Investigating microstructure evolution in block copolymer membranes

Anthony J Cooper; Douglas J Grzetic; Kris T Delaney; Glenn H Fredrickson

doi:10.1063/5.0188196

Investigating microstructure evolution in block copolymer membranes

J Chem Phys. 2024 Feb 21;160(7):074903. doi: 10.1063/5.0188196.

Authors

Anthony J Cooper¹, Douglas J Grzetic², Kris T Delaney³, Glenn H Fredrickson^{3

4}

Affiliations

¹ Department of Physics, University of California, Santa Barbara, California 93106, USA.
² Schrödinger Inc., 101 SW Main St, Portland, Oregon 97204, USA.
³ Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA.
⁴ Departments of Chemical Engineering and Materials, University of California, Santa Barbara, California 93106, USA.

PMID: 38380746
DOI: 10.1063/5.0188196

Abstract

Block copolymer self-assembly in conjunction with nonsolvent-induced phase separation (SNIPS) has been increasingly leveraged to fabricate integral-asymmetric membranes. The large number of formulation and processing parameters associated with SNIPS, however, has prevented the reliable construction of high performance membranes. In this study, we apply dynamical self-consistent field theory to model the SNIPS process and investigate the effect of various parameters on the membrane morphology: solvent selectivity, nonsolvent selectivity, initial film composition, and glass transition composition. We examine how solvent selectivity and concentration of polymers in the film impact the structure of micelles that connect to form the membrane matrix. In particular, we find that preserving the order in the surface layer and forming a connection between the supporting and surface layer are nontrivial and sensitive to each parameter studied. The effect of each parameter is discussed, and suggestions are made for successfully fabricating viable block copolymer membranes.