Structure of polymer solutions at interfaces: a Monte Carlo simulation study

Abstract

The canonical ensemble Monte Carlo method is applied to study the structure of polymer solutions confined between surfaces. The polymer molecules are modeled as fused-sphere freely rotating chains with fixed bond length and bond angles and the solvent as hard spheres. The simulation results for the configurational and conformational properties of the chains are presented with varying interfacial distances, chain concentrations, and chain lengths. The chains are depleted at the wall at lower density, which, however, becomes less at higher density. With an increase in the interfacial distance, the enhancement/depletion of the chains at the wall becomes more marked. At all interfacial distances and chain lengths, increasing the concentration of the solvent makes the oscillation in the density profile of the chains more pronounced. Conformational properties provide important indications regarding the behaviour of chains as they approach surfaces.

Keywords:

• Polymer solutions
• Surface and interface
• Structure of fluids
• Monte Carlo simulations

Acknowledgements

The author gratefully acknowledges Prof. A. Yethiraj for useful discussions. It is a pleasure to thank Dr. Swapan K. Ghosh and Dr. T. Mukherjee for their interest and constant encouragement.