Polar-molecules-driven enhanced colloidal electrostatic interactions and their applications in achieving high active electrorheological materials

We have fabricated a class of colloidal electrorheological (ER) fluids, in which suspended TiO2 particles were synthesized by a sol-gel method and modified by 1,4-butyrolactone molecules with a permanent molecular dipole moment of 4.524 D. Compared with pure TiO2 ER fluids, the quasi-static yield stress of the polar- molecules-modified ER fluid is enhanced as high as 48.1 kPa when subjected to an external electric field of 5 kV/mm. Also, it possesses other attractive characters such as low current density (