新型石墨烯接枝强化聚乙二醇复合固--固相变材料的分子结构调控与储热特性研究

This project will use molecular structure design method through an interdisciplinary and macroscopic perspective such as thermochemistry, material chemistry, nanotechnology and so on to solve the limitations of poor thermal conductivity, flowability and leakage, and slow thermal response rate for inorganic phase change materials. A novel composite solid-solid phase change material based on graphene grafted polyethylene glycol with a lamellar structure, high thermal conductivity, high latent heat and excellent thermal cycling stability will be prepared through self-assembly between functional groups and grafted polymerization. In this project, high thermal conductive graphene will be by creatively used as a grafted and molecular structure regulated composition, PEG will be used as a functional segment for phase change energy storage, and isocyanate will be used as a cross-linked hard segment. The regular arrangement of graphene in the molecular chain will regulate the molecular structure, reduce the limitation of the hard segment on the PEG chain and improve the phase change energy storage property of PEG. Furthermore, phase change behavior and energy storage mechanism of PEG in the polymer chain will be further studied. The combination rules of graphene and polymer chain will also be investigated to clarify the relationship among the thermal conductivity, thermal response rate, thermal cycling stability and micro-structure of the novel composite solid-solid phase change material. Consequently, the thermal energy storage property and thermal response capability will be highly improved. As a result, this project will supply a reference for the design and preparation of novel composite phase change materials.

针对传统相变材料存在易流动、导热系数低和热响应速率慢的缺陷，本项目从热化学、材料化学、纳米技术等多学科交叉角度进行分子结构设计，创新性地选取高导热石墨烯为高分子链段的接枝强化和分子结构调控成分，PEG为相变储热功能链段，异氰酸酯为高分子硬段交联结构，通过功能基团的自组装和接枝共聚合，设计制备具有层状结构的高潜热、高导热、热稳定性优异的新型石墨烯接枝强化聚乙二醇复合固-固相变材料。通过氧化石墨烯在高分子链结构中的规整排列进行分子结构调控，降低高分子硬段骨架对PEG功能链段的束缚，提高PEG链段的相变储能特性，深入研究PEG在高分子链结构内的相变行为和储能机理；通过考察氧化石墨烯在高分子链结构中的结合规律，弄清新型复合固-固相变材料的导热性能、热响应速率和热循环稳定性与其微观结构间的关系，大幅度提高复合固-固相变材料的储热性能和热响应能力，为新型复合相变材料的设计和制备提供借鉴与参考。

相变储热技术能有效提高能源利用率，对于实现碳达峰、碳中和的战略目标具有重要意义。为了解决相变材料易流动泄漏和导热系数低的缺陷，本项目从热化学、材料化学、纳米技术等多学科交叉角度对相变材料进行分子结构设计和功能强化，创新性地选取高导热石墨烯等功能单元为高分子链段的接枝强化和分子结构调控成分，通过功能基团的自组装和接枝共聚合，构筑了一系列高潜热、高导热、热稳定性优异的新型石墨烯接枝强化复合固-固相变材料；同时综合软硬链段优势，创新地采用各类聚合物材料与石墨烯分子链段交互连接强化，组装构筑了一系列新型高性能气凝胶基复合相变材料。并对这些新型复合固-固相变材料的微观结构、热性能和储能机理进行了深入研究，查明了石墨烯等纳米功能单元与聚合物材料的分子交互连接规律，探索了微观结构与热性能之间的联系及影响规律，揭示了相变材料在不同结构聚合物及气凝胶的三维多孔网络中的相变储热机理和热传导机理，探索了复合相变材料的结构调控机制和影响因子，提出了解决相变材料易流动泄露及导热系数低这一技术难题的结构调控路径和新思路，为高性能复合相变材料的设计和规模化应用提供借鉴和指导。通过上述研究工作，已在国际高水平期刊上正式发表SCI论文13篇，中国核心期刊论文2篇。其中，中科院一区论文5篇，二区论文7篇；单篇影响因子大于10的论文5篇。已申请中国发明专利10项，获授权发明专利5项，获广西自然科学一等奖一项（第五），培养博士毕业生3名，硕士毕业生7名。