Morphological Investigation of Midblock-Sulfonated Block Ionomers Prepared from Solvents Differing in Polarity
Morphological Investigation of Midblock-Sulfonated Block Ionomers Prepared from Solvents Differing in Polarity
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DOI：
10.1002/marc.201400627
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发表时间：
2015-03-01
影响因子：
4.6
通讯作者：
Spontak, Richard J.
中科院分区：
文献类型：
--
作者：
Mineart, Kenneth P.;Jiang, Xi;Spontak, Richard J.
带电多嵌段共聚物可以形成物理网络并显示出强大的机械性能，这方面的最新发展预示着需要两亲性属性的当代技术将迎来新的令人兴奋的机会。然而，由于存在强烈的相互作用，对这类材料的相行为的控制仍然具有挑战性，特别是因为它们的形貌可以被溶剂模板化。本研究采用透射电子显微镜和显微断层扫描技术研究了不同极性溶剂制备的中间嵌段磺化五嵌段离聚体的形态特征。结果图像证实，在相对非极性的溶剂浇铸的薄膜中，形成了离散的、球形的富离子微区，而当浇注溶剂的极性更高时，会产生明显混合的形态，并具有连续的富离子路径。形态特征的详细3D分析证实了六角填充的非极性柱体和片层的共存，这促进了离子和/或其他极性物种在纳米结构介质中的扩散。
Recent developments regarding charged multiblock copolymers that can form physical networks and exhibit robust mechanical properties herald new and exciting opportunities for contemporary technologies requiring amphiphilic attributes. Due to the presence of strong interactions, however, control over the phase behavior of such materials remains challenging, especially since their morphologies can be solvent-templated. In this study, transmission electron microscopy and microtomography are employed to examine the morphological characteristics of midblock-sulfonated pentablock ionomers prepared from solvents differing in polarity. Resultant images confirm that discrete, spherical ion-rich microdomains form in films cast from a relatively nonpolar solvent, whereas an apparently mixed morphology with a continuous ion-rich pathway is generated when the casting solvent is more highly polar. Detailed 3D analysis of the morphological characteristics confirms the coexistence of hexagonally-packed nonpolar cylinders and lamellae, which facilitates the diffusion of ions and/or other polar species through the nanostructured medium.