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arXiv 1306.5436cond-mat.soft
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碳纳米管水分散体中的向列相液滴

Nematic droplets in aqueous dispersions of carbon nanotubes

Nicolas Puech, Eric Grelet, Philippe Poulin, Christophe Blanc, Paul van der Schoot

摘要:

剥离的胆盐稳定的单壁碳纳米管的水分散体表现出一级转变为非晶液晶相。所述纳米相本身以微米级纳米液滴的形式存在,也称为类晶,自由漂浮在各向同性主体分散体中。微滴呈纺锤形,无论大小,其纵横比约为4。我们把这归因于一个导演场是均匀的,而不是双极,这是证实了偏振显微镜。因此,锚定强度和表面张力的比率必须是大约4,这比理论上预测的大得多,但与双极类触体的早期观察结果一致。从数据中的分散性,我们推断出共存的各向同性相和均质相的表面张力必须非常低,即,在nN/m的数量级。

英文摘要:

Aqueous dispersions of exfoliated, bile-salt stabilized single-wall carbon nanotubes exhibit a first order transition to a nematic liquid-crystalline phase. The nematic phase presents itself in the form of micron-sized nematic droplets also known as tactoids, freely floating in the isotropic host dispersion. The nematic droplets are spindle shaped and have an aspect ratio of about four, irrespective of their size. We attribute this to a director field that is uniform rather than bipolar, which is confirmed by polarization microscopy. It follows that the ratio of the anchoring strength and the surface tension must be about four, which is quite larger than predicted theoretically but in line with earlier observations of bipolar tactoids. From the scatter in the data we deduce that the surface tension of the coexisting isotropic and nematic phases must be extremely low, that is, of the order of nN/m.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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