Multi-stage chiral separation with electrospun chitin nanofiber membranes

Abstract

Chitin nanofiber membranes were fabricated via electrospray deposition. The nanofiber membrane adsorbed l-isomer from racemic mixture of Glu and Phe in preference to the corresponding antipodes, while d-Lys was preferentially incorporated into the membrane. The adsorption isotherms revealed that all enantiomers studied in the present study were incorporated into the nanofiber membrane without any specific interaction, in other words, those were simply adsorbed. In membrane transport experiments, d-isomers were preferentially transported through the nanofiber membrane. In order to attain higher permselectivity, a multi-stage cascade separation was applied in the present study. As expected, the permselectivity toward d-enantiomer was enhanced exponentially with the increase in number of stages from one to five stages via three by applying a multi-stage cascade membrane separation.