Europhys. Lett.
Volume 67, Number 3, August 2004
Page(s) 425 - 431
Section Condensed matter: structure, mechanical and thermal properties
Published online 01 July 2004
Europhys. Lett., 67 (3), pp. 425-431 (2004)
DOI: 10.1209/epl/i2003-10297-5

Irreversible vs. reversible coating

Nam-Kyung Lee1, 2 and A. Johner3

1  Institute of Fundmental Physics and Department of Physics, Sejong University Seoul 143-743, South Korea
2  LEA MPIP/ICS, Max-Planck Institute für Polymerforschung 55128 Mainz, Germany
3  LEA MPIP/ICS, Institut Charles Sadron - 67083 Strasbourg Cedex, France

(Received 25 November 2003; accepted in final form 28 May 2004)

We discuss theoretically the composition of a coating, formed by polymers that can adsorb by both ends, in terms of loops (double-bounded chains) and tails (single-bounded chains) as a function of surface coverage and concentration of the adsorbing solution. Both irreversible adsorption (e.g., by chemical surface reaction) and reversible adsorption (e.g., by van der Waals interactions) are considered. Tails are found to be scarce but their amount controls surface properties such as roughness, dewetting or early bridging interactions. The population of tails is a non-monotonic function of coverage. We show that for irreversible adsorption the composition as a function of (the time-dependent) coverage follows a universal (independent of sample history) law at high coverage. This law is similar to, but qualitatively different from, the Mass Action Law describing coatings at equilibrium.

68.43.-h - Chemisorption/physisorption: adsorbates on surfaces.
36.20.Ey - Exotic atoms and molecules; macromolecules; clusters: Conformation (statistics and dynamics).
05.70.Ln - Nonequilibrium and irreversible thermodynamics.

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