Experimental Investigation and Design Analysis of Hollow Glass Microsphere loaded PP/ABS Composites

The objective of the present is to investigate hollow glass microspheres (HGMs) experimentally and carry out design analysis of hollow glass microsphere loaded PP/ABS composites. The tensile and notched Charpy impact test of HGM-filled acrylonitrile-butadiene-styrene copolymer (ABS) and Polypropylene (PP) composites will be studied with varying the concentrations of PP/ABS composite with HGM. Also further the design analysis will be studied by conducting the simulation under the same criteria and comparing the results at the end. This is done to introduce a light weight material without compromising specific strength of PP/ABS composite by adding HGM to the composite. Keywords: Hollow Glass Microsphere (HGM), ABS-Acrylonitrile butadiene styrene, PP- Polypropylene, Composites.

Light-weight carbon fiber/silver-coated hollow glass spheres/epoxy composites as highly effective electromagnetic interference shielding material

Highly effective electromagnetic interference shielding materials with light-weight feature are urgently demanded for releasing electromagnetic pollution. In this study, the hollow glass spheres were coated with silver particles to produce electrically conductive microspheres. The Carbon fiber/silver-coated hollow glass spheres (Ag@HGMs)/epoxy composites were manufactured by composites liquid molding process. The electromagnetic interference shielding properties of the composites were investigated in the X-band (8.2–12.4 GHz) range. The Ag@HGMs play a role in filling up the vacancy of the conductive network of carbon fibers in the composites, which not only form new conductive pathways but also act as bridges to connect CFs and provide additional channels for the electron transfer within the composites thus improving the electrical conductivity. The total shielding effectiveness (SET) increases with increasing Ag@HGMs loadings and the maximum SET is high as 88.1 dB. The increased SET dominated by absorption loss SEA is attributed to the high conductivity and multilayer construction of carbon fiber veil. The maximum specific SE of the carbon fiber/Ag@HGMs/epoxy composites can achieve 128.8 dB cm3/g, simultaneously the tensile strength and modulus can reach 95.6 MPa and 2.71 GPa, which provides a facile and promising strategy for designing and developing light-weight and high performance electromagnetic interference shielding materials.

Influence of Graphene Nano Fillers and Carbon Nano Tubes on the Mechanical and Thermal Properties of Hollow Glass Microsphere Epoxy Composites

The present work aimed to analyze the roll of carbon nano tubes and graphene nano fillers on the mechanical and thermal characteristics of hollow glass microsphere reinforced epoxy composites. Composites with varying content of hollow glass microballoons (2, 4, 6, 8, and 10 wt %) reinforced in epoxy matrix were fabricated. Additionally, two more types of composites, one with graphene nano fillers and the other with carbon nano tube at a constant 0.5 wt %, were fabricated with varying weight percentages of hollow glass microballoons (2, 4, 6, 8, and 10%). The composites were fabricated using an open mold casting process. Composites were tested for thermal and mechanical properties. The tensile and flexural moduli were found to rise as the HGM concentration increased. Graphene-filled HGM/epoxy composites revealed the highest modulus compared with HGM/epoxy and HGM/CNT/epoxy composites. The impact strength of all composite types decreased as the HGM content increased. Neat epoxy specimens revealed low response as compared with all the composites tested. Further, the thermal conductivity of HGM/epoxy composites was lower as compared with other compositions and neat epoxy. Scanning electron microscopy was used to analyze the surface morphological behavior of the composites subjected to flexural test. It was found that HGM/G/E composites with 10% of HGM and 0.5% of graphene by weight in epoxy matrix were the optimum.

The effect of mesocarbon microbeads on magnetorheological fluid behavior

Magnetorheological (MR) fluids are composed of magnetizeable particles suspended in a carrier fluid and change apparent viscosity upon the application of a magnetic field. Previous studies have shown that passive particles, such as hollow glass spheres, can augment the yield stress of MR fluids, but this yield stress augmentation has limited endurance because the hollow glass microspheres are not sufficiently durable. This study evaluates mesocarbon microbeads (MCMBs) as an alternative passive particle with the potential for MR yield force augmentation but with greater durability. The yield properties of six MR fluid concentrations with varying carbonyl iron particle (CIP) and MCMB volume fractions were tested using a shear mode rheometer and flow mode MR damper. MCMBs did not augment yield stress in shear mode, but, in contrast, in flow mode, the yield force increased nonlinearly with MCMB volume fraction. Furthermore, this yield force-enhancing effect did not diminish over 100,000 cycles (or 5 km of piston travel). The theoretical non-dimensional plug thickness which arises from an approximate parallel plate analysis of a fluid element in flow mode is used illustrate to a potential mechanism for the yield force augmentation effect.