Electrorheological properties of poly(dimethylsiloxane) and poly(3,4-ethylenedioxy thiophene)/poly(stylene sulfonic acid)/ethylene glycol blends

Electrorheological properties of poly(dimethylsiloxane) and poly(3,4-ethylenedioxy thiophene)/poly(stylene sulfonic acid)/ethylene glycol PDMS_PEDOT/PSS/EG blends were investigated as potential actuator materials. Experiments were carried out under the oscillatory shear mode and with applied electric filed strength varying from 0 to 2 kV/mm. PEDOT/PSS particles were synthesized via the chemical oxidative polymerization and secondly doped with EG to improve the electrical conductivity. For the PDMS_PEDOT/PSS/EG blends of particle concentrations of 5, 10, 15, and 20 vol.%, the storage moduli G', without electric field, are evidently higher than those of pure PDMS and PDMS_PEDOT/PSS. The concentration dependence of G' of all material systems studied is nearly linear. Under electric field, PEDOT/PSS/EG particles within the crosslinked PDMS matrix are polarized, and induced dipole moments are generated, leading to intermolecular interactions. The storage modulus response varies with electric field following a scaling behavior of ΔG'α Eα, with the electric field strength between 0.002 and 1 kV/mm. The scaling exponent α   decreases with increasing particle concentration and electrical conductivity. The storage modulus sensitivity, ΔG′G′0, attains maximum sensitivity values of 8.7%, 9.0%, and 15.2%, at particle concentrations of 5, 10, and 15 vol.% at the electric field strength of 2 kV/mm, respectively.