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On the bulk modulus of the cell model of charged macromolecules suspensions

Gabriel Tellez·Emmanuel Trizac
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Abstract

We study theoretically the bulk modulus (inverse of the compressibility) of a suspension of charged objects (macro-ions), making use of a cell model to account for the finite density of macro-ions. The diffuse layer of charged micro-species around a macro-ion is described by a generic local density functional theory. Within this general framework, we obtain the condition for a positive bulk modulus, which is fulfilled by several proposals made in the literature and rules out the possibility of a critical point. We show that a sufficient condition for a positive compressibility also ensures that the same theory produces repulsive effective pair potentials.

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Gabriel Tellez, Emmanuel Trizac. 2002-12-03. On the bulk modulus of the cell model of charged macromolecules suspensions. https://doi.org/10.1063/1.1538604

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