A Homochiral Poly(2‐oxazoline)‐based Membrane for Efficient Enantioselective Separation

Chiral separation membranes have shown great potential for the efficient separation of racemic mixtures into enantiopure components for many applications, such as in the food and pharmaceutical industries; however, scalable fabrication of membranes with both high enantioselectivity and flux remains a challenge. Herein, enantiopure S‐poly(2,4‐dimethyl‐2‐oxazoline) (S‐PdMeOx) macromonomers were synthesized and used to prepare a new type of enantioselective membrane consisting of a chiral S‐PdMeOx network scaffolded by graphene oxide (GO) nanosheets. The S‐PdMeOx‐based membrane showed a near‐quantitative enantiomeric excess (ee) (98.3±1.7 %) of S‐(−)‐limonene over R‐(+)‐limonene and a flux of 0.32 mmol m−2 h−1. This work demonstrates the potential of homochiral poly(2,4‐disubstituted‐2‐oxazoline)s in chiral discrimination and provides a new route to the development of highly efficient enantioselective membranes using synthetic homochiral polymer networks. S‐Poly(2,4‐dimethyl‐2‐oxazoline)‐based membranes (S‐PdMeOx/GO) are prepared via a simple solution‐based method on porous substrates for chiral separation. The S‐PdMeOx‐based network within the graphene oxide scaffold induced homochirality in the membrane. The resulting S‐PdMeOx‐based membrane displays excellent enantioselectivity in separating racemic limonene mixtures.