Self-consistent field theory of brushes of neutral water-soluble polymers

The self-consistent field theory of brushes of neutral water-soluble polymers described by two-state models is formulated in terms of the effective Flory interaction parameter chi(eff)(T,phi) that depends on both temperature, T, and the monomer volume fraction, phi. The concentration profiles, distribution of free ends and compression force profiles are obtained in the presence and in the absence of a vertical phase separation. A vertical phase separation within the layer leads to a distinctive compression force profile and a minimum in the plot of the moments of the concentration profile versus the grafting density. The analysis is applied explicitly to the Karalstrom model. The relevance to brushes of Poly(N-isopropylacrylamide)(PNIPAM) is discussed. (C) 2003 American Institute of Physics.