Allotrope carbon materials in thermal interface materials and fuel cell applications: A review

The performance of allotrope carbon materials has been explored because of their superior properties in energy system applications. This review provides an understanding of the current work focusing on the applications of selected carbon materials in important energy systems, focus on thermal interface materials (TIMs), and fuel cell applications. This article begins with the introduction of TIMs and fuel cell in general working principle and presents details on carbon materials. The discussion focuses on updates from the latest research work and addresses current challenges and opportunities for research toward TIMs and fuel cell applications. The optimum performance of TIMs was seen when thermal conductivity achieved at a maximum of 3000 W (m K)⁻¹ by using vertically aligned carbon nanotubes (CNTs) and a minimum internal thermal resistance of 0.3 mm² K W⁻¹. Meanwhile for fuel cell, the platinum/CNTs catalyst applied proton exchange membrane fuel cell achieved high power density of 661 mW cm⁻² in the presence of Nafion electrolyte membrane. This review provides insights for scientists about the use of carbon materials, especially in energy system applications.     

Numerical Simulations of One-Directional Fractional PharmacokineticsModel

In this paper, we present a three-compartment of pharmacokinetics model with irreversible rate constants. The compartment consists of arterial blood, tissues and venous blood. Fick’s principle and the law of mass action were used to develop the model based on the diffusion process. The model is modified into a fractional pharmacokinetics model with the sense of Caputo derivative. The existence and uniqueness of the model are investigated and the positivity of the model is established. The behaviour of the model is investigated by implementing numerical algorithms for the numerical solution of the system of fractional differential equations. MATLAB software is used to plot the graphs for illustrating the variation of drug concentration concerning time. Therefore, the numerical simulations of the model are presented for different values of α which verified the theoretical analysis. Besides, we also observed the pattern of the simulations at the three-compartment of the model by using different values of initial conditions.     

Modification of rheological and filtration characteristics of water‐based mud for drilling oil and gas wells using green SiO2 @ZnO@Xanthan nanocomposite

In this study, a green, simple and economical approach was used to synthesise the SiO₂ @ZnO@Xanthan nanocomposite (NC) to modify the rheological and filtration characteristics of the water‐based drilling mud. The green synthesised NCs were identified using scanning electron microscopy, energy dispersive X‐ray spectroscopy, elemental mapping, X‐ray diffraction and UV–Vis analytical techniques. Additionally, the effect of SiO₂ @ZnO@Xanthan NCs on the filtration and rheological properties of mud including apparent viscosity, plastic viscosity, yield point, gel strength, mud cake and fluid loss was investigated. The obtained results confirmed that the synthesised NCs effectively improved the rheological properties of drilling mud, and considerably decreased its fluid loss and filter cake by about 54 and 92.5%, respectively. The results highly recommend the SiO₂ @ZnO@Xanthan NC as an excellent additive to improve the rheological properties, and reduce the fluid loss and the filter cake of the drilling mud.Inspec keywords: X‐ray diffraction, scanning electron microscopy, nanofabrication, additives, nanocomposites, X‐ray chemical analysis, drilling (geotechnical), yield point, rheology, filtration, industrial economics, silicon compounds, zinc compounds, ultraviolet spectra, visible spectra, nanofluidics, gelsOther keywords: rheological properties, fluid loss, drilling mud, filtration characteristics, water‐based mud, green approach, economical approach, X‐ray spectroscopy, mud cake, apparent viscosity, oil‐gas wells, nanocomposite synthesis, scanning electron microscopy, energy dispersive X‐ray spectroscopy, elemental mapping, X‐ray diffraction, Uv–Vis spectroscopy, plastic viscosity, yield point, gel strength, additive, SiO₂ , ZnO     

A review of progressive advanced polymer nanohybrid membrane in fuel cell application

This review provides a deep insight into the advanced polymer composite developed in fuel cell application. Organic polymer combined with inorganic filler has produced a new material known as a hybrid membrane or composite membrane. This combination has enhanced the various characteristics including conductivity properties, membrane permeability, and stability, cheaper, optimum water retention and mechanical properties. Properties of the hybrid membrane are influenced totally by several factors such as membrane preparation techniques as well as internal properties of particles involved, for example, inorganic fillers such as the size and type of particles, surface alkaline or acidity, shape and formation of networking between the polymer phase. The conventional membrane used in the fuel cell application is Nafion. Nafion potential is undoubtedly in obtains of high conductivity, but it faces some major problems such as CO poisoning, high cost, fuel crossover and water management that needs to be taken seriously. Hybrid composite is seen as an alternative material to addressing problems faced by a conventional membrane but promises even better potential if explored in depth. In this article, all inorganic fillers involved in the production of the composite membranes have been discussed comprehensively. Different types of polymers have been categorized with various fillers.     

Enhancement of thermal interface material properties using carbon nanotubes through simple electrophoretic deposition method

The industrial revolution development of electronic technologies has turned the electronic system into a complicated integration of high-power density and smart design. The complex integrated design has contributed to the excessive heat generation in electronic devices. Consequently, heat management devices have become crucial in prolonging the lives of devices and components and maintaining their optimal performance. Therefore, the passive heat management treatment through thermal interface materials (TIMs) in the devices is among the best options to remove heat from electronic devices. Carbon nanotubes (CNTs) with high-thermal conductivity was employed in this study for TIM development by using the simple electrophoretic deposition (EPD) method. The CNTs were synthesized and purified before TIM development. Several analyses, including transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy, and Fourier-transform infrared, were conducted. Analysis results showed that only 0.03 wt% was retained and carbon content increased up to 97.84% after purification. The purified CNTs were dissolved in a suspension medium with a ratio of 0.5 mg/mL to achieve suspension stability, and a Zetasizer was used for verification. The following three operating parameters of EPD were investigated: (a) range of applied voltage (100-200 V), (b) deposition time (1-20 min), and (c) gap between electrodes (10-20 mm). On the basis of the characterization results, the optimum process condition of EPD was achieved at 175 V, 10 minutes, and 10 mm with 1.6 mg of CNT deposition and 14.14 μm of CNT thickness. The maximum thickness of deposited CNTs was 56.95 μm, producing 27.08 W/m∙K and 2.09 mm²/s of thermal conductivity and diffusivity, respectively. These results indicate the high potential of CNTs in facilitating efficient heat removal in TIM fabrication.     

A Review on Food Values of Selected Tropical Fruits’ Seeds

Fruit seeds are usually thrown out as waste during processing or after human consumption. Over the years, researchers have dedicated their effort to assess the food and nutritional values of many different fruit seeds. In this review, the research findings releated to the food values of ten different fruit seeds namely, guava, pumpkin, papaya, honeydew, mangosteen, rambutan, watermelon, mango, and durian were discussed. For several fruit seeds, the macro nutrient components such as oil, protein, and carbohydrate of are found to vary due to either varietal defferences or geographical variations. Among the seeds discussed, the range of oil content was from 1.8 to 49.0% while the range of protein content was from 6 to 40.0%. While the high oil bearing fruit seeds are potential new sources of oil, those with high protein content can be used for recovery of protein. As some of fruit seeds are edible and found to possess a host of phytonutrients, they can be harnessed for medicinal purposes. This review concludes that utilization of fruit seeds could not only bring health and wealth but also help to minimize the waste disposal problem of agro-based industries.