It is a truth universally acknowledged that a metal exposed to the weather must be in want of a coating. Today’s protective coatings stick to metal for a while, but the trick is in making the relationship last – and Dr. Cathleen Crudden is the matchmaker for the job.
Dr. Crudden, of the Department of Chemistry, has a vision for how to protect vital industrial metals, from towering bridges to tiny cellphone parts, and Canada’s New Frontiers in Research Fund has awarded her $24 million over six years to pursue it.
Every country in the world faces the inevitable loss of expensive infrastructure and machines through the slow death of metal, much of it steel – bridges, pipelines, vehicles, and more.
But Dr. Crudden thinks chemistry could slow these losses. What if Queen’s can find a new weapon against rust and other metal degradation?
What if Queen’s can prevent your future car from rusting? What if metal can last longer in pipelines, aerospace, and wind turbines in the ocean with salt spray all around?
The wastefulness of degraded metal bothers Dr. Crudden. Think about how much energy we put into digging ore out of the ground and then smelting it and converting it into whatever we want. And then we expose machines to water, salt, and air “and eventually it all degrades, right?” she says.
Her quest is to improve the rust-resistant coatings on metal – spray-on coatings such as epoxy that work fine when they’re fresh, but don’t stick well enough to the metal they are supposed to protect.
She wants to “work with those coatings that are already really well designed, to help them work better.”
Even with better coatings, “eventually the coating will fail. Everything fails. The question is: How much longer can we keep things in service by this chemistry?”
“None of these [existing coatings] are fundamentally designed to stick to the metal,” she says.
Her plan: change the metal itself. “What we’re trying to do is to make the surfaces of these metals more organic” – in other words, more like the carbon- and hydrogen-based materials in organic chemistry.
Dr. Crudden’s vision is to develop a material that forms a chemical bond with the metal, bonding molecule--to-molecule with the metal surface instead of just sticking like paint or glue. This lets the epoxy coating grip better.
“We’ve developed a method to make these interactions [bonds] with metals very strong,” she says.
Her new material “forms a carbon-to-metal bond that is unique. These are the same kind of bonds that are used to hold molecules together, so they are very strong.”
People sometimes ask her what the “aha moment” was. That moment came about 10 years ago, in a seminar where someone mentioned a completely new offshoot of a research field where she was already working.
“And I thought, ‘Oh my God, we should try this on a surface!’
“It was such a new area for me that I literally had to track down a colleague and say: How do I do this? Here’s my idea, but I don’t even know how I will be able to tell if I’ve been successful! We had to learn a whole new set of techniques.”
This set her up with a new network of engineers, electrochemists, corrosion specialists, condensed matter physicists, and industrial partners. “And that’s where it actually comes together.
“As a scientist you’re always excited by what you do, but when industry players contact you and say: ‘Hey, how about this? And could we do that?’ and they are excited about what you’re doing, that’s amazing.”
But there’s a second use for her new approach: electronics. Your cellphone has tiny components, mostly made of copper, that need better protection against stress, largely heat that can make your phone short out. “The industry is looking for things that can protect these metals and new ways of manufacturing the devices.” She’s working on those.
And a third: medicine. Dr. Crudden works with the University Health Network (encompassing hospitals in Toronto as well as the University of Toronto) to investigate coatings for the tiny gold particles used in cancer treatment, in particular radiation therapy.
It works this way. One technique in radiation therapy involves binding gold nanoparticles – far too small to see – to a tumour. Once inside, researchers boost the power of radiation directed at the tumour without harming nearby healthy cells.
“The idea is going to be: Can we improve the efficacy of radiation therapy?
“We can use the coating to protect the nanoparticles that then attach to tumour cells… and then enhance the ability of the radiation to kill those cells.”
This research holds new hope for people in remote communities who today have to move to a city for six or eight weeks of treatment, she says. “What happens if we can make this more efficient and you only need a week? We don’t know, but that’s the goal: better outcomes and maybe shorter treatment times.”
Dr. Crudden’s work has to be hands-on in a lab, but luckily in pandemic times she has had one advantage. Her lab is designed to deal with hazardous chemicals, so the indoor air is constantly exchanged through vents and replaced with fresh air. This enables her to have staff and students actually in the lab.
“They don’t have as much opportunity to socialize [but] they do see each other in the lab.” Progress, she says, “often comes from lunchtime discussions.”
Dr. Crudden holds a Canada Research Chair in Metal Organic Chemistry. She’s grateful for the federal grant, but also to Queen’s for giving her valuable time to explore ideas. “Queen’s was super supportive just from Day 1. At every stage of the process, Queen’s said, ‘OK, what do you need?’”