Developing Composites from Shear-Thickening Fluids and Nanofibers for Protective Applications

Poster Session: 

A

Presenter: 

Behzad Nazari

Authors: 

Behzad Nazari, Gregory Rutledge

Author Affiliation: 

Massachusetts Institute of Technology

Abstract: 

Shear-thickening fluids (STFs), for instance a colloidal dispersion of non-aggregating particles in a polar organic solvent, are a type of Non-Newtonian fluids that exhibit increase in their dynamic viscosity with increase in the rate of shear deformation or shear rates. Among STFs, fumed nano-silica (NS) dispersed in poly (ethylene glycol) (PEG) is of special interest since at low shear rates, the fluid (60 vol.% NS in PEG) has low viscosity (~9 Pa.s at 2 s-1, flowing easily), whereas upon applying an impact (shear rate>10 s-1), the fluid adopts a solid-like state and due to an abrupt increase in viscosity becomes impenetrable. STFs can be impregnated into a nanofiber structure. This would prevent the STF from leaking out (at low shear rates <2 s-1) from the mat, due to capillary effect. In this work, we aim at developing STF/nanofiber composites for protective applications involving puncture resistance and energy dissipation.