Molecular modeling studies of interactions between sodium polyacrylate polymer and calcite surface

• Published in: Applied surface science Vol. 276; pp. 43 - 52
• Main Authors: Ylikantola, A., Linnanto, J., Knuutinen, J., Oravilahti, A., Toivakka, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2013; Elsevier
• Subjects: Adsorption; Calcite surface; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Force field method; Molecular modeling; Physics; Sodium polyacrylate polymer; Sodium polyacrylate polymer; Calcite surface; Adsorption; Molecular modeling; Force field method; Inorganic compounds; Sodium; Calcium carbonate; Modelling; Polymers
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.02.122

•Molecular weight, branching and the orientation of polymers influence interactions.•Branched polymer bonds better on flat calcite surface than non-branched polymer.•Extra calcium ions present on the surface increases adsorption efficiency. The interactions between calcite pigment and sodium polyacrylate dispersing agent, widely used in papermaking as paper coating components, were investigated using classical force field and quantum chemical approaches. The objective was to understand interactions between the calcite surface and sodium polyacrylate polymer at 300K using molecular dynamics simulations. A quantum mechanical ab initio Hartree–Fock method was also used to obtain detailed information about the sodium polyacrylate polymer structure. The effect of water molecules (moisture) on the interactions was also examined. Calculations showed that molecular weight, branching and the orientation of sodium polyacrylate polymers influence the interactions between the calcite surface and the polymer. The force field applied, and also water molecules, were found to have an impact on all systems studied. Ab initio Hartree–Fock calculations indicated that there are two types of coordination between sodium atoms and carboxylate groups of the sodium polyacrylate polymer, inter- and intra-carboxylate group coordination. In addition, ab initio Hartree–Fock calculations of the structure of the sodium polyacrylate polymer produced important information regarding interactions between the polymers and carboxylated styrene-butadiene latex particles.