微胶囊化相变材料多层级结构的设计及构筑机理

The microencapsulation of phase change materials (PCMs) can effectively prevent leakage and phase separation of PCMs in the liquid state and has become the one of main research areas in the energy and material science accordingly. However, the microencapsulation PCMs leads to a large supercooling degree and slow thermal response of PCMs, thus limiting their applications in advanced scientific and technological fields, where a precise temperature control is needed. This project will focus on the investigation of the hierarchical PCMs-based microcapsules with various multi-scale mesoporous cores and multi-dimensional inorganic shells. The synchronous formation of multi-scale mesoporous core and microencapsulation of inorganic shell as well as their regulation mechanisms will be studied intensively. The relationship between synthetic technology and microstructure will be determined, and the techniques for the ordered alignment of inorganic nanoparticles on the microcapsule surface and their controlled growth will be obtained. Meanwhile, the synthetic mechanisms of hierarchical structures will be clarified. Computer simulations will be conducted to investigate the internal correlation between the phase-change performance and microstructures of the hierarchical PCMs-based microcapsules. This project will provide a new strategy for the synthesis of microencapsulated PCMs with a low supercooling degree and rapid thermal response and open a new application for microencapsulated PCMs in the hi-tech areas.

相变材料微胶囊化可有效解决其应用过程中的泄露、流失、相分离等缺陷，实现其宏观形态稳定，是近年来能源材料领域活跃的研究方向。本项目针对相变材料微胶囊存在的过冷度大、热响应速度慢、无法满足高精尖科技领域对其精确控温特定要求等问题，提出了构建囊芯为多尺度介孔结构、外壳为多维度无机材料的多层级相变材料微胶囊的研究思路及技术路线。研究相变材料微胶囊化包覆与多尺度介观囊芯同步构筑的合成技术，探索多维度壳体微结构的调控方式，厘清合成工艺对介观和微观结构的影响规律，实现无机纳米粒子在壳层内部有序排列和外表面可控生长，掌握多层级结构的构筑机理。将计算模拟与实验结合，研究相变材料微胶囊的相变储热性能与其多层级结构之间的内在联系。基于本项目研究成果，将为具有低过冷度、快速热响应的相变材料微胶囊的合成提供新思路和借鉴，为满足相变材料微胶囊作为独立热温调控工作单元应用于尖端领域提供科学依据和理论指导。

项目针对相变材料微胶囊存在的过冷度大、热响应速度慢等问题，开展构建了多尺度多维度无机材料的多层级相变材料微胶囊。通过在非水体系中采用自组装乳液模板法，针对不同无机壁材具有多层级结构的相变材料微胶囊的合成开发，设计了一系列基于二氧化硅、二氧化钛和碳酸钙/相变材料微胶囊的多维度表面。通过对多层级相变材料微胶囊的组成、微观结构、壳材形貌进行调控，厘清了合成工艺对介观和微观结构的影响规律，实现了无机纳米粒子在壳材表面的可控生长，掌握了微胶囊多层级结构的构筑机理。基于相变材料微胶囊的多尺度囊芯结构构筑，发现与传统核壳结构的微胶囊相比，介孔囊芯结构增加了壳材与芯材的接触面积，可有效改善相变材料的过冷；通过调控相变材料微胶囊的多维度壳材，证实高导热和大比表面积的壳材可有效提升相变材料传热性能。利用本项目的研究成果，不仅开发了一系列基于多尺度和多维度的相变材料微胶囊制备技术，为满足相变材料微胶囊作为独立热温调控工作单元应用于尖端领域提供科学依据和理论指导，还进一步拓展了其应用，制备了一系列可用于电池原位热管理、高效光热吸收和储存、污水处理和废热回收、太阳光海水淡化、生物酶传感器热温调控、热致变色、荧光分子印迹等领域的多层级相变材料微胶囊，为相变材料微胶囊的应用研究开发提供了科学依据和技术支撑。