基于化学气泡解理法高产率制备高质量、横向尺寸可控的石墨烯片层

High crystal quality and appropriate lateral size are key factors in improving the application performance of graphene sheets. Aimed at the large-scale application prospects of high-quality graphene sheets and the different requirements for various applications on the lateral size, the main research objective of this project is to prepare high-quality and size-controllable graphene sheets in high yield, focusing on solving the problem of the existing techniques that high yield is not compatible with high quality and lateral size control. Chemical-bubble-driven cleavage will be utilized to prepare high-quality graphene sheets in this project. Microstructure evolution processes (cleaving pathways) of the cleaved products under various cleaving conditions are systematically investigated to reveal the mechanism of lateral sheet fragmentation during longitudinal cleaving, based on which the desirable pathway (deep cleavage yet no/less fragmentation) will be made clear along with the corresponding control method; the ultimate yields is correlated with the solvation-stabilization conditions of the cleaved products to elucidate the solvation processes and stabilization mechanism in the bubble cleaving system, based on with solvation-stabilization method is optimized; starting from raw graphite of different sizes, kinetic regulation of the bubble cleaving pathway is combined with the solvation stabilization of the cleaved products to establish the method for improving the yield and regulating the lateral size. This project will lay a theoretical and technical foundation for the property investigation and large-scale application of high-quality graphene sheets.

高晶格质量和合适的横向尺寸是提升石墨烯片层应用性能的关键因素，本项目瞄准高质量石墨烯片层的规模化应用前景和不同应用对横向尺寸的差异化需求，以高产率制备高质量、横向尺寸可控的石墨烯片层为主要研究目标，重点解决现有制备技术无法兼容高产率、高质量和横向尺寸调控的难题。本项目拟采用化学气泡解理法制备高质量石墨烯片层，通过系统研究不同解理条件下解理产物微结构的演变规律（解理路径），揭示纵向解理过程中片层横向碎裂的机理，明确深度解理和无/少碎裂的路径及其调控方法；构建解理产物的溶剂化稳定条件与产率的关系，阐明气泡解理体系中的溶剂化过程和片层稳定机理，优化溶剂化稳定方法；最终从不同尺寸的石墨原料出发，结合气泡解理动力学路径的调控和解理产物的溶剂化稳定，建立提升产率和调控横向尺寸的方法。本项目将为高质量石墨烯片层的物性研究及规模化应用奠定理论和技术基础。

本项目主要研究和解决石墨层状结构解理过程中的尺寸调控问题，通过控制化学反应体系和反应过程调控气泡及其与石墨的相互作用，促进石墨片层纵向剥离的同时限制石墨片层横向碎裂，以期实现不同尺寸高质量石墨烯材料的高效制备。通过提出多种原创气泡调控策略，综合考虑制备可控性和效率，结合机械分散或氧化修饰等溶剂化手段稳定分散石墨烯片层，形成石墨解理路径调控的系统方法并阐释相关机理，最终高效制备出常规方法难以获得的大尺寸高质量石墨烯材料，平均横向尺寸在亚微米至几百微米范围可控，电导率最高达到2.1×105 Sm-1，产率达到大于95 wt.%。同时，利用不同尺寸的石墨烯材料设计并构建新型石墨烯基复合膜结构，分别研制出高性能石墨烯导热膜、痕量分子低检出限探测衬底、柔性应变传感器和柔性肖特基结直流纳米发电机等器件，基于器件工作机理分析和结构优化实现器件性能突破。依托本项目的研究成果，在Advanced Materials、Advanced Functional Materials、Nano Energy、Chemical Engineering Journal、Small、Chemistry of Materials等期刊发表18篇论文，申请发明专利7项（其中1项已授权、1项为PCT专利、2项为国外专利），部分研究成果已成功应用于华为委托技术开发项目并形成华为认可的应用技术。项目执行期间，共培养博士研究生5人、硕士研究生6人。本项目基本按计划执行，基于气泡解理有效调控策略较好地解决了石墨烯可控制备问题，顺利完成项目目标，形成的多项石墨烯材料制备技术有望促进石墨烯粉体材料的规模化应用，研制的多个新型石墨烯复合膜结构将为石墨烯基器件的性能提升和应用提供新思路。