Hybrid approach for augmenting the impact resistance of p-aramid fabrics: grafting of ZnO nanorods and impregnation of shear thickening fluid

A novel hybrid approach has been developed and implemented to enhance the impact resistance of p-aramid fabric-based soft armour material. ZnO nanorods of diameter ca. similar to 100nm were developed on the surface of p-aramid (Kevlar((R))) fabrics by seed and growth method followed by impregnation of fabrics with silica-based shear thickening fluid (STF) having 65% (w/w) concentration. The impact resistance of neat Kevlar fabric (KF), ZnO nanorod grafted Kevlar fabric (ZnO-KF), STF impregnated Kevlar fabric (STF-KF) and ZnO nanorod grafted-STF impregnated Kevlar fabric (ZnO-STF-KF) was studied. The impact energy absorption by ZnO-KF and STF-KF was higher by 29.6% and 10%, respectively, as compared to that of neat fabric (KF). The hybrid approach of modifying the Kevlar fabric with ZnO nanorods and impregnation with STF (ZnO-STF-KF) enhanced the impact energy absorption by 36.6% as compared to that of neat Kevlar fabric. The substantial increase in impact energy absorption in the case of ZnO-STF-KF can be attributed to the combined contribution of increased inter-yarn friction caused by ZnO nanorods and shear thickening behaviour of STF. The ZnO nanorod grafted high-performance fabrics impregnated with STF could be a promising candidate for the development of soft body armour material.