The inhibition effect mechanisms of four scale inhibitors on the formation and crystal growth of CaCO3 in solution

Changjun Li; Chaoyi Zhang; Wuping Zhang

doi:10.1038/s41598-019-50012-7

The inhibition effect mechanisms of four scale inhibitors on the formation and crystal growth of CaCO₃ in solution

Sci Rep. 2019 Sep 16;9(1):13366. doi: 10.1038/s41598-019-50012-7.

Authors

Changjun Li^{1

2}, Chaoyi Zhang^{3

4}, Wuping Zhang⁵

Affiliations

¹ School of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu, 610500, China.
² CNPC Key Laboratory of Oil & Gas Storage and Transportation, Southwest Petroleum University, Chengdu, 610500, China.
³ School of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu, 610500, China. zcy864019940@163.com.
⁴ CNPC Key Laboratory of Oil & Gas Storage and Transportation, Southwest Petroleum University, Chengdu, 610500, China. zcy864019940@163.com.
⁵ Institute of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.

Abstract

The experimentation, molecular dynamics simulation and DFT calculation were used to study the inhibition effects of four scale inhibitors, including polyacrylic acid (PAA), hydrolyzed polymaleic anhydride (HPMA), polyepoxysuccinic acid (PESA) and polyaspartic acid (PASP), on formation and crystal growth of CaCO₃ in solutions. According to concentrations of Ca²⁺ in solutions, the sequence of inhibition effects of scale inhibitors on formation of CaCO₃ in the solution was PESA > PASP > HPMA > PAA. Characterization of CaCO₃ crystals by XRD and a laser particle size analyzer indicated that the sequence of inhibition effects of scale inhibitors on crystal growth of CaCO₃ in solutions was PESA > HPMA > PASP > PAA. Interaction energies between the scale inhibitor molecule and Ca²⁺, and between the scale inhibitor molecule and the CaCO₃ (104) surface indicated that the difference of the inhibition effects was derived from the difference in the interaction energy. The results of DFT calculation indicated that the difference between the interaction energies of these inhibitors and Ca²⁺ was derived from differences of number and the Mulliken population values of the chemical bonds which formed between the inhibitor molecule and Ca²⁺ and between the inhibitor molecule and the CaCO₃ surface.