Aramid fabric/nano-size dual phase shear thickening fluid composites response to ballistic impact

The dual phase STF is a combination of nanosilica and calcium carbonate dispersed in polyethylene glycol and ethanol. Its assimilation into aramid fibers has been accomplished through a combination of ultrasonic dispersion and airbrush. This technique led to an increase of the inter-yarn friction and the projectile's deformation. It also led to an increase on damaged layers, but at same time, the trauma cavity volume was reduced. From the ballistic tests performed, the 25% w/w nanosilica and 75% w/w calcium carbonate (STF4) combination obtained the best result. The work done by the soft ballistic plate into the body's tissue was reduced by 40% with the same ballistic protection of traditional bullet proof vests. A 19 layers of aramid fibers impregnated with STF4 proved to have the same ballistic performance of a traditional 32 layers of aramid fibers bullet proof vest.