Predicting the solution morphology of a sulfonated pentablock copolymer in binary solvent mixtures.

ABSTRACT The solution morphologies of a midblock-sulfonated pentablock copolymer in miscible polar/nonpolar solvent blends were characterized as a function of solvent composition and polymer concentration using small angle X-ray scattering. Three distinct solution morphologies are observed upon changing the composition of the solvent blend. At low weight fractions of polar solvent, spherical, sulfonated-core micelles are observed, while spherical, sulfonated-corona (inverted) micelles are observed at high weight fractions of polar solvent. Polymer solution scattering is observed at intermediate concentrations of polar solvent. Additionally, the characteristic dimensions of the sulfonated-core micelles were found to change strongly upon variation of the solvent blend composition, indicating that these solutions-and correspondingly the morphology and properties of polymer membranes into which they are cast-can be tuned through simple variations in the solvent blend chemistry. We demonstrate that the solution morphologies and the characteristic micelle dimensions of these complex pentablock copolymer/binary solvent blends can be reliably predicted by considering the relative interactions of each polymer block and the solvent blend using the Hansen solubility parameters. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 254-262 [ABSTRACT FROM AUTHOR]