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Adsorption of polyacrylic acid onto aluminum oxide and silicon carbide

Adsorption of polymers on mineral surfaces is of great importance in many industry branches and applications. Physico-chemical properties of polymers, substrates and general suspensions determine the adsorption at the solid / liquid phase boundary. The properties and structures of the polymer depend on the kinetics and the balance of adsorption processes. The paper deals with the adsorption of poly (acrylic) acids of different molecular masses on aluminum oxide and silicon carbide at different pH values. Aluminum oxide samples had the same mineralogical composition, but different porosity. Solid, porous aggregates made of fine crystals were characterized by application of raster electron microscope (SEM), and particle porosity was determined by adsorption of nitrogen (B.E.T.) and mercury porosimetry. Molecular dimensions of poly (acrylic) acids have been calculated in different conformations depending on pH: coiled and stretched. It has been found that the adsorption density is growing on the nephrotic surface and significantly decreases when the molecular mass increases when the particle surface is porous (at pH less than 7). In acidic suspensions, poly (acrylic) acid is largely not ionized and the adsorption surface available depends on the size of the polymer molecule. Tests have shown that when adsorption of polyacrylic acid on silicon carbide plates changes the ζ potential. It is known that aluminum oxide and silicon carbide are common ceramic materials and the results of this work can contribute to the development of different techniques for the production of various ceramic materials based on colloidal chemistry.

adsorption, polymer, poly (acrylic) acid, aluminum oxide, silicon carbide

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