Direct-force measurements between polymer-coated colloidal particles

Polymer chains that are chemically attached to solid surfaces have important commercial uses in colloidal stabilization. In this investigation, recently developed force measurement methods(atomic force colloid probe microscopy, Langmuir trough compression) have been employed to observe the interactions between colloidal particles stabilized by tethered polymer chains. Monodisperse latexes stabilized by hydrophilic side chains of surface-attached comb polymers are analyzed by the above methods in a water environment. By modifying the comb architecture to incorporate both hydrophilic and hydrophobic side chains, attractive wells are introduced into the force-distance profiles, in agreement with recent self-consistent mean field predictions.