Europhys. Lett.
Volume 63, Number 6, September 2003
Page(s) 895 - 901
Section Interdisciplinary physics and related areas of science and technology
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00602-4
Europhys. Lett., 63 (6) , pp. 895-901 (2003)

The slowly formed Guiselin brush

B. O'Shaughnessy and D. Vavylonis

Department of Chemical Engineering, Columbia University - New York, NY 10027, USA

(Received 6 March 2003; accepted in final form 8 July 2003)

We study polymer layers formed by irreversible adsorption from a polymer melt. Our theory describes an experiment which is a "slow" version of that proposed by Guiselin (Europhys. Lett. , 17 (1992) 225) who considered instantaneously irreversibly adsorbing chains and predicted a universal density profile of the layer after swelling with solvent to produce the "Guiselin brush". Here we ask what happens when adsorption is not instantaneous. The classic example is chemisorption. In this case the brush is formed slowly and the final structure depends on the experiment's duration, $t_{\ab{final}}$. We find the swollen layer consists of an inner region of thickness $z^* \sim
t_{\ab{final}}^{-5/3}$ with approximately constant density and an outer region extending up to height $h \sim N^{5/6}$ which has the same density decay $\sim z^{-2/5}$ as for the Guiselin case.

82.35.-x - Polymers: properties; reactions; polymerization.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
68.08.-p - Liquid-solid interfaces.

© EDP Sciences 2003