Gas permeation properties, physical aging, and its mitigation in high free volume glassy polymers – chemical reviews (acs publications) electricity quiz ks2

Ze-Xian (Nicholas) Low received his Ph.D. in Chemical Engineering at Monash University under the direction of Prof. Huanting Wang in 2015. He then joined Dr. Darrell Patterson’s, and later Prof. Davide Mattia’s group as a postdoctoral research associate in the Centre of Advanced Separations Engineering, University of Bath. His current research focuses on the advanced characterization of polymer membranes, 3D printing of polymer membranes, and hybrid membranes for water purification. Biography

Peter Budd is a Chartered Chemist and is Professor of Polymer Chemistry at the University of Manchester. He obtained his B.Sc. (1978) and Ph.D. (1981) from Manchester. He spent eight years as a research chemist with BP before taking up an academic position at Manchester in 1989. He has extensive experience in materials development relevant to membrane processes and other applications. He is coinventor (with McKeown) of “Polymers of Intrinsic Microporosity” (PIMs). Biography

Neil McKeown is the Crawford Tercentenary Chair of Chemistry at the University of Edinburgh. His expertise is in the synthesis of organic materials with a focus on the preparation of membrane-forming Polymers of Intrinsic Microporosity (PIMs), of which he is coinventor (with Budd) and for which he was awarded the 2008 Beilby Medal and the 2017 Tilden Medal by the Royal Society of Chemistry. Biography

Darrell Patterson completed his Ph.D. in Chemical and Biochemical Engineering at Imperial College London in 2001. He worked as a Technology Development Consultant for Atkins Water between 2001 and 2003. He then went on to Imperial College as a postdoctoral research associate, developing novel methods of enhancing solvent based pharmaceutical reactions through integration with solvent resistant membranes. He returned to the University of Auckland in 2005, where he worked as a Lecturer and then Senior Lecturer in the Department of Chemical and Materials Engineering before joining the University of Bath in 2011. His research was recognized with a University of Auckland Early Career Research Excellence Award in 2009 and a Highly Commended awarding in the IChemE Sir Frederick Warner Prize in 2011. He passed away on 19th February 2017, while this manuscript was in preparation.

Hundreds of polymers have been evaluated as membrane materials for gas separations, but fewer than 10 have made it into current commercial applications, mainly due to the effects of physical aging and plasticization. Efforts to overcome these two problems are a significant focus in gas separation membrane research, in conjunction with improving membrane separation performance to surpass the Robeson upper bounds of selectivity versus permeability for commercially important gas pairs. While there has been extensive research, ranging from manipulating the chemistry of existing polymers (e.g., thermally rearranged or cross-linked polyimides) to synthesizing new polymers such as polymers of intrinsic microporosity (PIMs), there have been three major oversights that this review addresses: (1) the need to compare the approaches to achieving the best performance in order to identify their effectiveness in improving gas transport properties and in mitigating aging, (2) a common standardized aging protocol that allows rapid determination of the success (or not) of these approaches, and (3) standard techniques that can be used to characterize aging and plasticization across all studies to enable them to be robustly and equally compared. In this review, we also provide our perspectives on a few key aspects of research related to high free volume polymer membranes: (1) the importance of Robeson plots for membrane aging studies, (2) eliminating thermal history, (3) measurement and reporting of gas permeability and aging rate, (4) aging and storing conditions, and (5) promising approaches to mitigate aging.