Preparation of silica-layered multi-walled carbon nanotubes activated by grafting of poly(4-vinylpyridine)
Preparation of silica-layered multi-walled carbon nanotubes activated by grafting of poly(4-vinylpyridine)
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DOI：
10.1016/j.synthmet.2008.07.019
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发表时间：
2009-01-01
期刊：
影响因子：
4.4
通讯作者：
Shim, Sang Eun
中科院分区：
文献类型：
--
作者：
Kim, Myunghun;Hong, Jinho;Shim, Sang Eun
本论文采用分步反应法制备了均匀包覆二氧化硅的碳纳米管，并将氧化过程中碳纳米管的损伤降至最低。首先以高锰酸钾和四丙基溴化铵(TPABR)为相转移催化剂，在碳纳米管表面生成羟基，然后在碳纳米管表面接枝硅烷偶联剂。甲基丙烯氧丙基三甲氧基硅烷(MPTMS)。利用原位溶液聚合中末端的乙烯基基团，在碳纳米管中生长了聚4-乙烯基吡啶(P4VP)刷，促进了碳纳米管与正硅酸乙酯(TEOS)之间的酸碱相互作用。通过氨水催化正硅酸乙酯在P4VP功能化碳纳米管存在下的溶胶-凝胶反应，得到了均匀包覆二氧化硅的碳纳米管。二氧化硅层的厚度可以很容易地由反应物的量来控制。包覆二氧化硅的碳纳米管在焙烧后只剩下外层的二氧化硅，形成了二氧化硅纳米管。皇冠版权所有(C)2008由爱思唯尔出版。保留所有权利。
Herein, uniformly silica coated carbon nanotubes (CNTs) were fabricated by step reactions with minimized damage of CNTs during oxidation process. First, hydroxyl groups were generated on the surface of CNTs using KMnO4 in conjunction with tetrapropyl ammonium bromide (TPABr) as a phase transfer catalyst, followed by the grafting of a vinyl group carrying silane coupling agent. methacryloxypropyl trimethoxy silane (MPTMS). Utilizing terminal vinyl groups in in-situ solution polymerization, poly(4-vinylpyrridine) (P4VP) brush was grown from the CNTs which promotes the acid-base interaction between CNTs and tetraethylorthosilicate (TEOS). By means of well-known ammonia catalyzed sol-gel reaction of TEOS in the presence of P4VP-functionalized CNTs, uniformly silica-coated CNTs were obtained. The thickness of the silica layer could be readily controlled by the amounts of reactants. After calcination of silica-coated CNTs, only outer silica remained which resulted in silica nanotubes. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.