Molecular dynamics simulation on the interaction between polymer inhibitors and β-dicalcium silicate surface

Abstract

Molecular dynamics simulations were conducted to study the interactions between the (110) surface of β-dicalcium silicate (C2S) and polymer inhibitors, such as the polyacrylic acid (PAA), polyacrylamide (PAM), polyethylene glycol (PEG) under the conditions of the vacuum and water solution respectively. The simulated results showed that the order of binding energy between polymers and the surface of β-C2S with and without water are same as follows: PAA>PAM>PEG, which is consistent with experimental results. The binding energies without water are far larger than those with water for the same polymer. Multi-layers water molecules are distributed on the surface of β-C2S. The polymers can be adsorbed on the surface of β-C2S by overcoming the barrier of water layers under the interaction between polymers and β-C2S. The interaction energies are mainly contributed by the coulomb interaction in the non-bonding interaction, which is basically formed between the O atoms of polymer inhibitors and the Ca atoms of β-C2S surface. In water solution, parts of the polymer can directly be adsorbed on the surface of β-C2S due to the formation of hydrogen bonds and ionic bonds, while the other part of polymer inhibitor interact indirectly with β-C2S surface by forming the hydrogen bond network between polymer–H2O and H2O–β-C2S. Those simulated results provide a theoretical support for the development of novel and efficient polymer inhibitors.