Simple Process for Sidewall Modification of Multi-Walled Carbon Nanotubes with Polymer Side Chain Radicals Generated by Ultraviolet-Induced C-Cl Bond Dissociation of Polystyrene Derivatives
Simple Process for Sidewall Modification of Multi-Walled Carbon Nanotubes with Polymer Side Chain Radicals Generated by Ultraviolet-Induced C-Cl Bond Dissociation of Polystyrene Derivatives
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DOI：
10.3390/c2030020
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发表时间：
2016-07
期刊：
影响因子：
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通讯作者：
Tomoya Takada;T. Baba;S. Abe
中科院分区：
文献类型：
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作者：
Tomoya Takada;T. Baba;S. Abe
在这项工作中，我们研究了一个简单的一步过程中，多壁碳纳米管（MWCNTs）和苄基型侧链自由基的紫外光分解的聚苯乙烯衍生物含有氯甲基（-CH 2Cl）基团之间的化学键的形成。聚（4-氯甲基）苯乙烯，或苯乙烯/4-（氯甲基）苯乙烯无规共聚物，与多壁碳纳米管在1-甲基-2-吡咯烷酮混合，并用紫外（UV）光照射。制备了聚合物/多壁碳纳米管混合物在紫外光照射前后的薄膜，并用X射线光电子能谱（XPS）和拉曼光谱进行了表征。根据XPS分析，发现混合物中的Cl原子的量在UV照射后减少，这表明通过氯甲基的光解产生的Cl原子以气态Cl 2的形式从反应体系中逃逸。通过比较紫外光照射前后的拉曼光谱的G/D比（G带与D带的强度比），观察了紫外光照射后碳纳米管的结构变化。类似的现象也证实了在聚合物/多壁碳纳米管混合物的情况下，含有羟基氯化铵作为多壁碳纳米管的分散剂。这些结果证实了UV诱导的聚合物侧链和MWCNTs之间的共价键形成。
In this work, we investigated a simple one-step process for the formation of chemical bonds between multi-walled carbon nanotubes (MWCNTs) and benzyl-type side chain radicals generated by UV photolysis of polystyrene derivatives containing the chloromethyl (–CH2Cl) group. Poly(4-chloromethyl)styrene, or styrene/4-(chloromethyl)styrene random copolymer, was mixed with MWCNTs in 1-methyl-2-pyrrolidone and irradiated with ultraviolet (UV) light. Films of polymer/MWCNT mixtures before and after UV irradiation were fabricated, and then examined by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. According to the XPS analysis, the amount of Cl atoms in the mixture was found to decrease upon UV irradiation, indicating that the Cl atoms generated by photolysis of chloromethyl groups escaped from the reaction system in the form of gaseous Cl2. The structural change of CNTs after UV irradiation was also observed by comparing the G/D ratios (the intensity ratio of the G to D bands) of the Raman spectra obtained before and after UV irradiation. Similar phenomena were also confirmed in the case of the polymer/MWCNT mixture containing hydroxylammonium chloride as a dispersant of MWCNTs. These results confirmed the UV-induced covalent bond formation between polymer side chains and MWCNTs.