Exact bounds are obtained for the quenched free energy of a polymer with random hydrophobicities in the presence of an interface separating a polar from a non-polar solvent. The polymer may be ideal or have steric self-interactions. The bounds allow one to prove that a 'neutral' random polymer is localized near the interface at any temperature, whereas a 'non-neutral' chain is shown to undergo a delocalization transition at a finite temperature. These results are valid for a quite general a priori probability distribution for both independent and correlated hydrophobic charges. As a particular case we consider random AB-copolymers and confirm recent numerical studies.
Heteropolymers in a solvent at an interface
MARITAN, AMOS;TROVATO, ANTONIO
1999
Abstract
Exact bounds are obtained for the quenched free energy of a polymer with random hydrophobicities in the presence of an interface separating a polar from a non-polar solvent. The polymer may be ideal or have steric self-interactions. The bounds allow one to prove that a 'neutral' random polymer is localized near the interface at any temperature, whereas a 'non-neutral' chain is shown to undergo a delocalization transition at a finite temperature. These results are valid for a quite general a priori probability distribution for both independent and correlated hydrophobic charges. As a particular case we consider random AB-copolymers and confirm recent numerical studies.Pubblicazioni consigliate
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