Colloido-chemical characteristics of nanoporous glasses with different compositions in solutions of simple and organic electrolytes. 1. Structural and transport characteristics of membranes

Abstract

The regularities of variations in the structural (bulk porosity, structural resistance coefficient, and average pore radius) and transport (specific electrical conductivity and ion transport numbers) characteristics of nanoporous glass membranes with different compositions have been studied as depending on their preparation conditions and the type of electrolyte (sodium, potassium, ammonium, tetramethylammonium, and tetraethylammonium chlorides). An additional alkaline treatment of the porous glasses, which increases the average pore radius and modifies the morphology of pore channels, leads to variations in the electrotransport characteristics of the glasses. In solutions containing inorganic counterions, the dependences of the transport characteristics of the porous glasses on the solution concentration and pore size have a classic character. The high specificity of tetraalkylammonium ions in relation to the surface gives rise to a region of negative values of the specific surface conductivity and complex dependences of efficiency coefficients and transport numbers on electrolyte concentration and pore channel size. The duration of the thermal treatment of initial sodium-borosilicate glass containing small amounts of phosphorus oxide and fluoride ions, as well as the conditions of its leaching, has almost no effect on the properties of the membranes in tetraethylammonium chloride solutions.