双亲聚合物复合超分子微结构的界面组装

Much more attention has been paid to the self-assembled supramolecular microstructures of amphiphilic block copolymers. This is important for the development of supramolecular science, nanoscience, polymer science and colloid and interface science. These assemblies have special functions and important applications. At present, the fabrication of amphiphilic block copolymers is focused on bulk, in solution, in thin films and at the air/water interface. The planar liquid/liquid interface unique properties. The fabrication of microstructures through self-assembly of the adsorbed amphiphilic polymer molecules has been attracted increasing attention. In this project, studies will be carried out in two aspects: (1), investigating adsorption and self-assembly of coil-coil, crystalline rod-coil and multi-arm star-like block copolymers at the interface formed by two immiscible liquid phases, discussing the impact of the polymer structure and properties and the conditions on the assembling process, understanding the assembling process and mechanism, and researching the properties and functions of the formed supramolecular microstructures; (2), making use of the mass transfer across the liquid/liquid interface formed by an aqueous phase and a organic phase that composed of a liquid immiscible with water and a liquid miscible with water, self-emulsification, self-assembly of the block copolymer molecules, and adsorption of the assemblies at the air/water or liquid/liquid interface to fabricate pure polymer and composite microstructures where nanoparticles, functional molecules and other species are embedded in, investigating the influence of the molecular structure,  value and the hydrophilic-hydrophobic properties of the block copolymers on the assembling process. It is anticipated that these methods can be developed into common techniques to fabricate much more functional supramolecular microstructures.

双亲性嵌段共聚物在体相、溶液中、薄膜内和气/液界面上自组装形成的超分子微纳米结构的研究受到了极大关注，在液/液界面上的组装也正引起人们越来越浓厚的兴趣。本项目拟深入开展两方面的研究。1，观察在互不相溶的两液相形成的界面上coil-coil型、含结晶性嵌段的rod-coil型、多臂星型等多种嵌段共聚物的吸附和自组装，探讨聚合物的结构和性质及各种条件对组装的影响，了解组装过程和机理，研究组装体的性能；2，将嵌段共聚物溶解在由与水混溶的和不与水混溶的有机溶剂组成的混合液中。观察其与水溶液形成液/液界面时发生的穿越界面的物质迁移、自发乳化、自组装、组装体在液/液界面和气/液界面的吸附和进一步组装等过程，研究在界面上形成的薄膜的结构和性能，探讨聚合物的结构、值和亲水亲油性等因素对超分子微纳米结构组装过程和形成的薄膜的结构和性能的影响。希望这些简便的组装方法能够发展成为普适的技术。

双亲分子，包括双亲小分子和聚合物具有丰富的自组装行为，在溶液中、薄膜内和界面上可形成具有形貌各异、性质独特且应用广泛的聚集结构。探讨这些聚集结构的形成条件、形成过程和机制对于聚集结构的构建和调控是十分重要的，但界面上，特别是液/液界面上的组装还没有受到应有的关注。本课题就嵌段共聚物和双亲小分子在界面上的自组装行为开展了以下三个方面的探讨：（1），利用液/液界面相转移、溶液中自组装来构建复合纳米结构。研究了双亲嵌段共聚物通过相转移在水相和油相中的自组装行为，对形成的纳米结构进行了表征，探讨了形成机理；将这一方法推广到胶体粒子，如金粒子和双亲小分子，如长链脂肪酸分子的自组装上，分别得到了纳米粒子形成的超晶格和超结构以及由双亲分子和金属离子形成的多层纳米片；（2）进一步探讨了嵌段共聚物在由两互不相溶的液相形成的液/液界面上的自组装。某些聚合物可在液/液界面上吸附并结合无机组分和水后返回油相，且进一步转化为囊泡；利用改进的液/液界面组装法，即先由油相与纯水形成液/液界面，然后向纯水中加入第二组分的方法分别对嵌段共聚物、双亲小分子的吸附和自组装进行了探讨。结果表明，嵌段共聚物PS-b-P2VP在液/液界面上形成了大面积纳米点阵、平行纳米带、层状薄膜、蜂巢单层膜和泡沫薄膜等基本形貌，这与嵌段共聚物在液/液界面上的吸附、分相、不完全和完全的自发乳化有关；有机配体和其它双亲分子则可与金属离子配位，形成大面积层状薄膜；（3）以可与水混溶的有机溶剂作为铺展剂，双亲分子在气/液界面上形成了Janus型纳米片。通过这些研究，我们发展了多种界面组装方法，得到了多种功能性聚集结构，深化了对双亲分子在界面上自组装行为的理解。