The electrorheological effect for polyhedral silsesquioxane cage structures with cyanopropyl functional groups

• Cyanopropyl-POSS (c-POSS)/PDMS mixtures exhibit significant ER activity.
• Determined the effect of concentration of c-POSS on the viscoelastic shear modulus.
• Determined the effect of concentration of c-POSS on the yield stress.
• Storage modulus increases with electric field with an exponent between 1.0 and 2.0.

Previous research has shown that sulfonated polyhedral silsesquioxane (s-POSS) material when mixed with silicone oil (PDMS) exhibits a significant ER effect. For the first time here we show that cyanopropyl POSS (c-POSS) particles in silicone oil also show significant ER activity. The yield stress, τy, scales with the electric field, E, as τy∝E. The elastic storage modulus of the suspension at small strains (γ=0.10) scales with the electric field E as G’∝E0.99–1.76.