Ammonia solution strengthened three-dimensional macro-porous graphene aerogel
Ammonia solution strengthened three-dimensional macro-porous graphene aerogel
复制标题
氨溶液增强三维大孔石墨烯气凝胶
DOI：
10.1039/c3nr00971h
复制
发表时间：
2013-01-01
期刊：
影响因子：
6.7
通讯作者：
Yang, Junhe
中科院分区：
文献类型：
--
作者：
Han, Zhuo;Tang, Zhihong;Yang, Junhe
最近，许多方法被应用于将石墨烯薄片组装成三维结构。然而，干燥后获得具有高机械强度的三维大孔石墨烯网络仍然是一个巨大的挑战。在此基础上，制备了氨气增强的三维石墨烯气凝胶。基于石墨烯化学和冰物理原理，石墨烯水凝胶在常温下经氨水处理后，其机械强度有了较大的提高。结果表明，在没有氨水处理的情况下，石墨烯气凝胶的三维结构被彻底破坏，而90℃氨水处理1h后，石墨烯气凝胶的三维结构保持不变，静载荷下的抗压强度提高到152kPa.这是由于氨水溶液的凝固点低，有效地延缓了石墨烯气凝胶的冻结，从而保持了石墨烯气凝胶的孔结构不被破坏；(2)氨水与石墨烯水凝胶发生反应，在石墨烯薄膜之间形成了一定的共价键.我们相信，我们的努力将为三维石墨烯材料的开发和应用铺平道路。
Recently, many approaches were applied for assembling graphene sheets into a three-dimensional structure. However, it is still a great challenge to obtain a three-dimensional macroporous graphene network with high mechanical strength after drying. Herein, an ammonia strengthened three-dimensional graphene aerogel was prepared. Based on graphene chemistry and ice physics, the mechanical strength of graphene aerogel was improved greatly when the graphene hydrogel was treated by ammonia solution at an ambient temperature. The results demonstrated that the three-dimensional structure of graphene aerogels was destroyed thoroughly without ammonia solution treatment; conversely, the three-dimensional structure was maintained and the compressive strength was improved to 152 kPa at the static load after it was treated by ammonia solution at 90 degrees C for only 1 h. This phenomenon is due to two reasons: (1) the low freezing point of ammonia solution, which effectively retarded its freezing and then kept the porous structure undestroyed; (2) the reaction between ammonia and graphene hydrogel, which brought some covalent bonds among graphene sheets. We believe our efforts may pave the way for the development and application of three-dimensional graphene based materials.