Australian researchers have developed a nanodiamond-coated fabric that distributes body heat better than traditional materials. They mixed nanodiamonds with polyurethane and applied the mixture to the side of the fabric in contact with the skin. Experiments have shown that the treated material cools faster than control samples. However, wearing such a fabric may not be that comfortable.

With the onset of global warming, experts are looking for ways to make people’s lives more comfortable. One of these areas is the development of individual clothing.

The removal of heat from the body can be organized in two ways: active and passive. But active refers to large electrical devices intended for ventilation or liquid cooling. Passive involves fabric modification using, for example, nanoporous polyethylene. However, there are other problems associated with this type of additive: unpleasant sensations and staining on the body, complexity in production and limitations in design.

Australian researchers decided to create a lightweight and comfortable cooling fabric based on nanostructures with good thermal conductivity. Scientists chose nanodiamonds because they had previously demonstrated effective heat dissipation on wool fabric, changing the approach to creating composite materials. The study on this subject was published in the journal Polymers for Advanced Technologies.

Scientists took 100% cotton fabric as a basis because it is ecological, comfortable and biocompatible. Nanodiamonds, approximately 190 nanometers in size, were mixed with a polyurethane solution that served as a binding agent. The resulting polymer was applied to one side of the fabric by electrospinning, creating nanofibrous structures. According to the researchers, this method greatly simplifies the production of the material.

Heat transfer analysis was evaluated using infrared thermography: samples were placed on a plate heated to 37°C and observed for one minute. It was then removed, allowed to cool to room temperature, and placed again on a warm surface, but with the other side.

It turned out that the open side of the treated samples was heated more strongly than in the control samples – 31.8-33.5°C versus 34-34.5°C. This is explained by the presence of a nanodiamond layer on the back. As the experimenters explained, the temperature difference means that the fabric cools quickly if the coated side is close to the skin.

Another experience showed a similar result. The bare hand of a person with a temperature of 29°C was covered with two tissue samples. The temperature of the hand with control materials was 25.5°C, and the temperature of the hand with nanodiamonds was 26.9°C. The authors concluded that the new coating dissipated heat more quickly into the atmosphere and that the material itself cooled more intensely than the control. Experiments conducted in sunlight showed the results themselves.

The researchers also tested the abrasion resistance of the fabric with nanodiamonds. The treated material absorbed an average of 8-12% more ultraviolet light than the control. The air permeability of the fabric with the nanodiamond layer was slightly lower, but they absorbed water much worse: one of the samples did not absorb anything because the polyurethane layer formed a film that did not let moisture in. material. The authors of the scientific paper noted that the best resistance to UV radiation in nanodiamond samples makes them attractive UV protective agents. However, from a comfort perspective, wearing such a fabric can be problematic.

“Contrary to popular belief, nanodiamonds are not the same as diamonds used in jewelry. In fact, they are cheap to produce; It is cheaper than graphene oxide and other types of carbon materials. Although they have a carbon cage structure, their dimensions are much smaller. They are also easy to produce by explosion or from waste,” explained Shadi Houshiar, one of the authors of the study.