Long-Range Periodicity in Carbon Nanotube Sidewall Functionalization

Using the Bingel reaction as a model for side-wall functionalization of single-walled carbon nanotubes, we report the discovery of highly regular, long-distance (several nanometer) patterns and examine the conditions for the occurrence of such patterns, possibly due to long-range induced reactivity. Varying periodicities of the patterns have been observed via scanning tunneling microscopy and are attributed to nanotube geometry. Patterns are most prominent on medium heavy functionalized nanotubes and likely tied to a nucleophilic reaction mechanism

Functionalization and Dissolution of Nitric Acid Treated Single-Walled Carbon Nanotubes

We report an investigation of the nature and chemical functionalization of nitric acid treated single-walled carbon nanotubes (SWNTs). SWNTs washed with diluted sodium hydroxide solutions were characterized by near-IR, mid-IR, and Raman spectroscopy as well as TEM, and the remaining carboxylic acid content was determined to assess the effect of base washing on the removal of carboxylated carbon fractions, which are generated by the nitric acid treatment. It was found that even after exhaustive washing with aqueous base the purified SWNTs contain carboxylic acid groups in sufficient quantity to prepare high quality soluble SWNT materials by covalent functionalization with octadecylamine