Interaction mechanism between copolymer inhibitor and β-dicalcium silicate surface based on molecular dynamics simulation

Abstract

Copolymer inhibitor with multifunctional groups has a good effect on inhibiting the secondary reaction in the clinker leaching process for alumina production, but the inhibition mechanism of the copolymer is not clear yet. In this paper, molecular dynamics simulation was used to study the adsorption process of the copolymer inhibitor with multifunctional groups, such as acrylic acid-vinyl alcohol copolymer (PAV) and acrylic acid-hydroxypropyl acrylate copolymer (PAH), on the β-dicalcium silicate (C2S) crystal surface, and reveal its inhibiting mechanism. Meanwhile, the polyacrylic acid (PAA) with only the carboxyl group also is simulated for comparing the inhibition effect with copolymer inhibitors. The results show that the binding energy between copolymer (PAV, PAH) and β-C2S is greater than that of PAA with a single functional group. The order of binding energy is as follows: PAH > PAV > PAA. In aqueous solution, the water molecule can restrict the degree of deformation of polymers, increase the distance between polymers and β-C2S and then lead to weakening of the adsorption of polymers on the crystal surface. The comprehensive and coordination effect of carboxyl and hydroxyl functional groups in PAV and PAH can strengthen the adsorption of copolymers on the β-C2S surface. The different spatial distribution of multifunctional groups in the molecular structure has a different influence on the adsorption of the copolymer. The results can provide a theoretical basis for researching new and highly effective copolymer inhibitors with multifunctional groups. Compared the adsorption state: The comprehensive and coordinate action of carboxyl and hydroxyl groups of the inhibitor with multifunctional groups make the inhibitor have a stronger adsorption ability on the surface of β-C2S than that with a single functional group. The results obtained in this paper can provide a theoretical basis for the research and development of new and highly effective polymeric inhibitors with multifunctional groups. Highlights The interaction between copolymer and β-C2S was investigated by MD simulation. The binding energy order between polymers and β-C2S is PAH > PAV > PAA. The presence of water molecules can weaken the adsorption of the copolymer on the surface of β-C2S. The comprehensive and coordinate action of carboxyl and hydroxyl groups of the inhibitor with multifunctional groups make the inhibitor have a stronger adsorption ability on the surface of β-C2S than that with a single functional group.