The inhibitory effects of four inhibitors on the solution adsorption of CaCO3 on Fe3O4 and Fe2O3 surfaces

Changjun Li; Chaoyi Zhang; Wuping Zhang

doi:10.1038/s41598-019-50127-x

The inhibitory effects of four inhibitors on the solution adsorption of CaCO₃ on Fe₃O₄ and Fe₂O₃ surfaces

Sci Rep. 2019 Sep 23;9(1):13724. doi: 10.1038/s41598-019-50127-x.

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

This study presents the inhibitory effects of four scale inhibitors, including polyacrylic acid (PAA), hydrolyzed polymaleic anhydride (HPMA), polyepoxysuccinic acid (PESA) and polyaspartic acid (PASP), on the adsorption of CaCO₃ on the surfaces of Fe₃O₄ and Fe₂O₃. Samples were characterized using SEM and EDS and the average atomic number ratios of Ca/Fe were calculated. Inhibition effects followed the trend: PESA > PAA > PASP > HPMA and PESA > PASP > HPMA > PAA for Fe₃O₄ and Fe₂O₃, respectively. Molecular dynamics simulations based on the adsorption model of the scale inhibitor on the surface and calculations of the adsorption energy between the scale inhibitor molecule and the surface revealed that the relatively high scale inhibitory effect is due to low adsorption energy between the inhibitor molecule and the surface. Density Functional Theory (DFT) calculations of the model after adsorption revealed that the relatively low adsorption energy depends on the number of H-O bonds formed as well as those with higher Mulliken population values between the scale inhibitor and the surface.