Lung Cancer: Progress in Therapeutic Research Progress in Cancer Research and Therapy 1978 Raven Press New York

Abstract

Carbon molecular sieve (CMS) membranes are a special class of nanoporous membranes with angstrom-level molecular discrimination properties, which make them appealing for separating a wide spectrum of gas-pairs. The mechanism of pyrolysis by which a polymer coil is transformed into these rigid sieves is complex; however, we present a framework that can explain this transformation. Representative polymer precursors and pyrolysis conditions are discussed that yield attractive CMS membrane separation performance for extremely challenging gas pairs. Control of penetrant motions in the diffusion activated state, reflected in the entropy of activation of subtly different penetrants, enables the attractive diffusion selectivity of such membranes. This control, virtually absent even in rigid state-of-the-art polymeric membranes, makes CMS materials extraordinarily attractive. Moreover, unlike other rigid sieving materials, CMS membranes have the added advantage of being processable into highly productive, flexible hollow fibers with good mechanical properties and long-term stability under constant gas feeds. In this article, we also identify some key areas of CMS which would greatly benefit from expertise from other fields like computation or materials characterization that can potentially complement transport-based studies.