Adsorption behavior of carbon nanotubes on polystyrene surfaces

Polystyrene (PS) was prepared using two different polymerization methods (dispersion polymerization and seed polymerization) to investigate the steric stabilizer effect during the adsorption process of carbon nanotubes (CNTs) on the surface of PS microspheres. Experiments with different microsphere diameters and difference types of CNTs were conducted to analyze the curvature effect of the spheres on the adsorption mechanism. The results showed that PS microspheres prepared through dispersion polymerization exhibited preferable adsorption behavior compared to PS spheres prepared through seed polymerization, suggesting that poly(N-vinylpyrrolidone) led to improved adsorption interactions between the CNTs and the PS microspheres in the CNTs dispersion. Additionally, the PS diameter and CNT curvature were examined with respect to the adsorption behavior between the PS microspheres and the CNTs. Multiwalled carbon nanotubes (MWCNTs) were found to be well adsorbed on the surface of PS microspheres measuring 2 microm. However, the MWCNTs were adsorbed much less on the surface of submicron-sized PS microspheres, compared with thinwalled carbon nanotubes (TWCNTs). On the other hand, TWCNTs were found to be suitable for adsorption on submicron-sized PS microspheres. These results also indicate that the curvature of the CNTs and the polymer microspheres are important to the CNT adsorption process.