Micelle-encapsulated carbon nanotubes: A route to nanotube composites
Micelle-encapsulated carbon nanotubes: A route to nanotube composites
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DOI：
10.1021/ja034082d
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发表时间：
2003-05-14
影响因子：
15
通讯作者：
Taton, TA
中科院分区：
文献类型：
--
作者：
Kang, YJ;Taton, TA
我们报告了一种通过将单壁碳纳米管 (SWNT) 封装在交联胶束内来将单壁碳纳米管 (SWNT) 分散在溶剂和聚合物材料中的通用方法。由聚苯乙烯-嵌段-聚丙烯酸（PS-b-PAA）（一种两亲性嵌段共聚物）制成的胶束首先通过将水逐渐添加到纳米管在二甲基甲酰胺中的悬浮液中而组装在单壁碳纳米管周围。然后，这些胶束的亲水外壳与双官能连接分子进行化学交联。然后可以通过连续的离心和再分散循环将纯封装的单壁碳纳米管 (e-SWNT) 与空的交联胶束分离。所得纳米结构的原子力和透射电子显微镜表明，单个纳米管（而不是束）已完全包裹在聚合物壳中，其厚度略大于空胶束的厚度。封装在 PS-b-PAA 中的 e-SWNT 可以通过最少的超声处理永久地再分散在 H2O、有机溶剂以及疏水性和亲水性聚合物基质中。胶束封装可以改善单壁碳纳米管在结构、电子和热应用的各种聚合物材料中的复合。
We report a general approach toward dispersing single-walled carbon nanotubes (SWNTs) in solvents and polymer materials, by encapsulating SWNTs within cross-linked micelles. Micelles made from polystyrene-block-poly(acrylic acid) (PS-b-PAA), an amphiphilic block copolymer, are first assembled around SWNTs by gradually adding H2O to a suspension of nanotubes in dimethylformamide. The hydrophilic, outer shells of these micelles are then chemically cross-linked with a difunctional linker molecule. Pure encapsulated SWNTs (e-SWNTs) can then be separated from empty cross-linked micelles by consecutive cycles of centrifugation and redispersion. Atomic force and transmission electron microscopies of the resulting nanostructures demonstrate that individual nanotubes (rather than bundles) have been completely encased in polymer shells whose thickness is slightly larger than that of empty micelles. e-SWNTs encapsulated in PS-b-PAA can be permanently redispersed in H2O, in organic solvents, and in both hydrophobic and hydrophilic polymer matrices with minimal sonication. Micelle encapsulation could improve the compositing of SWNTs in a wide variety of polymer materials for structural, electronic, and thermal applications.