Engineering Applications of Nanotechnology

Nanofluids are the dilute suspensions of nanomaterials with distinctive and enhanced features. Nanofluids can be used in a variety of industrial applications because of improved thermophysical properties. Stability of nanofluids is the only quandary factor which decreases the efficiency of such smart fluids in engineering applications. The information and studies on interaction of nanomaterials with the liquid have significant importance toward their usage in industrial applications. Agglomeration among particles is a common issue due to interactive forces, which effects the dispersion, rheology, and overall performance of nanosuspensions. Characterization of nanofluids plays an important role to evaluate the stability of nanofluids. The effect of agglomeration on the stability of nanofluids can be reduced by introducing different mechanical and chemical techniques to prolong dispersion of suspended particles in liquids. Complete understanding on the stability of nanofluids can lead to the preparation of different combinations of stable nanofluids with enhanced properties for variety of applications.

The properties such as viscosity, thermal conductivity, specific heat, and density of nanofluids have been determined by various investigators through experiments. An equation developed for specific heat and density employing the law of mixtures is observed to be valid when compared with the experimental data. However, the experimental data of viscosity and thermal conductivity reported by investigators are observed to vary by more than 25 % for certain nanofluids. Theoretical models for the estimation of properties are yet to be developed. The nanofluid properties are essential for the comparison of heat transfer enhancement capabilities. Equations are developed for the estimation of viscosity and thermal conductivity by Corcione and Sharma et al. These equations are flexible to determine the nanofluid properties for a wide range of operating parameters which can predict the experimental data of water-based nanofluids with a maximum deviation of 12 %.

The increasing demand of nanofluids for the industrial applications has led to focus on it from many researchers in the last decade. This thesis includes both experimental study and numerical study to improve heat transfer with slightly pressure drop in the automotive cooling system. The friction factor and heat transfer enhancement using different types of nanofluids are studied. The TiO₂ and SiO₂ nanopowders suspended to four different base fluids (pure water, EG, 10 %EG + 90 %W, and 20 %EG + 80 %W) are prepared experimentally. The thermophysical properties of both nanofluids and base fluids are measured and validated with the standard and the experimental data available. The test section is setup including car radiator and the effects under the operating conditions on the heat transfer enhancement analyzed under laminar flow condition. The volume flowrate, inlet temperature, and nanofluid volume concentrations are in the range of (1-5LPM) for pure water and (3-12LPM) for other base fluids, (60–80 °C) and (1–4 %), respectively. On the other side, the CFD analysis for the nanofluid flow inside the flat tube of a car radiator under laminar flow is carried out. A simulation study is conducted by using the finite volume technical to solve the continuity, momentum, and energy equations. The processes of the geometry meshing of problem and describing the boundary conditions are performed in the GAMBIT then achieving of FLUENT software to find the friction factor and heat transfer coefficient. The experimental results show the friction factor decreases with the increase of the volume flowrate and increases with the nanofluid volume fraction but slightly decreases with the increase of the inlet temperature. Furthermore, the simulation results show good agreement with the experimental data with deviation, not more than 4 %. The experimental results show that the heat transfer coefficient increases with the increase in the volume flowrate, the nanofluid volume fraction, and the inlet temperature. Likewise, the simulation results show good agreement with the experimental data with deviation not more than 6 %. In addition, the SiO₂ nanofluid appears high values of the friction factor and heat transfer coefficient than TiO₂ nanofluid. Also, the base fluid (20 %EG + 80 %W) gives high values of the heat transfer coefficient and proper values of friction factor than other base fluids. It seems that the SiO₂ nanoparticles dispersed to (20 %EG + 80 %W) base fluid are a significant enhancement of the thermal properties than others. It is observed that the SiO₂ nanoparticles dispersed to (20 %EG + 80 %W) base fluid are a significant augmentation of heat transfer in the automobile radiator. The regression equations among input (Reynolds number, Prandtl number, and nanofluid volume concentration) and response (friction factor and Nusselt number) are found. The results of the analysis indicated a significant input parameters to enhance heat transfer with the automotive cooling system. The comparison between experimental results and other researchers’ data is conducted, and there is a good agreement with a maximum deviation approximately 10 %.

Carbon nanotubes have fascinating chemical and physical properties as indicated by graphite and diamond characteristics, and the reason is their individual atomic structure. They have acquired critical achievements in various fields such as materials, electronic devices, energy storage, separation, and sensors. Recently, antireflective coatings with self-cleaning properties attract critical consideration for their theoretical characteristics and their wide-ranging applications. In this chapter, the benefits of using CNTs as an antireflection and self-cleaning thin coating layer have been discussed to improve mechanical and electrical behavior of solar cells. Transfer-matrix method (TMM) and finite-difference time-domain (FDTD) method were studied as most suitable technique for thin films.

Over the recent years, addressing solar energy utilization for different applications has grabbed attention of many research groups around the world. From the past few decades, scientists had made progress in innovating new devices and methods for harnessing solar energy. In this respect, they developed new materials to improve energy efficiency as one of the major focal domain. During twentieth century, scientists engineered the application of nanotechnology in various domains including solar thermal conversion devices. Nanofluids, a homogeneous dispersion and stable suspension of nanoparticles in the base fluids, have made possible progress to achieve higher thermal properties at the smallest possible concentrations. This chapter intends to summarize the research done on the nanofluid applications in different solar thermal conversion systems. This chapter includes comprehensive information about thermophysical properties of nanofluids, the design of solar thermal system at optimum conditions, and the applications of solar collector with nanofluid. Also, challenges and opportunities for future research are identified and reported as well.

Analysis of thin film lubrication of (i) nanoparticle additive three-layered journal bearing lubricated with Newtonian fluid, (ii) nanoparticle additive three-layered journal bearing lubricated with couple stress fluid, (iii) Newtonian fluid lubricated partial slip slider bearing with electric double layer, and (iv) porous-layered carbon nanotubes (CNTs) additive Newtonian fluid lubricated slider bearing with electric double layer are presented. The analysis of three-layered journal bearing with nanoparticle additives incorporates Reynolds boundary conditions to predict load capacity parameter and coefficient of friction. The load capacity parameter increases for thick, high-viscosity fluid film layers and nanoparticle additive fluid film. Coefficient of friction is reduced for high viscosity surface adjoining layer. Stokes microcontinuum theory is used in the analysis of couple stress fluids in a three-layered journal bearing lubricated with nanoparticle additives. A three-layered journal bearing using couple stresses fluids with nanoparticle additives increases nondimensional load capacity and decreases coefficient of friction. A slider bearing with partial boundary slip and electric double layer leads to an increase in apparent viscosity of lubricant and hence load carrying capacity in thin film lubrication. A parallel slider bearing with partial slip on bearing and electric double layer increases the bearing load capacity. The flow of lubricant with CNT additives in a slider bearing in thin film and porous layers with electric double layer is governed by Stokes and Brinkman equations, respectively, including electrokinetic force. The nondimensional load capacity of slider bearing increases with decrease in permeability and increase in thickness of porous layer as well as increase in both electro-viscosity and CNT additives volume fraction. A thin film slider bearing using CNT additive lubricants with porous and electric double layer provides higher load capacity.

Nanofluid plays an important role in a drilling process which includes the removal of cuttings, lubricating, and cooling the drill bits. Nonetheless, production increases from the reservoirs which are non-conventional, and the stability and performance of conventional drilling fluids under high-temperature and high-pressure (HTHP) environment have apprehensiveness. Both water- and oil-based drilling fluids are likely to experience a number of degenerations such as degradation of weighting materials, gelation, and disintegration of polymeric additives under HTHP conditions. Lately, nanotechnology has shown a lot of promise in the oil and gas sectors, including nanoparticle-based drilling fluids. This chapter is focused on to explore the influence of nanoparticles on the heat transfer efficiency of drilling fluids to make the drilling phenomena smooth and cost effective. The chapter begins with explaining the importance of drilling fluid during the drilling process with a historical assessment of drilling fluid industry development. It is followed by definitions, uses, and types of drilling fluid as well as the additives that are appended to enhance drilling fluid performance. Moreover, the progress of the oil production industry from unconventional wells has been discussed after which the limitations and degradation of the traditional drilling fluid have been taken up. Finally, this chapter discusses the great potential of nanotechnology in solving drilling problems in addition to the technical and the economic benefits of using nanomaterials in drilling fluids before offering a brief conclusion.

Using electrical discharge machining (EDM), it is possible to machine material that is difficult to machine by conventional machining technique as long as it is electrically conductive. The performance of EDM is highly dependent on the type of electrode being used, the power supply system, and the dielectric system. Copper–tungsten electrode combines the higher melting point of tungsten with the good electrical and thermal conductivity of copper, but it is difficult to manufacture due to the variation in melting point and zero miscibility of copper with tungsten. Thus, newly modified copper–tungsten–silicon (Cu–WC–Si) electrode was synthesized using ball milling method. The method was used to synthesize the new electrode material due to the possibility to overcome the problems encountered in alloying materials which have a large variation in melting temperature or low miscibility at low temperatures. Taguchi method is the main statistical tool used to design and analyse ball milling and machining processes. Material removal rate and electrode wear are the parameters used for comparing the performance between the existing copper–tungsten and new developed electrode. Milling results show a clear change in the thickness of crystalline and d-spacing of the milled powder. The performances of Cu–WC–Si electrode in machining of hardened die steel show an improvement in MRR and EW compared with that achieved by using Cu–W electrode when it is milled for less than 10 h.

Duplex stainless steel (DSS) which has a dual nature of ferrite and austenite with nearly equal ratio has found a good application in oil and gas industries because of its excellent corrosion resistance, high yield strength, good weldability, and relative low life cycle costing from reduced operating cost. Dual phases of DSS or combination of two-phase existence to be more characterize with better mechanical properties than a single-phase metal of ferrite or austenite. Nitrogen is a good strengthening alloy for DSS because it forms a solid solution of (Fe, Cr)₂N which is responsible for the hardness and wear resistance in DSS. Spontaneous formation of oxide or passivated layer is responsible for shield and direct exposure of surface of stainless steel to corrosive medium though is susceptible to depletion and deterioration in high chlorine water and low pH level in production environment. Total damage of passivated region on the surface of DSS prompts initiation of localized defect such as pit which grows over a time to form crack. Oil and gas environment is characterized with high H₂S content which is a constraint in application of DSS in this environment because of its insignificant resistance to sulfide stress corrosion cracking (SSCC) and hydrogen-induced cracking (HIC).

Hot corrosion arises when metals are excited in the temperature range 700–900 °C in the existence of sulphate deposits, formed as a result of the reaction among sodium chloride and sulphur mixtures in the gas phase adjoining the metals. No alloy is resistant to hot corrosion occurrence indefinitely even though there are certain alloys that require a prolonged origination time at which the hot corrosion progression from the beginning stage to the circulation stage. Superalloys have been established for high-temperature applications. However, these alloys are not constantly able to meet both the high-temperature strength and high-temperature corrosion resistance simultaneously, so the need is to protect from hot corrosion. The high-temperature guarding system must meet numerous benchmarks, provide satisfactory environment resistance, be chemically and mechanically compatible with the substrate, be practically applicable, reliable and economically viable. This chapter briefly reviews the hot corrosion of some Ni- and Fe-base superalloys to recognise the occurrence. Extensive reviews on the hot corrosion of coatings have looked regularly since early 1970; the purpose of this chapter is not to repeat the published resources but relatively to emphasis on research developments and to point out some research forecasts.

Cancer is one of the most common chronic diseases in man that accounts for 14 million new cancer cases and 8 million deaths per year worldwide. The current trend in the management of cancer includes established triad of surgery, radiation, and chemotherapy supplemented by biological and targeted therapy in specific cancers. Recent years saw tremendous progress in the field of biotechnology and human genomics leading to better understanding about cancer pathogenesis, discovery of cancer markers, and promising novel therapy. Despite above advances, the surgery involves loss of organ and function, radiation-induced complications, and chemotherapy-related second malignancies and drug resistance. In some cancers, both radiotherapy and chemotherapy remain ineffective. In recent years, nanotechnology shows potential promise in the management of cancer. Nanoparticles attached to cancer marker targeted antibodies could detect cancer at earlier phases of cancer development, better than existing methods. Novel designed nanomaterials could carry payload of cytotoxic drugs or lethal toxins inside cancer cells and defy host immune defence and protect normal cells, thereby could result in cancer cure with least side effects. Radiation treatment is non-specific; therefore, intratumour injection of nanomaterials could generate short-range electrons inside tumour and enhance radiation lethality to tumour and no effects to the normal tissues. Topical or parenteral injection of nanomaterials during surgical procedure could add surgeons to precisely take out tumour with useful surgical margin. Nanotechnology is a vast field of unexplored science which is unknown to medical field could possibly redefine cancer treatment. However, we do not know the long-term consequences, metabolism of nanoparticles inside body, excretion from body fluids, safety profile, and environmental effects. Despite of extensive hype in science for over a decade, there are very few nanotechnology-based drugs used in clinical practice, mostly using PEG micelle technology to avoid immune reactions and increased absorption of cancer pain medications. Lot more translational clinical research is necessary to use nanotechnology as part of oncological management in future.

The efficiency of a drug depends on target specificity and its solubility. The non-specificity of the drug molecules not only needs extra doses to treat diseases but also is associated with adverse drug reactions. Thus, newly engineered nanoparticles as a vector represent an exciting example which has shifted the paradigm from conventional therapies such as surgery, chemotherapy, and radiation to the novel drug delivery system. Among the nanocarriers developed so far, silica and gold nanoparticles have emerged as potential candidates who can deliver different drug molecules at target sites in a controllable and sustainable approach. In the present era, drugs released and delivered by engineered nanoparticles have attracted enough attention because of the prospects in cancer therapy, in particular, and in the treatment of other ailments. The fundamental properties of nanoparticles in drug loading, releasing, and biochemical competency can be altered by means of suitable conjugation with appropriate coatings or external magnetic fields. Therefore, this book chapter is focused on preparation, development, and application of very recently reported silica and gold nanoparticle system as a drug delivery cargo.