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Title: Molecular modeling of micelle formation and solubilization in block copolymer micelles. 2. Lattice theory for monomers with internal degrees of freedom

Abstract

A self-consistent mean-field lattice theory of the micellization and solubilization properties of poly(ethylene oxide)-poly(propylene oxide) block copolymers is described. The polymer segments are allowed to assume both polar and nonpolar conformations (corresponding to the gauche and trans rotations of the C-C and C-O bonds), which permits the dependence of the segment-segment interactions on temperature and composition to be accounted for in a physically realistic manner. The phase diagrams of poly(ethylene oxide) and poly(propylene oxide) in water, both of which exhibit lower critical solution temperatures, can be reproduced semiquantitatively. The predictions of the theory compare favorably with published light scattering results on the aggregation behavior of block copolymers and with the authors experimental results for the solubilization of naphthalene in these micelles as a function of polymer composition and molecular weight. The dependence of the micelle-water partition coefficient on polymer composition is not simply related to the proportion of the hydrophobic constituent but depends on the detailed micelle structure. The strong effect of the molecular weight and PPO content of the polymer on the amount of naphthalene solubilized observed experimentally was interpreted in terms of the model results.

Authors:
;  [1];  [2]
  1. (Massachusetts Institute of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering)
  2. (Wageningen Agricultural Univ., Wageningen (Netherlands))
Publication Date:
OSTI Identifier:
5847797
DOE Contract Number:
FG02-92ER14262
Resource Type:
Journal Article
Resource Relation:
Journal Name: Macromolecules; (United States); Journal Volume: 26:19
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COPOLYMERS; CHEMICAL COMPOSITION; SOLUBILITY; AQUEOUS SOLUTIONS; MATHEMATICAL MODELS; MICELLAR SYSTEMS; PHASE DIAGRAMS; DIAGRAMS; DISPERSIONS; MIXTURES; ORGANIC COMPOUNDS; ORGANIC POLYMERS; POLYMERS; SOLUTIONS; 400201* - Chemical & Physicochemical Properties

Citation Formats

Hurter, P.N., Hatton, T.A., and Scheutjens, J.M.H.M. Molecular modeling of micelle formation and solubilization in block copolymer micelles. 2. Lattice theory for monomers with internal degrees of freedom. United States: N. p., 1993. Web. doi:10.1021/ma00071a008.
Hurter, P.N., Hatton, T.A., & Scheutjens, J.M.H.M. Molecular modeling of micelle formation and solubilization in block copolymer micelles. 2. Lattice theory for monomers with internal degrees of freedom. United States. doi:10.1021/ma00071a008.
Hurter, P.N., Hatton, T.A., and Scheutjens, J.M.H.M. 1993. "Molecular modeling of micelle formation and solubilization in block copolymer micelles. 2. Lattice theory for monomers with internal degrees of freedom". United States. doi:10.1021/ma00071a008.
@article{osti_5847797,
title = {Molecular modeling of micelle formation and solubilization in block copolymer micelles. 2. Lattice theory for monomers with internal degrees of freedom},
author = {Hurter, P.N. and Hatton, T.A. and Scheutjens, J.M.H.M.},
abstractNote = {A self-consistent mean-field lattice theory of the micellization and solubilization properties of poly(ethylene oxide)-poly(propylene oxide) block copolymers is described. The polymer segments are allowed to assume both polar and nonpolar conformations (corresponding to the gauche and trans rotations of the C-C and C-O bonds), which permits the dependence of the segment-segment interactions on temperature and composition to be accounted for in a physically realistic manner. The phase diagrams of poly(ethylene oxide) and poly(propylene oxide) in water, both of which exhibit lower critical solution temperatures, can be reproduced semiquantitatively. The predictions of the theory compare favorably with published light scattering results on the aggregation behavior of block copolymers and with the authors experimental results for the solubilization of naphthalene in these micelles as a function of polymer composition and molecular weight. The dependence of the micelle-water partition coefficient on polymer composition is not simply related to the proportion of the hydrophobic constituent but depends on the detailed micelle structure. The strong effect of the molecular weight and PPO content of the polymer on the amount of naphthalene solubilized observed experimentally was interpreted in terms of the model results.},
doi = {10.1021/ma00071a008},
journal = {Macromolecules; (United States)},
number = ,
volume = 26:19,
place = {United States},
year = 1993,
month = 9
}
  • A self-consistent mean-field lattice theory used to model the solubilization of polycyclic aromatic hydrocarbons in poly(ethylene oxide)-poly(propylene oxide) block copolymer micelles is able to reproduce the experimental finding that the micelle-water partition coefficient of naphthalene increases with an increase in the poly(propylene oxide) content of the polymer and with polymer molecular weight. With the polycyclic aromatic hydrocarbons treated as flexible benzene chains, the model indicated a strong correlation between the micelle-water partition coefficient and the octanol-water partition coefficient of the solute, which was also observed experimentally. Linear, triblock copolymers and starlike, branched copolymers were studied. It was found that themore » linear polymers formed larger micelles with a more hydrophobic core environment, resulting in higher micelle-water partition coefficients.« less
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