"Tuning Colloidal Interactions with Adsorbed Functional Polymers"
Abstract: Colloidal dispersions are fascinatingly
versatile materials; they are ubiquitous in nature and form the basis
of many industrial products we encounter every day. The
stability, transport and optical
properties of colloidal dispersions hinge on the interaction between
the particle surfaces. This interaction can be modified by adsorbed
further tuned by the polymer?s response to changes in the surrounding
solution. We have studied the effects of charged and neutral polymer
the interaction of a colloidal particle with a flat substrate, using
the uncommon but particularly sensitive method of total internal
microscopy (TIRM). The results reveal a subtle interplay of steric,
electrostatic, and van der Waals forces. The same principles
govern the behavior of emulsions, another type of colloidal systems.
Additional emulsion-specific properties like the instability against
and ripening can also be addressed through adsorbed polymeric species.
As an example, novel surfactant-free emulsions stabilized by pH and
temperature switchable microgels shall be discussed, which offer
unprecedented stability control.