Polymers of intrinsic microporosity are glassy-type materials that possess an excess of fractional free volume (up to 30%) due to the loose packaging of the rigid polymeric chains. These polymers have been synthesized and investigated for various membrane applications starting from the 1980s. Thanks to a unique microporous structure with a size of about 1 nm, these polymers can act as the most permeable membrane materials among know polymers, but also as barriers that can withstand the hydraulic trans-membrane pressure of up to 200 bar (we could not go higher due to technical limitations). All of these make polymers of intrinsic microporosity promising materials for organic solvent nanofiltration and membrane contactors. A certain structuring of materials like PIM-1 can lead to an increase in gas selectivity by a factor of two or greater. At the same time, the polymers of intrinsic microporosity typically possess the rapid decline of their initially high transport characteristics in time
due to the relaxation of excess free volume (physical aging) and adsorption of low-volatile and undesired compounds in free volume elements (fouling). Such phenomena can be still mitigated by partial restriction of macrochains mobility (e.g. cross-linking or incorporation of fillers), molecular design of such polymers (e.g. CANAL type polymers), or soaking in solvents. However, 25 years of experience working with this type of polymers gave me the confidence that we can still utilize the unique properties of polymers of intrinsic microporosity in some practical applications.
Alexey Volkov was graduated from Moscow State University, chemical department (Russian Federation) in 2001. Doing his PhD, he spent about 2 years in University of Twente (the Netherlands) as visiting scientist. Alexey Volkov received his PhD degree in polymer science and membrane separation in 2017, and his Dr. Habil. degree in membrane science and petrochemistry in 2017. From 2009, he is holding position of deputy director of Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, and head of Polymeric Membranes Laboratory in the same Institute from 2018. Alexey Volkov is also serving for membrane community as Vice-President of European Membrane Society, and board member of World Association of Membrane Societies. In KAUST, Alexey Volkov is holding the position of Visiting Professor of Biological and Environmental Science and Engineering Division (BESE), Advanced Membranes and Porous Materials (AMPM) Center.