Researchers from Melbourne, Australia-based RMIT University are taking advantage of the amazing thermal conductivity of nanodiamonds to create "smart" textiles that can keep you cooler in the summer.

The study published in Polymers for Advanced Technologies found that fabric made from cotton coated with nanodiamonds — using a method called electrospinning — can draw out body heat and release it from the fabric.

The process delivers a comfort advantage of 2 to 3 degrees Celsius during the cooling down process, compared to untreated cotton.

Project lead and senior lecturer Dr. Shadi Houshyar said there is a big opportunity to use these insights to create new textiles for sportswear and even personal protective clothing, such as under-layers to keep fire fighters cool.

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

“While 2 or 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.

The potential widespread use of nanodiamond-treated fabric in clothing was projected by the researchers to lead to a 20-30% energy saving due to lower use of air conditioning.

Nanodiamonds are unimaginably small. They measure from 5 to 100 nanometers in diameter. For reference, there are 25.4 million nanometers in one inch. A human hair is approximately 80,000-100,000 nanometers wide.

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

In the study, cotton material was first coated with an adhesive, then electrospun with a polymer solution made from nanodiamonds, polyurethane and a solvent. This process created a web of nanofibers on the cotton fibers, which were then cured to bond the two.

Lead researcher and 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," Rehman said. "The nanodiamonds then transfer heat from the body into the air. Because nanodiamonds are such good thermal conductors, it does it faster than untreated fabric.”

Rehman added that nanodiamonds are also biocompatible, so they’re safe for the human body.

Researchers at RMIT's Centre for Materials Innovation and Future Fashion will continue to study the durability of the nanofibers, especially during the washing process.

Credits: Photo of research supervisor and senior lecturer Dr. Xin Wang, lead researcher and research assistant Dr. Aisha Rehman and project leader and senior lecturer Dr. Shadi Houshyar by Cherry Cai, RMIT University. Nanodiamonds photo by Cherry Cai, RMIT University.