Facile and fast synthesis of polyaniline-coated poly(glycidyl methacrylate) core-shell microspheres and their electro-responsive characteristics.

Electro-responsive core-shell structured particles were fabricated in two steps. In the first step, a spherical and monodisperse poly(glycidyl methacrylate) (PGMA) core was prepared by dispersion polymerization with an epoxy group, which was then functionalized with an amine functional group (ami-PGMA) via an epoxide-amine reaction with ethylenediamine. In the second step, a conducting polyaniline (PANI) shell was grafted onto the ami-PGMA surface via the in situ polymerization of an aniline monomer with a uniform thickness. The epoxy group on the PGMA microspheres provided a simple and fast way to react with amine functional groups without the need for a further swelling or grafting process. The morphology of the core-shell structure was confirmed by scanning election microscopy and transmission electron microscopy. The electrorheological properties of the PGMA/PANI particles-based suspension were examined using a Couette-type rotational rheometer under an applied electric field. The shear stress curves were fitted to the Cho-Choi-Jhon (CCJ) model of the rheological equation of state.