| 1. |
- Forsman, Jan, et al.
(författare)
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Evaluating the accuracy of a density functional theory of polymer solutions with additive hard sphere diameters
- 2004
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 120:1, s. 506-510
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Tidskriftsartikel (refereegranskat)abstract
- We assess the accuracy of a density functional theory for athermal polymer solutions, consisting of solvent particles with a smaller radius than that of the monomers. The monomer and solvent density profiles in a slit bound by hard, flat, and inert surfaces are compared with those obtained by a Metropolis Monte Carlo simulation. At the relatively high density at which the comparison is performed, there are considerable packing effects at the walls. The density functional theory introduces a simple weight function to describe nonlocal correlations in the fluid. A recent study of surface forces in polymer solutions used a different weighting scheme to that proposed in this article, leading to less accurate results. The implications of the conclusions of that study are discussed. (C) 2004 American Institute of Physics.
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| 2. |
- Woodward, C E, et al.
(författare)
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Density functional study of surface forces in solutions containing star-shaped polymers
- 2004
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 37:18, s. 7034-7041
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Tidskriftsartikel (refereegranskat)abstract
- Density functional theory is used to study polymer solutions between surfaces in equilibrium with a bulk solution. We investigate the effect on the surface interaction free energy of having star polymers with different numbers of arms. In addition, we consider the role played by the strength of the adsorption potential and the concentration of the polymer molecules. The interaction free energy is found to scale quite well with the number of arms on the stars, and the separation dependence of the interaction scales approximately with the radius of gyration. When the adsorption potential is weak, the polymer molecules are depleted. A free energy barrier is nevertheless present-a phenomenon often referred to as depletion stabilization. The barrier scales with the number of arms on the star polymers.
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