Preparation of electro conductive nano-composite from surface modified carbon nanotube and their application to sensing material
Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants|
Composite materials/Physical properties
|Research Institution||Niigata University|
TSUBOKAWA Norio Niigata University, Institute of Science and Technology, Professor, 自然科学系, 教授 (20018675)
|Project Period (FY)
2003 – 2005
Completed(Fiscal Year 2005)
|Budget Amount *help
¥13,900,000 (Direct Cost : ¥13,900,000)
Fiscal Year 2005 : ¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 2004 : ¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 2003 : ¥7,900,000 (Direct Cost : ¥7,900,000)
|Keywords||Carbon nanotube / Vapor grown carbon fiber / Carbon micro coil / Surface grafting of polymer / carboxyl group / Ligand-exchange reaction / Nano-composite / Sensing material / 表面グラフト化 / ラジカル捕捉 / ペルオキシ基 / ラジカル重合 / ビニルフェロセン / マクロモノマー / 放射線グラフト / 両親媒性ポリマー|
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
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
Research Products (7results)