Functionalization of multiwalled carbon nanotubes with polystyrene under atom transfer radical polymerization conditions

Linear Polystyrene (PS) was grafted onto the convex surfaces of multiwalled carbon nanotubes (MWCNTs). Bromine-terminated polystyrene synthesized by atom transfer radical polymerization (ATRP) was directly reacted with MWCNTs under ATRP conditions using CuBr/2,2'-bipyridine as catalyst. The PS-grafted MWCNT samples were characterized by scanning electron microscopy, transmission electron microscopy, FT-IR spectra, Raman spectra, H-1 NMR, UV-vis spectra, thermal gravimetric analyses, and X-ray diffraction. The products can dissolve in organic solvents such as 1,2-dichlorobenzene, tetrahydrofuran and chloroform to form well-dispersed solutions. Optical limiting property measurements in chloroform were carried out at 532 nm using the open-aperture z-scan technique. The results demonstrate that the samples preserve good optical limiting properties when the polymer is covalently attached to the carbon nanotube. (c) 2006 Elsevier Ltd. All rights reserved.