Molecularly Imprinted Membranes: Past, Present, and Future

Abstract

More than 80 years ago, artificial materials with molecular recognition sites emerged. The application of molecular imprinting to membrane separation has been studied since 1962. Especially after 1990, such research has been intensively conducted by membranologists and molecular imprinters to understand the advantages of each technique with the aim of constructing an ideal membrane, which is still an active area of research. The present review aims to be a substantial, comprehensive, authoritative, critical, and general-interest review, placed at the cross section of two broad, interconnected, practical, and extremely dynamic fields, namely, the fields of membrane separation and molecularly imprinted polymers. This review describes the recent discoveries that appeared after repeated and fertile collisions between these two fields in the past three years, to which are added the worthy acknowledgments of pioneering discoveries and a look into the future of molecularly imprinted membranes. The review begins with a general introduction in membrane separation, followed by a short theoretical section regarding the basic principles of mass transport through a membrane. Following these general aspects on membrane separation, two principles of obtaining polymeric materials with molecular recognition properties are reviewed, namely, molecular imprinting and alternative molecular imprinting, followed the methods of obtaining and practical applications for the particular case of molecularly imprinted membranes. The review continues with insights into molecularly imprinted nanofiber membranes as a promising, highly optimized type of membrane that could provide a relatively high throughput without a simultaneous unwanted reduction in permselectivity. Finally, potential applications of molecularly imprinted membranes in a variety of fields are highlighted, and a look into the future of membrane separations is offered.

Chiral Separation in Preparative Scale: A Brief Overview of Membranes as Tools for Enantiomeric Separation

“…Among the different types of enantioselective membranes, only some MIMs have been developed after the last review (2016) specifically focusing this type of membranes [52].…”

“…In fact, it was found that molecularly imprinted polymers (MIPs) exhibit well-defined structures, high selectivity and binding affinity for the target molecules, considering that the caves created within MIPs are complementary to them in shape, size, configuration and functional moieties. Moreover, they have excellent chemical properties and comparing with other methods to introduce chiral recognition sites in polymeric membranes, the preparation of molecularly imprinted membranes (MIMs) are simple, low-cost, and effective [45,52]. Various review articles are found in literature regarding MIPs [45,48,49,[100][101][102][103][104][105][106][107] and among them focusing on MIMs [52,98,99].…”

Molecular Imprinting of Cyclodextrin Supramolecular Hydrogels Improves Drug Loading and Delivery

“…proposed the use of molecular imprinting of supramolecular hydrogels for drug delivery of small molecules in 2007, there has been virtually no progress in that direction since then. Nevertheless, the field of molecular imprinting has continued to grow, but growth has primarily been in two areas: molecular detection/sensing and separation . The separations field faces the same challenge as the drug delivery field did, in generating high affinities toward small molecules using only linear polymeric systems of low‐affinity components, so investigations have continued using novel matrix components including binary and ternary deep eutectic solvents, ionic liquids, and zwitterionic polymers .…”

Optical resolution and mechanism using enantioselective cellulose, sodium alginate and hydroxypropyl‐β‐cyclodextrin membranes

“…Since the advantages of solid membranes are high-throughput, energy-saving, pollution-free, low-cost, and easy operation, solid membrane technologies have been widely used in the desalination of seawater, wastewater treatment, chemical engineering, the medical field, metallurgy, etc. [8][9][10][11][12][13][14][15] Recently, some new optical resolution membranes have also been reported. [8][9][10][11][12][13][14][15] Recently, some new optical resolution membranes have also been reported.…”