Pickering乳液模板法对石墨烯/聚苯胺空心微球的高效构筑和电化学性能调控研究

Graphene-polyaniline hollow spheres, possessing high specific areas, well-defined hollow structure with thin shell, could enhance the electrode/electrolyte interface area, reduce the transport length for both charge and ion, which render them interesting candidates for high performance supercapacitor electrode materials. However, it still remains a great challenge to develop a simple and efficient strategy to fabricate graphene-polyaniline hollow spheres. And the control of the hollow structure and tunability of electrochemical properties for the graphene-polyaniline hollow spheres needs a systematic and in-depth study. This project proposes a novel strategy to fabricate hollow-structured graphene-polyaniline spheres via Pickering emulsion polymerization. Graphene with proper amphiphilicity is first synthesized via modification of graphene and used as Pickering stabilizer to stabilize an oil phase containing aniline. Upon aniline polymerization at the oil/water interface and the removal of oil phase, a series of graphene-polyaniline hollow spheres could be generated. The influence of the graphene structure and emulsion conditions as well as the interaction between graphene and aniline monomer on the structure and electrochemical properties of the obtained graphene-polyaniline hollow spheres will be systematically investigated. The formation mechanism and the structure-electrochemical performance relationship of the graphene-polyaniline hollow spheres will be clarified. The application of the as-prepared hollow-structured graphene-polyaniline spheres for high performance supercapacitor electrode will be investigated.

石墨烯/聚苯胺空心微球具有高的表面积、规整的空心结构和薄的壳层，可提供增强的电极/电解液界面区域，减少电子/离子扩散距离，成为高性能超级电容器电极的关键材料。但目前还缺少高效快捷的石墨烯/聚苯胺空心微球制备方法，且对其结构的可设计性和性能的可调控性还有待系统深入的研究。本项目提出基于Pickering乳液模板法来实现石墨烯/聚苯胺空心微球的高效构筑和性能调控。拟通过对石墨烯进行改性使其具有适当的润湿性，以改性石墨烯作为Pickering乳化剂来稳定含有苯胺的油相，通过苯胺在乳液滴的界面聚合来构筑一系列石墨烯/聚苯胺复合空心微球。系统研究石墨烯结构、乳化条件、石墨烯与苯胺间的相互作用等因素对所构筑石墨烯/聚苯胺空心微球的结构及电化学性能的影响，阐明石墨烯/聚苯胺空心微球的形成机理，建立复合空心微球结构与电化学性能之间的构效关系，实现对空心微球结构与性能的调控，进而探索其在电荷存储方面的应用。

本项目通过对石墨烯进行表面改性得到一系列具有适当润湿性的改性石墨烯，以其为Pickering乳化剂来稳定含有苯胺的油相，引发苯胺在油水界面聚合实现了一系列具有独特空心结构石墨烯/聚苯胺微球的构筑。研究了石墨烯结构、乳化条件、石墨烯与苯胺之间的相互作用等因素对所构筑石墨烯/聚苯胺空心微球的结构和电化学性能的影响，实现了高性能石墨烯-聚苯胺超级电容器电极材料的构筑。此外，利用其空心结构用于负载自修复剂和腐蚀抑制剂，利用聚苯胺与石墨烯本身的独特性能以及所负载物质之间的协同效应，拓展了其在智能防腐涂层方面的应用。研究结果如下：.1.磺化石墨烯/聚苯胺空心微球的制备及在超级电容器中的应用。直接以磺化石墨烯（GSA）作为Pickering乳化剂稳定含有苯胺单体的油相，引发苯胺在油水界面发生聚合得到石墨烯/聚苯胺空心微球。GSA/PANI HS的比电容最大可达545.85F/g，相比于二维GSA/PANI提高了131.2%。在电流密度由0.5A/g增加至8.0A/g时，空心微球的电容保持率高达83.5%。.2.离子液体修饰石墨烯/聚苯胺空心微球的制备及在超级电容器中的应用。以离子液体修饰石墨烯为Pickering乳化剂稳定含有苯胺的油相，引发苯胺聚合得到石墨烯/聚苯胺空心微球（rGO-IL/PANI HS）。离子液体一方面能够调节石墨烯的润湿性，另一方面保持石墨烯良好的导电性。rGO-IL/PANI HS比电容为451.75F/g，电容保持率为92.4%。.3.二氧化锰/石墨烯/聚苯胺三元空心微球的制备及在超级电容器中的应用。通过原位氧化还原法制备了二氧化锰修饰石墨烯（MnO2/GR），以MnO2/GR作为Pickering乳化剂稳定含有苯胺的油相，引发苯胺聚合得到MnO2/GR@PANI三元空心微球。MnO2/GR@PANI比电容可达743.8F/g，经过2000次循环后空心微球仍然保持了初始比电容的93%。.4.多功能石墨烯/聚苯胺空心微球的构筑及在防腐涂层中的应用。以氧化石墨烯作为Pickering乳化剂稳定含有苯胺和功能试剂（自修复剂、腐蚀抑制剂）的油相，引发苯胺聚合得到负载有功能试剂的聚苯胺/石墨烯微球。将该微球加入到水性环氧涂层中能够赋予涂层优异的防腐蚀与自修复功能，延长涂层的服役寿命和维护周期。