Statistics of a hydrophobic chain near a hydrophobic boundary

TL;DR

This study models the behavior of a hydrophobic chain near a hydrophobic boundary in two dimensions, revealing temperature-dependent adsorption and configuration states through exactly solvable Hamiltonians.

Contribution

Introduces two exactly solvable Hamiltonians based on a decorated lattice model to analyze hydrophobic chain behavior near a boundary.

Findings

Chain is detached at low and high temperatures.

Chain adsorbs onto the wall at intermediate temperatures.

Results agree with Monte Carlo simulations.

Abstract

We study the behaviour of a hydrophobic chain near a hydrophobic boundary in two dimensions, using the decorated lattice model of Berkema and Widom [G.T. Barkema and B. Widom, J. Chem. Phys. 113, 2349 (2000)] to obtain effective, temperature dependent intrachain and chain-boundary interactions. We use these interactions to construct two model hamiltonians which can be solved exactly. Our results compare favorably with preliminary Monte Carlo computations, using the same effective interactions. At relatively low temperatures and at high temperatures, we find that the chain is randomly configured in the ambient water, and detached from the wall, whereas at intermediate temperatures it adsorbs onto the wall in a stretched or partially folded state, again depending upon the temperature, and the energy of solvation.