外场响应性复合型乳液体系的构筑及其相行为多重驱动机理研究

Complex emulsion has varied immiscible components in its inner phase, and can be used as template to develop anisotropic materials. This characteristic is gaining growing interests. It has become a new hotspot of research for its anisotropic composition and special structure. It is key to develop new methods that can easily and mass produce complex emulsion with tunable morphology of microstructure and phase behavior. Herein, we proposed a new method to develop smart complex emulsions by employing multiple stimuli-responsive surfactants, in which the phase transition behavior and topological structure of complex emulsion can be smart adjusted simply, sustainably and precisely controllably by environmental factors such as light，pH and redox. Exploring the effects of stimuli-response characteristics of the smart complex emulsion on the stability of emulsion. The corresponding relation between the structure of surfactant molecules and topological structure of complex emulsion will be revealed, and systematical investigating the mechanism of the multiple driving processes of the stimulus response factors on complex emulsion from the molecular structure and interfacial tensionl. Furthermore, spherically functional particles with anisotropic and controllable micro-structure and property will be large-scale developed by employing complex emulsions as templates. We expect that the project will help enrich and develop smart complex emulsion system, understand the topology self-propelled change process and provide scientific basis for the development of novel materials.

复合型乳液由于内相拥有多种不相溶的组份且可做为模板制备各向异性材料而备受关注，其特殊的结构和性能已成为科学研究热点，如何实现复合型乳液相行为及拓扑结构进行简单可控和批量化制备是该研究方向中的重点和难点。本项目首次提出基于多重外场响应性表面活性剂来构建智能复合型乳液，并利用外场因素如光、pH和氧化还原等刺激响应驱动复合型乳液相行为转变，及拓扑结构进行简单、连续及精确的智能调控，探究智能复合型乳液的刺激响应特性对乳液的稳定性的影响，揭示表面活性剂分子结构的变化和复合型乳液形貌的对应关系，从分子结构和界面张力解释外场响应因素对复合型乳液相行为的多重驱动过程的机理。另外，利用智能复合型乳液的模板效应可批量化制备结构可精细调控的球形各向异性粒子。本项目的实施，有助于丰富和发展智能复合型乳液体系，理解拓扑结构自驱动变化过程，为设计新型材料提供科学依据。

复合型乳液因具有独特的结构特征而备受关注，如何实现复合型乳液形貌的连续性精准调控是该领域亟待解决的重要问题。本项目分别合成了三种具有光响应性、氧化还原响应性及pH响应性的两亲分子，并研究了这些两亲分子在外场刺激因素作用前后分子结构、表面张力及CMC的变化特征。结合两种不相溶的内相，构建了多种具有外场响应性的复合型乳液，该乳液在光、电场及pH的不断作用下，可以诱导复合型乳液的液滴拓扑结构发生持续演变，通过控制刺激因素作用时间和程度，可以实现外场因素对液滴形貌的精准调控。研究了刺激作用前后液滴内部多相界面张力的变化，结合马兰戈尼效应，揭示了复合型乳液液滴形貌的连续性演变机理，液滴内部多相界面之间的张力梯度引起的微流场是乳液形貌发生自驱动变化的主要原因。利用复合型乳液形貌的变化过程，可以有效控制乳液液滴内部油相的蒸发。当乳液内部油相之一为可聚合单体时，控制刺激因素作用程度并进行光聚合，可实现中空、半球形、蘑菇状及球形等多种形貌特征聚合物颗粒的制备。本项目的实施为复合型乳液的形貌调控提供了一种更加便捷且智能的途径，这将为可控微反应及新材料表面微结构的精细调控奠定了科学依据及基础。