8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Wed 711:10-14:00P5.127Electrorheology under non-uniform electric field: apreliminary investigationRosina Ponterio, 1 Pietro Calandra, 1 and Francesco Aliotta 11 CNR, V. le F. Stagno D’Alcontres, 37, I-98158, Messina, ItalyThe application of intense non-uniform electric field to a non-homegeneous fluid is known toresult in electrostriction effects. The effect observed at the air liquid interface are presented anddiscussed. The obtained results have suggested the idea that the application of a periodically nonuniformelectric field to a colloidal suspension can result in a periodic modulation of the dispersedphase concentration. Such a situation has been hypothesized to reduce the entropic contributionto the free energy of the system resulting in the enhancement of its apparent viscosity. The resultsobtained by means of an ad hoc laboratory viscometer are presented for some investigated colloidalsuspensions and compared with the conventional results under uniform electric fields.127