石墨烯/高分子自组装复合薄膜的可控制备及其光学气敏性能研究

Graphene has been demonstrated to be a promising gas sensing material because of its unique two-dimensional nanostructure, extremely high carrier mobility and large surface area. However, the electrochemical test dependent output, difficulty in morphology control and poor selectivity limits are essentially required to be solved. This project proposes to fabricate graphene/polymer hybrid thin films by alternating assemble single-layer graphene with linear polymer molecules. The sequential assembly is realized through spin-coating assisted layer-by-layer self-assembly with π-π, hydrogen bonds or static interactions as driving forces. Three hybrids named as graphene oxide/poly(styrene sulfonate), reduced graphene oxide/polyaniline and graphene oxide/poly(vinyl alcohol) will be prepared. By modulating compositions, number of layers and packing interactions, the relations in-between interference colors could be concluded. The results will enrich optical theory of graphene materials. Finally, a series of visualized arrays based on thin film interference will be fabricated and the gas sensing properties toward nitrogen dioxide, toluene and alcohol will also be studied from both experimental and theoretical simulation view. The expected results will reveal the response mechanisms between thin films and gas molecules, providing experimental basis to develop new graphene based optical sensing materials.

石墨烯具有独特的二维纳米结构、高的载流子迁移率和大的比表面积，成为最有应用前景的气敏材料之一，但材料本身存在依赖于电化学信号输出、易聚集、检测选择性差等问题亟待解决。项目提出将石墨烯片状分子和线型高分子进行单分子层交替复合制备石墨烯/高分子复合薄膜的新概念。以石墨烯与线性高分子之间的静电力、π-π作用或氢键为驱动力，采用层层自组装原理，设计制备三种复合膜：氧化石墨烯/聚苯乙烯磺酸钠、还原氧化石墨烯/聚苯胺和氧化石墨烯/聚乙烯醇。探索旋涂辅助层层自组装法制备复合膜的优化条件，并对其结构进行表征；研究复合膜组成、分子层数和堆积方式等结构因素与其干涉光性能的相关性，将丰富石墨烯光学性质的理论内容。设计构筑基于薄膜干涉的可视化气体传感器件，从实验和模拟计算角度研究二氧化氮、甲苯和乙醇等有机小分子对复合膜的插层作用及其干涉光响应规律，为开发新型石墨烯光学探针材料提供实验依据。

本项目面向痕量气体目标物快速可视化检测的需求，利用石墨烯和功能高分子独特的结构特点，将氧化石墨烯和线型高分子进行层层交替复合制备石墨烯/高分子复合光学传感薄膜，很好的克服了传统石墨烯基气敏材料易聚集，传感依赖于电化学信号输出和检测选择性差等难题，实现了痕量气体的快速可视化分析。主要研究成果如下：（1）发展一种新的光学传感体系，通过SA-LbL 可控制备具有可视化色彩的石墨烯/高分子复合薄膜，调控、优化组装条件，探索了石墨烯/高分子复合材料的结构与性能的关系，揭示了薄膜颜色与厚度、涂膜速度、组分、衬底之间的关系；（2）探索了几种基于薄膜干涉的可视化气体的响应性，从实验和模拟计算角度研究了二氧化氮、水和乙醇等小分子对复合膜的插层作用及其干涉光响应规律，并利用其实现痕量目标气体的快速检测，建立基于石墨烯复合薄膜干涉的可视化检测方法；（3）探索了石墨烯衍生物与高分子间的表面和界面作用，有针对性地考察其在可穿戴性、自愈合性等方向的应用。本项目共发表论文9篇，申请国家发明专利1项，授权1项。