Photophoresis in Single Walled Carbon Nanotubes
| Autor: | Madhusudana Gopannagari, Vikram Bakaraju, Harsh Chaturvedi |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Polymers and Plastics Condensed Matter - Mesoscale and Nanoscale Physics business.industry Metals and Alloys FOS: Physical sciences Carbon nanotube Photophoresis Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Biomaterials Metal symbols.namesake Semiconductor law visual_art Mesoscale and Nanoscale Physics (cond-mat.mes-hall) symbols visual_art.visual_art_medium Optoelectronics Absorption (electromagnetic radiation) business Raman spectroscopy |
| DOI: | 10.48550/arxiv.1503.07353 |
| Popis: | We report specifically two things, one the phenomenon of optically induced motion in pristine single walled carbon nanotubes (SWNT) on the macro-scale and other the consequent separation of metallic and semiconducting enriched SWNT aggregates. Experiments provide direct evidence of both positive and negative photophoresis of SWNTs in solution i.e. motion away and towards light respectively. This optically induced motion was found to be dependent on frequency and intensity of light. Aggregates of pristine SWNT, moving under UV and Visible lamp were separated and characterized using absorption and Raman spectroscopy. Aggregates separated from pristine SWNT show enrichment in metallic or semiconducting SWNTs, depending on the spectral frequency of the lamp. Photophoresis in selective SWNTs show direct relation between frequency of illumination and absorption of specific nanotubes. The observed phenomenon is also verified using pre-separated, metallic and semiconducting SWNTs in solution. Metallic SWNTs show enhanced photophoresis with an UV lamp, whereas pre-separated semiconductor SWNT exhibit motion with a mercury lamp with broadband visible frequency. However, under IR lamp, both metallic and semiconducting enriched SWNT show continuous motion, as seen for un-separated pristine SWNTs, where no specificity was observed and all particles were seen moving. Comment: 4 figures |
| Databáze: | OpenAIRE |
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