Statistics of a hydrophobic chain near a hydrophobic boundaryP. Önder1 and A. Erzan1, 2
1 Department of Physics, Faculty of Sciences and Letters, Istanbul Technical University, Maslak 80626, Istanbul, Turkey
2 Gürsey Institute, P.O. Box 6, Çengelköy 81220, Istanbul, Turkey
(Received 17 September 2002 and Received in final form 31 December 2002 / Published online: 11 February 2003)
We study the behavior of a hydrophobic chain near a hydrophobic boundary in two dimensions, adapting the decorated lattice model of Berkema and Widom (G.T. Barkema, 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. The resulting partition functions may be integrated numerically. 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.
05.50.+q - Lattice theory and statistics (Ising, Potts, etc.).
64.75.+g - Solubility, segregation, and mixing; phase separation.
87.15.Aa - Theory and modeling; computer simulation.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002