DOI: 10.1051/jp2:1994207
J. Phys. II France 4 (1994) 1417-1426

Interaction between two polymer brushes in binary solvent mixture

Tuan-Anh C. Tran¹, Andrea J. Liu² and P. Pincus<sup>1, 3

1</sup>  Department of Physics, University of California, Santa Barbara, CA 93106, U.S.A.
²  Department of Chemical and Nuclear Engineering, University of California, Santa Barbara, CA 93106, U.S.A.
³  Department of Materials, University of California, Santa Barbara, CA 93106, U.S.A.

(Received 27 January 1994, received in final form 19 April 1994, accepted 22 April 1994)

Abstract
The system of two polymer brushes in a near-critical binary mixture of good and poor solvents is studied within the framework of the Alexander-de Gennes model. When the brushes do not overlap, the problem is shown to be analogous to the system of two hard walls in a near critical binary mixture. As in the two-wall case, it is found that the disjoining pressure between the brushes is negative. This attractive interaction, which arises from the preferential attraction of the good solvent to the brushes, has a range comparable to the correlation length of the mixture. When the brushes do overlap, the interaction between the brushes is repulsive. This leads to a minimum in the disjoining pressure at contact.

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