Truly cool clothes

Truly cool clothes

An all-new fabric that radiates heat away

If the heat's got you this time, here's some cool news. A new textile made from fabric, plastic and silver nanowires can keep a person up to 16 degrees cooler than silk or other cooling materials. This three-layered textile is designed to stay cool in urban settings by taking advantage of a principle known as radiative cooling—the natural process by which objects transfer heat to their surrounding space.

Radiative cooling is a promising body cooling technology, as radiative heat transfer is the primary heat dissipation pathway for the human body, accounting for about half of the total heat transfer from it. More importantly, it dissipates human body heat with no energy input and no carbon output, making it a promising alternative to existing energy-intensive cooling systems.

How does it work?

The material selectively emits infrared radiation within the narrow band of wavelengths that can escape Earth’s atmosphere. At the same time, it blocks the sun’s radiation and infrared radiation emitted by surrounding structures. Some cooling fabrics and building materials already rely on this radiative cooling principle, but most of those designs do not account for radiation from the sun or infrared radiation from structures like buildings and pavement.

What else can it be used for?

Researchers suggest this cooling textile could be used on buildings, in cars, or even for food storage and shipping in order to lessen the need for refrigeration, which has a significant climate impact of its own. The textile could have health benefits for those in extreme heat conditions.

High temperatures can lead to a lot of health related issues. According to the World Health Organisation, heat stress is actually the leading cause of weather-related deaths. As climate change makes heat waves more common and more severe, it’s increasing the number of people exposed to this heat, and the potential health risks they face.

There's some way to go yet. Researchers have established that this new fabric can cool skin temperatures but public acceptance and mass production remains to be worked on.

How is it different from other radiative textiles?

1. The top layer is made of polymethylpentene or PMP, a type of plastic commonly used for packaging; the researchers had to figure out how to spin it into a fiber.

2. The second is a sheet of silver nanowires, which acts like a mirror to reflect infrared radiation.

3. The top two layers block both the solar radiation and the ambient radiation reflected off of surfaces.

4. The third layer can be any conventional fabric, like wool or cotton.

5. The main thickness comes from the conventional fabric, the top layer is about 1/100th of a human hair.

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The New Indian Express
www.newindianexpress.com