Electrorheological application of polyaniline/multi-walled carbon nanotube composites

Conducting polyaniline (PANI) was synthesized via an oxidative dispersion polymerization using poly(vinyl alcohol) (PVA) as a polymeric stabilizer in the presence of multi-walled carbon nanotubes (MWNT) which were purified in an acidic solution. The formation of nanocomposites and their morphology in which the PANI was pierced with MWNT like a pearl necklace structure, were confirmed by scanning electron microscopy (SEM). An electrorheological (ER) fluid was prepared with synthesized MWNT/PANI particles dispersed in insulating silicone oil and its ER properties were investigated by controlling applied DC electric field strengths. Synthesized MWNT/PANI particles have enhanced interparticle interactions, and the shear stresses increase with the electric field strength for a broad range of shear rate as the degree of polarization of MWNT/PANI particle increases with applied electric field strengths.