通过氧化还原法合成石墨烯，结合1-萘甲酸的双极性作用防止石墨烯发生自团聚，得到稳定的胶体分散液。通过分析拉曼光谱的特征峰确定了氧化石墨烯的还原程度；利用 TEM观察到了单层、双层以及多层的石墨烯。通过测试分散液的 zeta 电位、粒径以及丁达尔效应，参照胶体的经典稳定理论-DLVO 理论，阐述了石墨烯分散液稳定存在的原因和机理，并进一步通过蒸发溶胶合成了自组装无基底的石墨烯薄膜。各项结果表明，利用该法合成的石墨烯分散液具有大量稳定存在的单层石墨烯，是当前石墨烯基微纳器件所需的优良前驱体。为液相化学法制备石墨烯提供了理论支撑，为石墨烯的后续应用开辟了新的途径。%A stable graphene colloidal dispersion was synthesized through redox method.During the process,1-naphthoic acid,with its amphiphilic nature,was added for the prevention on graphene’s self-aggregation.Ra-man spectroscopy was used to confirm the reduction degree of graphene oxide by analyzing the characteristic peaks.Monolayer,bilayer and multilayer graphene sheets were observed under the transmission electron micro-scope (TEM).After the testing of zeta potential,average particle sizes and the Tyndall effect,according to the classical Derj aguin-Landau-Verwey-Overbeek theory,we elucidated the reason and mechanism why graphene colloidal dispersions existed stably and further produced the self-assembled free-standing graphene membrane by evaporating the hydrogel.All the results have demonstrated the as-prepared graphene dispersions have abun-dant stably-existed monolayer graphene,which played an important role as the excellent precursor of current graphene-based micro-nano devices.By pointing out this idea,we may provide theoretical support for the solu-tion-based method on graphene’s synthesis and find a new route for further application of graphene.
展开▼
