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将单壁碳纳米管分散到溶有光引发剂2-羟基-2-甲基-1-苯基-1-丙醇的四氢呋喃溶液中,在紫外光辐照下,光引发剂裂解生成2-羟基异丙基自由基。通过自由基的偶合反应,2-羟基异丙基自由基偶合到碳纳米管表面。用UV-Vis光谱、FTIR、拉曼光谱、TGA-MS及HRTEM等表征方法,证实在单壁碳纳米管表面引入了羟基。UV-Vis光谱上范霍夫吸收峰的消失表明碳纳米管表面被功能化。羟基化的SWCNTs样品在FTIR光谱中出现的3420cm-1(O—H键)、2930和2859cm-1(烷基C—H键)峰进一步证实了碳纳米管的功能化。拉曼光谱显示,随着SWCNTs的功能化,其切向模式吸收带与杂碳原子吸收带的相对比值(IG/ID)下降。TGA-MS的m/z59峰(400℃)揭示了SWCNTs上存在着异丙醇基团。HRTEM和溶解数据表明,光解改性有助于碳纳米管管束间缠结的解开,进而提高了其在有机溶剂中的溶解性,并且在一定程度上保持了碳纳米管的结构。
The single-walled carbon nanotubes were dispersed into a tetrahydrofuran solution containing 2-hydroxy-2-methyl-1-phenyl-1-propanol as a photoinitiator. Under ultraviolet light irradiation, the photoinitiator was cleaved to produce 2- Hydroxy isopropyl radical. By radical coupling reaction, 2-hydroxy-isopropyl radical is coupled to the carbon nanotube surface. The UV-Vis spectra, FTIR, Raman spectra, TGA-MS and HRTEM were used to confirm the introduction of hydroxyl groups on the surface of single-walled carbon nanotubes. The disappearance of the van Hoff absorption peak in the UV-Vis spectrum suggests that the carbon nanotube surface is functionalized. The 3420 cm-1 (O-H bond), 2930 and 2859 cm-1 (alkyl C-H bond) peaks of the hydroxylated SWCNTs samples in the FTIR spectra further confirmed the functionalization of the carbon nanotubes. Raman spectroscopy showed that with the functionalization of SWCNTs, the relative ratio (IG / ID) of the tangential mode absorption band to the Hb band decreased. The m / z 59 peak (400 ° C) of TGA-MS revealed the presence of an isopropanol group on the SWCNTs. HRTEM and dissolution data show that photodegradation can help to unravel the entanglement between carbon nanotube bundles and improve their solubility in organic solvents, and to a certain extent, maintain the structure of carbon nanotubes.