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arXiv 1503.07353cond-mat.mes-hall
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单壁碳纳米管中的光泳

Photophoresis in Single Walled Carbon Nanotubes

Gopannagari Madhusudana, Vikram Bakaraju, H. Chaturvedi

摘要:

我们报告具体的两件事,一个在原始的单壁碳纳米管(SWNT)的宏观尺度上的光诱导运动的现象和其他随之而来的金属和半导体富集的单壁碳纳米管聚集体的分离。实验提供了SWNT在溶液中的正向和负向电泳的直接证据,即分别远离和朝向光的运动。发现这种光诱导运动依赖于光的频率和强度。聚集体的原始单壁碳纳米管,在紫外线和可见光灯下移动分离和特征在于使用吸收和拉曼光谱。从原始单壁碳纳米管分离的聚集体显示富集金属或半导体单壁碳纳米管,这取决于灯的光谱频率。选择性单壁碳纳米管中的光泳显示出照明频率与特定碳纳米管的吸收之间的直接关系。观察到的现象也验证了使用预分离,金属和半导体单壁碳纳米管在溶液中。金属单壁碳纳米管表现出增强的电泳与紫外灯,而预分离的半导体单壁碳纳米管表现出运动与汞灯与宽带可见光频率。然而,在IR灯下,金属和半导体富集的单壁碳纳米管都显示出连续的运动,如未分离的原始单壁碳纳米管所见,其中没有观察到特异性,并且看到所有颗粒都在运动。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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