多壁碳纳米管在硫酸溶液中的γ辐射剪切

Gamma-radiation Cutting of Multi-walled Carbon Nanotubes in the Presence of Sulfuric Acid

在硫酸溶液中系统地研究了γ辐射法剪切多壁碳纳米管,以及影响碳管长度的反应条件,详细讨论了多壁碳纳米管的剪切机理。采用透射电子显微镜(TEM)、傅立叶变换红外光谱(FT-IR)、紫外可见分光光度计(UV-Vis)和Raman光谱对短多壁碳纳米管进行了分析与表征,分析了多壁碳纳米管浓度与其对UV270nm吸光度的关系,得出了多壁碳纳米管质量浓度与其对UV270nm吸光度的线性回归方程。结果表明,γ辐射和硫酸氧化作用在剪切多壁碳纳米管的过程中存在协同效应。随着辐射剂量和酸浓度的增加,剪切后的碳管长度不断缩短。当辐射剂量增加到200kGy、酸浓度为5mol/L时,短多壁碳纳米管长度为200～300nm。辐射剪切的方法在碳纳米管外侧及末端引进C-OH、-COOH等官能团,从而对MWNTs的石墨型结构造成微弱损伤。另外,制备的短多壁碳管在水中可以均匀分散2周而不出现沉淀。

Research on presence of sulfuric acid. The the cutting of multi-walled carbon nanotubes（MWNTs） with gamma radiation in the influences of reaction conditions on nanotube length are investigated and the proposed mechanism for the cutting process of MWNTs is also analyzed. The short MWNTs are characterized and analyzed using transmission electron microscopy（TEM）, fourier transform infrared spectroscopy（FT-IR）, ultraviolet-visible spectroscopy（UV-Vis） and Raman spectroscopy. Results indicate there is a synergetic effect between the gamma radiation and sulfuric acid oxidation during the cutting of MWNTs. The length of short nanotubes decrease significantly with the increase of radiation dose and sulfuric acid concentration. When the radiation dose increase to 200kGy and the concentration of sulfuric acid increase to 5mol/L, the short MWNTs has a length distribution of 200-300nm. The cutting approach induces the production of a certain number of-OH, -C（X）H functional groups on the short MWNTs and resulted in tiny destruction to the graphitie structure of MWNTs. Moreover, MWNTs can be uniformly dispersed in water for two weeks and there is not precipitation.