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This study focused to optimize the performance of polyethersulfone (PES) hemodialysis (HD) membrane using carboxylic functionalized multiwall carbon nanotubes (c‐MWCNT) and lower molecular weight grade of polyvinylpyrrolidone (PVP‐k30). Initially, MWCNT were chemically functionalized by acid treatment and nanocomposites (NCs) of PVP‐k30 and c‐MWCNT were formed and subsequently blended with PES polymer. The spectra of FTIR of the HD membranes revealed that NCs has strong hydrogen bonding and their addition to PES polymer improved the capillary system of membranes as confirmed by Field Emission Scanning Electron Microscope (FESEM) and leaching of the additive decreased to 2% and hydrophilicity improved to 22%. The pore size and porosity of NCs were also enhanced and rejection rate was achieved in the establish dialysis range (<60 kDa). The antifouling studies had shown that NCs membrane exhibited 30% less adhesion of protein with 80% flux recovery ratio. The blood compatibility assessment disclosed that NCs based membranes showed prolonged thrombin and prothrombin clotting times, lessened production of fibrinogen cluster, and greatly suppressed adhesion of blood plasma than a pristine PES membrane. The results also unveiled that PVP‐k30/NCs improved the surface properties of the membrane and the urea and creatinine removal increased to 72% and 75% than pure PES membranes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 513–525, 2019.

Summary Solid‐state thermoelectric (TE) devices are known for converting solar energy and waste heat into electricity, which provides a substitute path for energy production and utilization to commence the challenges of energy sustainability. To develop TE devices, it is important to identify thermoelectrically active materials with the potential converting solar energy and heat into electrical energy. In ambient settings, TE devices are one of the most pollution‐free methods of energy conversion since it is noiseless, essentially maintenance‐free, and able to provide electricity continuously for several years. A surge in interest in TE harvesting for diverse uses, including extracting waste heat from automobile exhaust and industrial processes has occurred in recent years. For an efficient TE device, a number of variables must be addressed. These include the availability of TE materials with high ZT, construction of ohmic connections between thermoelements and metallic interconnect, material engineering and defects systems, and the control of maximum heat transport through the device. The current review summarized a recent understanding of a reliable and eco‐friendly strategy for synthesizing pure MgAgSb alloy and its TE performance enhancement. First, a discussion on the various strategies employed to improve ZT and band structure determination is described. Then, we provided an overview of excellent TE performance, applications of bandgap engineering to enhance TE ZT value and their capacity to produce energy, and good quality nanostructured a‐MgAgSb to produce long‐term, thermally stable microstructure. Finally, we will look at how well a single‐leg device converts power. The current mysteries, along with future perspectives and challenges for this material system, are described in the outlook section.

In this work the thermoelectric performance of MgAgSb was improved by enhancing electrical conductivity, Seebeck coefficient and reducing thermal conductivity simultaneously. We synthesized MgAgSb at various sintering temperatures and researched its thermoelectric properties in detail. The effect of impurities associated with MgAgSb on the thermoelectric properties shows that their presence can deteriorate the performance. The resultant samples were tested after 2, 3 and 8 months from its preparation for thermoelectric performance and a significant enhancement in thermoelectric properties are observed. The resultant power factor improved from 8.5 μWcm-1K-2to 15.8 μWcm-1K-2 and the thermal conductivity is reduced from 1.12 Wm-1K-1 to 0.86Wm-1K-1 and we find an improved ZT~0.91. The internal mechanism for the reducing thermal conductivity is presented which plays an important role in improving ZT value of MgAgSb.Furthermore, we discussed that the strength of the chemical bonding among the atoms may also be reduced with the passage of time in thermoelectric materials and resulting in decrease in localized frequency of vibration, which has an ultimate effect in reducing the thermal conductivity of the material.

In this study, the hydrothermal method was employed to synthesize an oriented ZnO nanorod array on an annealed gold seed layer coated on a glass substrate from different precursor concentrations. Zinc nitrate hexahydrate and hexamethylenetetramine were used as starting materials for ZnO nanorod growth. The effect of gold seed layer roughness on the orientation of ZnO nanorods is presented. The morphology of the nanorods shows that oriented ZnO nanorods were obtained after deposition on the annealed gold seed layer. Energy dispersive x-ray spectroscopy was used to identify the elemental composition and identify the elements present in the samples. The XRD pattern shows that the nanorods have a good crystalline structure, with dominant (002) peaks for all concentrations, which reflects that the c-axis of the elongated nanorods is oriented normal to the substrate. The proposed growth mechanism for the growth of ZnO nanorods is presented.