Abstract： The electrorheological (ER) behaviors of 31 kinds of ER suspensions, 16 kinds of rare earth oxide and 15 kinds of rare earth hydroxide [RE(OH)3] are tested systematically under electric field. The microscopy shows that only Gd2O3, Pr6O11 from rare earth oxides and RE(OH)3. nH2O (RE = La, Y, Pr, Gd, Sm, Lu) from rare earth hydroxides dispersed in silicone oil produce fibrous chains in the direction of the ac field vector. The viscosities of ER suspensions with Gd2O3, Pr6O11, RE(OH)3. nH2O (RE = La, Y, Gd, Pr) dispersed in hydrocarbon oil are determined under different field strength (dc field). The results show that the ER activity of the materials is not influenced by the coordinated water with the rare earth ion, and it is related with the microstructure of the molecule.
1998, Vol. 15 
