Effect Ph On Rheological And Electric Properties
EFFECT pH ON RHEOLOGICAL AND ELECTRIC PROPERTIES
OF AEROSIL A‑175 DISPERSIONS, MODIFIED BY IONIC SURFACTANTS
A.V. Synyts\’ka, V.P. Zakordons\’kyj, M.M. Soltys
Lviv Ivan Franko National University, Lviv, Ukraine
Effect pH medium on structure-mechanical and electro surface properties of the aerosil A‑175 dispersions, modified by cationic benzetonium chloride (BTC) and anionic sodium dodecylbenzenesulfonate (SDbS) was studied by the rotational viscosimetry and macro electrophoresis methods. Surfactants concentration was stated 2´10-3 mol/l, pH medium changed from 2 until 12.
First, different character of effect BTC and SDbS concentration on rheological properties of investigated systems must be noted. The concentration surfactant ranges, where, benzetonium chloride and sodium dodecylbenzenesulfonate displays appreciable structurization action exist. The recharging range in case of cationic BTC at CBTC = 2´10-4 – 2´10-3mol/l leads to the intensification of structure formation in aerosil A‑175 dispersions. In the presence of anionic sodium dodecylbenzenesulfonate investigated systems have anomalous flow mode at CSDbS = 1.44´10-5mol/l ("half adsorption" range).
So, with allowance of these factors, the pH change can be expected and it will cause different behavior for studied surfactants. The obtained results indicate the correlation in variation of electro kinetic x-potential and effective viscosity hef of the investigated systems. For aerosil A‑175 dispersions, modified by anionic sodium dodecylbenzenesulfonate, at pH increase the electro kinetic potential of aerosil particles and dispersion viscosity increase too. But for aerosil dispersions, modified by benzetonium chloride, exists "plato" range at pH = 8-12, where x and hef parameters are unchanged.
The obtained results are analyses from position of complex effect pH on ionization of surface of the sylanolic\’s groups and colloidal-chemical properties of the investigated surfactant solutions.
In this manner, received results of effect pH medium on rheological and electric properties aerosil dispersions are indicate decisive electrostatic factor contribution in properties of the investigated systems.
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