Novel chiral composite membranes coated by microporous hyper-crosslinked polymer for efficiently enantioselective separation

Abstract

With the rapid development of the pharmaceutical industry, efficient enantiomeric resolution is of great significance for the preparation of single enantiomer drugs. Herein, several kinds of chiral hyper-crosslinked polymer composite membranes (CHCPs/PSS) were fabricated by surface-initiated Friedel-crafts alkylation reaction on the porous SiO2 substrate for enantioseparation. The membrane fabrication conditions were optimized by changing various monomer concentrations, polymerization times and substrate pore sizes using phenylalanine as separated substance and the percent enantiomeric excess (ee%) reached 91.2 % with a permeability up to 6.31 × 10−2 m2/h which was 1012 folders higher than the traditional chiral polymer membranes. Besides, the enantioseparation of disparate enantiomers including clinical drug were also evaluated using CHCPs/PSS membranes to expand its application scope. The ee% and permeability reached 9.48 % and 5.13 × 10−1 m2/h for tryptophan and 24.4 % and 1.56 m2/h for ibuprofen, respectively. Static adsorption and quantum chemical computation were utilized to analyze the separation mechanism and the results indicated that the adsorption energy difference which resulted from the multiple interactions contributed to the effective separation of enantiomers. Consequently, this work will provide a new method for the application of chiral hyper-crosslinked polymer membranes in enantiomeric separation.