Polyaniline microsphere encapsulated by poly(methyl methacrylate) and investigation of Tits electrorheological properties

Microspheres consisting of a poly(methyl methacrylate) (PMMA) shell wrapping the conductive polyaniline (PANI) particle as a core were prepared by an in-situ suspension polymerization method and then adopted as an electrorheological (ER) material. The polymerization reaction and encapsulation were confirmed by Fourier transform infrared spectrum analysis. The rod-like PANI particles were synthesized via an emulsion polymerization protocol and observed by transmission electron microscopy. In addition, a spherical shape of encapsulated PANI\PMMA (core\shell) microspheres was observed by scanning electron microscopy. The thermal stability of PANI\PMMA particles was examined by use of thermogravimetric analysis. The PANI\PMMA particle-based suspension in silicone oil exhibited typical ER behavior. The conductivity of PANI\PMMA particles was much lower than that of the rod-like PANI.