Guwahati (Assam) [India], November 26 : Researchers at the Indian Institute of Technology Guwahati have developed a corrosion-resistant epoxy coating to protect steel structures exposed to seawater and high-salinity environments.
The findings of this research have been published in the prestigious journal Advanced Engineering Materials, in a paper co-authored by Prof. Chandan Das, Dept. of Chemical Engineering, IIT Guwahati, and research scholar Dr Anil Kumar.
Corrosion is a natural and gradual process that weakens metal surfaces and shortens the lifespan of essential structures, particularly those exposed to saltwater environments, such as offshore platforms, coastal bridges, port infrastructure, and marine pipelines. It has also played a role in major industrial incidents such as the 1984 Bhopal gas tragedy and the 1992 Guadalajara explosion.
Corrosion also causes environmental degradation and impacts human and aquatic life. Although barrier coatings are widely used for corrosion protection, they do not completely protect the surface and develop microscopic defects over time, allowing moisture and salts to penetrate and damage the underlying metal.
To address this challenge, researchers worldwide have experimented with strengthening epoxy coatings by adding various nanomaterials.
Nanomaterials are ultra-small particles, thousands of times smaller than the width of a human hair, that can enhance the strength, durability, and protective performance of coatings. While many studies have explored individual materials or simple combinations, no prior work has combined reduced graphene oxide (RGO), zinc oxide (ZnO), and polyaniline (PANI) within a single epoxy coating for marine corrosion protection.
Researchers at IIT Guwahati have combined these three materials into one coating system. The novel nanocomposite has been developed by attaching zinc oxide nanorods to reduced graphene oxide and then wrapping this structure with polyaniline.
The composite was then blended into an epoxy coating and evaluated using several characterisation methods.
The developed epoxy coating has shown improved performance compared to standard epoxy. It formed a denser and more uniform barrier, showed stronger adhesion to the steel surface, and slowed the movement of corrosive elements more effectively.
These characteristics make it suitable for applications in marine infrastructure, offshore platforms, shipbuilding, coastal pipelines, and other steel structures that must withstand continuous exposure to saltwater.
Speaking about the research, Prof. Chandan Das said, "The incorporation of RGO-ZnO-PANI nanocomposite into epoxy coating offers a promising strategy for achieving long-term corrosion resistance in harsh marine environments. As the next step, we are working towards assessing the long-term durability, real-world performance, and life-cycle impact of this coating."
The work from IIT Guwahati contributes to ongoing research on corrosion-resistant materials and provides a pathway to improve the reliability and longevity of structures operating in marine and high-salinity environments.