Enhancing the corrosion resistance of waterborne epoxy coatings with functionalized biochar

Weiyue Zhu; Xin Li; Xiaoyan Liu; Liang Bai; Xiaohu Wang; Ao Li; Yujie Han; Chunguang Wei; Junhui Dong; Zeyu Guo; Jun Liu; Ding Nan

doi:10.1039/d4ra07421a

Enhancing the corrosion resistance of waterborne epoxy coatings with functionalized biochar

RSC Adv. 2024 Dec 17;14(53):39747-39758. doi: 10.1039/d4ra07421a. eCollection 2024 Dec 10.

Authors

Weiyue Zhu¹, Xin Li², Xiaoyan Liu¹, Liang Bai¹, Xiaohu Wang¹, Ao Li¹, Yujie Han¹, Chunguang Wei³, Junhui Dong¹, Zeyu Guo⁴, Jun Liu¹, Ding Nan^{1

2}

Affiliations

¹ Inner Mongolia Key Laboratory of New Materials and Surface Engineering, School of Materials Science and Engineering, Inner Mongolia University of Technology Hohhot 010051 China clxylj74@imut.edu.cn nd@imu.edu.cn.
² College of Chemistry and Chemical Engineering, Inner Mongolia University Hohhot 010021 China.
³ School of Renewable Energy, Inner Mongolia University of Technology Ordos 017010 China wcg@imut.edu.cn.
⁴ Inner Mongolia Key Laboratory of Sandy Shrubs Fibrosis and Energy Development and Utilization, College of Materials Science and Art Design, Inner Mongolia Agricultural University Hohhot 010018 China.

Abstract

This study utilizes discarded tree leaves as a substrate to synthesize biomass porous carbon nanosheets (PCNS) through high-temperature carbonization and pore-forming treatment, followed by functional modification using carboxymethyl chitosan (CMCS) and the corrosion inhibitor 8-hydroxyquinoline (8-HQ). The functionalized PCNS fillers were incorporated into water-based epoxy (WEP) coatings to enhance corrosion resistance. Electrochemical impedance spectroscopy (EIS) testing showed that after 60 days, WEP/PCNS@CMCS@8-HQ exhibited a low-frequency impedance of 1.7 × 10⁹ Ω cm² at the lowest frequency, with significantly improved salt spray corrosion performance compared to WEP. The study demonstrates that CMCS effectively captures Cl^- and acts as a repair agent, working synergistically with the external corrosion inhibitor 8-HQ to improve the dispersion of PCNS within the WEP matrix and enhance corrosion resistance. These findings indicate that green-modified PCNS offers a promising approach to improving the corrosion resistance of coatings.