复杂界面行为作用下的非稳态纯胺液滴微胶囊化成壳机理及调控

Synthesis and property tailoring of polyamine microcapsules are the keys for the practical application of self-healing materials based on microencapsulated two-part epoxy-amine chemistry. For direct microencapsulation of non-equilibrium polyamine micro-droplet via integrating microfluidic and rapid interfacial polymerization, this project aims to study the interfacial physical and chemical behaviors near the interface of the non-equilibrium polyamine micro-droplet and their influences on the microencapsulation mechanism and property regulation of polyamine microcapsules. For an in-depth investigation, a comprehensive research route was adopted based on experimental study, while combining with numerical simulation and theoretical analysis. The behaviors and evolution of the liquid polyamine in the co-flow solvent will be investigated carefully during the formation of polyamine micro-droplets in the microfluidic T-junction. Light will be shed on the influence of the interfacial physical interactions on the macroscopic behaviors of the polyamine/co-flow solvent interface. For shell formation on the non-equilibrium polyamine micro-droplet in the reaction solution, the involved physical and chemical processes, as well as the influential factors for the corresponding processes, will be studied separately and carefully during the microencapsulation process. Emphasis of this part will be on the shell formation mechanism under the collaboration of interfacial physical and chemical behaviors around the non-equilibrium polyamine micro-droplet. During shell growth of the polyamine microcapsule, focus will be on the formation mechanism of the multi-level complex shell structure and the shell growth kinetics. For a comprehensive investigation, the relationships among different physical and chemical processes will be established, and theoretical models for formation of polyamine micro-droplet, shell formation, and shell growth will be proposed. Finally, the microencapsulation process will be optimized, and the governing process(es) and key factor(s) will be obtained. The achievement of this project will lay solid foundation theoretically and technically for the development and practical application of the self-healing system based on microencapsulated epoxy-amine chemistry.

含胺微胶囊的合成及性能调控是基于环氧-胺化学的自修复材料实用化发展的关键。本项目针对微流控-快速界面聚合法直接包裹非稳态纯胺微液滴，以实验研究为主、结合数值模拟及理论分析，研究非稳态下纯胺微液滴界面处的复杂物理化学行为及其作用下的微胶囊成壳机理及性能调控。围绕T型结中纯胺微液滴的形成，研究共流相中胺液的行为、演变及控制，揭示两相微观相互作用对宏观界面行为的影响规律及调控机制；围绕反应溶液中非稳态纯胺微液滴的形壳，厘清各物理化学过程及其影响因素，重点研究各物理化学过程协同作用下的微胶囊形壳机理及调控机制；围绕微胶囊的长壳，深入研究微胶囊囊壁复杂结构的形成机理及囊壁生长动力学。综合微胶囊化全过程，探究各物理化学行为间的关联机制，建立非稳态纯胺微液滴形成、形壳及长壳的理论模型，获得该方法的控制步骤及关键参数，优化微胶囊性能，为基于环氧-胺化学的自修复体系的实用化发展提供强有力的理论及技术支持。

本项目围绕反应活性高、两亲性强、与水及绝大多数有机溶剂互溶的胺类固化剂难以使用传统微胶囊化技术制备成微胶囊的问题，提出了直接包裹非稳态微液滴的微胶囊化原理与技术，在国家自然科学基金资助下，针对T型结微流控-界面聚合（T-IP）技术直接包裹非稳态纯胺微液滴，以实验研究为主，结合理论分析，研究了非稳态下纯胺微液滴界面处的复杂物化行为及其作用下的微胶囊成壳机理及性能调控。围绕T型结中纯胺微液滴的形成，研究了共流相中胺液的行为、演变及调控，揭示了两相微观相互作用对宏观界面行为的影响规律及调控机制；围绕反应溶液中非稳态纯胺微液滴的形壳，厘清了各物化过程及其影响因素，阐明了各物化过程协同作用下的微胶囊形壳机理及调控机制；围绕微胶囊的长壳，揭示了微胶囊囊壁复杂结构的形成机理。综合微胶囊化全过程，建立了非稳态纯胺微液滴形成、形壳及长壳的理论模型，获得了该方法的控制步骤及关键参数，优化了微胶囊化过程，制备了综合性能优异的纯胺微胶囊，为基于微胶囊化环氧-胺化学的自修复体系的实用化发展提供强有力的理论及技术支持。相关研究成果在国内外期刊上发表论文7篇，其中SCI收录6篇，包括中科院一区1篇、二区2篇、三区3篇；申请中国发明专利4件，其中1件已获得授权。项目按时完成了预期计划，达到了预期目标，完成了各项主要考核指标。