Use of high surface area untreated fumed silica in MR fluid formulation

摘要

A magnetorheological fluid formulation exhibiting high yield stress at high surfactant concentrations. The formulation has a strong network formation due to incorporation of a high surface area untreated fumed silica as a thixotropic agent. This untreated fumed silica has a surface area of at least about 250 m2/g, which enables a surfactant concentration in the formulation in an amount up to about 35% by weight relative to the weight of the fumed silica.