The summary is made by artificial intelligence and checked by a human.
Fabric layered with silver threads, plastic and wool can cool surfaces and skin by 2-8 degrees in a big city.
The developers of the fabric are engineers from the University of Chicago who wanted to design it especially for cities.
The fabric can block more than half of the radiation that radiates from buildings and the ground.
The improved fabric would also be suitable for protecting clothes, buildings and cars and storing food.
Silver threadsfabric layered with plastic and wool can cool surfaces and skin by 2–8 degrees in a big city.
The fabric has three layers. The fabric clearly cools the feeling, more than, say, the familiar silk, say the developers of the fabric. They are from the University of Chicago Molecular Research Unit.
They wanted to design a fabric especially for big cities. The idea is to block the heat radiation glowing from different surfaces of the city with fabric.
In cities asphalt and building surfaces radiate heat. It can raise the temperature of the city by several degrees.
In urban heat islands, the sun is only one source of heat. When it glows from above, in the city, heat radiation penetrates the body and clothes from the sides and below as well.
For example, the silver of the fabric reflects not only the sun’s radiation, but also the infrared radiation emitted by the city’s structures.
Small silver nanowires reflect much of the radiation.
One developer of the fabric Po-Chun Hsu says the fabric could block more than half of the radiation that radiates from buildings and the ground. In general, cooling fabrics do not take into account the radiation that comes from asphalt and houses.
In heat waves for example, in the cities of Mexico, India, Pakistan and Oman, the temperature has recently risen close to 50 degrees Celsius, in some places even more than that.
There are more and more heat islands in the world’s cities, where it can be downright oppressive.
Uncomfortable heat may increase, for example, in Southeast Asia and China, as well as in Arizona, Nevada and California in the United States.
The fabric’s designers believe that its cooling effect can reduce heat-related hospitalizations and even deaths.
The fabric has been tested in the Arizona sun. In outdoor tests, the textile remained about 8.9 degrees Celsius cooler than ordinary silk fabric.
When tested on the skin, the textile was about 1.8 degrees Celsius cooler than cotton fabric, says the Techxplore news service.
People usually use materials in their clothing designed to reflect direct sunlight.
Their hats, shoulders and shoe tips are directly exposed to the light coming from above.
However, those body parts cover only about three percent of the entire clothing.
The remaining 97 percent of clothing warms up from the sides and bottom, i.e. as thermal radiation, kertoo New Scientist.
“The sun is visible light and thermal radiation is infrared, so they have different wavelengths. That’s why we needed materials with different properties for the fabric”, says the person who developed the fabric Chenxi Sui in the University of Chicago Bulletin.
Thick version of the new fabric is protected by a plastic layer of polyethylene.
The fabric would also be suitable for protecting buildings and storing food.
For example, milk and many other foodstuffs need protection during transport. Otherwise, they may spoil in the heat.
He told about the fabric science journal Science.