a) b - École Polytechnique de Montréal

macromolecules from the substrate. Depletion of polystyrene, soluble in toluene, from a mica
substrate is an example of this case(Luckham & Klein, 1985).
The type of surface and its internal structure significantly affects the adsorption process. The
potential of the surface can be either short-range, influencing on monomers which are in direct
contact with or close to the surface, or it can be long-range, affecting on farther monomers
through van der Waals or electrostatic interactions. Various possible substrates include: 1) a flat
and homogeneous substrate (Figure 2-36a), 2) rough and corrugated surfaces (Figure 2-36b), 3) a
curved surface or spherical substrate in which curvature effects can be neglected if the radius of
curvature is much larger than the polyelectrolyte size (Figure 2-36c), 4) some other particular
surfaces, including chemically non-homogeneous substrates, interfaces of two immiscible
liquids, or surfaces with internal degrees of freedom like surfactant monolayers (Figure 2-36d).
Figure 2-36. Different possibilities of substrates:
(a) the prototype, a flat, homogeneous substrate;
(b) a corrugated, rough substrate. Note that
experimentally, every substrate exhibits a certain
degree of roughness on some length scale; (c) a
spherical adsorption substrate, such as a colloidal
particle. If the colloidal radius is much larger than
the polymer size, curvature effects (which means
the deviation from the planar geometry) can be
neglected; (d) a flat but chemically heterogeneous
substrate;
Adsorption of polymers on the substrate can be performed through various mechanisms such as
grafting of an end-functionalized polymer via a chemical or physical bond. One of the most
influencing parameters on adsorption characteristics is polymer topology. Adsorption of star
polymers and ring polymers, investigated by some research groups, have been found to be
a)
b)
c)
d)
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