Preparation of electro conductive nano-composite from surface modified carbon nanotube and their application to sensing material

表面改性碳纳米管导电纳米复合材料的制备及其在传感材料中的应用

基本信息

批准号：
15360357
负责人：
TSUBOKAWA Norio
金额：
$ 8.9万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

1.The grafting of polymers onto carbon nanotube (CNT) and vapor grown carbon fiver (VGCF) by ligand-exchange reaction of polymers containing ferrocene moieties with aromatic ring of these surfaces was successfully achieved in the presence of Al powder and AlCl_3 as catalyst. The percentage of grafting (wt% of grafted polymer to CNT) reached to 60.9%. It was also found that the percentage of poly(vinyl ferrocene-co-methyl methacrylate) grafting increased with increasing vinyl ferrocene content of the copolymer. The copolymer was also grafted onto VGCF and carbon micro coil surface by use of the ligand-exchange reaction.2.The introduction of carboxyl groups onto CNT and VGCF surface was successfully achieved by the ligand-exchange reaction of polycondensed aromatic rings of these surfaces with 1,1'-dicarboxyferrocene. The grafting of hydroxyl and amino group terminated polymers, such as poly(ethylene glycol) (PEG) and poly(ethylene adipate), onto CNT surface was achieved by direct conden … More sation of carboxyl groups of CNT and VGCF with terminal hydroxyl groups of these polymers in the presence of N,N'-dicyclohexylcarbodiimide.3.The introduction of peroxyester groups onto CNT by the trapping of radicals having peoxyester moieties which were formed by the thermal decomposition of Perhexa C in toluene at 70℃ for 10 h was examined. As a result, peroxyester groups were successfully introduced onto CNT surface. The amount of peroxy groups introduced onto CNT was determined to be 9.5 mmol/g by titration. It was found that the radical graft polymerization of vinyl monomers was successfully initiated by the peroxyester groups introduced onto the CNT surface at 100℃ to give the corresponding polymer-grafted CNT. The percentage of grafting of ptoly(methyl methacrylate) reached to 6.6%.4.Poly(vinyl ferrocene-co-methyl methacrylate)-grafted CNT gave a stable dispersion in good solvent for grafted polymer, such as THF. The precipitation of the polymer-grafted CNT was scarcely observed even after 4 weeks. In addition, polymer-grafted VGCF and CNT readily and uniformly dispersed in grafted polymers to give nano-composites.It was found that electric resistance of the composites prepared from PEG-grafted VGCF and CNT drastically increased at melting point of PEG, 50℃. Therefore, the composites from PEG-grafted VGCF and CNT show positive temperature coefficient (PTC) characteristic.The electric resistance of the composites prepared from polymer-grafted VGCF and CNT suddenly increased in organic solvent vapor, such as methanol, THF, and toluene, and returns immediately to initial resistance when the composite was transferred in dry air. The responsiveness of electric resistance was reproducible even after 20 cycles of exposure to methanol vapor and dry air. Less

1.以Al粉和AlCl_3为催化剂,通过表面带有芳香环的二茂铁聚合物的配体交换反应,成功地实现了聚合物在碳纳米管(CNT)和气相生长碳纤维(VGCF)上的接枝。接枝百分比(接枝聚合物对CNT的wt%)达到60.9％。还发现聚(乙烯基二茂铁-共-甲基)的百分比。随着共聚物中乙烯基二茂铁含量的增加，共聚物也通过配体交换反应接枝到VGCF和碳微线圈表面。2.成功地将羧基引入到CNT和VGCF表面。这些表面的缩聚芳环与1,1'-二羧基二茂铁的配体交换反应，羟基和氨基的接枝终止。通过在 N 存在下将 CNT 和 VGCF 的羧基与这些聚合物的末端羟基直接缩合，将聚乙二醇 (PEG) 和聚己二酸乙二醇酯等聚合物沉积到 CNT 表面， N'-二环己基碳二亚胺.3.通过捕获具有过氧化酯部分的自由基将过氧化酯基引入CNT上，该自由基是由热分解形成的将Perhexa C在甲苯中于70℃放置10小时，结果表明，过氧化酯基团成功引入到CNT表面。通过滴定测定，引入到CNT上的过氧基量为9.5mmol/g。在100℃下通过在CNT表面引入过氧酯基团成功引发了乙烯基单体的自由基接枝聚合，得到了相应的聚合物接枝CNT的接枝百分比。聚甲基丙烯酸甲酯的含量达到6.6%。4.聚(乙烯基二茂铁-共-甲基丙烯酸甲酯)接枝CNT在接枝聚合物的良溶剂(例如THF)中得到稳定的分散体，聚合物接枝的CNT几乎不沉淀。甚至在 4 周后观察到，聚合物接枝的 VGCF 和 CNT 容易且均匀地分散在接枝聚合物中，得到接枝聚合物。研究发现，在PEG熔点50℃时，PEG接枝VGCF和CNT制备的复合材料的电阻急剧增加，因此，PEG接枝VGCF和CNT制备的复合材料表现出正温度系数(PTC)。聚合物接枝VGCF和CNT制备的复合材料在甲醇、THF、甲苯等有机溶剂蒸气中电阻突然增加，并立即恢复到初始状态当复合材料在干燥空气中转移时，即使在暴露于甲醇蒸气和干燥空气中 20 次之后，电阻的响应性仍然可以重现。