Advances in membrane-based chiral separation

Chiral separation is essential in discovering bioactive substances because the enantiomer of chiral drugs usually exhibits different or even opposite biological activity and toxicity. As a result, the development of novel strategies to separate enantiomers has been an active area worldwide. Among these, membrane separation has become an emerging technology and is considered the most promising process for large-scale production due to its energy efficiency, low cost, and ease of operability. Currently, many advances in chiral separation using chiral or non-chiral membranes have been achieved, while the systematic reviews of such processes and critical materials thereof are few. This review presents a survey of the advances in the enantio-separation technique using solid and liquid membranes. In particular, the present polymeric chiral separation membranes, such as non-chiral polymer membranes, chiral dense and porous membranes, and mixed-matrix membranes, are extensively reviewed. Other membranes, such as biomembranes and liquid membranes, are also discussed for comparison. In addition, the study presents a comprehensive summary and discussion of the state-of-the-art development and prospects of such materials to provide relevant guidance for improving the performance of membrane chiral separation.