Phase behavior of random copolymers in quenched random media

Journal Article · Fri Dec 22 04:00:00 EST 1995 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.469861· OSTI ID:165902

Chakraborty, A K ^[1]; Shakhnovich, E I ^[2]

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1. Department of Chemical Engineering, University of California, Berkeley, California 94720 (United States)
2. Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States)

In this paper, we consider the behavior of random heteropolymers in a quenched disordered medium. We develop a field theory and obtain a mean-field solution that allows for replica symmetry breaking. The presence of an external disorder leads to the formation of compact states; a homopolymeric effect. We compute the phase diagram for two classes of problems. First, we consider the situation wherein the bare heteropolymer prefers like segments to segregate, and second, we examine cases where the bare heteropolymer prefers unlike segments to mix. For the first class of systems, we find a phase diagram characterized by a replica symmetry broken phase that exists below a particular temperature. This temperature grows with the strength of the external disorder. In the second class of situations, the phase diagram is much richer. Here we find two replica symmetry broken phases with different patterns separated by a reentrant phase. The reentrant phase and one of the two replica symmetry broken phases are induced by interactions with the external disorder. The dependence of the location of the phase boundaries on the strength of the external disorder are elucidated. We discuss our results from a physical standpoint, and note the testable experimental consequences of our findings. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 165902
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 24 Vol. 103; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ADHESION
ADSORPTION
INTERFACES
PHASE DIAGRAMS
POLYMERS
SOLIDS
SURFACES