Selective and Reversible Noncovalent Functionalization of Single-Walled Carbon Nanotubes by a pH-Responsive Vinylogous Tetrathiafulvalene-Fluorene Copolymer
Selective and Reversible Noncovalent Functionalization of Single-Walled Carbon Nanotubes by a pH-Responsive Vinylogous Tetrathiafulvalene-Fluorene Copolymer
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DOI：
10.1021/ja409918n
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发表时间：
2014-01-22
影响因子：
15
通讯作者：
Adronov, Alex
中科院分区：
文献类型：
--
作者：
Liang, Shuai;Zhao, Yuming;Adronov, Alex
制备了一种乙烯型四硫富瓦烯（TTFV）单体，并将其与芴共聚，得到一种构象可转换的共轭共聚物。研究表明，该共聚物在被三氟乙酸（TFA）质子化时会发生构象变化。当与单壁碳纳米管（SWNTs）混合时，这种TTFV - 芴共聚物与SWNT表面表现出强烈的相互作用，从而在甲苯中形成稳定、浓缩的纳米管分散液。光致发光激发图谱显示，该共聚物选择性地分散小直径的SWNTs，这与其在纳米管表面形成紧密卷曲构象的能力相符。向共聚物 - SWNT分散液中加入TFA会导致快速的构象变化以及聚合物从SWNT表面解吸，从而使完全无聚合物的纯SWNTs沉淀出来。重要的是，经TTFV - 芴共聚物分散和释放后分离出的纳米管比最初分散的原始SWNTs更纯。
A vinylogous tetrathiafulvalene (TTFV) monomer was prepared and copolymerized with fluorene to give a conformationally switchable conjugated copolymer. This copolymer was shown to undergo a conformational change upon protonation with trifluoroacetic acid (TFA). When mixed with single-walled carbon nanotubes (SWNTs), this TTFV-fluorene copolymer exhibited strong interactions with the SWNT surface, leading to stable, concentrated,nanotube dispersions in toluene. Photoluminescence excitation mapping indicated that the copolymer selectively disperses low-diameter SWNTs, as would be expected from its ability to form a tightly coiled conformation on the nanotube surface. Addition of TFA to the copolymer SWNT dispersion resulted in a rapid conformational change and desorption of the polymer from the SWNT surface, resulting in precipitation of pure SWNTs that were completely free of polymer. Importantly, the nanotubes isolated after dispersion and release by the TTFV fluorene copolymer were more pure than the original SWNTs that were initially dispersed.