The synthesis and electrorheological effect of a strontium titanyl oxalate suspension

Strontium titanyl oxalate (STO) particles were synthesized with the co-precipitation method. Suspensions made by dispersing the STO particles in silicone oil exhibit an excellent electrorheological (ER) effect with high yield stress, high shear stress at higher shear rate, and low current density. By analyzing the Fourier transform infrared spectra of STO particles heated at different temperatures and measuring the yield stresses of the corresponding ER fluids, it is confirmed that the polar molecules absorbed on the particles play a crucial role in the giant ER effect. The phenomena observed in STO ER fluids can be explained by using the model of a polar molecule dominated electrorheological (PM-ER) effect