氧化石墨烯/聚甲基丙烯酸二甲氨基乙酯复合凝胶的制备及其性能研究

Preparation of Graphene Oxide/Poly(Dimethylaminoethyl Methacrylate) Composite Gels and Study of Their Properties

摘要: 采用原位聚合制备了一系列氧化石墨烯/聚甲基丙烯酸二甲氨基乙酯复合凝胶(G_mPBG)。研究了GO分散液的浓度对复合凝胶形成及形貌的影响，进一步研究了G_mPBG的溶胀性能和CO₂的吸附性能。结果表明，G_mPBG复合凝胶的宏观形成，微观分析以及性能与GO分散液浓度有很大的关联性。G_mPBG是pH和温度双响应的复合凝胶，在酸性条件下高分子中的叔胺基质子化，静电排斥力增加高分子链扩展，使溶胀率显著增加。G_mPBG存在LCST，表现为温度响应。此外，G_mPBG对CO₂的吸附主要归因于GO表面众多的含氧官能团以及PDMAEMA上的叔胺基，为吸附CO₂提供了化学活性位点。

Abstract: A series of graphene oxide/poly(dimethylaminoethyl methacrylate) composite gels (G_mPBG) were prepared by in situ polymerization. The effects of the concentration of GO dispersion on the formation and morphology of the composite gels were investigated, and the swelling properties and CO₂ adsorption properties of G_mPBG were further studied. The results show that the macroscopic formation, microanalysis, and performance of G_mPBG composite gels are highly correlated with the concentration of GO dispersion. G_mPBG is a pH and temperature dual-responsive composite gel, where the tertiary amine groups in the macromolecules are protonated under acidic conditions, and electrostatic repulsion increases the expansion of the macromolecular chains, resulting in a significant increase in the swelling rate. LCST was present for G_mPBG, which showed a temperature response. In addition, the adsorption of CO₂ by G_mPBG was mainly attributed to the numerous oxygen-containing functional groups on the surface of GO as well as the tertiary amine groups on the PDMAEMA, which provided chemically active sites for adsorption of CO₂.