Molecular Recognition-driven Membrane Processes

High-precision, selective and effi cient systems are strongly demanded in all productive sectors, including chemical manufacturing, pharmaceutical, medical treatment, food, energy, diagnostic, analytical tools. Precision separation, conversion, formulation at molecular level may rely on various mechanisms and properties, such as molecular sieving, electrical charge, chemical solubility, molecular recognition. Membrane operation can promote mass transport, separation, conversion, formulation on the basis of the mentioned mechanisms. Biomimic and biohybrid funtionalised membranes are particularly suitable for separations based on molecular recognition. Membranes can be formed by polymers or monolythes bearing the (biomimic) recognition sites. In alternative, biomimic, biomolecules and recognition sites can be loaded on a previously formed membrane support. In such cases, surface functionalization methods can improve the loading effi ciency. Molecularly imprinted membranes; membranes bearing affi nity ligands (Antigen-Antibody, avidine/- ligand, DNA-protein, sugar-lectin, RNA-ribosome,...); membranes functionalized with zeolite and nanoparticles; membranes with immobilized enantioselective enzyme for kinetic resolutions, are among examples of selective and effi cient operations driven by molecular recognition. Th is is the mechanism by means of which molecules are able to identify each other using non-covalent - (hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, ?-? interactions and electrostatic eff ects) and covalent interactions. In this chapter, the various examples including membrane preparation, surface functionalization to introduce recognition sites, membrane performance and application will be discussed. Initially, molecular recognition based separation promoted by molecularly imprinted membranes will be discussed. Th en, membrane processes based on affi nity interactions between receptor and target ligand molecule will be presented, highlighting the diff erence with the previous separation mechanism