Fabrication and application of graphene oxide modified cyclodextrin chiral separation membranes

Membrane separation technology has become one of the most promising methods in the field of chiral drug separation based on its advantages of high energy efficiency, continuous operation and economic efficiency. Mixed matrix membranes (GO/EDA-beta-CD MMMs) were successfully fabricated via the precipitation phase transformation method, incorporating cellulose acetate as the membrane polymer, graphene oxide (GO) as the modifier and mono(6-ethylenediamine-6-deoxy)-beta-cyclodextrin (EDA-beta-CD) as the chiral selector. The results showed that the addition of GO was beneficial to accelerate the speed of water transmission and contributed to enhancing the permeability and selectivity simultaneously. The enantioseparation performances of the GO/EDA-beta-CD MMMs were detected in the separation process of chiral drugs. The results showed that the ee% value of the GO/EDA-beta-CD MMMs for d-, and l-tryptophan was 58%, which was 3% higher than that of EDA-beta-CD mixed matrix membranes (EDA-beta-CD MMMs). The ee% value of (RS)-propranolol was 17%, which was about 4 times that of EDA-beta-CD MMMs. The resolution ee% of (RS)-warfarin was 8%, which was about 2 times that of EDA-beta-CD MMMs. Furthermore, using the ultrasonic cleaning method to regenerate the membrane, the regeneration efficiency reached about 50%. Finally, the chiral resolution mechanism of the membranes was studied by molecular simulations. Compared with EDA-beta-CD MMMs, the GO/EDA-beta-CD MMMs possessed better resolution performance and greater stability. Therefore, the GO/EDA-beta-CD MMMs possess possibilities of high enantioselectivity for chiral drug separation in industrial production.