Light Induced Aggregation of Specific Single Walled Carbon Nanotubes

We report optically induced aggregation and consequent separation of specific diameter of pristine single walled carbon nanotubes (SWNT) from stable solution. Well dispersed solution of pristine SWNTs, without any surfactant or functionalization, show rapid aggregation by uniform exposure to UV, visible and NIR illumination. Optically induced aggregation linearly increases with consequent increase in the intensity of light. Aggregated SWNTs were separated from the dispersed supernatant and characterized using absorption and Raman spectroscopy. Separated SWNTs distinctly show enrichment of specific SWNTs under UV visible and NIR illumination.