Fabrication of a Novel Silver-Based Electrical Contact Composites and Assessment of Its Mechanical and Electrical Properties

The electrical contactors play a crucial role in closing the circuit in many power distribution components like overhead lines, underground cables, circuit breakers, transformers, and control systems. The failure in these components mainly occurs due to the break-down of contactors due to the continuous opening and closing action of contacts. Silver (Ag)-based oxide contact materials are widely used in practice, among which silver tin oxide (AgSnO2) is most common. An attempt is made in increasing the performance of AgSnO2, by adding Tungsten Oxide (WO3) in various weight proportions, thus finding the optimal proportion of AgSnO2WO3 to have increased mechanical and electrical performances. All the composite samples are fabricated in-house using powder metallurgy process. The assessment of physical and electrical properties namely, density, hardness, porosity, and electrical conductivity, showed that 90%Ag-8.5%SnO2-1.5%WO3 composite yielded superior results. With help of morphological tests, wear characteristics are also investigated, which showed that 90%Ag-8.5%SnO2-1.5%WO2 composite has a wear coefficient of 0.000227 and a coefficient of friction of 0.174 at an optimized load of 10 N and sliding velocity of 0.5 mm/s

Investigation of viscoelastic behavior of Abaca-reinforced epoxy composites

Natural fiber-based composites demonstrate excellent and comparable static and dynamic mechanical properties to conventional materials, such as steel and aluminum. They also extend their applications to aeronautical, sports equipment, and marine fields. This experimental study aims to find the effect of untreated and treated Abaca-reinforced epoxy composites on the viscoelastic behavior and the optimum combinations of fiber and resin to produce better bonding efficiency. The different specimens used for this study were pure epoxy, untreated, and chemically treated composite specimens. The four weight percentages of Abaca fibers are 10%, 20%, 30%, and 40% used to prepare composite specimens. Similarly, four different sodium hydroxide (NaOH) concentrations, 4, 6, 8, and 10 wt. %/vol. %, have been used for the chemical treatment of fibers. The storage modulus of Abaca-reinforced epoxy composite specimen has been investigated with respect to temperature and fiber content. The result shows that the 30% weight fraction of fibers with chemically (8 wt. %/vol. %) treated fiber-reinforced epoxy specimen produces 41.67% higher storage modulus than the 10% weight fraction of fibers content of composite specimens. Fourier-Transform Infrared Spectroscopy (FTIR) broad transmittance has been used to distinguish the raw and chemically treated fibers. FTIR results reveal the removal of functional groups after NaOH treatment

Surface, thermal and hemocompatible properties of novel single stage electrospun nanocomposites comprising polyurethane blended with bio oilTM

<div><p>ABSTRACT In this work, the physicochemical and blood compatibility properties of prepared PU/Bio oil nanocomposites were investigated. Scanning electron microscope (SEM) studies revealed the reduction of mean fiber diameter (709 ± 211 nm) compared to the pristine PU (969 nm ± 217 nm). Fourier transform infrared spectroscopy (FTIR) analysis exposed the characteristic peaks of pristine PU. Composite peak intensities were decreased insinuating the interaction of the bio oilTM with the PU. Contact angle analysis portrayed the hydrophobic nature of the fabricated patch compared to pristine PU. Thermal gravimetric analysis (TGA) depicted the better thermal stability of the novel nanocomposite patch and its different thermal behavior in contrast with the pristine PU. Atomic force microscopy (AFM) analysis revealed the increase in the surface roughness of the composite patch. Activated partial thromboplastin time (APTT) and prothrombin time (PT) signified the novel nanocomposite patch ability in reducing the thrombogenicity and promoting the anticoagulant nature. Finally the hemolytic percentage of the fabricated composite was in the acceptable range revealing its safety and compatibility with the red blood cells. To reinstate, the fabricated patch renders promising physicochemical and blood compatible nature making it a new putative candidate for wound healing application.</p></div