Covalent and non-covalent SWCNTs modification under ~(60)Co γ-ray irradiation

摘要

The chemical reactions in SWCNT suspensions in an aqueous solution of cetyltrimethylammonium bromide (CTAB) and in SWCNT / HCN mixtures induced by ~(60)Co γ- radiation were investigated. A nanometer size of the nanotube arranges CTAB molecules on the nanotube walls and radiation induces cross-linking of CTAB molecules. TEM shows that the bundle and the nanotube are covered by a moss-like coating. This coating does not change UV-vis-NIR spectra of the SWCNTs essentially, so there is no covalent binding between SWCNTs and coating. This spectrum completely disappeared after radiation treatment of HCN / SWCNT mixture. After radiation weight of SWCNTs increased by ～3.5 times, the sample became soluble in alcohols, water, and acids. Solubility of treated SWCNTs in formic acid was 50mg/ml. SEM, TEM, x-ray diffraction, Raman, IR spectroscopies, and thermal decomposition with mass-spectrum product analysis tested these samples. All the data testify that HCN molecules penetrate between nanotubes in bundles and the chemical attaches to nanotube walls.