Large Deformable Multiwalled Carbon Nanotube Core-Shell Structure on Polystyrene Beads

Multiwalled carbon nanotube (MWCNT)-coated polystyrene (PS) beads have been prepared by dispersion polymerization followed by a layer-by-layer self-assembly method. The concentration of carboxylic acid groups on the MWCNTs increased from 1.81 x 10(21) to 3.43 x 10(22) COO- per g as the treatment time was increased from 3 to 9 h. The sulfonated polystyrene (SPS) beads changed from being negatively charged to positively charged when the cationic polyelectrolyte was self-assembled on their surface. The surface morphology of the adsorbed polyelectrolyte was smooth without any aggregation and the thickness of the polyelectrolyte coating on the SPS beads was;approximate to 0.6 mu m. The electrical conductivity and resistance of the MWCNT-coated SPS beads were measured to be 4.0 x 10(-2) S . cm(-1) and 12.8 Omega at a volume fraction of 91%, respectively.