Department of Materials Science and Engineering, Cornell University, Bard Hall, Ithaca, New York 14853, United States.
Langmuir. 2011 Jan 18;27(2):554-60. doi: 10.1021/la103318u. Epub 2010 Dec 15.
Incorporation of Nafion to aqueous solutions of Pluronics adversely impacts micellization due to extensive Nafion/copolymer interactions. Light scattering and zeta potential measurements provide evidence for the formation of sizable and stable Nafion/copolymer complexes, in expense of the neat copolymer micelles. At high copolymer concentrations, the overall interaction diagram of Nafion/copolymer reflects the competitive action of the release of packing constraints due to micellar destabilization induced by Nafion on one hand and the gelator nature of the Nafion on the other. Measurements using a quartz crystal microbalance (QCM-D) show that aqueous solutions of Pluronics (even at very low concentration) can dissolve the Nafion coating on the crystal resonator, while typical low molecular weight ionic surfactants fail to induce similar effects. These studies demonstrate that complexation with this class of copolymers is a facile route to impart dispersibility to Nafion in aqueous environments that otherwise can be achieved through tedious and harsh treatments.
将 Nafion 掺入 Pluronic 的水溶液中会由于 Nafion/共聚物的广泛相互作用而对胶束化产生不利影响。光散射和动电位测量为形成大而稳定的 Nafion/共聚物复合物提供了证据,而牺牲了纯共聚物胶束。在高共聚物浓度下,Nafion/共聚物的整体相互作用图反映了由于 Nafion 引起的胶束失稳而释放包装约束的竞争作用,以及 Nafion 的凝胶剂性质。使用石英晶体微天平(QCM-D)的测量表明,即使在很低的浓度下,Pluronic 的水溶液也可以溶解晶体谐振器上的 Nafion 涂层,而典型的低分子量离子表面活性剂则无法产生类似的效果。这些研究表明,与这类共聚物的络合是一种简便的方法,可以在水相环境中赋予 Nafion 分散性,否则可以通过繁琐和苛刻的处理来实现。