海藻酸钠/羟丙基甲基纤维素/氧化石墨烯复合气凝胶的制备及性能评价

Preparation of Sodium Alginate/Hydroxypropyl Methylcellulose/Graphene Oxide Composite Aerogels and Evaluation of Adsorption Properties

以海藻酸钠和羟丙基甲基纤维素等天然高分子化合物为原材料,通过引入氧化石墨烯,采用原位凝胶化方法制备了海藻酸钠/羟丙基甲基纤维素/氧化石墨烯新型气凝胶材料。研究结果表明,制备的气凝胶具有均匀多孔的空间结构,而且继承了氧化石墨烯材料典型的分层结构; XRD分析表明氧化石墨烯以氢键连接的方式均匀地分散在海藻酸钠体系中;以重金属Cu2+的吸附量为指标,气凝胶对铜离子的吸附量先急剧增加后趋于平衡;通过对经验方程的拟合分析,气凝胶对Cu2+吸附更遵循Freundlich吸附过程和准二级动力学模型,属于化学吸附。

Sodium alginate and hydroxypropyl methyl cellulose were used for the preparation of aerogels by introducing graphene oxide. The composite aerogel materials of sodium alginate/hydroxypropyl methylcellulose/ graphene oxide were prepared by in-situ gelation method. The results showed that the aerogels possessed the uniform porous structure and also inherited the hierarchical structure of graphene molecule. It was noted that there was no characteristic diffraction peaks of graphene found in XRD spectra of composite materials, which proved that graphene were uniformly dispersed in the alginate system by hydrogen bonds. The adsorption capacity of heavy metal Cu^2＋ was taken as index. The copper ion adsorption quantity increased sharply first and then reached equilibrium. By fitting the empirical equation, the adsorption behavior of Cu^2＋ was more belonged to the chemical adsorption of Freundlich adsorption process and pseudo-second-order kinetic model.