多维、多尺度聚合物基热电材料的构建及热电机理研究

In this project, polymer-based thermoelectric materials will be designed to improve power factor, the thermoelectric conversion mechanism and transport law of electrons and phonons in polymer thermoelectric material will be explored. This application is intended to use the zero-dimensional fullerenes, one-dimensional carbon nanotubes, two-dimensional graphene and three-dimensional graphite as a functional structure unit, to polymerize with a conjugated organic monomer having a specific structure can be designed, to manufacture a series thermoelectric materials which were polymer-based hybrid/ordered nanocomposite materials with multi-dimensional and multi-scale and short-rang ordered & long-rang disordered structure; The techniques of solid NMR, two-dimensional X-ray diffraction and pyroelectric spectroscopy will be used to characterize the molecular shape, molecular chain structure, texture, energy band gap of the polymer materials, the relationship between the dimensions, scale, crystalline and the thermoelectric properties of hybrid/nanocomposite materials will be researched systematically, The model of the relationship between material power factor and polymer molecular weight, molecular chain morphology, material morphology, dimensions scale and other parameters will be built, thereby establishing a method for the preparation of high performance polymer-based thermoelectric materials. Research projects will not only contribute to the development and application of new and efficient thermoelectric materials, theoretical research on polymer-based thermoelectric materials is also an important role in promoting.

旨在提高聚合物基热电材料的功率因子，探索高分子热电材料的热电转换和电子、声子的输运规律。本申请拟用零维的富勒烯、一维的碳纳米管、二维的石墨烯和三维的石墨作为功能性结构单元，进行功能化活化后与具有共轭结构和可设计功能基团的有机单体聚合，制备系列多维、多尺度、短程有序而长程无序的有序聚合物基纳米杂化/复合型热电材料；用固体核磁、二维X射线衍射、热释电谱等技术和手段对聚合物材料的分子形态、分子链结构、织态结构、能带带隙以及杂化/复合材料的维度、尺度、结晶性与热电功率因子之间的关系进行系统研究，建立聚合物分子量、分子链结构形态、材料形态形貌、维度、尺度等参数与材料功率因子的关系模型，探索相关的热电机理，进而建立一种具有高功率因子的聚合物基热电材料的制备方法。项目研究不但有助于新型高效热电材料的发展与应用，对聚合物基热电材料的理论研究也具有重要的促进作用。

热电材料是一类能通过塞贝克效应和帕尔贴效应实现热能和电能之间直接转换的功能材料。用热电材料制造的温差发电器和制冷器系统体积小、重量轻、无振动、无噪音、无磨损和泄漏而安全可靠、使用寿命长、对环境不产生污染，是人们追求的优质能源材料和先进的能源技术。目前只有Bi2Te3、PbTe、Si-Ge合金等无机半导体热电材料得到了一些实际应用。而高分子热电材料来源丰富、密度低、柔韧性好、热导率低、分子结构可设计，被认为是最有前途的热电材料。.本项目用碳纳米材料（零维的碳量子点和富勒烯、一维的碳纳米管、二维的石墨烯及纳米带）为功能性结构单元，与聚合物单体通过原位聚合以及纳米复合的方式合成了短程有序-长程无序的聚合物基有序纳米杂化/复合材料。系统研究碳粒子维数、尺度、聚合物单体结构以及所形成的杂化/复合材料的分子形态、链结构等与材料热电性能的关系和基本规律。研究发现聚吡咯/石墨烯/聚苯胺三元复合体系的功率因子PF可以达到52.5μWm−1 K−2，是纯聚合物的千倍以上。纳米管形态的聚吡咯/聚苯胺复合物的热电功率因子达到 0.74μWm-1.K-2，高于单一的聚合物纳米管。多巴胺（DA）可以在导电高分子链与碳纳米材料之间建立一种共价键的连接，增加电子迁移率，同时保持较低的热导率，提高聚合物复合材料的热电性质。800℃高温处理后，碳化聚多巴胺-碳复合材料的塞贝克系数转为负值，可以达到-30.2 μV K-1，功率因子PF达35.57 µW m-1 K-2。用未碳化的多元复合材料GNS/PDA/PANi做P型端，碳化的碳纳米管-聚多巴胺复合体系c-CNT/PDA为N型端，构造了24对P-N结，在60℃温差下产生了52.8mV的开路电压 ，同时聚合物复合材料还保持相当的柔性，这为用聚合物基热电材料制作柔性温差发电器带来了希望，也指明了方向。