Materials Science Forum Vol. 1065

Abstract: Inorganic-organic hybrid materials are of the materials of interest to researchers for the purpose of developing them in this work. A hybrid material consisting of conductive polymer polyaniline (PANI) doped with dodecyl benzene sulfonic acid (DBSA) C₁₈H₃₀O₃S with titanium oxide nanoparticles (TiO2 NPs ) was prepared by the direct chemical polymerization method, and then the optical and surface properties of the prepared materials were studied by UV-VIS spectroscopy, Scanning electron microscopy SEM , and Energy Dispersive X-Ray EDX. The EDX results confirm the presence of TiO2 in the composite material .The results clearly demonstrate that the composite films have good optical properties. As the content of TiO2 was increased in the polymer matrix, the shift of the optical absorption was observed.

Abstract: The impact of wavelength of the laser on several Topographical and Morphological characteristics of gold nanoparticles (Au NPs) was ablated utilizing pulsed laser ablation in liquid in this work. We employed a gold target with an extra purity to ablate the Nano-particles and a removal of tattoo Nd:YAG Q switching pulsed laser with a 10 Ns duration of pulses, the energy are 1000 mJ, the number of pulses are 600 pulses, and a frequency of 3 Hz to explore the gold NPs' characteristics using TEM and AFM. According to the greatest intensity of shorter wavelengths.

Abstract: II–VI nanocrystalline semiconductor materails provide a wide range of applications in electronics, optoelectronics and photonics. The present paper reports the preparation of colloidal Cadmium selenide (CdSe) nanoparticles and study their optical properties. (CdSe) was produced by a chemical route procedure, with the ligand tri sodium citrate (TSC) serving as a complexing agent. Cadmium acetate is used as a Cd source, and sodium selenide is used as a Se precursor. The morphological and optical properties of the produced nanoparticles were determined using a Transmission electron microscopy (TEM) and Ultraviolet – Visible spectroscopy (UV-VIS).Thin films of CdSe capped with are deposited on the glass and aluminum substrates . AL/ CdSe/Ag MSM photodetectors have been fabricated and the electrical properties were measured in dark and light. The output data display that the photo currents of all diodes are increased with light. The fact that the films had dark electrical conductivity and photoconductivity indicates that they were semiconducting materials.

Abstract: New strategies have been developed to design advanced functional biomimetic structures. This paper reviewed the benefits and drawbacks of biomaterials that are used to manufacture 3D scaffolds in tissue engineering. In this paper, latest technological methods, scaffold requirements in development of single form, composite form and cell-laden based scaffolds, classification on the basis of geometry and main material is explained elaborately. These scaffolds promote different molecules can be delivered to tissue and stimulate cell growth. These cells have a therapeutic effect. The paper discusses the various 3D bio printed structures and the difficulties they encounter. The impacts of biologically functionalized biomaterials on soft and hard tissue engineering in vitro and in vivo are discussed. The paper summarized the future prospects for bioactive scaffolds, that can be used in clinical therapy.

Abstract: Poly (methyl methacrylate) (PMMA) and chitosan composites were synthesized by means of the mechanochemical method. In addition, PMMA–chitosan films were obtained in polar (water) and non-polar (benzene) solvents. Obtained polymer composites were analyzed by the Fourier transform infrared spectroscopy method using the ATR attachment with diamond crystal. The presence of intermolecular hydrogen bonds in formation of PMMA and chitosan polymer composites was shown. С=О group of PMMA and OH and NH₂ groups of chitosan molecule take part in the formation of hydrogen bonds.

Abstract: The Proton Exchange Membrane Fuel Cells (PEMFCs) performance is improved by flow field channel design. The flow field reactant distribution geometry on PEMFCs is primarily influenced by the perceived effect of pressure and transmission characteristics of reactant flow fields on the efficiency of fuel cells. Nutrients distributed in the biological branching structures systems found their optimum arrangement have more efficiently in each part. The flow fields design channels in polymer electrolyte membrane (PEM) fuel cells serve the same roles as nutrient transport systems in plants and animals, so bio-inspired flow fields design with a similar could maximize reactant transport efficiency and improve fuel cell performance. In this analysis, the lung channel design of a humane lung and a tree leaf bio-inspired flow field design is used for the flow fields of the anode and cathode bipolar plates. SOLIDWORKS produces a 3-D numerical CFD design for four new flow field pattern designs: leaf design, lung design, single-serpentine, and triple-serpentine. The model is simulated using ANSYS FLUENT-15.0 software to obtain pressure distributions in the flow field, concentration profiles of hydrogen on anode and oxygen on cathode channel, current flux density on the membrane, water concentration on the membrane, water generating in a cathode channel, the polarization curve and the power curve. It is observed that bio-inspired leaf and lung design performs better than serpentine flow field channels. So, leaf and lung design can be used in mopeds and automobiles to enhance electrical efficiency and at the same time reduce fuel consumption.

Abstract: The paper presents studies aimed at producing a three-component alloy from the powders of cobalt, chromium and molybdenum (66 wt % Co, 28 wt % Cr, 6 wt % Mo), with a stable phase structure by selective laser melting. At the beginning of the work, the initial powders were graded on sieves with mesh sizes of 20-70 µm. The powder mixtures were obtained by mechanical mixing of various fraction powders and mechanical alloying in a planetary ball mill. The samples were produced using the VARISCAF-100MVS selective laser melting unit. The melting process of powder materials was completed in a chamber filled with inert gas argon after preliminary vacuum degassing. The microhardness analysis of the samples before and after the thermal treatment was completed. The results of phase composition studies, X-ray diffraction analysis, scanning electron microscopy are presented. Examination of the X-ray profiles of the samples proves that the obtained alloy mainly contains the epsilon-phase which improves the hardness and the wear resistance of the product.

Abstract: The polymer electrolyte membrane (PEM) fuel cells flow fields channels serve the same roles as nutrient and reactant circulation systems in plants and animals, so bio-inspired flow field channels with a similar could improve reactant uniform transport efficiency and boost fuel cell performance. In this analysis, the lung channel configuration of a humane lung and a tree leaf bio-inspired flow field channels are used as an anode and cathode bipolar plate. A channel model is developed for three new flow field patterns designs: leaf design, lung design and triple-serpentine. It has been observed that the performance improvement in terms of power in the bio-inspired flow field is 13.32% more than the triple serpentine. This indicates the bio-inspired design has good performance than other flow field design. Further a parametric steady is carried out experimentally to study the effect of cell operating temperature, anode and cathode humidity, hydrogen and oxygen flow rate on the cell performance.

Abstract: Antimony Telluride (Sb₂Te₃), a topological insulator is a layered semiconductor material with hexagonal unit cell similar to graphene. The characteristic presence of their conducting edges or surfaces with self-induced protection, promise for remarkable future applications. In this exertion based on the first principle approach, the structural and electronic properties of Sb₂Te₃ compound have been investigated for both without and with spin orbit coupling (SOC). Lattice structure, band structure, total density of states (TDOS), partial density of states (PDOS), energy bands of surface states are determined within Quantum Espresso simulation package. Furthermore, dispersive interactions, induced due to the presence of van-der-Waals forces have also been taken care of. The newly developed method of DFT-D3 has been incorporated for accurate predictions of band gap and lattice parameters. A proficient model, The Slab Model, has been used to observe the presence of single Dirac cone on the surface. To our knowledge, our theoretical investigations are valid and are found to be congruous with the observed data.

Abstract: This study investigates entropy production analysis in the flow of micropolar nanoliquid due to its application in thermal engineering systems for the identification of the factors which causes the destruction in the available energy and consequently affects overall performance of the thermal devices. The model is built on a two-dimensional porous stretching sheet with an incompressible fluid assumption and steady with the influence of variable thermal conductivity, nonlinear thermal radiation, haphazard motion and thermo-migration tiny particles. A prescribed surface temperature is adopted as the thermal heating condition while the impact of the reaction order and activation energy are incorporated into the concentration field. The model equations are restructured to ordinary derivative system, which is computationally solved by Fehlberg Runge-Kutta technique. The results agree well with previous outcomes for limiting situations while the effects of the embedded terms are presented graphs. The analysis reveals that a rise in variable thermal conductivity, the material term and viscous dissipation leads to a rise in the irreversibility process.