Ca2+ content.

Fengqi Wang, Hai Zhang, Wei Cai, Rongli Gao, Chunlin Fu
Microstructural Regulation and Optical Performance of Bismuth Ferrite Nanowires by Precipitant

Bismuth ferrite (BiFeO3, short for BFO) is a single-phase and multi-ferrous material with ferroelectricity and weak ferromagnetism at room temperature. One-dimensional nanomaterials have specific physical properties due to anisotropy and unique size effects. In this paper, bismuth ferrite nanowires were prepared by hydrothermal method. The effects of precipitant (NH3·H2O, NaOH) on the microstructures of bismuth ferrite nanowires were studied. The results show that NaOH is a precipitant to promote the formation of nanowires, and the single crystal nanowires can be obtained using NaOH precipitation agent. The nanowires are arranged in the same direction. The diameter is less than 45 nm and the length changes from several tens nm to several microns. The absorption of nanowires is stronger than that of nanoparticles at wavelength of 230–400 nm.

Jing Zhang, Xinlong Fang, Shenglan Wu, Chunlin Fu, Wei Cai, Rongli Gao, Jinyi Ma
Improvement of the Thermal Stability of Laminated Magnetoelectric (ME) Composites

In order to search for ME laminated composites with a good thermal stability, the temperature dependent ME coefficient in two kinds of laminates bonded by welding, namely, Ni/Pb(Zr,Ti)O3/Ni and Metal-glass/Pb(Zr,Ti)O3/Metal-glass were investigated. The ME effect of all laminated composites at temperature range from −20 to 100 °C was measured. Results showed that both two laminates bonded by welding exhibited very good thermal stability. A new phenomenon was found that the ME charge coefficient slowly increased with increasing temperature, which resulted from the increase of piezoelectric layer’s capacitance. These ME laminated composites bonded by welding supposed a good performance at high temperature, which were suitable for high temperature applications.

Zhan Shi, Mingyue Xu, Qun Huang, Shuiyuan Yang, Yong Lu, Jiajia Han, Cuiping Wang, Xingjun Liu
Mechanism of Preparing Laminar Composite Using Ti-Based Amorphous Alloy

In this article amorphous alloy was used in preparing Ti-Al system laminar composite. Amorphous alloy strips and TC4 were stacked interactively. After thermoforming process a new structure laminar composite was prepared by using the activity performance of amorphous alloy. Every layer phase composition was determined after TEM and energy dispersive spectrum analysis. The special diffusion mechanics of this process was disclosed, which including two stages. The first was the plastic deformation stage before amorphous alloy crystallization and interface atoms bonded together under van der Waals force in the first stage. The second was crystal plane diffusion. The result of test displayed that the conversion zone was much thicker because of using the amorphous alloy. With tension testing and fracture analysis, the laminar composite expressed well crack extension property. The conversion zone had a strengthening faction and it could consume some damage energy from outer force. TC4 had toughening faction which could prevent the material breaking crisply.

Rongxia Zhang, Wei Wu, Yuansong Zeng
Effect of Zr and Cu on Mechanical Properties, Glass Forming Ability and Thermal Stability of Zr63.68Cu16.2 Ni10.12 Al10 Amorphous Alloy

The effects of Zr and Cu content on mechanical properties, glass forming ability and thermal stability of Zr63.68−xCu16.2+x Ni10.12 Al10 (x = 0, 0.45, 0.9, 1.35, 1.8, 2.25, 2.7) bulk metallic glasses (BMGs) has been studied. The specimens with diameters of 2, 4 and 6 mm cut from the same ladder-shaped BMG rod by copper mold suction casting method were used in the present investigation. The results show that with the increase of Cu content and the decrease of Zr content the prepared alloy specimens with diameter of 2 mm are completely amorphous. The plastic strain shows the trend of increasing at first and then decreasing. At x = 1.8, the plastic strain reaches the maximum and its value is 38.74%, about 4.3 times of Zr63.68Cu16.2Ni10.12Al10 (BMG) 9.10%. The elastic modulus is 51,757 MPa, the yield strength is 2079 MPa, the compressive strength and the fracture strength are 3861 MPa. With the increase of specimens size, there is obvious scale effect in plastic strain. It is also found that the plastic strain is up to 30.94% for specimens with diameter of 4 mm, showing a great plasticity. With the increase of Cu atoms and the decrease of Zr atoms, the width of the super-cooled liquid region (ΔTx = Tx − Tg) and parameter (γ = Tx/(Tg + Tl)) both increase first and then decrease, the maximum values can reach 98 and 0.395 respectively at x = 1.35. The parameter γ tends to be constant at x = 1.8–2.7.

Chunyan Li, Jinfeng Yin, Juanqiang Ding, Fuping Zhu, Yanchun Zhao, Shengzhong Kou
Manifestation of Dynamic Anomaly in Metallic Glass-Forming Liquids by Their Crystallization Processes

More and more evidence has indicated the general existence of fragile-to-strong transition (FST) in metallic glass-forming liquids (MGFLs), but the thermodynamic properties corresponding to this dynamic anomaly remain unclear. For rare earth-based metallic glasses, the crystallization process is of importance to understand the dynamic anomaly of their supercooled liquids. In the present work, we studied the effects of thermal history (including cooling rate of fabrication, aging temperature and DSC scanning rate) on the crystallization behaviors of Ce-based, Pr-based and La-based hyperquenched glasses. Abnormal changes of crystallization processes were found in all these three rare-earth-based metallic glass ribbons, despite the distinct difference in their respective specific behaviors. The general non-monotonic change of crystallization characteristics corresponds to the non-monotonic structural evolution of supercooled liquid at a certain fictive temperature, which just falls in the temperature range where the fragile-to-strong transition occurs. Based on the observed abnormal crystallization behavior and its relation to the dynamic anomaly in supercooled liquids, as well as the convenience and reliability of measuring thermodynamic properties, we expect to provide a deep insight into the evolution of the supercooled metallic liquids.

Nannan Ren, Chao Zhou, Lina Hu, Fan Zhou, Jilin Tang, Xiaokun Song, Yining Liu, Yijing Zang, Yuzhong Chen
Effects of Iron on Microstructure and Properties of CoCrFexNi Multi-principal Element Alloys

In this work, CoCrFexNi (x = 2, 3, 4) multi-principal element alloys were designed and synthesized by vacuum arc melting technique, and effects of Fe on microstructure and properties of CoCrFexNi alloys were investigated. The crystal phase and microstructure of these alloys were studied by X-ray diffraction and scanning electron microscopy, while mechanical properties were measured by Vickers hardness and compressive tests, respectively. The CoCrFexNi alloys presented a single face-centered cubic (FCC) structure with columnar crystal morphology, indicating that the Fe content doesn’t change the microstructure of CoCrFexNi alloys. However, the lattice parameters of FCC phases decreased with the addition of Fe element. It was found that all the alloys exhibited excellent ductility without fracture. In addition, the yield strength decreased, and the Vickers hardness varied from 124 HV for CoCrFe2Ni to 109 HV for CoCrFe4Ni.

Linge Han, Hui Jiang, Dongxu Qiao, Yiping Lu, Tongmin Wang
Effects of La and Be on Glass-Forming Ability of Al84Co8Y8 Metallic Glass

The influences of Lanthanum (La) and Beryllium (Be) on glass forming ability (GFA) of amorphous Al84Co8Y8 were studied through replacing Y with 2, 4, 6 and 8 at.% La and Be, respectively. To directly compare the GFA of Al84Co8Y8 with different additions of La and Be, the melt-quenched alloys were fabricated by melt-spinning method under different rotating speeds. The amorphous nature of melt-quenched alloys was investigated by X-ray diffraction (XRD) and differential scanning calorimeter (DSC). The results indicate that certain amount of La can promote the GFA of Al84Co8Y8, and the best composition is Al84Co8Y4La4. However, it is found that Be has not distinct influence on the GFA of Al84Co8Y8. In addition, the investigation on thermal stability of amorphous Al84Co8Y8−xLax alloys shows that the thermal stability of amorphous Al84Co8Y8 alloy can be improved by La addition with a peak at the composition Al84Co8Y6La2. It is also found that the crystallization behavior of amorphous Al84Co8Y8 alloy will be changed by the addition of La, in the form of transforming from two-step to three-step crystallization process.

Qiang Yang, Yonghao Yu, Zhiping Sun, Zhiming Wang
Effect of Si and Y Addition on Glass Transition Kinetics of ZrCu Based Bulk Metallic Glass

Zr47Cu44Al9, (Zr47Cu44Al9)98.5Si1.5 and [(Zr47Cu44Al9)98.5Si1.5]97.5Y2.5 bulk metallic glass (BMG) were prepared by copper mould casting and studied using X-ray diffraction and differential scanning calorimetry. The influence of addition elements on the glass transition kinetics of the alloys were analyzed by the VFT equation. It is revealed that the glass transition behaviours of ZrCu based BMG were changed obviously by Si and Y addition, and the sensitivity of the glass transition temperature (Tg) to the heating rate is significantly increased. The fragility parameters m were reduced from 35.4 of Zr47Cu44Al9 to 31.5 of (Zr47Cu44Al9)98.5Si1.5, and that of alloy reached 30.7 after adding Y. The viscosity versus temperature relationship of alloy changes from characteristic of brittle fluid to strong fluid. The normalized glass transition temperature and heating rate show a clear VFT relationship. With the addition of Si and Y elements, the melt viscosity is close to that of the strong fluid.

Baoqing Zhang, Xinhang Lu, Kun Liu, Zhi Zhang, Guohua Cao
Effects of Pre-compression on the Microstructure and Corrosion Resistance of Cu50Zr50 Bulk Metallic Glass Matrix Composites

The effects of the pre-compression and cyclic compression treatment at room temperature on the microstructures, microhardness, and corrosion resistance in seawater solution of the Cu50Zr50 bulk metallic glass composites (BMGCs) have been investigated. Our work shows that pre-compression treatment suppressed the precipitation of B2-CuZr and Cu10Zr7 nano-crystals from amorphous matrix and induced phase transformations, $$ {\text{B}}{}_{2} - {\text{C}}{\text{u}}{\text{Zr}} + {\text{Cu}}{}_{10}{\text{Zr}}{}_{7} \to {\text{B}}{}_{19}^{\prime } - {\text{CuZr}} $$ . The compressive fracture strength of the as-cast sample reaches up to 1566 MPa while preserving a certain degree of plasticity with a larger microhardness of 392 HV. Moreover, appropriate pre-compression and cyclic compression treatment can enhance the microhardness of the Cu50Zr50 BMGCs. The 5 cycles compression treatment under the 1273 MPa shows the enhanced corrosion resistance in the seawater solution, while the as-cast sample exhibits the excellent pitting corrosion resistance.

Sicheng Zhai, Wen Wang, Yan Wang
Effect of Annealing Temperature of Fe78Si9B13 Amorphous Ribbons for Activation of Persulfate on Azo Dye Degradation

The effect of annealing temperature of Fe78Si9B13 amorphous ribbons for activation of persulfate on azo dye Orange G degradation was investigated. The ribbons annealed below 623 K have very rapid degradation rate, and the degradation efficiency within 10 min was 97%. The kinetic analysis elucidated that the degradation process could be described by pseudo-first-order kinetic model. The reaction rate was not strictly decreased with the increasing annealing temperature. In particular, the ribbons with different structures by annealing at different temperatures, after the reaction, show obviously discrepant surface corrosion morphology which also plays a role in the reaction rate.

Junjun Li, Lin Wu, Pengfei Liu, Lanjun Liu, Bo Zhang
Microstructures and Mechanical Properties of NixCoCrFeMo0.1 Multi-component Alloys

Five multi-principal component NixCoCrFeMo0.1 (x = 1, 2, and 3, in molar ratio) alloys were prepared by vacuum arc-melting in a water-cooled copper crucible. The effects of Ni on the microstructure and mechanical properties were studied. Results indicated the CoCrFeNi alloy exhibits a single face-centered cubic (FCC) solid-solution structure. The hardness of all these alloys have slightly different after annealing, which indicates the series of alloys have high thermal stability and good high temperature application.

Xiaoxue Chang, Hui Jiang, Yiping Lu, Tingju Li
Influences of Impurity Alloying on Thermal Stability and Mechanical Properties of Zr50Ti4Y1Al10Cu25Ni7Co2Fe1 Bulk Metallic Glass

In this study, influences of impurity concentration tuned by mixing sponge Zr and high-purity Zr on thermal stability and mechanical properties of a super-multicomponent Zr50Ti4Y1Al10Cu25Ni7Co2Fe1 BMG were investigated. The results show that, different concentrations of impurities in Zr raw materials have inconspicuous influences on glass transition temperature (T g ) and crystallization temperature (T x ), but can affect the crystallization process of this BMG. Moreover, it is interesting that, the plasticity of this alloy reaches a maximum value when using 80% sponge Zr + 20% high-purity Zr, indicating that proper amount of impurities have positive effects on mechanical properties of this BMG, and such phenomenon may be caused by the formation of nano-crystals in the glassy matrix. This study provides a guideline for the exploration of Zr-based BMGs which are applicable for industrial production.

Chen Chen, Guowen Sun, Hang Zhang, Xiaodong Jia, Ran Wei, Fushan Li
Corrosion Resistance of Fe-Based Bulk Amorphous Alloy with Sulfide Inclusion

Corrosion resistance of Fe-based bulk metallic glass with sulfide inclusion was investigated in HCl, H2SO4, NaCl and NaOH solutions at different ambient temperature. The results indicate that Fe-based amorphous alloy generally exhibits more excellent corrosion resistance in alkaline solutions than that in acidic solutions, and presents high spontaneous passivated ability and evident passivation region in all solutions. Electrochemical impedance spectroscopy results display that all of the Nyquist curves are composed of just a single capacitive loop, and the electrode reaction is mainly controlled by the electrode potential. The mass loss exceeds 0.67 mg/cm2 in 0.5 M H2SO4 solution, and rapider than that in another solutions. With increase of ambient temperature, the corrosion resistance decreases in all solutions. No pitting corrosion occurs in acidic solutions, though the inclusion particle is dissolved firstly. Seemly, some pit can be formed in NaCl solution, when ambient temperature exceeds 60 °C.

Y. Zuo, S. L. Wang, Y. Huang, S. X. Wang
Synthesis of In-Suit Ti46.8Zr19.5Nb11.7Cu5Be14.5Ag2.5 Amorphous Composite Materials with High Tensile Ductility

A high tensile ductility in-suit Ti46.8Zr19.5Nb11.7Cu5Be14.5Ag2.5 amorphous composite materials was prepared successfully by arc melting and injection casting into a water cooling copper mold. The composition and microstructure were characterized by X-ray diffraction (XRD) with Cu Kα radiation and scanning electron microscope (SEM). The results showed the fully developed dendritic structure of the β phase with green color was uniformly distributed in the amorphous matrix, while, the size and proportion of second phase were 30 μm and 78% respectively. Standard size of tensile specimen was designed to test its tensile mechanical properties. The occurrence of rare necking deformation in amorphous materials showed the Ti46.8Zr19.5Nb11.7Cu5Be14.5Ag2.5 amorphous composite materials possessed a good ductility ability. The fracture contained the fiber area, radiation area and shear lips. Large proportion dimple area showed the dendritic phase distributed uniformly played a great role in the process of deformation.

Yonghua Shen, Huanwu Cheng, Weiwei Chen, Yunfei Xue
Effect of Argon Filling Ratio on Heat Transfer Coefficient of Double-Glazing

In this work the effect of argon filling ratio and air space thickness on the heat transfer coefficient of double-glazing was studied. The heat transfer coefficient of double-glazing was measured by heat flow meter method (based on standards ISO10291, ISO 10292, ISO8301 and DIN EN 12939), during this process the testings of argon filling ratio and emissivity of coated glass surface were involved. For the thermal performance of double-glazing, the influence of various factors on heat transfer coefficient was analyzed. The comparison was conducted between coated double-glazing (one glass pane coated with low-emissivity) and non-coated double-glazing. Within the thickness of air space in the range of 9–18 mm, the higher the air space thickness, the higher the filling ratio of argon gas, the better the thermal insulation performance achieved. Under the same gas filling ratio, the heat transfer coefficient of coated double-glazing (emissivity is 0.13) which is much lower than that of non-coated double-glazing, can effectively meet the requirement of building energy efficiency in China.

Junjie Li, Yingliang Tian, Shibing Sun, Jinwei Li, Lu Zhang, Keyu Chen
Hydrothermal Synthesis and Characterization of Cs0.32WO3 Rod-like Nanoparticles with Excellent Near-Infrared Shielding Property

Cesium tungsten bronze (CsxWO3) nanoparticles were successfully synthesized via a hydrothermal method using sodium tungstate and cesium carbonate as raw materials, and citric acid and D-malic acid as mixed reducing agents. The results of XRD and SEM show that the sample with Cs/W (molar ratio) = 0.5 promotes formation of hexagonal Cs0.32WO3 with high crystallinity during hydrothermal synthesis. Moreover, with increasing reaction time, the morphology of the sample changes from irregular-shaped nanoparticles to rod-like nanoparticles. Cs0.32WO3 powders with high crystallinity and rod-like morphology have high near-infrared absorption. Additionally, transparent thermal insulation coatings and NIR shielding glass samples were prepared by coating the mixed dispersed solution of Cs0.32WO3 with organic silicon resin on glass substrate. The results of thermal insulation characterized by UV-Vis-NIR spectra show that NIR transmittance of glass substrate is 82% and that of the as-prepared NIR shielding glass is only around 12%, which is reduced dramatically, illustrating that the synthesized rod-like Cs0.32WO3 nanoparticles with high NIR absorption have promising prospects in the fields of automotive and architectural glass.

Shuying Lin, Xiaoqiang Zhang, Yue Huang, Zhonghua Zhou, Shirley Shen
High Order Laterally-Coupled Distributed-Feedback GaSb-Based Diode Lasers at 1.9 μm Wavelength

We reported on GaSb-based laterally coupled distributed-feedback (LC-DFB) quantum well lasers. The lateral grating of the LC-DFB lasers were patterned along both sidewalls of the ridge waveguide. Gratings with higher order could enhance the lithographic tolerance for lower resolution patterning, yielding lasers more amenable to mass-manufacturing. The lasers emitting wavelength was at 1.9 μm in a single longitudinal mode at room temperature. A low wavelength dependent current tuning coefficient of 0.13 nm/mA was measured for the laser output. We obtained high output power of 13.6 mW, which were suitable for gas analysis.

Huan Li, Sheng-wen Xie, Yu Zhang, Shu-Shan Huang, Jin-Liang Wang, Zhi-Chuan Niu
GaSb-Based QWs 2 μm High Power Laser Diode

2 μm high-power GaSb-based type-I quantum well diode lasers were fabricated in this study. Under direct current, the output power of the lasers with uncoated cavity length of 2 mm and 100-μm-wide ridge is about 0.533 W with injection current of 3 A. The maximum conversion efficiency of single emitter is 12.67%. Under pulse current, the output power is 1.946 W with injection current of 14 A of 1 kHz and 5% duty cycle. The output power of the laser with coated cavity is increased to 2.466 W with injection pulsed current of 16 A.

Kelu Zhang, Shengwen Xie, Yu Zhang, Yingqiang Xu, Jinliang Wang, Zhichuan Niu
Thermal Stability of Er2O3–Al2O3 Thin Films Grown on Si Substrates

The thermal stability of Er2O3 and Al2O3 doped Er2O3 thin films deposited on Si substrates has been investigated by x-ray diffraction and x-ray photoelectron spectroscopy. The structures for the as-grown Er2O3 and Al2O3 doped Er2O3 films on Si substrates are found to convert from amorphous to polycrystalline at the annealing temperatures above 450 °C in O2 ambience. The crystallinity and the surfaces roughness of Er2O3 thin films on p-type Si (001) substrates are decreased if Al2O3 is doped in them. However, the result is complicated if these Er2O3 and Al2O3 doped Er2O3 thin films deposited on n-type Si(001) substrates.

Xiaojie Pan, Zhifang Zhang, Yanyan Zhu, Zebo Fang, Haijing Cao
(GaSb)0.5–Ge1.6Te Alloys for High-Temperature Phase Change Memory Applications

In this paper, phase change characteristics of (GaSb)0.5–Ge1.6Te alloy were investigated for long data retention phase change memory application. (GaSb)0.5–Ge1.6Te film has high crystallization temperature (357 °C) and large crystallization activation energy (4.57 eV), resulting in a good data retention ability (251 °C for 10 years). The prominent advantages can be seen in comparison with those of pure GeTe and Ge2Sb2Te5. The fine crystal grain size is smaller than GeTe owing to GaSb doping, which is contributed to operation speed. Furthermore, as short as 20 ns electrical pulse can achieve Reset operation. The pulse width of 200 ns requires only a Reset voltage of 1.5 V, which is much lower than that of GeTe-based cells.

Yuan Xue, Sannian Song, Shuai Yan, Tianqi Guo, Lanlan Shen, Liangcai Wu, Zhitang Song, Songlin Feng
A Stretchable and Flexible Strain Sensor Based on Graphene Sponge

Flexible strain sensors have attracted extensive research all over the world for their great potential applications in wearable electronics, man-machine interaction system, and flexible human health monitoring system. Nevertheless, there still remains some problems such as low stretchability and poor durability. In this study, a highly flexible, stretchable and sensitive strain sensor has been fabricated with a low-cost strategy. The strain sensor was manufactured by graphene-coated polyurethane sponge and packaged by PDMS. The obtained strain sensor could be stretched up to 100% of its original length, showing excellent flexibility and stretchability. In addition, the gauge factor of 2 indicates high sensitivity of the sensor. Besides, the strain sensor exhibited high durability and reliability after 300 stretching-releasing cycles. The facile fabrication process, low-cost materials, and good performance of graphene-sponge based flexible strain sensor shows a good prospect for the application to flexible wearable devices.

Fei Han, Jinhui Li, Yuan Zhang, Guoping Zhang, Rong Sun, Chingping Wong
Self-healable Silver Nanowire-Based Composite for Elastic Strain Sensor

Stretchable and flexible sensors attract increasing interest due to their potential applications such as healthcare monitoring, wearable displays, and electronic skins. In these advanced application, high sensitivity, low detection limit, and conductive stability are essential features. Besides, the service life is also one of the important indicators, prolonged service life can greatly cut the cost. Self-healing can help materials recover its integrity in time after damage, which is an effective way to extend service life, thereby reducing costs and improving real engineering applications. In this work, a self-healable, stretchable and sensitive strain sensor based on the nanocomposite of AgNWs and polyurethane (PU) in the configuration of sandwich structure (AgNWs thin film was embedded between two layers of PU) was fabricated via vacuum filtration and transferring process. The as-prepared PU–AgNWs–PU sandwich structural composite showed a high gauge factors of 15 at the strain range of more than 11%. More importantly, the composite could be efficiently repaired by simply thermal treatment after damaged. All the results indicated that the as-fabricated PU–AgNWs–PU sandwich structural composites exhibited great potential applications as smart material for elastic strain sensor.

Feng Liu, Jinhui Li, Fei Han, Lei Ling, Xinxiu Wu, Guoping Zhang, Rong Sun, Ching Ping Wong
Morphology Evolution of Monolayer MoS2 Flakes with Seed Promotor Grown by CVD

We report a developed preparation process on the monolayer MoS2 which was grown on SiO2/Si substrates with seed promotor by atmospheric-pressure chemical vapor deposition (CVD) method. It is indicated that growth temperature and proportion of precursors play significant roles on the morphology of the monolayer MoS2 which can change from three-point star to triangle and hexagon. The dimension of the MoS2 flake is mainly dependent on the growth temperature, while its morphology is mainly influenced by the amount of the loaded MoO3. Raman spectra and AFM images show that the MoS2 flakes of the three morphologies are all monolayer.

Xin Zhang, HongBin Zhao, QingZhu Zhang, Feng Wei
Automatic Switching System of Voltage Pulse and Current Pulse Test in Phase Change Memory Devices

Voltage pulse and current pulse test of phase change memory (PCM) device is realized by computer controlling pulse generator, digital source meter, current pulse generating circuit, switching circuit and other hardware devices. The PCM device test includes several modules of the relationship between current and voltage, voltage and current, resistance and voltage pulse width or height, resistance and current pulse width or height, and fatigue characteristics. In these test modules, the automatic switching system achieves the automatic switching between voltage pulse and current pulse test. The automatic switching system of voltage pulse and current pulse test can not only achieve the automation of engineering testing, but also can reduce the noise interference.

Shuai Yan, Daolin Cai, Yuan Xue, Zhitang Song, Yifeng Chen, Yaoyao Lu
Synthesis and Characterization of New Block Copolymers for Direct Self-assembly

Due to its high resolution, easy process, and independence to complex optical exposure systems, Directed Self Assembly (DSA) is a promising alternative patterning technology in microlithography area. In this paper, a new block copolymer was designed and synthesized through anionic polymerization. It has large molecular weight and low PDI. The formation of lamellae was confirmed and the L0 of the polymer was analysed by using Small Angle X-ray Scattering (SAXS) and 2D-Fourier transform of SEM images. ICP dry etch data showed that the two blocks had a good etch rate ratio, which was good for pattern transfer. A neutral underlayer was crafted for the BCP to phase separate on and form perpendicular features. Annealing temperature and time were investigated for the phase separation of this BCP/Neutral layer system. It could be found this system shows phase separation after spin coating, without any anneal step, by analysis of finger print patterns. 50 nm lines could be found after spin coating. The dependence of L0 on MW is described along with approaches and results of directed self-assembly using graphoepitaxy and this polymer and neutral layer.

Haibo Li, Bing Li, Dejun Liu, Mark Neisser, Caleb L. Breaux, Clifford L. Henderson
In Vitro Cytocompatibility and Osteogenic Potential of Biodegradable Mg–Sr Alloys

The cytocompatibility and osteogenic ability of novel as-extruded Mg–xSr (x = 0.25, 1.0, 1.5, 2.5 wt%) alloys are systematically investigated by in vitro cell adhesion and proliferation, alkaline phosphatase (ALP) activity, real-time RT-PCR evaluation, and mineralization tests. The results indicate that in addition to no cytotoxicity towards MC3T3-E1 cells, the Mg–Sr alloys, particularly Mg–1.5Sr, obviously promote the adhesion, proliferation, alkaline phosphatase activity, matrix mineralization and collagen secretion of MC3T3-E1 cells compared to pure Mg. Nearly all the osteogenesis-related genes, namely Runx2, Opn, Sp7, and Bmp2, are up-regulated for Mg–xSr, compared to pure Mg. In particular, Mg–1.5Sr reveals the best osteogenic ability. Our work suggest that novel as-extruded Mg–1.5Sr alloy, which exhibits excellent in vitro cytocompatibility and osteogenic ability, is promising in expediting clinical acceptance of biodegradable magnesium alloys.

Chen Liu, Lili Tan, Ying Zhao, Peng Wan, Haobo Pan, Xinbing Zhao, Yongdong Xu, Ke Yang
Fabrication of Urethral Tissue Engineering Scaffolds Based on Multi-scale Structure of Bacterial Cellulose Matrix Materials: A Preliminary Study

Tissue engineering (TE) approaches provide an effective strategy for developing functional substitutes to repair or replace failing urethra. In urethral TE, one of the most important challenges is design and fabrication the urethral scaffolds that possess biomimetic multi-scale structures composed of urethral shape and micropore microporous structure with nanofibers for more biomimetic the native urethral ECM. In this study, ultrasonography was used to reconstruct a 3D digital model of human urethra. Then, the micro- and nano- structural characteristics of urethral ECM were studied by using FF-SEM. The indirect 3D printing technology and template biosynthesis method were used to fabricate a 3D gelatin/silk-bacterial cellulose (Gel/silk-BC) urethral scaffold, with defined macro-, micro- and nanostructure. The Gel/silk-BC scaffold has a urethral shape in macro-size, and highly interconnected micropore (140 ± 34 μm) with surface decorated of BC nanofibers (24.6 ± 5.0 nm), which serve as mimics for the native urethra ECM.

Zhe Li, Xiangguo Lv, Zhiyong Yan, Yongbo Yao, Chao Feng, Huaping Wang, Shiyan Chen
Peripheral Nerve Repair with Electrospinning Composite Conduit

Peripheral nerve injury is a common disabling disease, but autograft can’t meet the real needs due to its limitations. As a single material nerve conduit can’t repair nerve damage effectively, the study of composite nerve conduit is significantly important. In this article, a biomimetic artificial nerve conduit was prepared with PDLLA/β-TCP/I-collagen(c) via electrospinning method. The material properties and biocompatibility of PDLLA/β-TCP/I-collagen composite nerve conduit were studied, and then the feasibility of PDLLA/β-TCP/I-collagen conduit in repairing 10 mm rat sciatic nerve defects for 3 months was explored. PDLLA(a), PDLLA/β-TCP(b) and autograft groups(d) were set. PDLLA/β-TCP/I-collagen showed significant porosity and low swelling ratios. PDLLA/β-TCP/I-collagen has well biocompatibility and low antigenicity through subcutaneous test for 3 weeks from the analysis of Hematoxylin-eosin and Immunohistochemical staining analysis. The muscle recovery rate in PDLLA/β-TCP/I-collagen group is better than PDLLA and PDLLA/β-TCP groups after 3 months implantation. The myelinated nerve fiber diameter and myelin sheath thickness in PDLLA/β-TCP/I-collagen is bigger than in PDLLA and PDLLA/β-TCP groups (p < 0.05), which is closed to autologous transplantation groups (p > 0.05) through the observation of transmission electron microscopy (TEM). PDLLA/β-TCP/I-collagen composite conduits were prepared for the first time which could repair the nerve defects effectively.

Fei Lin, Xinyu Wang, Yiyu Wang, Rong Zhu, Yuanjing Hou, Zhengwei Cai, Yi Li, Zimba Bhahat
Preparation and Characterization of Mg–Zn–Al LDHs Nanoplates via In Situ Growth on Mg–Zn–Zr–Sr Alloy

Magnesium (Mg) and its alloy have been regarded as revolutionary bioabsorbable materials. However, high corrosion activity limits their applications as biomaterials. To improve the corrosion resistance and in vitro degradation of Mg–Zn–Zr–Sr alloy (MZZS), Mg–Al hydrotalcite (LDHs) was fabricated through in situ growing approach by hydrothermal treatment. The characteristics of the coatings were investigated using SEM, XRD, FT-IR and EDS. The corrosion resistance of the LDH coatings was also studied using potentiodynamic polarization and hydrogen evolution test. The results demonstrated that the LDHs coatings exhibited a promising application of improving corrosion resistance and degradability in vitro.

Wei Wang, Xiao Li, Yun Zhao, Minfang Chen
Microstructure, Mechanical Properties and Corrosion Behavior of Mg–Zn–Zr Alloys with Different Compositions

Mg–Zn–Zr alloys were studied as a promising biomaterial in terms of their excellent biocompatibility and mechanical properties. Cast Mg–Zn–Zr alloys with different compositions were immersed in Hank’s solution at 37 °C to investigate the effect of Zn content on the microstructure, mechanical properties and corrosion behavior. The microstructure observation showed the alloys were mainly composed of primary α-Mg matrix and a small amount of MgZn second phase. Mechanical tests showed that Mg–3Zn–0.6Zr alloy had optimum mechanical properties with the tensile strength of 219 MPa, yield strength of 65 MPa, elongation of 21% and hardness of 46 HV. The corrosion morphologies and immersion test proved that Mg–2Zn–0.6Zr alloy exhibited best corrosion resistance with an average corrosion rate of 1.68 mm/year.

Luanxiang Wang, Renbo Song, Feng Gao, Changhong Cai, Liang Huang
Preparation and Characterization of Polymer Nanoparticles with Multiple Response

Intelligent nanoparticles with core-shell structure have attracted much attention in the field of drug controlled release. 5-fluorouracil (5-FU) is an anti-metabolic drug that inhibits the formation of pyrimidine nucleotides in tumor cells and has a significant effect on a variety of tumors. However, 5-FU is more toxic and has more harmful reactions. In order to reduce the toxicity, the study of its controlled release system is attracting more and more attention. In this paper, PLA macromolecular monomers with double bond functional groups were prepared by ring-opening polymerization of lactide with hydroxyethyl methacrylate as an initiator. And then, N-isopropylacrylamide (NIPAm) was used as the thermosensitive monomer and methacrylic acid (AA) as the pH sensitive monomer, and the PLA macromonomer was subjected to free radical copolymerization. PH reaction, biodegradable properties of amphiphilic copolymer PLA-g-P(NIPAm-co-AA), and 5-fluorouracil are as a kind of model drug preparation of multi-functional nano-anti-tumor drugs. The results of in vitro drug release showed that PLA-g-P(NIPAm-co-AA) nanoparticles released 5-FU slowly in the buffer solution, and the cumulative drug release rate increased slowly with time and showed no bursting, good temperature and pH response. That can more accurately target controlled release drugs, reduce the toxicity of normal tissues and organs, improve its positioning and targeting ability.

Yushun Jin, Weijin Zhang, Jinhong Zhang, Tianyang He, Lujia Zhang, Yan Shang, Zimo Wang
High-Strength FeCrMo0.2(AlNi)0.5 High Entropy Alloy Strengthened by B2 Precipitate

The purpose of this study is to investigate the effects of Al and Ni addition on the microstructure and mechanical properties of FeCrMo0.2 alloy. The FeCrMo0.2 alloy displayed a disordered BCC solid solution structure. With the addition to Al and Ni elements, an ordered peak around 30.6° appeared in FeCrMo0.2(AlNi)0.5 alloy. A uniform microstructure was obtained in FeCrMo0.2 alloy while dense nano-scale or micron-scale particles precipitated in FeCrMo0.2(AlNi)0.5 alloys. Besides, with the addition to Al and Ni elements, the yield strength increased from 550 to 1600 MPa while the plastic strain εp decreased to 30%. And the Vickers hardness increased from HV380 to HV522. The strengthening mechanisms in the alloy system were the solid solution strengthening and the second-phase strengthening.

Yong Dong, Xingyu Ding, Wei Fu, Yongqi Cheng, Zhengrong Zhang
Compressive Strength of Al2O3 Composites Reinforced with Three-Dimensional Carbon Fiber Preform

The static compressive strength and the impact resistance of three-dimensional carbon fiber preform reinforced Al2O3 (C/Al2O3) composites were investigated in this paper. It was found that the static compressive strength in Z direction was 422.7 MPa, which is higher than that in X direction. The results from split-hopkinson pressure bar experiment indicated that the dynamic compressive strength of C/Al2O3 composites enhanced when the strain rate ranged from 400 to 1600 s−1, followed by decline at 2700 s−1. The relationship between structure and compressive strength is discussed.

Chaoyang Fan, Qingsong Ma, Kuanhong Zeng
Influence of Compaction Pressure on the Properties of Silica Ceramic Cores

Based on the application background of the ceramic cores for the hollow blades, silica ceramic cores were prepared by dry-pressing and subsequent pressureless sintering. The silica powders coated by silicone resin were used as the raw materials. The influence of compaction pressure on the properties of silica ceramic cores was analyzed. The results showed that with the increasing of compaction pressure, both the shrinkage rate and apparent porosity of the samples decreased. On the contrary, the increasing compaction pressure promoted the increasing of bulk-density and bending strength of the samples. The phase composition of the sample was composed of amorphous and crystallized silica. A number of cracks formed at the crystallization front of the grain owing to the volume change of crystallized silica during the cooling.

Jianbo Yu, Zhigang Yang, Zongcheng Song, Zhongming Ren, Kang Deng
Performances of Multiphase Ceramics of SiC and Praseodymium Aluminates

Multiphase ceramics of SiC based composites were prepared by hot pressed (HP) and pressureless sintering with Al2O3 and Pr2O3 as sintering additives. The compositions were designed according to the two binary compounds of PrAlO3(PrAP) and PrAl11O18[β(Pr)] formed in Al2O3–Pr2O3 system. And the performances of the multiphase ceramics with different content of the second phases were investigated. The results showed that the weight loss, linear shrinkage and relative density of the samples in the group 1/B (SiC–PrAl11O18) containing more Al2O3 were higher than those of the samples in the group 1/1(SiC–PrAlO3) by pressureless sintering, and its supreme relative density was 91.5%. By hot pressed sintering, the relative density of the densest sample in group 1/1 and group 1/B reached 94.8 and 95%, respectively. In group 1/1, sample with 10wt% of additives possessed the greatest hardness of 21.1 GPa, and the maximal flexure strength of 494.9 MPa was achieved when additives content increased to 15 wt%. The sample containing 10wt% of additives in group 1/B had the best fracture toughness of 7.4 MPa m1/2.

Wengao Pan, Laner Wu, Yong Jiang, Zhenkun Huang
Influence of SPS Sintering Temperature on Properties of ZrB2–SiC–Cr3C2 Ceramic

To investigate the influence of sintering temperature on properties of ZrB2-16vol.%SiC-4vol.%Cr3C2 ceramic (ZSC), ZSC was prepared by spark plasma sintering (SPS) process with different sintering temperature (1700 and 1800 °C). The microstructures and mechanical properties were characterized, and the oxidation behaviors were mainly studied at 1500 °C in air. The results showed that ZSC sintered at 1700 °C had better mechanical properties with higher hardness(13.37 GPa), fracture toughness (5.3 MPa m1/2), bending strength at 25 °C (529 MPa) and 1600 °C (128 MPa). However, ZSC sintered at 1800 °C had better oxidation resistance, the thickness of each oxidation layer was thinner and the oxidation depth was much shallower than ZSC sintered at 1700 °C.

Qi Li, Fengwei Guo, Lamei Cao, Xiaosu Yi
Effect of Different Crystallization Temperature on Dielectric Properties of BaO–SrO–PbO–TiO2–SiO2–Nb2O5 Glass-Ceramic Composites

Nanocomposite dielectrics in 2.5BaO–18.5SrO–8.5PbO–8TiO2–20SiO2–20Nb2O5 system were prepared via melt-quenching followed by controlled crystallization. X-ray diffraction studies revealed that Pb2Nb2O7, (Ba,Sr,Pb)Nb2O6 and (Sr,Pb)TiO3 phases formed from the as-quenched glass annealed in the temperature range from 800 to 1000 °C. Pb2Nb2O7, (Ba,Sr,Pb)Nb2O6 and (Sr,Pb)TiO3 crystallized at 800 °C and then Pb2Nb2O7 disappears at 900 °C, while PbNb2O6 formed at 900 °C. The microstructural observation showed that randomly oriented, the nanometer-sized crystalline grains were found with residual glass concentrated at phase boundaries. Meanwhile, the crystalline grain of the samples grew with the increase in crystallization temperature. And the dielectric constant is enhanced with the increasing crystallization temperature as well. The dielectric constant of the nanocomposites crystallized at different temperatures showed good temperature and electric field stability. In particular, the sample had a high dielectric constant of 900 after crystallized at 1000 °C, and the dielectric loss still remained at a low level of 0.0042, which is expected to be used as a promising candidate material for high voltage ceramic capacitor applications.

Junyou Chen, Qingmeng Zhang, Feihu Tan, Peng Zhou, Min Zhou
Densification of Tantalum Carbide Ceramics with 1–10 mol% LaB6

TaC ceramics were prepared by hot pressing at 1900 °C for 30 min under 30 MPa mechanical pressure. The effect of adding 1–10 mol% LaB6 as a sintering aid on densification, the phase composition, microstructure and mechanical properties of the consolidated materials were investigated. TaC and LaB6 reacted to form the solid solution. The grain average size decreased from 10 μm at 1 mol% LaB6 addition to 4 μm at 10 mol% LaB6 addition. The 5 mol% LaB6 composition had good flexural strength of 312 MPa.

Zhuang Lu, Limeng Liu
Effects of Fine Composite Powders Addition on Properties of Corundum-Spinel Refractory Castables

The enhanced properties of refractory castables are usually designed by the addition of multifunctional mineralizers and fine powders to satisfy the requirements of steelmaking industry. In this work, the effects of fine composite powders addition on properties of corundum-spinel refractory castables were investigated. Phase composition, microstructure, physical and mechanical properties of corundum-spinel refractory castables with different contents of fine composite powders were characterized. The results showed that the smaller spinel in the fine composite powders improved the sintering activity of the spinel particles, which had an influence on the morphology and the distribution of CA6 for the limited space. As the consequence of this, the cracks caused by in situ CA6 generation decreased and the firm link between particles was gained, finally the strength of castables containing fine composite powders improved.

Hai Tang, Nian Jiang, Wenjie Yuan, Chengji Deng, Hongxi Zhu
Preparation and Bench Test of SiC Honeycomb Ceramics with Macroporous Walls

Honeycomb ceramics is the main part of Diesel Particulate Filter. Because of its using environment it must have excellent performance such as thermal shock resistance. Silicon carbide can exactly meet the requirements. Silicon carbide honeycomb ceramic can be obtained via the processes including mixing materials, extrusion moulding, alternative block and sintering. The results of the bench test indicate that silicon carbide honeycomb ceramic can be used in Diesel Particulate Filter successfully.

Yuzhi Bao, Hu Li, Wei Jiang, Chunlei Duan
Effects of Annealing on Properties of PLZT (8/68/32) Electrically Controlled Light Scattering Ceramics

PLZT (8/68/32) electrically controlled light scattering ceramics with fully dense microstructure and high transmittance were prepared by a hot-press sintering method. The effects of annealing on dielectric, ferroelectric, optical and electrically controlled light scattering properties were examined and analysed. The XRD patterns indicated that all sintered specimens were well crystallized and the peak of 2θ∼30.8° gradually shifted to high degree. The temperature dielectric spectrum manifested the obvious relax or phase transition. And the double-look-like ferroelectric hysteresis loops revealed the tendency to transform a slim loop with the significant reduction in remnant polarization and coercive field via annealing treatment. Then the transmittance (from 58 to 62%, E = 0, λ = 632.8 nm) and contrast ratio (from 545:1 to 699:1) clearly increased after annealing treatment. The light scattering behavior of the PLZT samples was improved obviously.

Feifei Song, Dazhi Sun, Xia Zeng, Wenxiu Cheng, Pingsun Qiu, Bin Xia, Xiyun He
Luminescence Properties of Lu3+-Doped YAG Prepared by a Solid-State Reaction Method

Lu3+ is commonly used as activator and sensitizer for making light materials. In the present investigation Lu3+-doped YAG phosphor was synthesized by the high temperature solid-state method, whose chemical formula was Y3−x−0.06LuxAl5O12:0.06Ce3+, and x = 0–2.94, then the structure and luminescence characteristics of the sample were studied by X-ray diffraction, scanning electron microscopy and fluorescence spectroscopy. It was found that adding a small amount of Lu3+ to replace Y can make a significant improvement on the morphology, from rod-shape to nearly spherical. The emission spectra showed that the emission intensity at room temperature was 12% higher than that of undoped Lu3+, and with the Lu3+ concentration increasing the peak wavelength blue shift happened. Lu3+-doped YAG phosphor can reduce the drop of its emission intensity with rising temperature, which reduce the drop by about 7% compared to undoped Lu3+ at 185°C.

Haili Li, Hui Chen, Mengxi Guo, Na Zhang
Effects of Sintering Temperature on Microstructure, Electric Properties of Ba0.7Sr0.3TiO3 Ceramics

Barium strontium titanate is an important electronic functional ceramics, which has a strong dielectric nonlinearity and excellent ferroelectricity. In the present study Ba0.7Sr0.3TiO3 ceramics were synthesized by conventional solid state reaction method. The effects of sintering temperature on the microstructure, dielectric and ferroelectric properties of Ba0.7Sr0.3TiO3 ceramics have been investigated. The XRD results show that Ba0.7Sr0.3TiO3 ceramics sintered at 1350–1450 °C were single tetragonal phase. The lattice constant and tetragonality decreased as sintering temperature increasing. The grain size increased with the rise of sintering temperature. The dielectric properties of Ba0.7Sr0.3TiO3 ceramics sintered at 1350 °C were superior to that of the ceramic samples sintered at 1400 and 1450 °C. The decrease of tetragonality with the rise of sintering temperature leaded to the fall of the Curie temperature of Ba0.7Sr0.3TiO3 ceramics. Ba0.7Sr0.3TiO3 ceramics sintered at 1350–1450 °C were relaxor ferroelectrics. The diffuseness weakened as sintering temperature increase. The remnant polarization and coercive field gradually increased with the rise of sintering temperature.

Haifeng He, Wei Cai, Rongli Gao, Gang Chen, Xiaoling Deng, Chunlin Fu
Effect of Fused Silica Fiber on the Shrinkage and Properties of Silica Based Ceramic Core

To improve the dimensional accuracy and high-temperature performance of ceramic core, the content of fused silica fiber and its length effects on mechanical and dimension behavior of silica-based ceramic cores were investigated. In order to simulate the single crystal blades casting process, the sintered samples were also heated up to 1550 °C and kept for 0.5 h. The sintering and as-cast shrinkage, creep deformation and bending strength were characterized. The result showed that fused silica short fiber could obviously reduce the shrinkage rate of ceramic core. Short fiber has an anisotropic effect on inhibition of contraction. The shrinkage in the direction of length and injection direction was less than that of the other direction. The fused silica fiber with higher length/diameter ratio maintains the creep deformation resistance at high-temperature acting as skeleton structure.

Xin Li, Jiansheng Yao, Dingzhong Tang, Shuxin Niu, Junhao Yan, Chunxiao Cao
Temperature Dependence of Ga3+-Doped CaS:Eu2+ Phosphors

The temperature dependence of the photoluminescence spectra of Ga3+-doped CaS:Eu2+ phosphors were investigated. The results showed that at room temperature, the peak position was blue shifted by increasing the Ga3+ concentration from 0 to 0.2 mol. The peak intensity showed bandwidth broadened and emission intensity decreased with the increase of temperature. With the increasing of Ga3+ dopant, the declining rate and dilated trend aggravated. Increasing FWHMs and decreasing emission intensities can be explained in terms of thermal quenching in the configuration coordinate diagram. The formula explanation is due to the dominant electron-phonon interaction for thermal decay and bandwidth broadening.

Na Zhang, Suqin Luo, Renju Cheng, Haili Li, Ruoyu Zhang, Bin Jiang, Liu Yang
Infrared Emission Properties of Cr3+-Doped NiAl2O4 Spinel Ceramics

High infrared emissive NiAl2−xCrxO4 (x = 0, 0.1, 0.5, 1.0, 2.0) spinel ceramics were prepared by solid-state reaction method. The phase composition, microstructure, near infrared absorption and infrared emission properties of the prepared samples were investigated. With the addition of Cr3+, the samples maintained a spinel structure, and the grains grow to larger sizes. The absorptivity increased from 0.52 to 0.93 in the near infrared spectral region of 0.75–2.5 μm and the emissivity increased from 0.56 to 0.83 in the infrared spectral region of 3–5 μm with increasing Cr content. The band gap of NiAl2−xCrxO4 spinel ceramics decreased with increasing Cr content based on the calculation of the absorbance test results. The first-principles electronic structure calculations for NiAl2O4 and NiCr2O4 were performed. The high emissive spinel ceramics shows promising applications for energy-saving in high temperature thermal process equipment field.

Gang He, Jiaxi Liu, Xingxing Jiang, Jiangtao Li
Effect of Curing Temperature on the Properties of Quartz Fiber Felt Reinforced Fused Silica Densified with Simethicone

In this paper, the needle-punched quartz fiber reinforced fused silica composite was densified by impregnating simethicone in vacuum and then solidified at different temperatures. The volume density and mechanical properties were investigated by means of Archimedes method and three point bending method, while the micro-structure was tested by SEM. The results showed that the volume density of composite increased from the non-impregnation of 1.457 g/cm3 up to the maximum of 1.718 g/cm3. The compressive strength increased at higher temperatures, up to 84.4 MPa at 500 °C. The tensile strength was weaker with the increase of the temperature, while the bending strength first increased then reduced, and reached the maximum of 43.2 MPa at 160 °C with an increase of 41.64%.

Ping Zhai, Xiaofeng Duan, Hongbin Li, Hongsheng Wang, Qihong Wei, Changtao Shao
Preparation of Al2O3–Y2O3 Composite Coatings on Silica-Based Ceramic Core Surface

In order to study the interface reaction between silica-based ceramic core and superalloy during the process to fabricate the directional solidified and single crystal hollow blades, the Al2O3–Y2O3 composite coatings were prepared by dip-coating method and low pressure air spraying method. The Al2O3–Y2O3 composite coatings slurry was made through dispersing Al2O3 powders and Y2O3 powders into yttrium sol or yttrium nitrate solution. The results showed that Al2O3 and Y2O3 could restrain the interface reaction between ceramic core and superalloy due to their excellent high temperature stability. The coatings had to pre-sinter at 1200 °C so that the coatings themselves as well as the coatings and matrix would have a certain extend bonding strength. The dip-coating method was compared with low pressure air spraying method, as well as yttrium sol binder and yttrium nitrate solution for their influence on coating thickness and crackles. The coatings were characterized by SEM, EDS and XRD. The results indicated that the coating thickness was about 6 μm and easier controlled by low pressure air spraying method than dip-coating method. The coating surface was smoother with fewer microcracks by employing yttrium nitrate solution as coating binder other than yttrium sol. The phases of the coating are mainly Al2O3 phase and YAlO3 phase which can restrain the interface reaction.

Junhao Yan, Huiming Ji, Dingzhong Tang, Jiansheng Yao, Xin Li, Shuxin Niu, Lili Wang
Preparation of LaPO4 Nanoparticles by Coprecipitation Method

LaPO4 nanopowders were prepared by co-precipitation method using NH4H2PO4 and La(NO3)3 as raw materials. The influence of the composition of raw materials and the heat treatment process on the composition and microstructure of the synthesized powders were investigated by thermogravimetric-differential scanning calorimetry, X-ray diffraction and transmission electron microscopy. The synthesis mechanism of LaPO4 powder was discussed. The results showed that the precipitate prepared using NH4H2PO4 and La(NO3)3 with mole ratio of 1:1 was hexagonal LaPO4·0.5H2O, and it transformed into hexagonal LaPO4 after calcination at 400 °C. The precipitate calcined at 900 °C was not well crystalized monoclinic LaPO4, and it crystalized completely with particle size about 200 nm after calcination at 1000 °C.

Hongying Dong, Yingchai Shuang, Qinghong Sun, Qi Ren, Wen Ma
Preparation of 3Y-TZP Nanoceramics by a Modified Two-Step Sintering with Ultrahigh Heating and Cooling Rates

3 mol% yttria stabilized tetragonal zirconia polycrystal (3Y-TZP) nanoceramics were prepared separately through traditional two-step sintering (TSS) and a modified TSS, namely rapid-treating TSS (RT-TSS) in which ultrahigh heating and cooling rates during the first step were adopted. The comparison studies showed that in RT-TSS, the first-step sintering temperature required for full densification could be obviously lowered and the grain growth be more effectively suppressed than that in TSS. A nearly fully densified (>98%TD) ceramics with an average grain size of 150 nm was obtained through RT-TSS. While, the ceramics prepared by TSS showed the larger grain size of 180 nm. The results also showed that the suppression of grain growth in RT-TSS didn’t so strongly rely on the ‘frozen’ structure. Supersaturated vacancies generated during the cooling process might play a more important role.

Feng Chen, Zhiqiao Yan
Phase Transformation Mechanism of Self-reinforced Y-α-SiAlON Ceramic Tool Material Manipulated by Two-Step Sintering

In this study, self-reinforced Y-α-SiAlON was prepared by two-step phase transformation using single or dual rare-earth oxide addition. The process was implemented by a two-step sintering technique. The mechanism of two-step phase transformation and microstructure evolution of Y-α-SiAlON with or without Ce2O3 addition were investigated in detail. The predominant phase of the sample after the first step (i.e., pressureless sintering at low temperature) comprised elongated β-SiAlON grains. By contrast, the majority phase of sample after the second step (i.e., gas pressure sintering at high temperature) included coarse, elongated α-SiAlON grains. The driving force for β-to-α SiAlON phase transformation and liquid viscosity decreased, whereas the amount of liquid phase increased because of Ce2O3 addition, which contributed to anisotropic growth and resulted in more elongated α-SiAlON grains. The sample co-doped with Y and Ce exhibited the best mechanical properties with fracture toughness of 7.8 MPa m1/2 and Vickers hardness of 19.81 GPa.

Jing Li, Ruiming Yin
Preparation and Characterization of Electro-responsive Graphene Oxide/Hydrolyzed Polyacrylamide/Sodium Alginate Hydrogel Fiber

Electro-responsive hydrogels have attracted great attentions because the electric stimuli is easy to be applied and controlled. Thus, it is expected to generate electro-responsive hydrogel fiber to improve electro-response rate. In this paper, graphene oxide/hydrolyzed polyacrylamide/sodium alginate (GO/HPAM/SA) hydrogel fibers were prepared by microfluidic spinning. The structure and morphologies of hydrogel fibers were characterized by FTIR and SEM. The electro-response behaviours were also studied. The results indicate that GO/HPAM/SA hydrogel fibers exhibit bending deformation in an electric field. In Na2SO4 solution, the hydrogel fibers first bend toward the cathode, and then bend toward the anode. It is suggested the bending of the hydrogel fibers is caused by two major factors, one is the osmotic pressure difference, another is the pH gradient induced by electrochemical reactions.

Li Peng, Jinghua Gong, Jinghong Ma
Preparation and Study of Silicone Polyurethane Low Friction Coating

In this work, polyether functional polydimethylsiloxane (PDPS) were introduced into the backbone of waterborne polyurethane (WPU) as a part of soft segment to synthesize a series of silicone polyurethane (PSU) emulsions by pre-polymerization method. Then the PSU coatings were prepared on the PET cloth by dip coating. The structure and performance of the coatings were characterized by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), water dynamic contact angles (DCA), friction coefficient and scanning electron microscopy-energy dispersive spectrometer (SEM-EDS). The effect of the molecular weight and content PDPS on friction property of the PSU coatings was analyzed. The results showed that PDPS size and content had an evident influence on the lubricity of PSU coating, the friction coefficient of the coating was the lowest when the PDPS MW is 1000 and the content is 28 wt%. Moreover, the prepared PSU emulsion was greatly stable.

Yongyue Li, Kun Yan, Jinghong Ma, Jinghua Gong
Preparation of Superhydrophobic PVDF/P(HEMA-MMA-SMA)/SiO2 Composite Membranes by Electrospinning

The hydrophobic random copolymer P(HEMA-MMA-SMA) which contained 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA) and stearyl methacrylate (SMA) chains was successfully synthesized via radical polymerization. The composites membranes of poly (vinylidene fluoride) (PVDF) and P(HEMA-MMA-SMA) blends and PVDF/P(HEMA-MMA-SMA)/SiO2 were prepared by electrospinning. Scanning Electron Microscopy (SEM) and Water Contact Angle (WCA) revealed that morphology and hydrophobic properties of the membrane surface. With the condition of 12 wt% SiO2, the maximum WCA (154°) of the electrospun composite film can be obtained. Superhydrophobic materials have been widely used in the fields, such as oil-water separation and self-cleaning.

Yuanxia Hu, Jinghong Ma, Jinghua Gong
Uniformly Polyaniline-decorated Carbon Nanofibers as Active Materials for Improved Supercapacitor Properties

As electrode material for supercapacitor, the conducting polyaniline (PANI) and carbon nanofibers (CNFs) formed nanocomposites have also been studied, but how to load stable polyaniline on carbon fiber surface is also difficult. In this paper, aniline and CNFs were prepared in situ emulsion polymerization, using hydrochloric acid (HCl) and sodium dodecyl sulfate (SDS) as dopant, sodium dodecyl sulfate (SDS) can be as an emulsifier at the same time. SDS as an emulsifier is to strong the dispersibility and stability of PANI on the surface of CNFs and further to improve the specific capacitance and cycle life of nanocomposite. The measurements showed that the PANI uniformly coating had grown on the surface of CNFs. The CNFs/PANI nanocomposites and PANI were as electrode materials. Electrochemical analysis illustrated the specific capacitance of the CNFs/PANI nanocomposites was much better than pure materials. The high specific capacitance of 588 F/g at a current density of 0.5 A/g is due to the special structure (much better than the pure PANI) and capacitance retention of 55% after 2000 CD cycles at a current density of 10 A/g (also better than the pure PANI), indicating the electrode material is potential for supercapacitors.

Xiaoxiao Yang, Guang Li, Yang Wang
Rapid Deposition of Al2O3/SiO2 Composite Coating on Carbon Fiber Fabric

In the paper, a uniform and continuous Al2O3/SiO2 composite coating was prepared on each fiber of carbon fiber fabric via room-temperature aqueous plasma electrolysis technique. The micromorphology and anti-oxidation property of the Al2O3/SiO2-coated carbon fiber fabric were systematically investigated. The dense and continuous Al2O3/SiO2 composite coating was uniformly deposited on each fiber of carbon fiber fabric. The thickness of coating was 120–150 nm. The Al2O3/SiO2 composite coating could protect the carbon fiber fabric from oxidation above 1000 °C. In addition, it could be seen 300 m carbon fiber fabric were coated continuously by high-quality Al2O3/SiO2 composite coating.

Yuping Zhang, Yonghua Shen, Weiwei Chen, Huanwu Cheng, Lu Wang
Effect of Treatment Temperature on the Structure and Properties of Braiding Reinforced Thermoplastic Polyurethane Medical Hollow Fiber Tube for Invasive Medical Devices

To improve mechanical properties of the metal mesh reinforced thermoplastic polyurethane elastomer (TPU) hollow fiber tube, we first discussed the effect of treatment temperatures on microphase separation of the TPU. The chemical microstructures of the TPU were characterized by X-ray diffractometer (XRD). The dynamic mechanical properties of the TPU were measured by DMA. The results exhibited two glass transition temperatures, which showed the distinct microphase separation. In addition, the mechanical property of hollow fiber tube was analyzed by flexural stress and twisting performance, and the mechanical properties of the metal mesh to enhance the hollow fiber tube was increased at different treatment temperature, which indicated that the microphase separation has a great influence on the mechanical properties of the metal mesh to enhance the hollow fiber tube.

Zhaomin Li, Minglin Qin, Shu Zhu, Muhuo Yu, Yunyun Xue
Preparation of Core-Shell ZrO2@SiO2 Nanoparticles and Its Effect on Properties of Composites

In this study, ZrO2@SiO2 nanoparticles with core-shell structure were prepared by Stöber method using tetraethyl orthosilicate (TEOS) as the silicon source. The core-shell structure of nanoparticles was characterized via transmission electron microscopy (TEM). The results showed that the surface of ZrO2 could be uniformly coated with SiO2 and the thickness of the SiO2 shell was about 10 nm. The prepared ZrO2@SiO2 nanoparticles were modified with 3-methacryloxypropyltrimethoxysilane (γ-MPS) and the graft ratios were analyzed by FTIR and TGA. After modified with SiO2 shell, the graft ratio of γ-MPS on ZrO2@SiO2 nanoparticles increased to 4.03%. Then the modified ZrO2@SiO2 nanoparticles were added into the quartz fibers (QFs) reinforced composites to prepare fiber posts with radiopacity. The effects of the nanoparticles on the mechanical properties of fiber posts were investigated by universal testing machine. The flexural strength of the composite material is reduced with the addition of ZrO2. While with the modified ZrO2@SiO2 nanoparticles, the flexural strength can be improved even if the content of the inorganic nanoparticles is relatively high.

Hao Wang, Xiaoze Jiang, Li Qian, Wenping Chen, Meifang Zhu
Investigation of Tensile Property of Thin Ply Composite Laminate with Open-Hole Assisted by Acoustic Emission Technology

As the application of carbon fiber reinforced polymer composite (CFRP) laminates in aerospace and aircraft structures, opening hole is inevitable in design, fabricate and assemblage. However, the open-hole procedure has a bad effect on mechanical properties of the composite laminate. In this paper, characters of acoustic emission (AE) and curve of stress-strain of composite laminate with open-hole under tensile test were obtained. It was found that onset damage stress of a thin ply laminate detected using acoustic emission was higher than that of the standard ply laminate with the decreasing of ply thickness, while ultimate open-hole tensile strength of the thin ply laminate was lower than that of the standard ply laminate. More homogeneous microstructure and balanced stacking sequence make the thin ply laminate have higher initial damage stress. AE signals of matrix damage and delamination are presumably classified by the amplitude, which validate superior damage suppression and delamination resistance in the thin ply laminates. Stress concentration around the open-hole cannot be relaxed under tensile test as higher damage suppression and delamination resistance in the thin ply laminate. That can lead the thin ply laminate has lower open-hole tensile strength.

Chunfang Huang, Mingchang He, Yonglyu He, Jiayu Xiao, Jianwei Zhang, Su Ju, Dazhi Jiang
Effects of Purification on the Structure and Properties of Hardwood Kraft Lignin

Poor melt spinnability of lignin hinders the development of lignin-based high-value products, which can attribute to the diversity of its component and structure. In this work, hardwood kraft lignin (HKL), which was obtained from paper pulping process, was filtered using a 0.05 μm ceramic membrane followed by the heat-treatment under vacuum to evaluate the effects of different purification on the chemical structure, components, and thermal properties of HKL. Results showed that the contents of ash and lignin-carbohydrate complexes (LCCs), the molecular weight and its distribution were significantly decreased after purification, while the basic structure of HKL did not change. The thermal stability and carbon content increased a lot after the heat-treatment, while the content of methoxy and β-β or β-1 linkages decreased. However, the melt spinnability of HKL decreased significantly and many defects appeared in the obtained carbon fibers after heat-treatment for a long time.

Erqiang Yin, Zhe Zhou, Shichao Wang, Meifang Zhu
Preparation and Gas Sensing Property of PEDOT/Silica Aerogel Fibers

Porous materials, as their high specific surface area, are commonly used in NH3-sensing. And when NH3-sensing materials are made into the form with interconnected pore structure, low-dimensional structure or hierarchical structure, their gas-sensitivity will be improved remarkably. Here, firstly silica aerogel fibers were prepared by wet spinning. Those fibers do not only preserve high specific surface area (maximum one is 835.8 m2/g) and network organization, but also have unique hierarchical structure (macropores in the surface and mesopores in the middle regions) and regular hollow structure. And then PEDOT was synthesized and loaded on the net skeletons of silica aerogel fibers by gas phase polymerization. The specific surface area and pore structure of PEDOT/silica aerogel fibers can be adjusted by change aging bath. Finally, the results of NH3 sensitivity experiment showed that all fibers have good gas sensitive, especially A0.5-PEDOT/SAFs (resistance variation is over 40%).

Si Meng, Xi-yue Huang, Xing-ping Wang, Jun-yan Zhang, Wen-ping Chen, Mei-fang Zhu
A Novel Janus Thermosensitive Hydrogel with Bidirectional Shape Changing Property

A facile strategy has been successfully established to fabricate janus nanocomposite (NC) hydrogel with anisotropic swelling behavior, which results in inhomogeneous shape change. This janus hydrogel was fabricated via two-step free radical polymerization by using clay as crosslinker and N-isopropylacrylamide (NIPAM) as monomer nut with different molar ratio in two layers, respectively. The free radical polymerization of PNIPAM at the interface provided a homogeneous conjunctive manner to tolerate the inhomogeneous tension of both layer after swelling. Moreover, the novel janus hydrogel could be well designed with bidirectional shape changing under temperature variation. Therefore, diverse thermoresponsive architectures could be built to provide a great potential in the field of cargo transportation, soft robots and actuators.

Yan Li, Kai Hou, Peiling Wei, Zhouqi Meng, Meifang Zhu
Surface Modification of Quartz Fiber by Aqueous Plasma Electrolysis

The mechanical properties of quartz and ceramic fiber are easily destroyed at high temperature. There are many process methods for continuous fiber surface treatment, commonly used in a chemical vapor deposition method and sol gel method. In this work, a method of preparing surface coating is proposed to protect the mechanical properties of fiber at high temperature, at the same time to achieve high efficiency, low cost, and to meet the requirements of Engineering production. Treatment of quartz and ceramic fibers in a continuous liquid equal plasma, plasma bombardment of the fibers is carried out, in order to achieve the purpose of preparation of coatings. After coating the surface of the quartz fiber, the ceramic coating is coated by the liquid plasma process, and the breaking strength is tested after the high temperature treatment.

Yang Meng, Weiwei Chen, Huanwu Cheng, Yuping Zhang
GO/DNA/Au/PANi Nanocomposite with High Photoconductive Responses to Visible Light and NIR

In synthesis of nanomaterials with bottom-up approach, DNA (deoxyribonucleic acid) chain segment took an important role in self-assembly of nano/micro-structured materials. DNA chain segment not only has good recognition characteristics, but also holds excellent transporting properties of delivery for drugs, protein or gene. To functionalize and smart the nanocomposites for applications in several devices, in this paper, single-stranded DNA chain and graphene oxide (GO) were hybridized, and Au nanoparticles were formed in situ with chloroauric acid and aniline as reducing agent. The GO/DNA/Au/PANi (polyaniline) nanocomposite were characterized by several approaches. The photoconductive responses to weak visible light and 808 nm NIR (near infrared) were studied based on interdigital electrodes of Au on flexible polymer film substrate with casting method. The results indicate that the resulting nanocomposite exhibits good photo-switching behaviors, the ratio of On/Off is 1–2 orders of magnitudes, while the response and recovery are very rapidly. It can be used in developing an intelligent nano-carriers with external stimuli responses, light detector to NIR, nano-machine controlled by light, biomimetic materials, and so on.

Mingjun Gao, Shisheng Lv, Jianxun Qiu, Wei Du, Xintao Zhang, Xiaochun He, Xiangming Li, Xingfa Ma, Guang Li
Effect of Boron Content on Structure and High Thermal Stability of Polyborosilazane Precursor

In this paper, a novel polyborosilazane (PBSZ) for preparing SiBNC ceramics was successfully prepared via co-polymerization of propylamine (C3H7NH2), trichlorosilane (HSiCl3) with different amounts of boron trichloride (BCl3). Pyrolysis of these precursors yields amorphous SiBNC ceramics, which with different boron content whereas similar Si/C/N ratio. The FTIR, NMR, EA and TGA were used to analyze the polymerization mechanism, composition, structure and ceramic yield of PBSZ samples with different boron content. The results indicated that these PBSZ contained the major framework of –Si–N–B– and six-membered boron-nitrogen rings. As boron content increased, the residual ceramic weight of PBSZ at 900 °C increased. When the molar ratio of BCl3:HSiCl3 was 1:1, the ceramic yield of PBSZ was 71.6%. However, the ceramic yield decreased when the boron content was further increased.

Chenyu Zhang, Yong Liu, Keqing Han, Xuefeng Chang, Muhuo Yu
Dispersion of Graphene Oxide in Polyvinylidene Difluoride and Its Improvement of Photoresponse Properties of Nanocomposite

Graphene oxide (GO) and its nanocomposites are widely used in energy storage devices, membrane separation, multi-functional materials due to their good charge transferring property and excellent mechanical, physical, chemical properties. The performances of materials and devices are strongly dependent on the dispersion effects of GO in matrix. In the applications of polymer/GO nanocomposites, the re-dispersion of dried GO in matrix with good effects is still having some difficulties. Good dispersion of GO solution with polymer aqueous would be obtained easily. However, the dispersion of GO solution in non-aqueous polymers is still a great challenge. In this paper, attempts of the dispersion of GO solution in non-aqueous polymers were carried out with oil/water interface mixed approach. In the study, PVDF [poly-(vinylidene difluoride)] selected as representative polymer is based on the following reason. PVDF is a well-known organic multi-functional polymer, which is widely used in several devices due to its outstanding piezoelectric, pyroelectric, and dielectric performance. PVDF/GO nanocomposites were obtained with interface blend, and a series of characterizations were performed. The photoconductive responses to weak visible light and 808 nm NIR (near infrared) were studied based on interdigital electrodes of Au on flexible polymer film substrate with casting method. The results indicate that the GO has good dispersion in PVDF matrix and no obvious aggregation of GO is observed. The resulting nanocomposite exhibits good photo-switching behavior to visible light, while the response and recovery are very rapidly. The response to weak 808 nm NIR is relatively weak, this may be the results of PVDF possessing some absorbance to NIR. It can be seen that an intelligent composite film with external stimuli responses is developed and can be used in many fields, such as electronic skin, sensors and actuators, information storage, artificial muscle, biomimetic films, membrane separation controlled with external stimuli.

Xintao Zhang, Shizhen Wang, Jianxun Qiu, Wei Du, Xiaochun He, Mingjun Gao, Xiangming Li, Xingfa Ma, Guang Li
Antimony Doped Tin Oxide Infrared Shielding Films for Cooling Silicon Solar Cells

The operating temperature of silicon solar cells is strongly impacting on their photoelectrical conversion efficiency (PCE). The increasing temperature of the silicon solar cells can degrade device performance significantly. It is well known that antimony-doped tin oxide (ATO) shows the very high transmittivity in visible light region and heat-insulating properties. In this work, ATO nanoparticles with a crystallite size of 8 nm via a peroxo-route and hydrothermal process were prepared. Then the films were deposited by spin-coating method, furtherly studying the effect of varying Sb dopant concentration and film thickness on solar-heat shielding performance and device performance. To evaluate the IR-shielding and silicon solar cells properties, the ATO films on glass were used as the cover glass on the top of silicon solar cells under solar simulator. The experimental results showed that in presence of ATO films, PCE was effectively kept, which has proved that the properties of the ATO films could affect the cell performance after being irradiated for 30 min. Among them, 6-layer ATO film with 7 mol% doped concentration was the champion for silicon solar cells to keep its efficiency. After being irradiated for 30 min, the efficiency of solar cell was maintained 97.21% as the initial, which was much higher than that of in presence of bare glass.

Ruiqianling Gao, Hao Xiong, Ran Li, Chengyi Hou, Yaogang Li, Qinghong Zhang, Hongzhi Wang
Preparation and Properties of Cool-Feeling PA6 Fiber

In order to increase comfort of fabric, the development of fiber with the function of cool-feeling has been become the hotspot of chemical fiber industry. The cool-feeling fibers were prepared in this paper. The nano bowlder powder, aluminum nitride (AlN) powder, silicon carbide (SiC) powder were used as the cooling function powder, and the powders were modified by silane coupling agent 3-Aminopropyltriethoxysilane(KH-550). Nylon 6 (PA6) fibers with cooling function were prepared by melt blending method and melt spinning method. Further more, the properties of cool-feeling PA6 chip, fiber and fabric were characterized. The results show that the particle size of the powders become smaller and the distribution become narrower, the scale mainly distribute from 400 to 600 nm after the surface modification by KH-550. The results of thermal conductivity test and fabric contact cold test show that, the thermal conductivity of PA6 composite fiber reaches maximum with the value of 1.73 W/(m/K) when modified by AlN powder and bowlder powder. And the corresponding Q-max value of the fabric up to 0.162 J/cm2 s demonstrates that the cooling effect of composite fiber reach optimum.

Yiren Li, Xiaomin Zhao, Lian Tang, Peng Ji, Chaosheng Wang, Huaping Wang
Dispersion of Single-Walled Carbon Nanotubes in Organic Solvents DMAC

The effective use of single walled carbon nanotubes (SWCNT) for improving mechanical properties of polymers is the key to the efficient diffusion of carbon nanotubes into organic solvents to form a stable single solution. The single walled carbon nanotubes in dimethylacetamide (DMAc) with different dispersion methods (including homogenizer, ball mill, micro jet machine) were studied in this paper, adding different organic compounds (dispersant, polyacrylonitrile) and different chemical treatment methods (acid purification, etc.) affect the dispersion of single wall carbon nanotubes were also discussed. The best dispersing time, the effects of different conditions on the basic properties of Single-walled carbons and on the dispersed state of carbon nanotubes were determined by using optical microscopy, scanning electron microscopy, Raman and elemental analysis, in order to get the optimal dispersion conditions of single-walled carbon nanotubes in DMAc.

Baihua Liu, Jingwei Zhang, Cong Wang, Cuiqing Teng, Hui Zhang, Muhuo Yu
Preparation and Characterization of TPS/PBAT/Tourmaline Biodegradable Composite Films

To improve the compatibility between starch and poly(butylene adipate- co-terephthalate) (PBAT), thermoplastic starch (TPS) was prepared via treatment starch with KH-560, and then the melt blended with PBAT to get degradable TPS/PBAT blend membranes. The compatibility and thermal stability of TPS/PBAT blend membranes were effective improved, and its water absorption was reduced. And the degradable TPS/PBAT/tourmaline composite materials that had the functions of negative ion releasing and far-infrared radiation were prepared by adjunction the surface organic modified tourmaline in the blend procedure of TPS and PBAT. The dispersion stability of tourmaline, negative ion releasing amounts, far-infrared emissivity and mechanical property of TPS/PBAT/tourmaline composite were characterized. The experimental results demonstrated that the TPS/PBAT/tourmaline functional composite materials had excellent negative ion releasing, far-infrared radiation and mechanical properties.

Yingmo Hu, Quan Liu
Fire Performance Analysis of PVC and Cabtyre Cables Based upon the Ignition Characteristics and Fire Growth Indexes

The ignition characteristics and fire growth indexes of the PVC cable (Cable 1), the flame retardant PVC cable (Cable 2), the cabtyre cable (Cable 3), and the cabtyre cable with fireproof coating (Cable 4), were investigated experimentally. Twenty experiments were conducted by cone calorimeter, and the ignition time and fire growth index under different external radiation heat fluxes were focused primarily. Results showed that the ignition time of Cable 2 was longer than that of Cable 1, and the ignition time of Cable 4 was longer than that of Cable 3. The critical heat flux, under which the cable could be ignited for any length of time, was derived through data fitting. In the present study, the critical radiation heat fluxes for Cable 1–4 are 3.5, 9.5, 13.4 and 18.5 kW/m2. The ratio of peak heat release rate (HRR) to the time reached the peak HRR is defined as fire growth index. The fire growth index of Cable 1 is larger compared with that of Cable 2, and the fire growth index of Cable 3 is larger than that of Cable 4. The fire growth index of cables has well linear relationship with the external radiation heat flux in the present study.

Bosi Zhang, Jiaqing Zhang, Hui Xie, Qiang Li, Liufang Wang, Minghao Fan
Loading and Controlled Releasing of Anti-cancer Drug Bortezomib by Glucose-Containing Diblock Copolymer

A glucose-containing diblock copolymer was employed as nanocarrier in this study for delivery of the anticancer drug bortezomib (BTZ). Our system was based on pH-induced dynamical conjugation of boronic acid on BTZ to cis-diols on glucose-containing polymer. Diblock copolymer poly(ethylene glycol)-b-poly (gluconamidoethyl methacrylate) (PEG-PGAMA), was firstly synthesized via atom transfer radical polymerization(ATRP) by successive polymerization of monomer gluconamidoethyl methacrylate (GAMA) using a PEG-based ATRP macroinitiator. BTZ was then loaded in glucose-containing copolymer as chemical conjugation occurred of boronic acid to glucose groups and the drug-released behavior of this system was simulated in vitro. The results demonstrated that PEG-PGAMA copolymer had strong ability to bind BTZ at physiological pH of 7.4; it could also effectively release BTZ at acid pH of 5.5(close to environment of cancer tissue or the subcellular endosome) in a pH-dependent manner. In our study, a facile and interesting nanocarrier system for anti-cancer drug bortezomib (BTZ) was provided with a kind of glucose-containing block copolymer without any need of chemical modification, which only utilized dynamic chemical complexation to reach effective drug-loading and controlled release of BTZ upon responsiveness to external pH.

Xiao-Ting Zhang, Hai-Liang Dong, Zhong-Li Niu, Jia-Ming Xu, Dan-Yue Wang, Han Tong, Xiao-Ze Jiang, Mei-Fang Zhu
Trimethylisophthtalodinitrile Oxide as a Room-Temperature Curing Agent for Curing HTPB

In order to cure hydroxyl-terminated polybutadiene (HTPB) at room temperature, Trimethylisophthtalodinitrile oxide (TINO) was synthesized in four steps from mesitylene with total yield of 42.0%. Its structure was characterized by FT-IR 1H NMR and 13C NMR. Make curing agent TINO/HTPB equals 12, 14, 16, 18 and 20% to prepare the dumbbell-shaped cross-linked polymers. The FT-IR, tensile strength, DSC, TG and contact angle of the cross-linked polymers were tested and analyzed. With the increasing of TINO, tensile strength of cross-linked polymers increased from 0.077 to 0.300 MPa and the elongation at break decreased from about 437 to 104%. The Tg of the crosslink polymers are −75.01, −73.92, −73.42, −70.09 and −71.78 °C, respectively. The contact angles are 116.91°, 100.66°, 93.68°, 86.25° and 87.35°. The results showed that TINO can cure HTPB under room temperature and the cross-linked polymers are expected to be used in the composite solid propellant.

Xiaochuan Wang, Yuanjie Shu, Yonglin Lei, Jichuan Huo, Xianming Lu, Qian Zhang, Yingying Lu, Wei Wang
Effect of Coagulants on Phase Morphology and Property of Cellulose/Silk Fibroin Blend Fiber

In order to study the effect of coagulants on phase morphology and property of cellulose/silk fibroin blend fiber, coagulants of water, ethanol, ethanol/1-butyl-3-methylimidazolium chloride ([BMIM]Cl) were chosen for coagulation bath. Ethanol is effective coagulant for cellulose and silk fibroin. The uniform dispersion of silk fibroin along the radial distribution can be found when [BMIM]Cl was added in ethanol. The tensile strength of the blend fiber can be improved by adjusting coagulation bath composition.

Yongbo Yao, Zhiyong Yan, Zhe Li, Honglei Yi, Yumei Zhang, Huaping Wang
Insulation Failure of Class 1E Cable for Nuclear Power Station Under Fire Heat Radiation

In order to discover the regularity of insulation failure of typical cable for nuclear power plant in fire, the experimental research method was used to study the insulation failure of Class 1E cable for nuclear power plant under different simulated fire conditions by using cable thermal radiation test furnace in this paper. The results show that the insulation failure time and the breakdown time of the cable decrease exponentially with the increase of the ambient heat radiation flux, and the insulation failure temperature and the insulation breakdown temperature of the cable are basically the same.

Jinmei Li, Jiaqing Zhang, Qiang Li, Yichen Yang, Minghao Fan
Insulation Failure Mechanism of Cable in Fire Environment

In order to reveal the insulation failure mechanism of the cable under the fire condition, the conductive mechanism and aging mechanism of the cable insulation material were analyzed theoretically, and the relationship between the thermal decomposition weight loss curve and the insulation resistance and temperature of the cable insulation material was constructed. The results show that the reason for the failure of the cable in the fire is that the insulation performance of the insulating material decreases after heating. For different thermal aging degree of the cable, the decomposition process of insulating materials are divided into two stages. When the failure occurs, the insulating material is not decomposed; when the breakdown occurs, the insulating material is in the first stage of thermal loss. Therefore, the failure temperature of the cable can be considered mainly depends on the characteristics of its insulating material, regardless of the structure, shape and size of the cable.

Qiang Li, Jiaqing Zhang, Jinmei Li, Yichen Yang, Minghao Fan
Microstructure Evolution of Nanoporous Copper Fabricated by Electrochemical Dealloying Mn–Cu Alloy

The electrochemical dealloying behavior of single-phase Mn-Cu alloy in hydrochloric acid solution by applying different dealloyed voltages was investigated. The concentrations of HCl solution are also explored as a parameter for modulating the nanoporous microstructure. Phase constitution and microscopic morphology of precursor alloy and dealloyed samples were characterized using X-ray diffraction and scanning electron microscopy. The precursor alloy was single-phase CuMn4 solid solution. After dealloying, only face-centered cubic copper phase can be identified. The results show that different applied voltages make a small difference on nanoporous structure. The concentration of hydrochloric acid solution has a remarkable influence on the dealloying process and nanoporous microstructure. The dealloying in a 0.5 M HCl solution results in nanoporous copper with ligament size range of 43.76–160.66 nm. The high concentration of dealloying solution leads to the formation of coarsened nano structure.

Jinyi Wang, Yi Yang, Mingrui Zhang, Sen Yang
CeO2 Nanorod-Supported Transition Metal Catalysts Prepared by Dealloying for CO Oxidation

In this study, Al–Ce, Al–Ce–Ni, and Al–Ce–Mn precursor alloys were prepared by melt-spinning, and then dealloyed in 20% NaOH aqueous solution and calcined in air. The catalytic activities of the as-prepared precursors were evaluated for the oxidation of CO at atmospheric pressure. The results revealed that a novel CeO2 nanorod-supported skeleton structure could be obtained by dealloying and calcining the as-quenched Al–Ce ribbons. The CO conversion temperatures for the CeO2/NiO and CeO2/MnO2 composites were reduced to about 147 and 136 °C, respectively, which indicated the superior activity of these composites as compared to pure CeO2 (Zhang et al. in Nanotechnology 28, 45602, 2017) [11]. The reason for the increased catalytic performance can be attributed to the large number of active sites provided by the composite materials. The synergistic effects at the NiO/MnO2 and CeO2 interface as well as the increase in the concentration of oxygen vacancies in the composites also play important roles in the enhancement of the catalytic performance.

Dong Duan, Haiyang Wang, Xiaolong Zhang, Caihua Wei, Zhanbo Sun
Effect of Corrosion Potential on the Structure and Properties of Nanoporous Nickel

Taking the Ni–Mn alloy with 25% Ni as the precursor, nanoporous nickel (NPN) was fabricated by electrochemical dealloying, and the effect of corrosion potential on the material microstructure and electrochemical performance was studied in the article. Morphology, element species, content and phase of the sample were characterized and analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). Different from the previously report that the material surface presented the structure of “mud crack”, materials prepared in this article remained the porous skeleton structure, but also reduced the large cracks and increased the hairline cracks. After a deep research, it is found that the corrosion potential determines the morphology and structure of porous material. This was due to the fact that corrosion rate became quicker when the corrosion voltage was higher and the degree of corrosion increased accordingly; precursor alloy defects increased as the dissolution of Mn, and the internal stress increased as a result; in addition, the diffusion rate of Ni was so low that it couldn’t refill the vacancy of Mn timely, and then more cracks occurred, therefore there were significant differences for the number and size of cracks. In order to further understand the electrochemical performance of the electrode material prepared under a proper potential, cyclic voltammetry and charge-discharge technology were used to characterize the electrochemical performance of NPN. The results show that the specific capacitance of NPN was 1.69 F cm−2 which is 3 times of that of the nanoporous nickel martial reported previously. Therefore the prepared nanocomposite nickel in this article is a high-quality electrode capacitor material.

Jinxiong Wu, Siyue Dai, Xiankang Shan, Yu Zhang, Xiuling Yan
Effect of Two-Step Anodization on Structure of TiO2 Nanotube Arrays

A two-step anodic oxidation was used to prepare TiO2 nanotube arrays with controllable structure and reproducibility by the isobarically anodization of pure Ti foil. The morphology and structure of TiO2 nanotube arrays were characterized by high resolution scanning electron microscopy (SEM). Moreover, the formation mechanism of TiO2 nanotube arrays was discussed. While the effects of anodic oxidation voltage and oxidation time on the diameter and length of nanotubes were further studied. The “field-assisted dissolution” model can perfectly explain the four stages of the first oxidation process, combined with the theory of oxygen bubble mould, to produce an electron flow during the growth of the oxide film, and oxygen bubbles hinder the upward growth of the barrier oxide film. The formation of pores resulted by bubbles evolution can be a good explanation of the TiO2 nanotubes which show a large tube containing the structure of small tubes. The results demonstrate that with the increasing of oxidation time and oxidation voltage, the tube diameter, tube length and tube number of large tube have a tendency to increase obviously. The preparation of TiO2 nanotubes by anodic oxidation is simple and easy to operate. It can efficiently and easily prepare TiO2 nanotubes with excellent morphology and broaden its application range.

Siyu Chen, Shuhui Zhang, Zuojun Tan, Shu Zhang
The Influence Factor of Silicon Carbide Ceramic Sintering

Sintering is the key process to a pressureless sintering silicon carbide ceramic. From the perspective of industrial production, this paper discusses the influence factors of big size silicon carbide ceramic sintering from three aspects: sintering curves, the density of green body and particle size of raw material. The results were as follows: (1) Under the conditions that heating rate from 1000 to 1500 °C and from 2100 to 2150 °C is 3 °C per minute and 0.5 °C per minute respectively, a big size product of densification of the ceramics has been obtained. (2) Using dry pressing at 50 MPa, dwell time 2 min, and then with CIP at 180 MPa, dwell time 5 min, the green body densities will more uniform from center to edge. (3) Applying raw materials particle size below 0.6 μm the big size product will get more dense material. Combining with the above three methods. The final product can achieve densification. The sintered sample can been achieved with density of 3.12 g/cm3, Vickers hardness of 26 GPa, and three-point flexure strength 420 MPa.

Chunlei Duan, Xiaochen Li, Qiang Zhao, Wenlin Zhao, Lihua Fu, Guangrong Zhang, Yuhong Chen
Effect of Functional Additives on Performance of Internal Combustion Engine Lubricating Oil

In order to improve the quality of lubricants and prolong the life of oil products, functional additives should be added to the base oil. The functional additives of lubricating oil mainly include detergent, dispersant, antioxidant and rust inhibitor. The purpose of present research is to investigate the effect of additives and the dosage of them on the performance of internal combustion engine lubricants. Certain amount of additives were added to the base oil for testing. Detergent T106A and T115B, dispersant T154B, antioxidant T203 and rust inhibitor T705 were selected as functional additives in the experiment. The detergency of the oil was evaluated by coking test. The dispersibility of lubricating oil was evaluated by spot dispersion experiment at low temperature and high. The kinematic viscosity of the lubricating oil was determined according to the method of GB/T265. The infrared spectra of the lubricating oil were used to determine the oxidation value and nitrification value and the flash point of the lubricant oil was measured by flash point meter. The results showed that both detergent T106A and T115B had a good clean ability, and T106A showed better effect than T115B does. In combination with the standard of oil use in internal combustion engine, economic benefit and the reference amount provided by the manufacturer, the optimal dosage of detergent T106A is 2.0 wt%, and the optimal dosage of detergent T115B is 3.0 wt%. The dispersant T154B had good sensitivity at high temperature and also at low temperature, and the optimal dosage was 3.5 wt%. Antioxidant T203 had a good anti-corrosion function, and the optimal dosage was 3.0 wt%. The addition of the rust inhibitor T705 resulted in an overall reduction in the flash point and viscosity of the lubricating oil, and the optimal dosage of rust inhibitor T705 was 4.0 wt%.

Jingqiu Mu, Jinlong Wu, Fenglan Han, Xueyan Li, Yaguang Wang
Metadaten
Titel
Advanced Functional Materials
herausgegeben von
Prof. Yafang Han
Copyright-Jahr
2018
Verlag
Springer Singapore
Electronic ISBN
978-981-13-0110-0
Print ISBN
978-981-13-0109-4
DOI
https://doi.org/10.1007/978-981-13-0110-0

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