Polybenzimidazole assisted fabrication of multiwalled carbon nanotube buckypapers and their silver nanoparticle hybrids

Buckypapers represent an attractive form of a macroscopic material of carbon nanotubes with promising applications in electronics, microfilters, and composites, etc. The deposition of metal nanoparticles on buckypaper can further endow buckypapers with multifunctionalities such as unique optical, magnetic and catalytic properties. The homogenous dispersion and appropriate surface functionalization of carbon nanotubes are key factors for realization of high-performance buckypapers and their multifunctional metal hybrids. To this goal, this work reports the fabrication of multi walled carbon nanotube (MWNT) buckypapers and their silver nanoparticle (AgNP) hybrids with the assistance of a high-performance polymer, polybenzimidazole (PBI) for the first time. By optimizing the dispersion conditions of MWNTs in organic solvent with PBI as a non-covalent modifier, highly concentrated dispersions of homogenously dispersed MWNTs can be obtained, thus facilitating the subsequent fabrication of buckypapers by filtration method. The resultant MWNT/PBI papers show good mechanical and thermal properties due to the excellent intrinsic properties of PBI and the strong interactions between MWNTs and PBI. The effect of processing parameters of MWNT dispersions on the final performance of buckypapers was also evaluated. Making use of the coordination effect of imidazole groups to metal ions, AgNPs with relatively uniform sizes were then deposited on surfaces of the MWNTs/PBI buckypaper. The Ag/buckypaper hybrid was found to be a highly active and reusable catalyst for reduction of 4-nitrophenol.