Silica Colloidal Membranes with Enantioselective Permeability

Abstract Robust mesoporous membranes composed of silica spheres were surface‐modified with chiral selector moieties, including small molecules, macrocycles, and polymers. Diffusion rates of enantiomers of a chiral dye through the resulting asymmetrically modified colloidal membranes were measured and the corresponding permselectivities were calculated. The membranes showed enantioselectivities in the range of 1.2–1.8, which were not significantly affected by the structure of the surface‐immobilized chiral electors. This selectivity is on par with most reported polymer‐based solid membranes and bulk liquid membranes. The enantioselectivity results from the surface‐facilitated mechanism of transport of enantiomers through the mesopores.