Enhanced Electrorheological Properties of Elastomers Containing TiO₂/Urea Core-Shell Particles.

Polar molecule-coated core-shell particles have been used to prepare electrorheological (ER) fluids with high performance. Inspired by those studies, TiO2/urea core-shell structured particles were fabricated and used to prepare novel ER elastomers, whose properties were compared with the ER elastomers with bare TiO2 particles. Particles characterization results illustrate the TiO2/urea particles present little change in size, morphology and crystal structure with respect to the bare amorphous TiO2 particles, while clear core-shell structure is observed. Compared with the bare TiO2 particles filled elastomer, the TiO2/urea particles filled elastomer presents higher dielectric constant, indicating enhanced polarization. The viscoelastic properties of the two elastomers under different strain amplitude, frequency and electric field were tested. The results indicate that the TiO2/urea particles filled elastomer shows higher storage modulus G' and higher relative ER effect within the low field strength region from 0 to 2 kV/mm. Coating polar molecules is an effective method to improve the ER performance for ER elastomers.