石墨烯/聚合物相变储热微胶囊复合材料的制备及其热性能研究

Development and application of phase change thermal storage microcapsules play an important role in storing and efficient using of energy. Aiming at such shortcomings of polymeric microcapsules containing phase change material as poor thermal conductivity and low rate of heat storage or release, the project proposes an innovative plan of introducing graphene with high thermal conductivity and super large specific surface area into the polymeric shell material and the phase change core material of the microcapsules, building up the heat transmission path of graphene in the inner and outer of microcapsules, to improve their heat transfer performance and exert their thermal energy storage effect. The graphene can be prepared by using oxidation reduction method and then can be combined with polymer and phase change material to prepare composite shell and core material, respectively. Finally, the graphene/phase change thermal storage microcapsule composite material can be synthesized via in situ polymerization. The project intent to explore the method and its key factors for preparing graphene -based composite material, and study the relationship between the properties and structure of graphene -based composite material. The technical method for controlling the properties and structure of composite microcapsules will be also studied. According to the experiment research on the heat transfer and storage performance of microcapsule, the relationship between the microstructure and distribution of graphene in the microcapsule and its thermal properties will be discussed, to obtain the key influencing factors and ascertain the heat transfer mechanism of graphene -based composite material, promoting the coordinate development of composite material technology and phase change thermal storage technology.

相变储热微胶囊的研制和应用对于实现能量的存储和高效利用有着重要的作用，本项目针对聚合物相变储热微胶囊导热系数较低、储放热速率慢的问题，提出将具有较高导热系数、超大比表面积的石墨烯引入到胶囊的聚合物壁材和相变芯材中，在胶囊内外层构筑起石墨烯的导热通道，来进一步提升相变储热微胶囊的传热性能，并充分发挥其储热功能的创新方案。通过氧化还原法制备出石墨烯，然后分别与聚合物和相变材料进行复合，最后通过原位聚合法制备出石墨烯/相变储热微胶囊复合材料，弄清石墨烯基复合材料的制备方法和关键因素，探明其结构与性能的关系，掌握调控复合微胶囊结构与性能的技术手段，并基于胶囊传热、储热性能的实验研究，分析微胶囊中石墨烯的微结构、分布状态与胶囊传热、储热性能之间的关系，揭示影响相变储热胶囊热性能的关键因素，探明石墨烯基复合材料的传热机理，促进复合材料技术与相变储热技术的协同发展。

相变微胶囊有助于实现能量的存储和清洁能源的开发，本项目针对聚合物相变储热微胶囊导热差、储放热速率慢的问题，提出将石墨烯引入到聚合物胶囊中，提高胶囊的导热性能，并充分发挥其储热功能。通过氧化还原法制备出石墨烯，然后分别与聚合物和相变材料十二醇进行复合，当GO添加量为0.84 wt%时，复合材料导热系数增加32.0%。通过原位聚合法制备出以GO/密胺树脂为壁材，以正十二醇为芯材的相变储热微胶囊。GO的添加不会改变微胶囊化学结构，所制备的微胶囊具有较好的球形状态，含1wt%GO的微胶囊综合性能较好，其相变温度和相变潜热分别为26.04℃和125.2J/g，导热系数比未添加GO的胶囊增加50.21%。当GO添加量为4wt%时，微胶囊导热系数可提高66.29%。通过控制制备工艺，制备出一系列不同氧化程度的石墨烯并引入到胶囊中，发现石墨烯氧化程度越小，相变微胶囊的导热系数提高最多。随着GO添加量的增加，胶囊导热系数增加，且当GO添加量为0.5wt%时，胶囊导热系数提升最多，可提高115%。项目最终制备出表面光滑的球状核壳结构的微胶囊，其相变焓在170J/g左右，且相变循环稳定性较好。将自制的相变储热微胶囊添加至水泥砂浆板中，制备出具有良好调温性能和储热性能的相变储热水泥砂浆板。相关工作将促进材料学科和能源学科的交叉，推动复合材料技术与相变储热技术的协同发展。