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

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.

Highlights

Water produced from gas fields is a common byproduct in natural gas production
The adsorption energies between the scale inhibitor and the surface were calculated and the results indicated that differences in the effects of the scale inhibitor in the scale inhibition process are attributed to the differences www.nature.com/scientificreports in the adsorption energy of the scale inhibitor molecules adsorbed on the surface
This study presents a study of the inhibitory effects of polyacrylic acid (PAA), hydrolyzed polymaleic anhydride (HPMA), polyepoxysuccinic acid (PESA) and polyaspartic acid (PASP) on the adsorption of CaCO3 to the surfaces of Fe3O4 and Fe2O3

Summary

OPEN The inhibitory effects of four inhibitors on the solution

Received: 14 June 2019 Accepted: 5 September 2019 Published: xx xx xxxx adsorption of CaCO3 on Fe3O4 and Fe2O3 surfaces. 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. We established models of the scale inhibitor molecules with both the Fe3O4 and Fe2O3 surfaces using the Materials Studio. The. Castep module was used to calculate the bond number and the Mulliken population value between the scale inhibitor molecule and the surface, and its functionality is GGA and PBE16,17. Since adsorptions are in solution, a mixed layer was established in the Amorphous Cell module using a scale inhibitor molecule and 20 water molecules. GGA and PBE were selected as Functional, and Fine was selected as Quality

Results and Discussion

Conclusions

Additional Information