Eur. Phys. J. E 4, 93-101

Stiffness and conformations of molecular bottle-brushes strongly adsorbed on a flat surface

I.I. Potemkin¹, A.R. Khokhlov¹ and P. Reineker².

¹  Physics Department, Moscow State University, Moscow, 117234 Russia
²  Department of Theoretical Physics, University of Ulm, 89069 Ulm, Germany

igor@polly.phys.msu.su

(Received 13 April 2000 and Received in final form 18 August 2000)

Abstract
A theory of the conformational behavior and analysis of the persistence length of molecular bottle-brushes strongly adsorbed on a flat surface in a good solvent is presented. For long enough side chains we have shown that the adsorption of a small fraction of side chains already leads to significant increase of the stiffness and drastic conformational changes of the brush in comparison with the 3D case. For a symmetrical distribution of the adsorbed side chains with respect to the backbone, the equilibrium conformation of the brush is close to a rod-like one due to the very large stiffness of the molecule. Under certain conditions the excluded-volume interactions of the side chains of an asymmetrical brush can lead to its bending or twisting in spiral. The obtained results are in good agreement with computer simulations.

PACS
61.25.Hq - Macromolecular and polymer solutions; polymer melts; swelling.
61.20.Gy - Theory and models of liquid structure.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001