The present work is an attempt to demonstrate that incorporation of small amount of zinc oxide nanorods enhances the β crystal percentage, which is essential for improvement in piezo-electric performance of the poly(vinylidene fluoride) (PVDF) fiber. The zinc oxide nanorods were synthesized with aspect ratio of 26 and uniformly dispersed in PVDF by melt compounding process. Those compounded polymers were melt spun and subsequently cold drawn to obtain composite filaments. The effect of nanostructure, loading amount, melt draw ratio, cold draw ratio, and drawing temperature was investigated. The incorporation of nanorods resulted in 14% increase in β phase crystal content compared to control PVDF filaments. The β phase crystal content has been analyzed using the wide-angle X ray diffraction and FTIR spectroscopy. This increase in β phase crystal content was 10% more compared to circular zinc oxide nanoparticle reinforced PVDF composite filament. There was no significant change in mechanical properties of the composite filaments compared to the control PVDF filament.

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In this study, Nylon 6 nanofiber were prepared by needle-less wire electrospinning technique. Since, the fiber diameter determines the porosity, filtration efficiency, and mechanical properties of electrospun nanofiber mat, Central Composite Design (CCD) and Response Surface Methodology have been employed to design the experiments and evaluate the interactive effects of the operating variables such as concentration of the polymeric solution, the distance between two electrodes, applied voltage, and relative humidity (RH%) on the diameter of the Nylon 6 nanofiber. With this connection, an objective of this study was to find out the most influential variables for the finest nanofiber diameter during the spinning with wire type electrode to make the highest possible effective face mask without the addition of any functional additives in it. The overall results show that the combined effect of 12% polymer concentration, 65% RH, 155 mm distance between two electrodes, and 40 kV applied positive voltage have the strongest surface response and are the most significant than the other interactive effects. The Pareto chart illustrates the order of significance affecting the Nylon 6 nanofiber diameter in the order of concentration of the polymeric solution, RH%, the distance between electrodes, and applied positive voltage. Further, bacterial filtration efficiency% of the control sample and five-layer facemask incorporated with optimized nanofiber membrane was found to be 87.4% and 97.5%, respectively, against Staphylococcus Aureus ATCC 6538 bacteria.

Exhaust dyeing of aramid fibre is difficult due to its high crystalline and compact structure. In this study aramid yarn is pre‐treated with solvent dimethyl sulphoxide to facilitate the dyeing process and then dyeing is achieved with a cationic dye. Pre‐treatment at high temperature leads to the reduction in tensile strength of yarn which is not desirable. Therefore, in this work pre‐treatment has been carried out at different temperatures and time to standardise those parameters to enhance the dye uptake with minimum reduction in strength. Further, dyeing temperature and time has been standardised keeping the standard pre‐treatment parameters fixed. From the study, pre‐treatment temperature of 30°C for 10 min and dyeing temperature of 100°C for 30 min are found suitable for better colour strength without much compromising on strength of yarn. The fastness properties of untreated and treated dyed yarns were comparable.

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