Field theory for ionic systems. From fluctuations and structure at a hard wall to thermodynamics

Dung Di Caprio (1) , J. Stafiej (2) , J.P. Badiali (1)

1 LECA - Laboratoire d'Electrochimie et de Chimie Analytique
2 IPC - Institute of Physical Chemistry

We use a field theoretical approach to study ionic systems. In this paper we illustrate this formalism in a grand canonical ensemble for the long range Coulomb potential. For the inhomogeneous system near a hard neutral plane wall we go beyond the well known Debye–Hückel electrolyte results and predict the existence of a desorption profile. The results are compared with well established sum rules for ionic systems and thermodynamic relations are verified. We also calculate the differential capacitance in a slab using the linear response theory. The capacitance is calculated from the charge–charge correlations for the neutral system using the fluctuation–dissipation theorem.

Domaines: Chimie théorique et/ou physique

Dung Di Caprio, J. Stafiej, J.P. Badiali. Field theory for ionic systems. From fluctuations and structure at a hard wall to thermodynamics. Electrochimica Acta, 2003, 48 (20-22), pp.2967-2974. ⟨10.1016/S0013-4686(03)00362-1⟩. ⟨hal-02354770⟩