Size Influences of SiO2-graphene Barrier on the Corrosion Resistance of Epoxy-Acrylic Waterborne Coating

• Published in: International journal of electrochemical science 2021-01, Vol.16 (1), p.151018, Article 151018
• Main Authors: Shen, Yifan, Yang, Jingxia, Wang, Shuchuan, Jing, Lingzhi, Zheng, Hao, Du, Yangyang, Zou, Bingjie, Lei, Xuanzheng, Xu, Jingli
• Format: Article
• Language: English
• Subjects: Anti-corrosion; Barrier; Coating; Graphene; SiO2 sphere
• ISSN: 1452-3981; 1452-3981
• DOI: 10.20964/2021.01.33

SiO2-Graphene composited materials can be used as anti-corrosion barriers, which were dispersed in waterborne epoxy-acrylic (EA) resin. Under the same mass of SiO2 and Gr, the particle size of SiO2 determines the particle number and surface area, which further influence the coverage of Gr on SiO2 and their anticorrosion performance. In this research, SiO2 spheres with three different particle sizes (150, 400, 500 nm) were used to composite with graphene (Gr), and they were linked by bi-functional ligand para-aminobenzoic acid (P), and the designed SiO2-P-Gr were dispersed in EA resin as anticorrosion barriers, and the influence of SiO2 particle size is focused. SiO2-P-Gr barrier can greatly reduce the corrosion current density icorr, from 3.2×10-7 A/cm2 (pure EA coating) to 5.1×10-9 A/cm2 (EA+150nmSiO2+P+Gr coating), due to the increased resistances for charge transfer (according to EIS fitting) of SiO2+P+Gr barrier. Especially, 500nmSiO2-P-Gr exhibited excellent shield in both low and high frequency region according to Bode plot, which may be attributed to the different graphene coverage on the SiO2 particles with different size under the same mass control.