An innovative coating developed by RMIT engineer Kate Nguyen could save Australian homes from bushfires.
RMIT University’s Dr Kate Nguyen CPEng began her career as a chemical and materials engineer, but her success required one more step: just add heat.
An ARC DECRA Fellow and winner of the Batterham Medal for Engineering Excellence, Nguyen’s achievements include the development of a coating designed to help rural homes endure the fierce heat of a bushfire.
“I didn’t work on bushfires initially, but then when I came to Australia, every year I saw bushfires come back again and again and again, and each time there were people dying, there were people that lost their homes,” Nguyen, who grew up in Vietnam, tells create. “So, as an engineer, I like to do something to use the knowledge that I have to contribute to a possible solution to make sure that the damage is not that significant.”
Today, she leads RMIT’s Innovative Fire and Façade Engineering Group — and it is her materials expertise that places her well in the realm of fire research.
“When I work with materials, I work with materials at a high temperature, like refractory materials, ceramics,” she says.
“So I thought my background knowledge in that area — that may be useful for me when I work on fire safety engineering.”
City and country
Nguyen’s research into bushfire-resistant coating is a project she is undertaking as part of the L’Oreal–UNESCO Women in Science Fellowship, which she received in 2020, but her work involves a broad range of fireproofing applications.
These include non-combustible composite claddings for façades, which are suitable for high-rise buildings in inner cities.
She says, however, that creating fire-resistant materials for urban areas requires a different approach to those used in response to bushfires.
“We have metropolitan areas where we have a lot of high rises, but we also have a really widespread demographic geography here in Australia,” she says.
“Those detached houses are very different from high rises, so they would need different strategies.”
This housing tends to be one or two storeys and built close to vegetation. It’s here that Nguyen’s coating — rather than cladding — finds a use.
“We would really need to tailor the materials to meet those requirements,” she says.
The coating provides structures with a protective outer layer that shields them from the heat. This differs from intumescent paint, an alternative solution, which expands when exposed to heat, insulating the steel framework of a building.
“Paint will have a polymer component in there that will make it combustible,” Nguyen explains. “The material that I’m developing here is not highly combustible … So that’s one good thing because it will reduce the actual heat that the house has to undergo.”
The coating fills gaps in a building’s exterior as well, increasing its thermal efficiency. It also has a ceramic component to its makeup, which increases its heat resistance.
“It can withstand [heat] to over a thousand degrees [Celsius],” Nguyen says. “There starts to be some reaction around 750, but it can withstand up to a thousand.”
While the coating’s ability to protect homes from fire danger offers serious potential benefits in itself, Nguyen has also ensured that it can be produced sustainably.
“When I look at bushfire-prone areas, I really want to help the environmental impact there,” she says. “Climate change makes bushfires more severe each year. And then, the more bushfires, the more heat is released into the environment and that will feed back to climate change.”
That, she continues, results in more construction, which releases even more carbon into the atmosphere — a cycle to which she does not want to add. As a result, she has designed the cladding so it can be manufactured sustainably as well as so that it uses recycled materials, reducing its embodied energy in multiple ways.
“We have industry waste and that industry waste comes from the coal and mining industry,” Nguyen says of the raw materials going into the product. “It is out of the initial scope of the project, but I want to tailor it a little bit to include construction waste as well.”
The next step is to refine the coating so that it can be made commercially available. Nguyen says that when it can be produced at mass scale, its cost will be comparable to conventional materials. She also needs to convince the construction industry to take it up.
“It is a kind of conservative industry. When you have a new product, it is not easy to be accepted for wide use,” she says.
“Houses, they are there for 50, 100 years; we have to make sure that whatever material we are putting into the market will be able to perform or to provide the performance for that period.”
That’s why her current focus is on running accelerated tests to demonstrate the coating’s durability. She is also seeking to improve the spray technology through which the coating is applied.
Materials for new buildings
While the coating is currently designed for existing housing stock, Nguyen says that it is not out of the question for some of its properties to one day be incorporated into materials for new buildings.
“Perhaps we may be able to reformulate the material a little bit, because when you have new buildings or new houses, [there is more flexibility] in the material that you can use,” she says. “Because with this [coating], when you put it on a substrate, we have to make sure that it adheres to whatever is there … the prep and also the compatibility of those two materials need to be considered.
“But when you have a new building, that is not a problem anymore, so perhaps we can make the material even more efficient.”