PEDOT:PSS/碳纳米管/石墨烯量子点复合有序纳米纤维阵列的制备及热电性能

Power generation of plenty of waste heat is one of the most effective ways to solve the fossil energy crisis. At present, thermoelectric materials based on mature inorganic semiconductor, holding some defects with high cost, heavy metal pollution and poor processing, restrict the wide application in the field of waste heat power generation. Organic polymer becomes promising thermoelectric materials due to low cost, environment friendly and processability. However, how to realize the improvement of electrical conductivity and Seebeck coefficient simultaneously is the key scientific issues for organic thermoelectric materials. In the proposal, zero-dimensional graphene quantum dot and one-dimensional carbon nanotubes will be added into conductive polymer. And aligned nanofiber array will be prepared via electrospinning conductive polymer mixed solution with the assistant of magnetic field inducing and collection tube high-speed rotating. We will investigate the effects of relative content, total mass fraction, and distribution mode of graphene quantum dots and carbon nanotubes on the thermoelectric properties, and study the effects of nanofibers' size and arrangement. The relationship will be established between structure and thermoelectric properties. And preparation process will be optimized for high performance of conducting polymer based thermoelectric materials. The research will not only clarify the enhancement mechanism of organic thermoelectric materials with the synergistic effect of carbon nanotubes and graphene quantum dots and the alignment distribution of nanofibers, but provide a new way for researching and developing high performance conducting polymer thermoelectric materials.

利用地球上大量的废余热发电将会是缓解石化能源危机的有效方式之一。目前较成熟的无机半导体热电材料高成本、重金属污染、加工性差等问题制约着废余热发电的广泛应用。导电高分子以其低成本、环境友好、可加工性成为潜在的热电应用材料，但如何实现导电高分子的电导率和Seebeck系数同时提高，成为有机热电材料研究的关键科学问题。本项目将零维石墨烯量子点与一维碳纳米管一起复合到导电高分子中，采用磁场辅助与收集筒高速旋转相结合的方式制备有序纳米纤维阵列。研究石墨烯量子点与碳纳米管的相对含量、总质量分数及在基体中的分布情况对热电性能的影响，研究纳米纤维尺寸及排列方式对热电性能的影响，建立多重低维纳米结构与热电性能之间的关系，筛选出高性能导电高分子热电材料的制备工艺。本研究不仅能阐明碳纳米管与石墨烯量子点的协同作用及纳米纤维的有序排布对热电性能的增强机制，而且能为高性能的导电高分子热电材料研究和开发提供新的途径。

采用强氧化还原切割方法，将氧化石墨烯（GO）裁剪成石墨烯量子点（GQDs），然后将GQDs和单壁碳纳米管（SWNTs）共混，利用GQDs的π键和SWNTs的π键共轭作用，将SWNTs分散到水中或其他极性溶剂中，然后将分散好的GQD/SWNTs分散到PEDOT：PSS导电高分子中，通过溶液浇铸和静电纺丝的方法，制备复合膜。系统的研究了复合膜的组成、微结构、电导率、塞贝克系数和功率因子。由于GQDs与PEDOT：PSS中PEDOT的π-π共轭作用及与PSS的亲水性作用，GQDs在复合材料界面上具有能量过滤效应，极大地改善了导电高分子膜的塞贝克系数；同时，SWNTs的高电导率改善了基体的导电率。而静电纺丝加工方法通过电场作用将高分子链有序堆积，同时使高分子纤维有序排列，对复合膜的电导率和塞贝克系数均有极大的改善作用。本项目为高性能热电材料的研究和开发提供了新的方法和理论基础。完成了计划书中所列的计划内容。