Keywords
Glass transition, Interfaces, Membranes, Microstructures, Phase separation
Abstract
We report the first simulations of nonsolvent-induced phase separation (NIPS) that predict membrane microstructures with graded asymmetric pore size distribution. In NIPS, a polymer solution film is immersed in a nonsolvent bath, enriching the film in nonsolvent, and leading to phase separation that forms a solid polymer-rich membrane matrix and polymer-poor membrane pores. We demonstrate how mass-transfer-induced spinodal decomposition, thermal fluctuations, and glass-transition dynamics—implemented with mobility contrast between the polymer-rich and polymer-poor phases—are essential to the formation of asymmetric membrane microstructures. Specifically, we show that the competition between the propagation of the phase-separation and glass-transition fronts determines the degree of pore-size asymmetry. We also explore the sensitivity of these microstructures to the initial film composition, and compare their formation in 2D and 3D.
Original Publication Citation
https://pubs.acs.org/doi/10.1021/acsmacrolett.0c00609
BYU ScholarsArchive Citation
Garcia, Jan Ulric; Iwama, Tatsuhiro; Chan, Eva Y.; Tree, Douglas R.; Delaney, Kris T.; and Fredrickson, Glenn H., "Mechanisms of Asymmetric Membrane Formation in Nonsolvent-Induced Phase Separation" (2020). Faculty Publications. 6194.
https://scholarsarchive.byu.edu/facpub/6194
Document Type
Peer-Reviewed Article
Publication Date
2020-10-26
Permanent URL
http://hdl.lib.byu.edu/1877/8923
Publisher
ACS
Language
English
College
Ira A. Fulton College of Engineering
Department
Chemical Engineering
Copyright Status
Copyright © 2020 American Chemical Society
Copyright Use Information
https://lib.byu.edu/about/copyright/