Thermodynamic and kinetic study on protolytic reactions at the surface of porous matrices

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 105; no. 2; pp. 173 - 180
• Main Authors: Zhmud, Boris V, Golub, Alexander A
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 20.12.1995; Elsevier
• Subjects: Charge regulation; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Fractals; General and physical chemistry; Kinetics of adsorption; Porous materials; Porous silica; Solid-liquid interface; Surface charge distribution; Surface physical chemistry; Surface charge distribution; Porous silica; Fractals; Kinetics of adsorption; Charge regulation; Surface charge; Gibbs free energy; Liquid solid interface; Electrolyte solution; Ligand; Dielectric properties; Theoretical study; Fractal system; Porous material; Silica; Adsorption; Ionization; Mass action law; Models; Kinetics; Thermodynamic properties; Diffusion; Permittivity; Protolysis; Organic compounds; Modified material
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/0927-7757(95)03266-5

Taking advantage of formal thermodynamics, we have rederived a generalized form of the law of mass action that serves to substantiate the charge regulation model applied to describe protolytic and ionic reactions at the surface of rigid matrices in contact with electrolyte solutions. Making use of that model, we have attempted to reanalyze the theory and to systematize the influence on the protolytic properties of porous silicas modified with organic ligands of various factors, such as the pore structure and the fractality of matrices, the mechanism of charging and association phenomena at the matrix/solution interface, the spatial dispersion of the dielectric constant of the solution, etc. The distributions of surface charge density and surface potential over the surface charged according to the charge regulation model have been calculated. Besides, in the framework of the semi-infinite diffusion model, we have accounted for some features of diffusion-controlled protolytic reactions.