Squeeze flow viscoelasticity of electrorheological fluids based on microcrystalline cellulose

Dynamic viscoelasticity of electrorheological fluids based on microcrystall ine cellulose/castor oil suspensions was experimentally investigated in squ eeze flow. The dependence of storage modulus G' and loss modulus G" paralle l to external electric field on electric fields and strain amplitudes is pr esented. The experiments show that, when external electric field is higher than the critical field, the viscoelasticity of the ER fluids converts from linear to nonlinear, and the ER fluids transfer from solid-like state to f luid state with the growth of strain amplitude. The influences of strain am plitude and oscillatory frequency on the nonlinearity of viscoelasticity we re also studied.