MADE LIGHT, AND WON’T IGNITE

A new lightweight fire-retardant material looks like it may revolutionise safety for firefighters.

PROF GUAN HENG YEOH

University of NSW

DR JITENDRA MATA AND DR ANDREW WHITTEN

ANSTO

Clothing worn by firefighters is bulky and heavy, designed to minimise the heat and risk of fire posed by bushfires. This limits movement for the wearer and saps their energy, reducing the time they can stay on the front line and increasing the number of people needed to contain a blaze.

But new research by scientists from UNSW and Australia’s Nuclear Science and Technology Organisation (ANSTO) suggests that a new range of advanced materials may offer a viable alternative.

These materials have been shown to act as lightweight fire-retardant filler, which can self-extinguish if they ignite.

The team, led by Professor Guan Heng Yeoh—Director of the ARC Training Centre for Fire Retardant

Materials and Safety Technologies and the ARC Research Hub for Fire Resilience Infrastructure, Assets and Safety Advancements at UNSW, and Thermal-Hydraulic Specialist at ANSTO—is working to commercialise advanced products that might be used for firefighting.

But they haven’t limited their focus— they are also investigating options for building protection and other potential applications, such as in energy storage devices.

The groundbreaking research has focused on a family of two-dimensional transition metal carbides, carbonites, and nitrides, known as MXenes.

Using neutron scattering and other advanced techniques, researchers conducted detailed structural and surface characterisations of these materials to get a better understanding of how these affect their electrical, thermoelectric, magnetic, and other properties.

They found that MXenes are suspended in a colloidal solution consisting of nanosheets of ultrathin layers that overlap each other, giving a higher level of protection.

Protective suits made with traditional retardant are comprised of as much as 30 to 40% carbon compounds to achieve fire-retardant properties, which makes them heavy.

However, as Professor Yeoh explained, “Because we can use very low concentrations of the twodimensional material, it comprises only about 1 to 5% of the total weight of the final material.”

This reduces the need for much of the bulky material currently used, delivering a much lighter product.

“And because it can be applied as a post-treatment, it doesn’t complicate the manufacturing process,” Professor Yeoh said.

When heat comes from above the surface of the material, it is conducted and dispersed along the nanosheets,

A which also act as a heat shield.

This helps to reduce the heat transfer through the suit, giving the occupant more time before they start to feel the effects of the fire.

Ultimately, this would help to reduce the physical and mental impact upon firefighters, contributing significantly to their health and welfare.

According to Professor Yeoh, the amount of time currently taken to create the materials is still considerable, but work is underway to streamline and upscale production.

“We also need to look at the performance and characteristics of the material at higher temperatures up to

800°C,” he added.

However, at the macro level, early tests have found the material to be an effective fire retardant.

Chair of the AFAC PPE Technical Group, Mark Tarbett of the Country Fire Authority, commended the innovative research, and supported further testing of the material to ensure compliance for firefighting use.

“AFAC and its member agencies always look forward to the development of new and innovative firefighting components and products that provide demonstrated improvements to the safety and effectiveness of firefighters in the hostile environments in which they work,” he said.

“While we are currently unaware of any performance testing results against the Australian/New Zealand or International Standards for this emerging product, we will look to that type of independent data to confirm compliance for use across the emergency services sector in Australia and New Zealand.”

If testing is successful, MXenes may represent a great step forward in firefighting and fire protection, leading to greater safety of both the community and frontline firefighters.

A version of this article was originally published by ANSTO at www.ansto.gov.au/news/investigatinga-prospective-light-weight-fireretardant-material-superior-properties.