层层组装石墨烯/导电聚苯胺及其衍生物复合热电薄膜材料

Current, it is of important significance in theory and real sense to study the performance of thermoelectric thin-film material for the effective utilization and conversion of energy. The main objective of this project to construct a layered graphene/conducting polyaniline and its derivatives composite thermoelectric thin-film material by layer-by-layer (LBL) assembled technique, using graphene and conducting polymer based on their strong interactions. Graphene, a kind of zero-gap and two-dimensional (2D) material, possesses many unique features and outstanding electronic properties such as thinness, mechanical strength, flexibility and high carrier mobility. Meanwhile, conducting polymer has several advantages such as synthetic tailorability, cost, processability, and low thermal conductivity that make it ideal candidate for composite with graphene. The project design desires to adhere to the high conductivity, high carrier mobility and excellent environmental stability of graphene and the unique electronic structure and low thermal conductivity. In order to achieve an effective complementary and enhancement for the thermoelectric performance of composite thin-film, a series of work need to be done such as optimizing the prepared conditions of graphene/conducting polyaniline and its derivatives composite, adjusting the relative thickness of the conducting polyaniline and its derivatives, the molecular structure and doping degree. Additionally, special attentions will be paid to the study on the interactions between graphene and conducting polyaniline and its derivatives, and the ways to improve the thermoelectric properties of conducting polyaniline and its derivatives molecule struture, as well as to develop a new method for high performance composite thin-film thermoelectric materials. Accomplishment of this project will provide valuable theoretic foundation and experimental support for the development of novel composite thin-film thermoelectric materials.

基于热电薄膜材料在能源的有效利用和转换研究中具有重要的理论和实际意义，本项目旨在以石墨烯和导电聚苯胺及其衍生物为主体材料，利用石墨烯与导电聚合物之间较强的共轭相互作用和静电引力作用，通过层层组装(LBL)技术，构建层状结构的石墨烯/导电聚合物复合薄膜热电材料。该实验方案设计冀望石墨烯/导电聚合物复合材料能秉承石墨烯的高电导性、高载流子迁移率和良好的环境稳定性，以及导电聚合物独特的电子结构和较低的热导率等优点，使石墨烯和导电聚合物之间形成有效互补。通过优化复合条件，调节导电聚合物的相对厚度、分子结构和掺杂度等，进而实现石墨烯/导电聚合物复合薄膜电子输运性能的变化。同时，研究石墨烯与导电聚合物之间的作用力对薄膜材料组装的影响，探索提高热电性能的导电聚合物分子结构和关键因素，为构筑和研究高性能无机非金属复合热电薄膜材料提供理论指导和实验支持。

本项目申请目的是以石墨烯和导电高分子聚苯胺及其衍生物为研究重点，采用层层组装的方式制备复合薄膜，实现石墨烯与导电聚合物苯胺及其衍生物的有效结合，并通过定量掺杂探索掺杂度对复合薄膜电子传输性能的影响。为复合材料的深入研究提供一定的科学依据。三年预期目标为：获得独立知识产权的成果，预计发表相关的高质量SCI研究论文3～5篇(影响因子>3.0)，申请国家发明专利1～2项，协助培养研究生2～3名，大学生1～2名，参加国际、国内相关学术会议3～4次。从项目的运行情况来看，虽然未能按原计划进行，但是在实验过程中及时发现了问题，改进了实验方案，达到了预期目标，并超额完成任务。首先，利用改进的Hummers方法制备了GO，然后分别采用酰氯化和末端氨基化反应制备了胺封端的rGO（GO-NH2），并利用原位复合方法成功制备了PANI接枝的rGO，实现了rGO和PANI的有效复合，有效的提高了rGO的电导率和功率因子，并对掺杂度对复合薄膜热电性能影响进行了系统的研究；同时，我们还发现二维石墨烯材料能够明显提高有机导电高分子PEDOT:PSS的Seebeck系数，并实现热电性能的新突破。基于以上发现，我们还制备了其他的一些二维类石墨烯材料（MoS2，WS2，MoSe2，BN）和一维纳米材料（Te、Bi2Te3，SiC）与PEDOT:PSS的纳米热电复合薄膜，并对其热电性能进行了系统的研究，均取得了重大进展；基于制备的薄膜，组装了薄膜热电器件，展现了较好的输出功率密度，推动了薄膜材料和器件的发展；在前期工作的基础上，总结了PEDOT在热电领域的发展历程和影响PEDOT:PSS热电性能的因素，形成了在该领域具有指导意义的综述论文。在基金资助下，2015-2017年共计发表SCI论文26篇（其中影响因子大于6.0的4篇，大于3.0的16篇，封面论文1篇），EI论文1篇，申请专利7项，参加国际学术会议7次。这些成果不仅探讨了掺杂度和无机非金属材料对导电高分子热电性能的影响，也为纳米复合薄膜热电材料的应用奠定了一定的基础。