Smart textiles for cooler safety clothes

Nanodiamonds are being used by researchers to create smart textiles that have the ability to cool people down faster when worn.

The study undertaken by RMIT University found that fabric made from cotton coated with nanodiamonds — using a method called electrospinning — showed a reduction of 2–3°C during the cooling down process compared to untreated cotton.

The thermal conductivity of nanodiamonds allows them to draw out body heat and release it from the fabric. Often used in IT, nanodiamonds can also help improve thermal properties of liquids and gels, as well as increase corrosive resistance in metals.

Project lead and RMIT Senior Lecturer Dr Shadi Houshyar said there was a real opportunity to use these insights to create new textiles for sportswear and personal protective clothing, such as underlayers to keep firefighters cool.

The study also found nanodiamonds increased the UV protection of cotton, making it suitable for outdoor summer clothing.

“While 2–3 degrees may not seem like much of a change, it does make a difference in comfort and health impacts over extended periods and in practical terms, could be the difference between keeping your air conditioner off or turning it on,” Houshyar said.

“There’s also potential to explore how nanodiamonds can be used to protect buildings from overheating, which can lead to environmental benefits.”

The use of this fabric in clothing was projected to lead to a 20–30% energy saving due to lower use of air conditioning.

Based in the Centre for Materials Innovation and Future Fashion (CMIFF), the research team is made up of RMIT engineers and textile researchers who have strong expertise in developing next-generation smart textiles, as well as working with industry to develop realistic solutions.

Contrary to popular belief, nanodiamonds are not the same as the diamonds that adorn jewellery, Houshyar said.

“They’re actually cheap to make — cheaper than graphene oxide and other types of carbon materials,” she said.

“While they have a carbon lattice structure, they are much smaller in size. They’re also easy to make using methods like detonation or from waste materials.”

Nanodiamonds. Image credit: Cherry Cai, RMIT University.

How the research was undertaken

Cotton material was first coated with an adhesive, then electrospun with a polymer solution made from nanodiamonds, polyurethane and solvent. This process creates a web of nanofibres on the cotton fibres, which are then cured to bond the two.

Lead researcher and RMIT research assistant Dr Aisha Rehman said the coating with nanodiamonds was deliberately applied to only one side of the fabric to restrict heat in the atmosphere from transferring back to the body.

“The side of the fabric with the nanodiamond coating is what touches the skin. The nanodiamonds then transfer heat from the body into the air,” she said.

“Because nanodiamonds are such good thermal conductors, it does it faster than untreated fabric.”

Nanodiamonds were chosen for this study because of their strong thermal conductivity properties, Rehman said. In addition, they are biocompatible and are safe for the human body.

Further research will study the durability of the nanofibres, especially during the washing process.

Top image credit: iStock.com/natalie_board