Core–shell structured poly(2-ethylaniline) coated crosslinked poly(methyl methacrylate) nanoparticles by graft polymerization and their electrorheology

Abstract

This paper reports the synthesis of core–shell structured poly(2-ethylaniline) (PEAN) coated cross-linked poly(methyl methacrylate) (PEGDMA) particles and their electrorheological property under an applied electric field. Primarily, monodisperse poly(methyl methacrylate) nanoparticles (∼700 nm) were synthesized by dispersion polymerization. The PEAN–PEGDMA microspheres with an average diameter of 1.6 μm were then prepared by an oxidative polymerization process. The application of a suspension of these particles as an electrorheological ER fluid (10 vol%) was assessed using a rotational rheometer, and the effects of the electric field strength were examined. Direct observation of the fibrillation phenomenon of the ER fluid was also investigated using an optical microscope. The results showed that the performance of the ER fluids was enhanced by increasing the electric field strength. The dielectric spectra were further correlated with their ER effect using a LCR meter.