China News Service, Shanghai, October 21 (Chou Yuanfang) The coating is like a "protective coat" covering the surface of the material. Once this coat is damaged, the internal metal will be directly exposed to the corrosive environment. The environmental conditions in the deep sea are harsh, and corrosion is the "invisible killer" that restricts the long-term service of offshore wind power equipment. East China University of Science and Technology announced on the 21st that the "Corrosion Protection-Green Dynamic Adaptive Intelligent Anti-corrosion Materials" project team of the School of Chemistry and Molecular Engineering has developed a "self-healing" smart coating to promote anti-corrosion protection from passive "shielding" to green, dynamic, and adaptive active protection.
In the fall of 2023, Ma Yuan, a graduate student at the School of Chemistry and Molecular Engineering at East China University of Science and Technology, will begin his first-stage graduate studies. The Fengxian campus of the school is located near the sea. Many steel structures on the campus are corroded by the sea wind all year round and have obvious rust, which gave him an intuitive feel for the dangers of corrosion. While researching the topic, he walked into a nearby offshore wind farm, looked at the towering wind turbines, and began to think: How can these powerful and important equipment standing in the deep sea resist ocean corrosion?
At that time, my country's offshore wind power was accelerating its expansion into the deep sea. In the marine environment with high salt spray and long-term seawater immersion, corrosion problems are prominent; the splash zone alternates between dry and wet, and chloride ions continue to accumulate. It is difficult to repair the damaged coating. In addition, the long distance from the shore and high operation and maintenance costs seriously restrict the long-term and stable service of offshore wind power facilities.
Ma Yuan aims at the national strategic demand of offshore wind power anti-corrosion, thus starting a scientific research path from the laboratory to the front line of industry.
"Scientific research must go to the front line to find real problems." Under the guidance of Liu Jinku, a professor at East China University of Science and Technology who has been involved in the field of anti-corrosion for more than 20 years, Ma Yuan and his team conducted in-depth industry chain research. In a few months, they visited nearly 20 companies, from upstream raw material production companies to downstream offshore wind farms. After field investigation, the research direction gradually became clear: the areas with high corrosion risk are concentrated in the splash zone, and the filler is the core element that determines the service life of the coating.
"The traditional coating idea is simply 'barrier protection'. Can the coating be given the ability to actively respond?" The team innovatively proposed a "barrier-photoelectric-corrosion inhibition" collaborative protection system. Test results show that the protective performance of the coating remains stable after long-term seawater immersion, and its comprehensive performance benchmarks against top international similar products.
In order to select the optimal filler blending ratio, the team made repeated trials and errors. Each set of proportions must go through the entire process of synthesis, painting, soaking, and performance testing. The single-round test cycle is as long as one month. "I often sit in front of the electrochemical test bench for a whole day, staring closely at the impedance spectrum curve, not daring to miss any detail." said team member Zhang Wenjing.
Getting through the small laboratory test is just the starting point, and the scale-up of the pilot test is a greater test. When upgrading from a small laboratory test beaker to a large-capacity reactor, parameters such as temperature, stirring rate, and feeding sequence need to be re-adjusted. After the first batch of products was produced, team members gathered around the reactor to take samples and test them. They breathed a sigh of relief after confirming that the impedance indicators matched the test results. The kilogram-level scale-up test was successfully completed, and the core performance has not declined. The long-term breakthrough has finally ushered in a phased breakthrough.
Currently, the team is accelerating the transformation of results from "samples" to "products". They admitted that differentiated protection of different corrosion zones in offshore wind power plants, improvement of cyclic self-healing performance, and engineering adaptation of large-scale coatings are still difficult points that need to be overcome in the next stage. Next, the team will iterate on the low-light adaptation formula, explore solutions for combining photoelectric protection and cathodic protection, simultaneously promote product pre-certification, and carry out formula cost reduction research.
"In the future, we will carry out long-term service performance tracking under real ocean working conditions and strive to complete the first batch of engineering application verification in the field of offshore wind power tower coatings." Ma Yuan said.
