J. Phys. II France
Volume 3, Numéro 4, April 1993
Page(s) 443 - 448
DOI: 10.1051/jp2:1993142
J. Phys. II France 3 (1993) 443-448

Surface-tethered polymers in polymeric matrices

Miguel Aubouy and Elie Raphaël

Laboratoire de Physique de la Matière Condensée, URA 792 CNRS, Collège de France, 11 Place Marcelin-Berthelot, 75231 Patis Cedex 05, France

(Received 30 November 1992, accepted 29 January 1993)

Recently Budkowski et al. used nuclear reaction analysis to study polymer brushes consisting of end-tethered deuterated polystyrene tails within a polystyrene homopolymer matrix. They measured the concentration-depth profile as a function of the surface coverage $\sigma$ of tails and the degree of polymerisation of the matrix. For the matrix with the largest degree of polymerisation, the variation of the effective brush thickness L with $\sigma$ can be fitted by the apparent power law $L\propto\sigma^{q}$ with $q=0.54\pm 0.06$. This scaling law is not expected theoretically for surface-tethered polymers exposed to a polymeric matrix consisting of chemically identical chains ( $\chi =0$, where $\chi$ is the interaction parameter). in the present note we would like to propose an explanation based on the fact that mixtures of deuterated and protonated polystyrene chains are characterized by a small (but non-zero) value of $\chi$.


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