Functionalized carbon nanotube/polyacrylonitrile composite nanofibers: fabrication and properties

The functionalized multi-walled carbon nanotubes (f-MWCNTs) were obtained by FriedelCrafts acylation, which introduced aromatic amine groups onto the sidewall. And the grafted yield was adjusted by controlling the concentration of the catalyst. The composite solutions containing f-MWCNTs and polyacrylonitrile (PAN) were then prepared by in-situ or ex-situ solution polymerization. The resulting solutions were electrospun into composite nanofibers. In the in-situ polymerization, morphological observation revealed that f-MWCNTs was uniformly dispersed along the axes of the nanofibers and increased interfacial adhesion between f-MWCNTs and PAN. Furthermore, two kinds of f-MWCNTs/PAN composite nanofibers had a higher degree of crystallization and a larger crystal size than PAN nanofibers had, so the specific tensile strengths and modulus of the composite nanofibers were enhanced. And the thermal stability of f-MWCNTs/PAN from in-situ method was higher than that of ex-situ system. When the f-MWCNTs content was less than 1wt%, the specific tensile strengths and modulus of nanofibers were enhanced with increase in the amounts of f-MWCNTs, and f-MWCNTs/PAN of in-situ system provided better mechanical properties than that of ex-situ system. Copyright (C) 2010 John Wiley & Sons, Ltd.