Complex fluids with mobile charge-regulating macro-ions. (15th January 2018)

• Record Type: Journal Article
• Authors: Markovich, Tomer; Andelman, David; Podgornik, Rudi
• Is Part Of: Europhysics letters. Volume 120:Number 2(2017:Oct.)
• Publication Date: 2018-01-15
• Subjects: 61.20.Qg -- 82.45.Gj; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/120/26001
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: We generalize the concept of charge regulation of ionic solutions, and apply it to complex fluids with mobile macro-ions having internal non-electrostatic degrees of freedom. The suggested framework provides a convenient tool for investigating systems where mobile macro-ions can self-regulate their charge ( e.g., proteins). We show that even within a simplified charge-regulation model, the charge dissociation equilibrium results in different and notable properties. Consequences of the charge regulation include a positional dependence of the effective charge of the macro-ions, a non-monotonic dependence of the effective Debye screening length on the concentration of the monovalent salt, a modification of the electric double-layer structure, and buffering by the macro-ions of the background electrolyte.