Effective Adjustment of Crystallinity and Regular Anti-Corrosion Activity of Zinc Tungstate Pigments

Abstract

It is important to reduce costs and improve performance by microstructure-control of materials. The direct precipitation method and hydrothermal method were adopted to adjust the crystallinity of zinc tungstate (ZnWO4) pigments. Correlation between the crystallinity of ZnWO4 and its anti-corrosion performance is explored. The results confirm that ZnWO4 crystals prepared by hydrothermal reaction for 12 h have high crystallinity, and the corrosion resistance is enhanced by 737.0% compared with blank coating in the epoxy resin system. The improvement in corrosion inhibition is due to the enhancement of the shielding effect of the multilayer passivation film and electronic suppression effect resulted from the high ZnWO4 crystallinity. The low ZnWO4 crystallinity can weaken the corrosion resistance because of the defect-enriched effect. Advancement in anticorrosive performance by crystallinity-control meets the reduction of costs and energy consumption in the coatings industry.