Traditionally, the development of shear thickening fluid (STF) begins with micron size silica suspended in water. This material is transformed into STF through centrifugation and exchange processes. In other approaches polyethylene glycol (PEG) is added in incremental quantity to the silica suspension and water is removed through evaporation, repeatedly, until the admixture reaches the desired ratio of silica to PEG by weight. STF developed in this manner is usually dissolved in ethanol and impregnated into Kevlar fabric and then dried to remove ethanol. The resulting composite is Kevlar impregnated with a mixture of PEG and silica. The intention, in this investigation, was to directly disperse nanometer size silica particles into a mixture of PEG and ethanol by ultra sonic cavitation. The approach bypasses the STF fabrication route but maintains the proper ratio of silica to PEG in the composite to provide desired stab resistance properties.
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