Ultrasonication-assisted surface functionalization of double-walled carbon nanotubes with azobis-type radical initiators

Abstract

This paper reports the development of a facile approach for the functionalization of double-walled carbon nanotubes (DWNTs) with azobis-type radical initiators under combined thermal and sonic conditions. The thermal decomposition of azobis-type radical initiators generates free radicals of the alkyl group terminated with various chemically active sites along with the liberation of nitrogen. These radicals are capable of opening the π-bonds of DWNTs, and the generation of chemically active sites on their surface. With the assistance of ultrasonication they can effectively separate DWNT bundles for radical addition and therefore significantly shorten the reaction time.