Functionalization of carbon nanotubes for polymeric carbon nanocomposites and biological conjugates

The exploration of the applications of single-walled (SWNTs) and multiple-walled carbon nanotubes (MWNTs) is strongly limited by their poor processibility. This might be solved by the functionalization of carbon nanotubes with various oligomeric or polymeric species. Thus, the nanotubes might be solubilized into various organic solvents and/or water.;In this dissertation, different methods for the functionalization and solubilization of carbon nanotubes with an aminopolymer are described and compared. The soluble products were characterized by various techniques, with the results suggesting that the functionalization reactions for nanotube solubilization were successful. It was also demonstrated in a set of repeated functionalization reactions, using a dendritic functional molecule, that there was little size selectivity for solubilization of MWNTs.;Carbon nanotubes were functionalized and solubilized by poly(vinyl alcohol) (PVA), which was also used as the matrix polymer for polymer-carbon nanotube composites. Such matrix polymer-functionalization strategy was under the notion to fabricate high-quality polymeric carbon nanocomposites with well-dispersed nanotube fillers and maximal filler-matrix compatibility. It was found that the dispersion of the matrix polymer-functionalized nanotubes in the composite was indeed as good as those in the solution as expected.;The conjugations of SWNTs and ferritin proteins were studied. It was shown that SWNTs are naturally affinitive to ferritins in water, resulting in nanotube aqueous solubilization which could be further enhanced when a functionalization reagent was used. However, water-soluble functionalized SWNTs, such as those with poly(ethylene glycol) functionalities, were resistant to ferritins. The current state-of-art research advances of carbon nanotubes for their potential biological and biomedical applications were also reviewed and discussed.