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Amphiphilic polymer brush in a mixture of incompatible liquids
Author(s) -
Birshtein Tatiana M.,
Zhulina Ekaterina B.,
Mercurieva Anna A.
Publication year - 2000
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/(sici)1521-3919(20000101)9:1<47::aid-mats47>3.0.co;2-j
Subject(s) - brush , solvent , polymer , solvation , thermodynamics , chemistry , phase (matter) , flory–huggins solution theory , homogeneity (statistics) , polymer brush , polymer chemistry , materials science , organic chemistry , polymerization , physics , statistics , mathematics , composite material
An analogue of the Alexander‐DeGennes box model is used for theoretical investigation of polymer brushes in a mixture of two solvents. The basic solvent A and the admixture B are assumed to be highly incompatible (Flory‐Huggins parameter χ AB = 3.5). Thermodynamics of a polymer in the solvents A and B are described by parameters χ B < χ A ≤ 1/2. The equilibrium behavior of a brush is investigated in dependence on solvent composition, grafting density, polymer‐solvents and solvent‐solvent interactions. The possibility of a phase transition related with a strong preferential solvation of a brush by a minor solvent component with higher affinity to polymer is shown and examined. Microphase segregation inside a brush is also demonstrated despite overestimating of the brush homogeneity given by the box model. A further simplification of the model permits to obtain scaling formulas and to investigate main regularities in the brush behavior. This offers a clear physical picture of the phase segregation inside a brush in correlation with the phase state of a bulk solvent.