Electrorheological behavior of copper phthalocyanine-doped MCM-41 suspensions

A type of anhydrous electrorheological (ER) material of copper phthalocyanine (CuPC)-doped MCM-41 was synthesized by in situ micelle-assisted incorporation of CuPC during MCM-41 synthesis. The ER behavior of the suspensions of CuPC-doped MCM-41 particles in paraffin liquid with a 30 wt.% was investigated under an applied electric field. It is found that the ER effect increased with increasing the CuPC-doping ratio. The dopants of CuPC molecules within the mesochannel of MCM-41 mesoporous sieve improved the conductivity of the particles, and produced a proper conductivity of ∼10−7 S m−1. Dielectric spectra of the fluids were also measured to examine their possible correlation with the ER behavior, and the results were explained based on Ikazakiʹs criterion that the relaxation frequency must be in the range 100–105 Hz and the difference in the dielectric constant must be large below and above the relaxation frequency for an appreciable ER effect.