Graphene Oxide Based Gas Separation Composite Membrane Prepared By Interfacial Polymerization

Development of high-performance composite membrane with nano materials as fillers has become a frontier research direction in the field of membrane technology.In order to improve gas separation performance of composite membranes,graphene oxide(GO)was used as the filler to develop composite membrane by interfacial polymerization.The size of GO was adjusted by ultrasonic in pure water,and the dspacing of GO was controlled through in-situ modification to build gas separation channels in the membrane.Firstly,in order to control the size of GO,GO was cutted by ultrasonic in pure water.The effects of ultrasonic cutting on the species and content of functional groups of GO were investigated.The results indicate that the species of functional groups of GO do not change in the process of ultrasonic cutting,but the content of functional groups changes.Based on the experimental results,the mechanism of ultrasonic cutting was proposed.After that,the GO was modified by diethylene glycol bis(3-aminopropyl)ether(DGBAmE)in aqueous solution.The amino groups of DGBAmE can react with carboxylic acid and epoxy groups of GO to control the d-spacing of GO.The results of FTIR and XPS indicate that chemical reactions occur between DGBAmE and GO.The XRD results confirm the changes of d-spacing of GO by modification.Finally,the GO based composite membranes were prepared by interfacial polymerization with aqueous solution of modified GO and hexane solution of 1,3,5-Benzenetricarbonyl trichloride(TMC).The effects of GO size,modification of GO,and the modification temperature on gas separation performance were investigated.Resutls indicate that,the GO with smaller size(70 nm)could improve the gas separation performance of composite membranes.The d-spacing of modified GO could effectively separate gas molecules.The CO2/N2 selectivity of the membrane with modified GO is improved obviously,and the CO2 permeance is changed little.By using the optimized modification temperature,the prepared membrane displays CO2 permeance of1600 GPU and CO2/N2 selectivity of 238,which shows promising applications.