Zhu Jintao, Hayward Ryan C
Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, USA.
J Am Chem Soc. 2008 Jun 11;130(23):7496-502. doi: 10.1021/ja801268e. Epub 2008 May 15.
We introduce a method for the formation of block copolymer micelles through interfacial instabilities of emulsion droplets. Amphiphilic polystyrene-block-poly(ethylene oxide) (PS-PEO) copolymers are first dissolved in chloroform; this solution is then emulsified in water and chloroform is extracted by evaporation. As the droplets shrink, the organic solvent/water interface becomes unstable, spontaneously generating a new interface and leading to dispersion of the copolymer as micellar aggregates in the aqueous phase. Depending on the composition of the copolymer, spherical or cylindrical micelles are formed, and the method is shown to be general to polymers with several different hydrophobic blocks: poly(1,4-butadiene), poly(-caprolactone), and poly(methyl methacrylate). Using this method, hydrophobic species dissolved or suspended in the organic phase along with the amphiphilic copolymer can be incorporated into the resulting micelles. For example, addition of PS homopolymer, or a PS-PEO copolymer of different composition and molecular weight, allows the diameter and morphology of wormlike micelles to be tuned, while addition of hydrophobically coated iron oxide nanoparticles enables the preparation of magnetically loaded spherical and wormlike micelles.
我们介绍了一种通过乳液滴的界面不稳定性形成嵌段共聚物胶束的方法。两亲性聚苯乙烯-嵌段-聚环氧乙烷（PS-PEO）共聚物首先溶解于氯仿中；然后将该溶液在水中乳化，并通过蒸发除去氯仿。随着液滴收缩，有机溶剂/水界面变得不稳定，自发产生新的界面，导致共聚物以胶束聚集体的形式分散在水相中。根据共聚物的组成，会形成球形或圆柱形胶束，并且该方法对具有几种不同疏水嵌段的聚合物（聚（1,4-丁二烯）、聚己内酯和聚甲基丙烯酸甲酯）均适用。使用该方法，与两亲性共聚物一起溶解或悬浮在有机相中的疏水性物质可以被并入所得的胶束中。例如，添加聚苯乙烯均聚物或不同组成和分子量的PS-PEO共聚物，可以调节蠕虫状胶束的直径和形态，而添加疏水包覆的氧化铁纳米颗粒则能够制备磁性负载的球形和蠕虫状胶束。
