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Title: Communication: Cosolvency and cononsolvency explained in terms of a Flory-Huggins type theory

Standard Flory-Huggins (FH) theory is utilized to describe the enigmatic cosolvency and cononsolvency phenomena for systems of polymers dissolved in mixed solvents. In particular, phase boundaries (specifically upper critical solution temperature spinodals) are calculated for solutions of homopolymers B in pure solvents and in binary mixtures of small molecule liquids A and C. The miscibility (or immiscibility) patterns for the ternary systems are classified in terms of the FH binary interaction parameters (χ{sub αβ}) and the ratio r = ϕ{sub A}/ϕ{sub C} of the concentrations ϕ{sub A} and ϕ{sub C} of the two solvents. The trends in miscibility are compared to those observed for blends of random copolymers (A{sub x}C{sub 1−x}) with homopolymers (B) and to those deduced for A/B/C solutions of polymers B in liquid mixtures of small molecules A and C that associate into polymeric clusters (A{sub p}C{sub q}){sub i}, (i = 1, 2, …, ∞). Although the classic FH theory is able to explain cosolvency and cononsolvency phenomena, the theory does not include a consideration of the mutual association of the solvent molecules and the competitive association between the solvent molecules and the polymer. These interactions can be incorporated in refinements of the FH theory, and themore » present paper provides a foundation for such extensions for modeling the rich thermodynamics of polymers in mixed solvents.« less
Authors:
;  [1] ;  [2]
  1. The James Franck Institute and the Department of Chemistry, The University of Chicago, Chicago, Illinois 60637 (United States)
  2. Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
Publication Date:
OSTI Identifier:
22489665
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BINARY MIXTURES; COMPARATIVE EVALUATIONS; COPOLYMERS; INTERACTIONS; LIQUIDS; MIXED SOLVENTS; MOLECULES; SIMULATION; SOLUBILITY; SOLUTIONS; THERMODYNAMICS