Noncovalent porphyrin-functionalized single-walled carbon nanotubes in solution and the formation of porphyrin–nanotube nanocomposites

Abstract

Porphyrins are functional dyes with a variety of unique physical (photophysical), chemical and biological properties. We report on the first finding that porphyrin molecules dissolve single-walled carbon nanotubes (SWNTs) in organic solutions and that the SWNTs–porphyrin hybrid nanomaterials can be separated from the solutions. Atomic force microscope investigation revealed that both individually dissolved nanotubes and bundled nanotubes coexisted in the solution. The solid purified SWNTs (p-SWNTs)–porphyrin nanomaterials were readily separated from the p-SWNTs–porphyrin solution, and this nanomaterial was re-dissolvable in DMF. Measurements of its fluorescence spectrum gave evidence for the interaction between the nanotube sidewall and porphyrin molecules in solution.