LAUSR

The magnetic response of magnetorheological organogels is investigated by using a commercial plate-plate magnetorheometer at oscillatory shear. The experimental characteristic time results show that the field-induced aggregation of iron particles can be accelerated by increasing the strength of field. In contrast, the gel structure of matrix could hinder the particle motion and the microstructure development. The fast aggregation process dominates in the contribution to the total growth of storage modulus. Nonetheless, this contribution of fast process decreases with increasing the gelator content, and in the meanwhile, the corresponding proportion of slow aggregation process increases. The rearrangement from on-state structures to another on-state structures take a longer time than the off-on response as verified in the pre-magnetization tests. The particle aggregation induced by magnetic field is thermally influenced due to the temperature sensibility of the matrix. The periodical step magnetic field perturbation tests suggest that response is reversible.