The slowly formed Guiselin brush

B. O'Shaughnessy; D. Vavylonis

doi:doi:10.1209/epl/i2003-00602-4

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)

Abstract
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.

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

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