Electro-active elastomer composites based on doped titanium dioxide

Recently, electro-active composites have been considered by several researchers because they exhibit an interesting change in their viscoelastic properties under an applied electric field. However, their relative elastic modulus change Delta G' = G'(E) - G'(0) is still low and rarely exceeds 100 kPa. In this article, we demonstrated that, by synthesizing mesoporous aggregates of titanium dioxide (TiO2) and by adsorbing acetylacetone dipolar molecules (Acac) onto the TiO2 surface, the TiO2-Acac/PDMS electrorheological elastomer achieved a relative elastic modulus change Delta G' higher than 500 kPa for an applied electric field of 2 kV mm(-1). The dependence of the electrorheological response of TiO2-Acac/PDMS on the DC electric field strength, AC electric field frequency and shear strain magnitude was discussed regarding the conductivity ratio and permittivity ratio between doped TiO2 semiconducting particles and the PDMS matrix. The high electrorheological performance of TiO2-doped Acac as semiconducting particles filled in the elastomeric matrix makes this kind of material a promising candidate for application in the automotive industry, robotics, vibration isolators, building applications or electro-active actuators.