title: Structuring of polymer solutions upon solvent evaporation.
abstract: The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady solvent evaporation. In contrast to what is the case for a classical, thermal quench involving immiscible blends, the spinodal instability initially develops slowly and the associated length scale is not time invariant but decreases with time as t(-1/2). After a time lag, phase separation accelerates. Time lag and characteristic length exhibit power-law behavior as a function of the evaporation rate with exponents of -2/3 and -1/6. Interestingly, at later stages the spinodal structure disappears completely while a second length scale develops. The associated structure coarsens but does not follow the usual Lifshitz-Slyozov-Wagner kinetics.
authors.affiliation: Dutch Polymer Institute, P.O. Box 902, 5600 AX Eindhoven, The Netherlands.|Theory of Polymers and Soft Matter, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Schaefer
authors.affiliation: Theory of Polymers and Soft Matter, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: van der Schoot
authors.affiliation: Holst Centre/TNO, High Tech Campus 31, 5656 AE Eindhoven, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Michels