The calcite/water interface II. Effect of added lattice ions on the charge properties and adsorption of sodium polyacrylate.

The origin of the surface potential of calcium carbonate in aqueous dispersions and the dissolution of calcite in systems containing excess Ca(2+) and CO(3)(2-) have been the subjects of this study. In addition, stabilization of calcite particles with an anionic polyelectrolyte (sodium polyacrylate (NaPA)) and the effect on surface potential and dissolution of calcite have been studied. Preferential dissolution of either Ca(2+) or CO(3)(2-) from the surface, which is governed by the partial pressure of CO(2) in solution and the pH of the solution, mainly determines the surface potential.

Influence of ligand structure on the stability and oxidation of copper nanoparticles.

The stability and oxidation of copper nanoparticles stabilized with various ligands have been studied. Lauric acid-capped copper nanoparticles were prepared by a modified Brust-Schiffrin method. Then, ligand exchange with an excess of different capping agents was performed.

The calcite/water interface I. Surface charge in indifferent electrolyte media and the influence of low-molecular-weight polyelectrolyte.

Suspensions of calcium carbonate in water with an indifferent background electrolyte (NaCl) have been investigated using several techniques. Particular attention was paid to the dissolution of calcite at equilibrium and as a function of sodium polyacrylate (NaPA) concentration. Also of interest was how this affects the magnitude of the surface charge and the zeta potential.

Viscoelastic properties of cationic starch adsorbed on quartz studied by QCM-D.

The adsorption and viscoelastic properties of layers of a cationic polyelectrolyte (cationic starch, CS, with 2-hydroxy-3-trimethylammoniumchloride as the substituent) adsorbed from aqueous solutions (pH 7.5, added NaCl 0, 1, 100, and 500 mM) on silica were studied with a quartz crystal microbalance with dissipation (QCM-D). Three different starches were investigated (weight-average molecular weights M(w) approximately 8.