Corrosion and Fouling: Is There a Solution?

Fouling is another huge problem. Dirt accumulates on valves, pumps and pipes, which impacts their performance and plant productivity. Cleaning them can be difficult, with several potential environmental impacts. Furthermore, cleaning can cause erosion, which causes other problems.

Imagine what it would mean to industry, power generation, mining, oil and gas production and dozens of other sectors like transportation, if metals did not rust, corrode or foul. Imagine what it would mean for municipalities if they did not have to constantly budget for replacing bridges and signs and roads because of corrosion, and for offshore oil producers if they did not have to replace equipment due to corrosion from harsh salt air and acids.

If the discovery by a couple of graduate students proves to be as valuable as it appears at first glance, this could be a reality.

Kargar was working on a nature-inspired coating that would repel everything. He was having success but could not figure out how to make it work in an industrial setting. It had a durability and scalability problem. The lack of durability was mainly due to the use of polymeric materials with the lack of a strong physical bond to the surfaces. The scalability issue was related to the manufacturing processes used in academic settings: they are usually expensive and cannot be used to coat large objects.

One day, Kargar went to his partner’s office. On the wall, Haghdoost had a beautiful, colored electron-microscopy image. It was of microstructures she’d produced on metal surfaces. Haghdoost had been aiming for another result in the process that was depicted, but the surface in her opinion turned out to be "a failed experiment." However, she felt it was still beautiful, so she took a photo and hung it there.

As Kargar looked at it, he realized that, while the process hadn’t been particularly successful, the adhesion to the surface was solid. He guessed that it might be “superhydrophobic,” which means very water-repellent. Lab tests proved he was right.

Immediately Kargar realized this had potential for his own discovery and asked Haghdoost what she had used. Electroplating. Haghdoost and Kargar felt that this could be the answer to the durability and scalability problem Kargar was having with his product.

As they worked more with the material and the adhesion process, the team realized this could mean large metal objects could be affordably water-proofed with the process they were developing. It would make a smooth surface more textured, so water and dirt would not adhere.

Simply put, a solution of ions is applied to the metal product, and the deposited ions turn into solids distributed unevenly across the surface. The resulting texture resembles minuscule “valleys and mountains,” so a water droplet encounters much less solid surface area. So, instead of sticking to an area, the droplets sit on the air pockets trapped between the microstructures on the surface and roll right off.

Upon receipt of considerable encouragement from early stage funding sources and potential customers, Kargar and Haghdoost formed a company, Maxterial, in 2015 to develop the product, which they say could offer a solution for major billion-dollar problems such as fouling and corrosion. “Can you imagine what cost savings there could be for the oil and gas, chemicals and power industry?” Kargar asked.

Kargar and Haghdoost’s work came to the attention of the Thiel Foundation, and became the beneficiary of seed funding through Breakoutlabs, the National Science Foundation and Virginia Tech Foundation. Kargar said that, not only were these organizations a source of money, they were mentors, offering expertise and information that has been of tremendous benefit to this project, as they are to many other start-ups.

Thanks to the assistance from the above-noted foundations, Maxterial teammates were able to develop what they call Max 1, which resists a variety of corrosive materials, including strong acids, by modifying the surface shape of the materials to which it is applied.

We asked Kargar what benefit this coating could have for valve manufacturers. “Less expensive materials, for example, steel, could be coated by MAX 1 corrosion resistance materials as a potential replacement for expensive super alloys,” he replied. “This enables a huge cost saving. Depending on the application, such replacement can reduce the cost of products by multiple times. Furthermore, the end users of the valves, for example chemical, oil and gas and power industries, all are dealing with problems such as fouling. Adopting such a coating will enable the valve industry to supply their customer with a superior product that addressees their major issues.”

Kargar offered this example: In many applications, valves are exposed to corrosive gases. In these cases, if the moisture available in the gas stream condenses, it can cause a severe corrosion issue. Therefore, in many applications the valves need to be heated up to mitigate the problem associated with the condensation. But, if there is a durable corrosion resistant and repellant coating, there is no need to heat the valves. That means a less sophisticated and expensive system and it also saves energy as no further heating is needed.

Although Maxterial is still in the research stage, Kargar says the company has already produced stainless steel that doesn’t get wet. Initially, the process will most likely be used to create longer-lasting bathroom fixtures like faucets, but the founders have been in discussions with valve manufacturers and end users to hear their ideas about potential practical uses for the material in real-world products.

If you as a valve manufacturer or end user would like to learn more and explore how this technology could be of use to you, contact Mehdi Kargar.

Kate Kunkel is senior editor of VALVE Magazine.