Chen Yusheng, Xu Yongqian, Perry Kelly, Sokolov Alexei P, More Karren, Pang Yi
Department of Chemistry & Maurice Morton Institute of Polymer Science, University of Akron, Ohio 44325, United States.
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6197, United States.
ACS Macro Lett. 2012 Jun 19;1(6):701-705. doi: 10.1021/mz3001308. Epub 2012 May 21.
A water-soluble poly[(-phenylenevinylene)--(-phenylenevinylene)] (PmPV) has been synthesized, which exhibits an unsymmetrical substitution pattern on the -phenylene unit. With one substituent being hydrophilic while the other being hydrophobic, the polymer chain has a higher tendency to fold in aqueous solution, thereby promoting helical conformation. The polymer is found to selectively disperse the single-walled nanotubes (SWNTs) of small diameters ( = 0.75-0.84 nm), in sharp contrast to PmPV with a symmetrical substitution pattern. The intriguing diameter-based selectivity is believed to be associated with the confined helical conformation, which provides a suitable cavity to host the SWNT of proper sizes. The study thus provides a useful demonstration that the polymer conformation can have a profound impact on the SWNT sorting.
一种水溶性聚[（-亚苯基亚乙烯基）-（-亚苯基亚乙烯基）]（PmPV）已被合成，它在亚苯基单元上呈现出不对称的取代模式。一个取代基是亲水性的，而另一个是疏水性的，聚合物链在水溶液中有更高的折叠倾向，从而促进螺旋构象。发现该聚合物能选择性地分散小直径（=0.75-0.84纳米）的单壁纳米管（SWNTs），这与具有对称取代模式的PmPV形成鲜明对比。这种基于直径的有趣选择性被认为与受限的螺旋构象有关，该构象提供了一个合适的空腔来容纳适当尺寸的SWNT。因此，该研究提供了一个有用的例证，即聚合物构象对SWNT的分类有深远影响。
