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arXiv · 0704.0544

Crossover behavior in fluids with Coulomb interactions

O. V. Patsahan·J. -M. Caillol·I. M. Mryglod
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Abstract

According to extensive experimental findings, the Ginzburg temperature $t_{G}$ for ionic fluids differs substantially from that of nonionic fluids [Schr\"oer W., Weig\"{a}rtner H. 2004 {\it Pure Appl. Chem.} {\bf 76} 19]. A theoretical investigation of this outcome is proposed here by a mean field analysis of the interplay of short and long range interactions on the value of $t_{G}$. We consider a quite general continuous charge-asymmetric model made of charged hard spheres with additional short-range interactions (without electrostatic interactions the model belongs to the same universality class as the 3D Ising model). The effective Landau-Ginzburg Hamiltonian of the full system near its gas-liquid critical point is derived from which the Ginzburg temperature is calculated as a function of the ionicity. The results obtained in this way for $t_{G}$ are in good qualitative and sufficient quantitative agreement with available experimental data.

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O. V. Patsahan, J. -M. Caillol, I. M. Mryglod. 2007-04-04. Crossover behavior in fluids with Coulomb interactions. https://doi.org/10.1140/epjb/e2007-00247-7

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