季铵盐改性氧化石墨烯的制备及其性能研究

本论文采用改进的Hummers法制备了氧化石墨烯(GO),并将氧化石墨烯用十二烷基二甲基苄基氯化铵(1227)进行修饰,得到1227非共价改性的氧化石墨烯(GO-1227)。用拉曼光谱、漫反射红外光谱分析、X-射线光电子表面能谱技术表征了其化学结构;用X-射线衍射分析、扫描电子显微镜与透射电子显微镜观察了其剥离情况和微观形貌;分析了它们在不同溶剂中的分散性。结果表明,季铵盐改性后,1227阳离子通过静电作用插入到GO片层之间,使GO片层进一步剥离,且在极性较弱的有机溶剂中的溶解性增加。热失重分析表明,GO-1227的初始分解温度提高了约70℃。将GO-1227与聚甲基丙烯酸甲酯与苯乙烯的嵌段共聚物(PMMA-b-PS)凝胶聚电解质复合,制备了纳米复合凝胶聚合物电解质(NGPE),并用交流阻抗法测试其电性能,发现占聚电解质总质量2‰的GO-1227可以将其离子电导率提高8.6倍。

Preparation of Quaternary Ammonium Salt Modified Graphene Oxide and Its Properties

Graphene oxide(GO) was prepared by the modified Hummers method,and modified by dodecyl dimethyl benzyl ammonium chloride (1227) to produce 1227 non-covalent modified graphene oxide(GO-1227). Raman spectrum, Diffuse reflection infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the chemical structure of GO-1227. X-ray diffraction was used to observe the exfoliated morphology of GO-1227. It is found that the layers of GO became more complete disordered and exfoliated after modified by 1227. Scanning electron microscope and Transmission electron microscope was used to characterize the micro structure of GO-1227. The results show that GO-1227 presented curling and folded layer structure. The disperse property of GO-1227 was measured and thermal stability of GO and GO-1227 was compared by thermogravimetry analysis. The solubility of GO-1227 was enhanced in the relatively weak polar solvent since the 1227 cations surround the layers of GO, and thermal stability of GO was improved due to the thermolysis of oxidation group was prevented by 1227 cations. Finally, nano-filler of the GO-1227 was mixed with gel polyelectrolyte based on polymethylmethacrylate and polystyrene block copolymer(PMMA-b-PS) to prepare the nanocomposited gel polymer electrolytes (NGPE). The result of alternating-current impedance shows that the improvement of ionic conductivity is 8.6 times when the mixed ratio of GO-1227 is two over one thousand.