Materials for Sustainable Environmental, Energy, and Bioresource Applications

The elimination of isovaleraldehyde in air was experimentally studied in a tubular reactor that combines plasma barrier discharge (DBD) and photocatalysis. The influence of key parameters on the degree of pollution was tested. The study of the effect of residence time shows that when this parameter decreases, the elimination efficiency also decreases. When the residence time is reduced by five times, the removal efficiency drops from 83 to 59%. The influence of relative humidity shows that when this parameter increases, the CO₂ selectivity’s are greater. The by-products identified and analyzed are classified into three groups: intermediate products, carbon monoxide, carbon dioxide and ozone. Regarding the org. components, we find that as the energy of the input plasma increases, this leads to a higher mineralization of the pollutant, i.e. the intermediate products formed decrease and the carbon dioxide increases. The mass balance of carbon products is reached at approximately 100%. The formation of ozone is favored by the increase in the input energy. It is interesting to note the existence of the synergy effect for a cocktail of pollutants such as the case of two aldehydes.

Paper-based food packaging materials offer the advantages of renewability and biodegradability. However, their inherent porous structure and the hydrophilic nature of cellulose limit their resistance to water, water vapor, gas, and grease. This study presents a novel solution: a bio-based bilayer coating using whey protein isolate (WPI) and carnauba wax (CW), successfully applied to standard paper substrates using a rod coater. We investigated the effects of WPI and CW to determine their impact on the barrier and mechanical properties of the coated paper. Results demonstrated a significant improvement in grease/oil resistance, as measured by a 99.7% increase in hydrophobicity. Additionally, water vapor permeability was reduced by an impressive 97.7%, and air permeability reached 0 mL/min. To enhance flexibility, glycerol was added as a plasticizer within the WPI formulation, resulting in improved elongation at break values for the coated papers. The viscosities of both the WPI and CW coating solutions exhibited good processability, suggesting potential suitability for scaling up to industrial processes. Finally, scanning electron microscopy and contact angle measurements confirmed the uniformity of the paper’s coated layer and strong interlayer adhesion, which are crucial factors for effective barrier performance.

This work aims to use fly ash waste as a reinforcing filler for alkali-resistant wall primer. The fly ash surface was treated with an alkaline solution. The results of color analysis, mechanical properties, and FESEM analysis show that fly ash slightly reduces the brightness of the coating, increases its washout resistance and alkali resistance, and reduces its water permeability. Usable fly ash content is from 10 to 30%, the surface coating has few defects, only a few fly ash particles appear on the surface, and fly ash particles tend to distribute inside. The coating creates a tight structure. At these concentrations, the primer has technical specifications that meet and exceed the requirements of wall primer coating, according to TCVN 8652:2012. In particular, the washout durability, alkali resistance, and waterproofing of the coating have been enhanced. Paint formulations containing fly ash can be applied and commercialized.

This study explores the development of novel biodegradable and antimicrobial materials for personal protective equipment (PPE), focusing on environmental sustainability and biological resistance. The research introduces an innovative approach using biodegradable polyhydroxybutyrate (PHB) polymer, combined with Zinc Oxide (ZnO) NPs to enhance antibacterial properties. The report categorizes various antibacterial materials, emphasizing the unique qualities of PHB as a biodegradable alternative to petrochemical-sourced plastics. Additionally, it delves into the mechanisms of antibacterial action of ZnO NPs, highlighting their effectiveness in generating reactive oxygen species (ROS) and Zn²⁺ ions to combat bacterial threats. The study concludes with the successful synthesis of PHB films embedded with ZnO NPs, demonstrating their potential as a sustainable and effective solution for PPE in response to the increasing demand for environmentally friendly and biologically resistant materials.

The use of effective antimicrobial surfaces could reduce both healthcare-associated infections and the proliferation of antibiotic-resistant bacterial strains. This paper introduced a new method of embedding ZnO-Ag hybrid NPs into cotton using a simple two-step synthesis. The effect of the concentration of the Ag nitrate solution, the hydrophobicity of the samples, their morphology, and the quantity of NPs on the samples were determined. The amount of ZnO in the samples ranged from 0.049 to 0.27 mg/cm², and the amount of Ag varied between 0.0108 and 0.022 mg/cm². The antibacterial activity of the samples was tested against Gram-negative E. coli bacteria in the dark and under LED light. The samples exhibited up to 100% antibacterial efficiency under LED light in just a few tens of minutes. From these results, a mechanism of photocatalytic inhibition under LED light of bacterial growth was proposed. Together, these results demonstrate that cotton coated with ZnO-Ag hybrid NPs prepared in this study is a promising material for the creation of antimicrobial textiles.

The current work offers an insightful literature review on the intersection of pathogenic agents and textile technology. It begins by classifying and discussing the characteristics of pathogens, such as bacteria and viruses, alongside their transmission methods and risks. The review progresses to explore the strategies for mitigating these risks, focusing on the adhesion of pathogens to surfaces and innovative solutions like Reactive Oxygen Species (ROS) generation and surface modifications. A significant emphasis is placed on the advancements in textile technology, including the exploration of antimicrobial agents like metallic NPs and natural products, as well as the development of self-cleaning textiles through techniques like the sol–gel process. This chapter encapsulates the critical role of textile innovation in addressing pathogenic challenges, highlighting the importance of ongoing research and development in this dynamic field.

This study presents a novel photocatalytic method for Bisphenol A (BPA) degradation using graphitic carbon nitride (g-C3N4) coupled with carbon quantum dots (CQDs) as a co-catalyst. Addressing the challenge of plastic pollution, particularly in marine ecosystems, the research focuses on enhancing the efficiency of BPA degradation through photocatalysis. The composite material synthesized using urea and CQDs and exposed to LED light demonstrated significant improvement in BPA degradation. UV–visible spectrometry confirmed a 100% degradation rate within 6 h using 0.1% CQDs, surpassing typical environmental degradation rates. The study highlights the potential of this photocatalytic method as an effective, environmentally friendly solution for mitigating plastic pollution, with future work aimed at optimizing the method’s efficiency and structure.

This work aims to clarify the difference between the influence of TiO₂ particles at micrometer and nanometer sizes on the mechanical properties and weathering durability of water-based acrylic coatings. Micro-R-TiO₂ and nano R-TiO₂ particles with 2 wt% content were dispersed in the emulsion acrylic polymer by ultrasonic vibration to prepare coatings. The coatings without TiO₂ particles, with 2 wt% micro R-TiO₂ and with 2 wt% nano R-TiO₂ were tested for abrasion resistance, weathering aging in UV/CON accelerated weathering chamber. Weathering aging was assessed by IR quantitative analysis, as well as the weight loss of the coating. The results showed that the micro R-TiO₂ with the 2 wt% content simultaneously enhanced the abrasion resistance and weathering durability of water-based acrylic coatings but not as effectively as nano R-TiO₂. The incorporation of 2 wt% micro-R-TiO₂ slightly increased the abrasion resistance of coating from 78.4 to 98.9 lite/mil (26% increase) while with addition of nano-R-TiO₂ at the same content, the abrasion resistance was significantly improved from 78.4 to 129.3 lite/mil (65% increase). After 48 aging cycles, the alkane CH groups and weight of the coatings without R-TiO₂ particles, containing 2 wt% micro-R-TiO₂, containing nano-R-TiO₂ lost 34.2% and 17.4%; 23.8% and 13%; 13.7% and 13%, respectively.

Water pollution is a critical global issue exacerbated by the release of domestic and industrial wastewater into the environment. This wastewater often contains harmful contaminants like heavy metals (e.g., Pb, As, Hg, Zn, Ni) and synthetic organic dyes (e.g., methylene blue, congo red, crystal violet), posing threats to human health and ecosystems. Adsorption using carbonaceous adsorbents offers a cost-effective, efficient, and environmentally sound solution to remove these pollutants, making it ideal for developing countries. Biomass-derived, graphene-like materials show promise as eco-friendly adsorbents with superior contaminant removal capabilities. Salix, a rapidly growing willow tree common in Canada, provides a potential source for graphene-like carbon materials through pyrolysis. This study explores a two-stage thermal pyrolysis process of Salix with NaCl addition to synthesize graphene-like materials tailored for wastewater treatment. Extensive characterization methods analyze the surface area, morphology, and crystallinity of the resulting carbon materials. The adsorption efficiency is tested by varying parameters like adsorbent dosage (0.25–1.25 g/L), contact time (0–180 min), and initial MB dye concentration (80–180 ppm). Results indicate pseudo-first-order adsorption kinetics. The synthesized carbon materials demonstrate an impressive maximum adsorption capacity of 195.4 mg/g at room temperature.

Pyrolysis is a solution using thermochemical processes to recover solid waste. The conditions for pyrolysis of activated carbon from palm leaf sheath have been optimized. The best results in terms of Methylene Blue removal efficiency were obtained for chemical activation in sulfuric acid (H₂SO₄) 96% for a period of 2 h at room temperature (30 °C), and a ratio 1:3. Carbonization was carried out by conventional heating at different temperatures (from 350 to 450 °C) and for different durations of 1.5–2.5 h. The best dye removal efficiency (87.8%) was observed for pyrolysis carried out at 450 °C and 2.5 h. The effects of temperature and duration of pyrolysis were studied using an experimental design. The final removal efficiency after activation was modeled as a first-order polynomial model:

Assessing tool wear is crucial for determining the machinability of cutting operations, with the initial cutting conditions having a significant impact on both tool wear and longevity. This study examines how starting cutting parameters affect tool wear during the machining of TiMMC. Findings indicate a rapid increase in initial wear alongside rises in cutting force and speed. The peak cutting force is reached within approximately 5 s, coinciding with the period where initial wear stabilizes across all tested cutting conditions. Notably, the early stage of tool wear, which unfolds in a brief timeframe, contributes to as much as 39% of total wear across both initial and steady wear phases. The primary mechanisms of wear in this phase are identified as adhesion and diffusion. To optimize the initial cutting conditions with the goal of reducing early tool wear, this research employs response surface methodology (RSM) and central composite design (CCD). Further, an analysis of variance (ANOVA) is utilized to evaluate the regression model of the cutting process, enabling the optimization of cutting parameters through empirical response equations and the development of a 3D model to visualize the effects.

This work deals with the identification of organic and inorganic elements of a rubber supplied by an industrial partner. The rubber formulation is not known. For this purpose, a methodology based on reverse engineering was followed to identify the rubber composition. Information on the material composition and rubber formulation was obtained using several characterization techniques such as acetone extraction, TGA and DSC thermal analysis, infrared spectroscopy, GC-MS and X-ray fluorescence. The interpretation of the results showed that industrial rubber is mainly composed of styrene-butadiene polymer, additives such as BHT and carbon black. Also, mineral elements like zinc, silica, aluminum and magnesium.

This study discusses the predictive analysis of elastomer service life, emphasizing the importance of thermal and mechanical testing data. It explores the responses of various elastomer types to environmental stressors and their implications for durability and application. The research highlights the need for refined testing methodologies to enhance predictive accuracy and discusses future directions, including the integration of advanced technologies like AI and nanotechnology. The findings offer significant insights into the sustainable development and efficient use of elastomers in diverse industrial applications.

The fundamental principle of two techniques, namely the 3-omega (contact) and Modulated photothermal radiometry (contactless) have been described. Models for identifying the thermal properties of thin film structures have been presented with a specific focus on a multi-layer thin film (IST/SiO₂/Si) configuration featuring a phase change chalcogenide material known as InSbTe (IST) on top. This IST thin film is used as the active layer in Phage Change Memory (PCM), an emerging technology for non-volatile storage. Despite the difference in the shape of the heat flux distribution, the heat transfer model shows similarities for both techniques. Finally, by using a protocol, the thermal conductivity k and related thermal boundary resistances (TBRs) of layer of interest can be estimated.

The presence of pharmaceutical compounds in hospital and domestic effluents poses a serious environmental problem, hence the need to treat them before discharging into nature. Among the treatment methods, the activated carbon (AC) adsorption process is the method of choice for its simplicity and ease of implementation. However, the high regeneration cost of AC has prompted the scientific community to search for new adsorbents. Our study involves testing a polymer made of cyclodextrins cross-linked with citric acid. The adsorption capacity of this polymer is evaluated against the ibuprofen molecule. To study the effect of certain parameters on the adsorption process, we used the experimental design method, which allows us, with a minimum of experimental trials, to draw a maximum of information on the process under study. The results of the experiments conducted, following a five-level central composite design and respecting the rotatability criterion, are used to find a relationship between the adsorption rate y (%) and the three considered and deemed influential parameters, namely the initial ibuprofen concentration [IB]₀, the flow rate of the solution (W), and the mass of the adsorbent (mads). The statistical model that fits our experimental data well is a second-degree model without any interaction between the three factors. A maximum adsorption rate of 78.5% is obtained under the following optimal conditions: [IB]₀ = 16.3 mg/L, W = 16.4 rpm, and mads = 147.5 mg. The plotting of iso-response curves allows locating the optimum in the plan of two chosen factors.