title: Comparison of adsorption affinity of polyacrylic acid for surfaces of mixed silica-alumina.
abstract: The influence of solution pH (in the range 3-9) on the adsorption of polyacrylic acid (PAA) on the mixed silica-alumina surface (SA-3: SiO297 %-Al2O33 % and SA-96: SiO24 %-Al2O396 %) was investigated. The following methods were applied in experiments: spectrophotometry, viscosimetry, potentiometric titration, and microelectrophoresis, which enable determination of adsorbed amount of the polymer, thickness of its adsorption layers, surface charge density, and zeta potential of solid particles in the presence and absence of PAA, respectively. The obtained results indicate that rise of solution pH causes the decrease of PAA adsorption and the increase of its adsorption layer thickness on surfaces of both solids. Moreover, significantly higher adsorption of polyacrylic acid was obtained on the SA-96 surface. This is a result of more favorable electrostatic interactions occurring between the adsorbing polymer chains and the SA-96 surface and formation of a greater number of adsorbate-adsorbent connections through hydrogen bridges.
authors.affiliation: Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Wiśniewska
authors.affiliation: Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
authors.forename: Teresa
authors.initials: T
authors.lastname: Urban
authors.affiliation: Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Grządka
authors.affiliation: National Academy of Sciences of Ukraine, Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev, Ukraine.
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Zarko
authors.affiliation: National Academy of Sciences of Ukraine, Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev, Ukraine.
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Gun'ko
keywords: Adsorption; Mixed silica–alumina; Polyacrylic acid; Polymer conformation; Zeta potential