Neutral and charged polymers at interfaces
Physics Reports-Review Section Of Physics Letters, 380 (1-2):
1--95 (June 2003)Abstract
Chain-like macromolecules (polymers) show characteristicadsorption
properties due to their flexibility and internal degrees of freedom,
when attracted to surfaces and interfaces. In this review we discuss
concepts and features that are relevant to the adsorption of neutral
and charged polymers at equilibrium, including the type of polymer/surface
interaction, the solvent quality, the characteristics of the surface,
and the polymer structure. We pay special attention to the case of
charged polymers (polyelectrolytes) that have a special importance
due to their water solubility. We present a summary of recent progress
in this rapidly evolving field. Because many experimental studies
are performed with rather stiff biopolymers, we discuss in detail
the case of semi-flexible polymers in addition to flexible ones.
We first review the behavior of neutral and charged chains in solution.
Then, the adsorption of a single polymer chain is considered. Next,
the adsorption and depletion processes in the many-chain case are
reviewed. Profiles, changes in the surface tension and polymer surface
excess are presented. Mean-field and corrections due to fluctuations
and lateral correlations are discussed. The force of interaction
between two adsorbed layers, which is important in understanding
colloidal stability, is characterized. The behavior of grafted polymers
is also reviewed, both for neutral and charged polymer brushes. (C)
2003 Elsevier Science B.V. All rights reserved.