The Scale Inhibition Performance and Mechanism of Polyepoxysuccinic Acid for Calcium Phosphate

Abstract

The static scale-inhibiting method was employed to investigate the scale inhibition performance of polyepoxysucci-nic acid (PESA) on calcium phosphate, and molecular dynamics (MD) method was used to simulate the interactions between PESA and (001), (010) surfaces of hydroxyapatite (HAP, the most thermodynamically stable phase of calcium phosphate) in aqueous solution. The results show that the scale inhibition efficiency of PESA increases as the increase in the concentration and PESA possesses better scale inhibition performance compared with PAA while poor performance compared with POCA. Moreover, PESA molecules adsorb on the surfaces rather than remain in the bulk water in MD simulations and the binding energy of PESA with (010) is significantly stronger (1.8 times) than that with (001) surface, which is mainly provided by hydrogen bonds and coulomb interaction verified by the analysis of radial distribution functions. The adsorption of PESA changes the growth rate of crystal surfaces and leads to changes in the crystal morphology of HAP, according well with the scanning electron microscopy (SEM) results. These suggestions may be useful for the synthesis of new, highly effective scale inhibitors.