Development of flexible puncture resistant materials system using silica nanoparticles

Nanoscale silica particles are functionalized and ultrasonically dispersed into a mixture of polyethylene glycol and ethanol, and then reinforced with Kevlar. The stab or puncture resistance of the flexible nanophased materials system supersedes recent advances made in this area. Through SEM scans, thermal and chemical analysis, it is evident that the funetionalized nanoparticles offer multiple facets of resistance to penetration of a sharp impactor. The improvement in protection is traced to the formation of siloxane bonds during functionalization. The framework for a theoretical model is established to estimate penetration depth under low velocity impact of a sharp object through the flexible composite. For comparison of these novel fabric composites, a method is also introduced to evaluate penetration resistance quantitatively. The method is capable of showing subtle changes that would otherwise be missed.