氧化石墨烯-Ag纳米粒子/聚酰亚胺混合基质膜及其渗透汽化性能

以聚乙二醇（PEG-400）为还原剂，AgNO₃为前驱体，采用浸渍-还原法合成氧化石墨烯-Ag纳米粒子（GO-AgNP）复合物，再通过共混法制备氧化石墨烯-Ag纳米粒子/聚酰亚胺（GO-AgNP/PI）混合基质膜，用于苯/环己烷混合物的渗透汽化分离。使用透射电子显微镜、红外吸收光谱、拉曼光谱、热失重以及X射线光电子能谱等分析表征GO-AgNP复合物、GO-AgNP/PI混合基质膜的形貌和结构；探讨了Ag掺杂量对GO-AgNP复合物的结构以及GO-AgNP/PI混合基质膜的结构和渗透汽化性能的影响。结果发现，Ag⁺被还原形成AgNP的同时，GO失去了部分含氧官能团；Ag掺杂破坏了GO的结构，使其无序度增加，但改善了GO-AgNP复合物在混合基质膜中的分散性，提升了GO-AgNP/PI混合基质膜的苯/环己烷渗透汽化性能。然而过量的Ag掺杂将使GO片层上产生Ag粒子团聚，从而降低混合基质膜的渗透汽化性能。当Ag掺杂量为15%时，GO-AgNP/PI混合基质膜渗透汽化性能最佳，渗透通量为1 404 g·m^-2·h^-1，分离因子可达36.2。

Preparation and Pervaporation Property of GO-AgNP/PI Mixed Matrix Membranes

Graphene oxide-Ag nanoparticle(GO-AgNP) composites were synthesized by impregnation-reduction method using polyethylene glycol (PEG-400) as the reducer and AgNO₃ as the source of AgNP, which were then blended with polyimide(PI) to prepare GO-AgNP/PI mixed matrix membranes. The structure of GO-AgNP composites and GO-AgNP/PI mixed matrix membranes were characterized by Transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FT-IR), Raman spectroscopy, Thermo-gravimetric analysis(TGA), X-ray photoelectron spectroscopy(XPS). The effect of AgNP-doping on pervaporation property of GO-AgNP/PI mixed matrix membranes was investigated for separation of benzene/cyclohexane mixture. The results reveal that the dope of AgNP would slightly destroyed the structure of GO, and the disorder degree of GO structure increased, the oxygen-containing functional groups of GO decreased in Ag⁺ reduced to form AgNP. But the dope of AgNP which was helpful to improve the dispersion of AgNP-GO composite in the mixed matrix membrane, thus enhance the pervaporation performance of the mixed matrix membrane. However, the excess of AgNP-doping would lead to the aggregation of Ag particles on the GO surface, which depressed the pervaporation performance of the mixed matrix membrane. When AgNP-doping reached 15% in GO-AgNP composite, the mixed matrix membrane demonstrates good pervaporation perporty, and the separation factor reached 36.2 and the flux is 1 404 g·m^-2·h^-1.