Electrorheological Behavior of Conducting Paste Containing Surfactant Capped Spherical Silver Nanoparticles

Surfactant capped uniform silver nanoparticles were synthesized by the chemical reduction reaction in a microemulsion media, which is formed under high shear mixing condition. Silver nitrate solution and 2-ethyl hexanol were taken as aqueous and organic phase, sodium borohydride was used as reducing agent and Span-80 (sorbitan monooleate) as the capping agent. Synthesized silver nanoparticles were characterized by transmission electron microscopy and dynamic light scattering technique for their size, shape and particle size distribution. The Crystalline structure of silver nanoparticles is ascertained by Xray diffraction analysis. Uniform silver nanoparticles of average particles diameter (10-20) nm thus prepared have been incorporated into fumed silica matrix using polyethylene glycol as the carrier fluid to prepare electrorheological (ER) paste. Different compositions of ER paste have been prepared using the different concentration of silver nanoparticles. The prepared electrorheological paste has shown commendable response with respect to viscosity and dynamic yield stress enhancement under applied electric field.