C. Singh et al., INTERACTIONS BETWEEN POLYMER-COATED SURFACES IN POOR SOLVENTS .1. SURFACES GRAFTED WITH A-HOMOPOLYMER AND B-HOMOPOLYMER, Macromolecules, 29(23), 1996, pp. 7559-7570
Using a two-dimensional self-consistent field theory, we investigate t
he interaction between two planar surfaces where (1) each surface is g
rafted with both A and B homopolymers and (2) one surface is coated wi
th end-grafted A's and the other is coated with end-grafted B's. The c
hains are grafted at low densities and the B polymers are chosen to be
solvophobic. We vary the solvent affinity of the A chains and the int
eraction between the A and B monomers. We determine the morphology of
the layers and the energy of interaction as the layers are compressed.
The energy of interaction versus distance profiles show a wide region
of attraction as the surfaces are brought together. This attractive i
nteraction is due to the self-assembled structures that appear at low
grafting densities in poor solvents. The properties of the attraction
can be tailored, as we demonstrate in a simple scaling picture. Our fi
ndings indicate that fine control over the pair interaction function o
f coated colloidal particles can be gained through grafting mixtures o
f homopolymers.