New procedure for preparation of highly stable and well separated carbon nanotubes in an aqueous modified polyacrylonitrile

Abstract

Carbon nanotubes (CNTs) due to their nonreactive surface can not effectively disperse in polymeric matrix. Efficient exploitation of CNTs properties to improve material performance is generally related to the degree of dispersion, saturation by the matrix and interfacial adhesion. In order to obtain a suitable dispersion, the CNTs usually need treatment before they can be utilized. In this work, an easy procedure for preparation a stable dispersion of well separated and individual CNTs in an aqueous polymeric solution by using of Gum Arabic (GA) and modified polymer has been described. The applied polymer was a modified water soluble acrylonitrile polymer. The modification was carried out through functionalizing polyacrylonitrile by 2-amino-ethanol. Individual dispersion of the CNTs in the aqueous GA solution after two month can be observed. By incorporating the modified polyacrylonitrile to the solution, the stability of the individual CNTs dispersion several times was increased in such a way that after six month, the CNTs were still kept at their individual positions. According to the suggested mechanism of dispersion, hydrogen bonds between GA/CNTs and the modified polyacrylonitrile chains can be formed that increasing the dispersion ability. The effects of salts and temperature on dispersion ability of GA were also studied. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.