Electrorheology at small strains and strain rates of suspensions of silica particles in silicone oil

摘要: Abstract The electrorheological behavior of suspensions in silicone oil ultrafine silica particles (0–3.16 wt.%) coated with a surfactant was investigated at room temperature electric fields up to 2 kV mm−1. studies consisted situ observations an optical microscope and determination the rheological properties for shears range 10−2−2.8 shear rates 10−3 -101 s−1. microscopy revealed that fibrated structure formed immediately on application field, which ruptured near center gap when suspension sheared. Swirling fluid occasionally noted, occurred more frequently higher field strength or rate. Strain hardening yield point-type phenomenon during tests. stress given strain complex function For rate, proportional two-thirds power concentration particles. attributed polarization molecules adsorbed their alignment into by external field. effects rate were concluded reflect influence continuing rupture re-formation structure.