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Formation mechanism of asymmetric porous polymer films by photoinduced phase separation in the presence of solvent
Author(s) -
Yoshihara Hirokazu,
Yamamura Masato
Publication year - 2019
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.47867
Subject(s) - solvent , porosity , raman spectroscopy , polymer , monomer , materials science , chemical engineering , ultraviolet , diffusion , ultraviolet light , photochemistry , phase (matter) , porous medium , polymer chemistry , chemistry , optics , organic chemistry , composite material , optoelectronics , physics , thermodynamics , engineering
Photoinduced phase separation in the presence of a nonreactive volatile solvent provides a simple, light‐tunable, and cost‐effective route for fabrications of porous polymer films. Here, we show that the short‐time (<10 s) ultraviolet irradiation of a photoreactive solution film promotes particular asymmetries in the composition and porosity across the thickness. Confocal Raman spectroscopy revealed that the compositional asymmetry is maximum at a certain critical light intensity. We discuss the film formation mechanism based on the light‐driven diffusion of the solvent and monomer. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47867.