Multiwalled carbon nanotubes-coated polymeric microspheres

POLY 492

Seok Ho Yoon, Minsung Kang, and Hyoung-Joon Jin, hjjin@inha.ac.kr. Department of Polymer Science and Engineering, Inha University, 253 Yonghyun-dong, Incheon 402-751, South Korea
Surface-conductive microspheres consisting of synthetic polymer core and mutliwalled carbon nanotubes (MWCNTs)-adsorbed shell were prepared using a truly simple process involving the blending of two colloidal solution; an aqueous MWCNT dispersion with surfactants and an aqueous poly(methyl methacrylate) (PMMA) microsphere (6.5 μm) colloid. These were adopted as the suspended particles for electrorheological (ER) fluids, in which the electrical conductivity originated primarily from the surface-coated conducting MWCNT layers. The MWCNT-coated polymeric microspheres were monodisperse and spherical in shape. The PMMA/MWCNT composite suspensions in silicone oil showed the typical ER characteristics of forming a chain-like structure under an applied electric field (1.4 kV/mm). The PMMA/MWCNT composite microspheres exhibited a conductivity ranging from 0.00006 to 0.0005 S/cm, which is an acceptable conductivity range for ER fluids. This phenomenon can be explained by the interfacial polarizability of MWCNTs adsorbed on the surface of the polymeric microspheres.