Innovative biomimetic superhydrophobic coating combines repair and buffering properties for superior anti-erosion

The long-term erosion and corrosion issues during the development of offshore oil and gas fields pose significant threats to the safe and efficient operation of these facilities. Superhydrophobic coatings, known for their ability to reduce interactions between corrosive substances and substrates, have garnered considerable attention. However, their poor mechanical properties often hinder their long-term application in practical working environments. To address this challenge, a research team led by Prof. Yuekun Lai from Fuzhou University and Prof. Xuewen Cao from China University of Petroleum (East China) has developed a biomimetic dental enamel coating with the amylose hydrogel layer (DEA coating). This innovative coating, characterized by strong erosion–corrosion resistance, is designed for use in complex underwater pipeline systems.

This coating material, known as biomimetic enamel, integrates three protective strategies. First, a multi-layer gradient structure is created by combining lauric acid (LA)-modified TiO₂ particles with carbon nanotubes (CNTs) to enhance the tensile strength and impact resistance of the coating surface. Second, an amylose hydrogel layer is utilized as an intermediate buffer to effectively disperse impact energy. Additionally, the hydrogel’s fluidity allows it to spontaneously fill gaps on damaged surfaces, preventing water penetration and mitigating local corrosion issues.

Repair tests demonstrate that, unlike conventional hydrophilic hydrogels, the amylose hydrogel can fully repair cracks up to 50 μm wide after they occur, effectively preventing coating failure caused by cracking or delamination.

Further validation was provided by a 24-hour erosion loop experiment, demonstrating that the DEA coating significantly reduced erosion rates to 39.52–55.88 nm/s. Compared to 316L stainless steel, the erosion rate was reduced by 57.6%, confirming the effectiveness of its enamel structure and hydrogel repair strategy. Additionally, electrochemical corrosion tests and chemical stability analyses highlighted the coating’s excellent resistance to corrosive media penetration.

By incorporating innovative repair and buffering structures, the impact resistance and corrosion resistance of the DEA coating have been significantly enhanced. The development of DEA coatings by the research team offers novel insights into improving the mechanical durability of such coatings. This study establishes a theoretical foundation for erosion–corrosion inhibition and introduces new technologies for erosion–corrosion protection, particularly in pipeline safety and erosion–corrosion prevention.

The paper “A Biomimetically Constructed Superhydrophobic Coating with Excellent Mechanical Durability and Chemical Stability for Gas Transmission Pipelines,” authored by Xuerui Zang, Yan Cheng, Yimeng Ni, Weiwei Zheng, Tianxue Zhu, Zhong Chen, Jiang Bian, Xuewen Cao, Jianying Huang, Yuekun Lai. Full text of the open access paper: https://doi.org/10.1016/j.eng.2024.03.024. For more information about the Engineering, follow us on X (https://twitter.com/EngineeringJrnl) & like us on Facebook (https://www.facebook.com/EngineeringJrnl).