聚乙二醇/多巴胺仿生改性介孔硅定形相变材料的制备及其储热特性调控

To solve the problems of complicated technology, high cost and environmental contamination risk existing in the typical method of synthesizing mesoporous silica, a novel strategy using plant polyphenols as templates will be applied to synthesize mesoporous silica, which will be used as the support of polyethylene glycol (PEG) for producing shape-stabilized phase change materials (PEG/SiO2). The pore size and structure of the mesoporous silica will be optimized, and the dopamine will be grafted onto the surface of the silica via a biomimetic coating to improve the heat storage properties and phase change performance of the PEG/SiO2. More specifically: (1) the mesoporous silica using plant polyphenols as templates will be synthesized, and the pore size and structure of the silica will be regulated and optimized through controlling the synthesis conditions; (2) dopamine-functionalized mesoporous silica will be synthesized as a novel support of PEG, and the mechanism of modification will be elucidated. Additionally, the synthesis conditions will be optimized; (3) the novel support synthesized in this project will be used to adsorb PEG for the preparation of shape-stabilized phase change materials, and its heat storage properties will be regulated. The relationship between the structure and performance will be clarified, and the phase change mechanism will be revealed. Moreover, the technologies and methods that are used to prepare novel shape-stabilized phase change materials with excellent properties will be obtained. The research results of this project will not only provide a simple and environment-friendly method to synthesize mesoporous silica, but also offer novel methods and supports for the shape stabilization of PEG. Furthermore, the study achievements will be beneficial to the development of the basic theory of shape-stabilized phase change materials preparation using mesoporous silica as supports, and promote the practical applications of techniques used for the shape stabilization of phase change materials.

针对介孔硅固定聚乙二醇（PEG）制备定形相变材料（PEG/SiO2）过程中，介孔硅合成工艺复杂、成本高、易污染等问题，提出以植物多酚为模板剂合成新型介孔硅的思路；为提高PEG/SiO2的相变性能，提出优化载体孔径尺寸和孔道微环境，并利用多巴胺仿生改性介孔硅，调控相变材料储热特性的思路。具体研究如下：（1）以植物多酚为模板剂制备新型介孔硅，通过调节合成条件对孔径和孔道微环境进行调控与优化，实现该介孔硅可控制备；（2）利用多巴胺改性介孔硅合成新型相变材料载体，优化改性条件，阐明改性机理；（3）利用该载体固定PEG制备新型定形相变材料，调控其储热特性，揭示储热构效关系和相变机理，获得制备新型高效定形相变材料的技术与方法。本项目研究成果不仅为新型介孔硅的可控制备提供了一条简便绿色的途径，还为PEG定形提供了新的载体与方法，有利于介孔硅基相变材料基础理论的阐述与发展，促进相变材料定形技术的实际应用。

以新型多孔材料为载体的定形相变材料设计制备是储能材料领域的研究热点之一。本项目针对介孔硅固定有机相变材料制备定形相变材料过程中，介孔硅合成工艺复杂、成本高、易污染等问题，利用鞣酸为模板剂合成介孔氧化硅载体，研究结果表明，鞣酸为模板制备介孔硅只需水洗即可去除模板，具有操作简单、绿色环保等优势；为提高定形相变材料的储热性能，利用多巴胺对载体进行仿生改性，调控相变材料的储热特性，研究结果表明，多巴胺仿生改性能够改善有机相变材料分子的结晶行为，提高相变焓；为提高定形相变材料的导热率，利用多孔碳吸附金属离子后通过原位还原在多孔碳表面形成金属微球，进而以其为载体制备定形相变材料，研究结果表明，原位还原法制备金属微球有效提高了定形相变材料的储热性能，并且该方法具有操作简单、成本低等优点；为降低定形相变材料的成本，利用杏仁壳、枣核、松果等农林废弃物为原材料制备生物碳，并以其为载体制备定形相变材料，研究结果表明，生物炭能够有效防止有机相变材料使用过程中发生泄漏，并能够显著提高其导热率，此外，生物炭为载体制备定形相变材料能够实现农林废弃物的再利用。本项目属于新型材料制备、仿生改性、工程热物理等交叉学科的研究，研究成果不仅为定形相变材料储热性能调控提供了一条简便绿色的途径，还为有机相变材料的定形提供了新的载体与方法，有利于以多孔材料为载体制备定形相变材料基础理论的阐述与发展，促进相变材料定形技术在实际生产中的应用。