Nanosheets could enable lightweight PPE for firefighters

Scientists at UNSW and the Australian Nuclear Science and Technology Organisation (ANSTO) are working to commercialise advanced products for firefighting, building protection and other applications, utilising a material made of two-dimensional transition metal carbides, carbonites and nitrides known as MXene.

Experiments at ANSTO’s Australian Centre for Neutron Scattering were undertaken on the Bilby small-angle neutron scattering (SANS) instrument to characterise the two-dimensional structure of the titanium carbide nanosheets and investigate the influence of temperature on the structure. The team’s findings were published in the journal Composites Part C.

Measurements revealed that MXene that is suspended in a colloidal solution consists of nanosheets of ultrathin multilayers with clear sharp edges. The material comprises nanolayers, which overlap each other and form clusters of micro-sized units that endow a level of protection. The nanolayers can be added on top of organic fire-retardant polymers.

The result is an inorganic compound that produces a coating which can be used in place of traditional fire protection measures. When heat comes from above the surface of the material, it is conducted and moved along the nanosheets dispersing it. The nanosheets also act as a heat shield, forming an additional layer of protection.

“Protective suits made with traditional retardant use as much as 30–40% carbon compounds to achieve the fire-retardant properties, which makes them heavy,” said ANSTO Thermal-Hydraulics Specialist Professor Guan Heng Yeoh. This means that simply wearing existing fire suits in Australia’s 40°C summers can be a hazard. In comparison, the total thickness of MXene was found to be 3 nm, as the researchers can get away with using very low concentrations of the two-dimensional material.

“This new process has great potential to revolutionise firefighting clothing and materials, which means new suits could be better designed to Australian conditions,” Prof Yeoh said.

Prof Yeoh, who is also Director of the ARC Training Centre for Fire Retardant Materials and Safety Technologies at UNSW, said the material could potentially be applied to other surfaces, such as buildings and vehicles, as it uses nanolayer technology. “Because it can be applied as a post-treatment, it doesn’t complicate the manufacturing process,” he said.

At the macro level, early tests have found the material to be an effective fire retardant; now the process will be further explored in a raft of different conditions.

“We also need to look at the performance and characteristics of the material at higher temperatures up to 800°C,” Prof Yeoh said.

Image credit: ©stock.adobe.com/au/storm

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