Chiral mixed matrix membranes with the (S,S)-Whelk-O®1 selector supported on polyethersulfone/MCM-41

Abstract

This research work aims to develop low-cost hybrid polymeric membranes with high chiral resolution capacity. A mesoporous material (MCM-41) obtained from rice husk biomass was used to support the chiral selector (S,S)-1-(3,5-dinitrobenzamido)-tetrahydrophenanthrene (Whelk-O®1). This material was incorporated into the polyethersulfone matrix and the structural variables, such as the incorporated content and the polymer–mesoporous material compatibility, were investigated regarding the chiral resolution capacity. Mixed matrix membranes (MMMs), prepared by the phase inversion method, were characterized by FTIR, XPS, and SEM, confirming the presence of MCM-41-(S,S)-Whelk-O®1. Membrane enantioselectivity was evaluated through filtration tests with the enantiomeric pair of naproxen and using a xanthone derivative, 6-methoxy-9-oxo-N-(1-(p-tolylethyl)-9H-xanthene-2-carboxamide). The concentration of both enantiomers throughout the filtration was monitored by liquid chromatography equipped with a Whelk-O®1 column (25 cm, 4.6 mm i.d., 5 mm particle size, 100 Å pore size) from Regis Technologies. The MMMs exhibited excellent enantioselectivity (α = 16.78) for the xanthone derivative.