Localization transition of a random polymer at an interface
Department of Chemical Engineering, Massachusetts Institute of
Cambridge, MA 02139-4307, USA
Accepted: 21 January 1999
An analysis is presented of the phase transitions arising from the presence of a random heteropolymer (RHP) at a flat interface between two fluids whose physicochemical interactions with the different monomers comprising the chain differ from one another. We re-examine the analysis of Garel et al. (Europhys. Lett., 8 (1989) 9) to probe the low temperature adsorbed regime. Utilizing the Martin-Siggia-Rose formulation with Hartree approximation we derive the dynamical equations governing the correlation functions. The long-time limit of the dynamical equations indicate a possible ergodicity-breaking transition of the polymer, corresponding to the localization transition predicted in the above-quoted analysis. However, in contradiction to the analysis of Garel et al., we predict that this phenomenon occurs at a finite temperature. This result contrasts with the behavior that might be expected from studies of 1+1 Directed Polymer in Random Media (DPRM), and resembles the behavior of d+1 DPRM for d > 2. Our conclusions are corroborated by transfer matrix simulations.
PACS: 64.70.Pf – Glass transitions / 36.20.-r – Macromolecules and polymer molecules / 68.10.-m – Fluid surfaces and fluid-fluid interfaces
© EDP Sciences, 1999