title: Electrostatic correlations and the polyelectrolyte self energy.
abstract: We address the effects of chain connectivity on electrostaticfluctuations in polyelectrolyte solutions using a field-theoretic, renormalizedGaussian fluctuation (RGF) theory. As in simple electrolyte solutions [Z.-G. Wang,Phys. Rev. E 81, 021501 (2010)], the RGF provides a unified theory forelectrostatic fluctuations, accounting for both dielectric and charge correlationeffects in terms of the self-energy. Unlike simple ions, the polyelectrolyte self energydepends intimately on the chain conformation, and our theory naturally provides aself-consistent determination of the response of intramolecular chain structure topolyelectrolyte and salt concentrations. The effects of the chain-conformation on theself-energy and thermodynamics are especially pronounced for flexiblepolyelectrolytes at low polymer and salt concentrations, where application of thewrong chain structure can lead to a drastic misestimation of the electrostaticcorrelations. By capturing the expected scaling behavior of chain size from dilute tosemi-dilute regimes, our theory provides improved estimates of the self energy at lowpolymer concentrations and correctly predicts the eventual N-independenceof the critical temperature and concentration of salt-free solutions of flexiblepolyelectrolytes. We show that the self energy can be interpreted in terms of aninfinite-dilution energy μm,0eland a finite concentrationcorrelation correction μcorrwhich tends to cancel out the formerwith increasing concentration.
authors.affiliation: Division of Chemistry andChemical Engineering, California Institute of TechnologyPasadena, Pasadena, California 91125,USA.
authors.forename: Kevin
authors.identifier: 0000000197157474
authors.initials: K
authors.lastname: Shen
authors.affiliation: Division of Chemistry andChemical Engineering, California Institute of TechnologyPasadena, Pasadena, California 91125,USA.
authors.forename: Zhen-Gang
authors.identifier: 0000000233616114
authors.initials: ZG
authors.lastname: Wang