连续胶黏剥离法制备石墨烯及其高分子原位复合材料的结构与性能研究

Graphene has been well investigated in term of their preparation ,among which the mechanical exfoliation technique has not been paying enough attention,possibly due to its difficulty and the insufficiency.As we all know, the graphene prepared from "Scotch tape,"which known as micromechnical exfoliation,has been proven to be the most structural perfection and best in properties,and has advantages in mechanical modification for polymer composites. For the purpose of seeking an effective method of graphene preparation, we try to set up a novel technique which based on the "Scotch tape" mechanism. Thus,a modified three-roll miller will be used cooperated with polymer adhesive in order to exfoliate the graphite flake.Polymer adhesive on the miller will tear off the carbon layers on the graphite flake,producing the graphene, with its strong stick force towards graphite surfaces via a assist of rolling.The resulted graphene may in situ blend with the polymer adhesive applied,producing the so-called polymer/graphene composites.The factors which effecting on the preparation of graphene,and the polymer/graphene composite will be investigated.The work will find out the dispersion situation of graphene in the polymer matrix.The relation between the structure and its properties , the mechanism for the mechanical modification such as reinforcement or toughen improvement of graphene on polymer composite will be intensively studied. The functional properties,such as their electrical and thermal conducting properties of the prepared composites will also be revealed.The results of the project will be very much helpful for the high-quality graphene preparation and their polymer composites with excellent mechanical or multifunctional properties.

机械剥离法制备石墨烯由于效率低，难于大量制备，因而其相关复合材料研究多年来进展缓慢。众所周知，机械剥离法石墨烯结构较完美，性能优良，其对高分子的增强、改性也将存在很多优势。因此，开辟高效的机械剥离法进行石墨烯的制备对于石墨烯复合材料的研究具有重要意义。本项目针对机械法石墨烯制备效率低的问题，以及石墨烯不易在聚合物基体中良好分散的传统问题，建立连续胶黏剥离制备石墨烯新方法，采用改进型三辊研磨机与高分子胶黏剂配合，利用高分子胶黏剂的撕裂力，实现对石墨层的连续剥离，并原位制备其复合材料。研究制备条件与影响因素；研究机械剥离法石墨烯在聚合物基体中的原位分散特征；揭示聚合物/石墨烯原位复合体系的结构与性能；揭示石墨烯对聚合物基体的增强、增韧规律并及其机制；研究聚合物/石墨烯原位复合材料的电学、热学等功能特性；为高效率制备高质量石墨烯以及高性能、多功能聚合物/石墨烯复合材料奠定理论基础。

化学法制备石墨烯效率高但存在环境污染问题；机械剥离法制备石墨烯质量好但不容易规模生产。本研究基于微机械胶带法制备石墨烯的原理，建立了连续胶黏剥离法制备高质量石墨烯。设计加工了合适参数的三辊剥离机，通过添加各种胶黏剂（包括高分子胶黏剂、蔗糖类胶黏剂等）以及鳞片石墨，利用胶黏剂的粘扯拉力，对鳞片石墨进行逐层剥离，制备石墨烯，石墨烯碳层数小于5层。当将聚合物作为剥离胶黏剂时，可原位剥离，制备聚合物/石墨烯复合材料，研究了剥离过程、剥离机理，复合材料的结构与性能，包括电学、热学等。. 项目根据微晶石墨中石墨晶片的尺寸仅为200-300 nm 这一特点，利用连续胶黏剥离法，成功地将微晶石墨剥离成小片径石墨烯。该法制备的石墨烯片径分布在100-200 nm，厚度小于5层。石墨烯产品具有荧光性质，制备的小片径石墨烯尺寸分布较均一，解决了现有制备方法存在的低效率、高能耗、高成本等问题。. 项目研究了在体系中添加聚乙烯吡咯烷酮（PVP），在机械剥离制备石墨烯的同时，原位将PVP修饰在石墨烯上，解决了石墨烯的二次团聚问题。所制备的石墨烯能方便分散于极性介质（如乙醇等）并形成稳定的分散体系。该工艺对于规模制备改性石墨烯以及石墨烯分散液具有很好的意义。. 石墨烯的表面改性是近年来石墨烯应用研究的关键。利用对氨基苯磺酸重氮盐功能化制备亲水性石墨烯，受到很多关注。但是一般这类反应，大多适用于氧化还原法石墨烯的改性。本项目尝试了对机械剥离法石墨烯进行改性。研究表明，利用辅助球磨技术，也能成功地将机械法石墨烯功能化，最终出制备亲水性磺化石墨烯。. 项目还开展利用电泳技术对机械剥离法石墨烯进行电泳分离，成功将不同片径的石墨烯分离开来，为石墨烯的应用奠定基础。. 项目结果分别在Journal of Physical Chemistry C、Electrochimica Acta、Advanced Engineering Materials等期刊发表论文18篇，项目组在国内外学术交流会共进行24 次的口头报告；培养研究生20余人,申请发明专利 18项(其中2 项授权），与7家国内相关企业合作，实现技术转让收入700万余元。