A team of chemical engineers from Zhejiang University (China) has managed to make a fiber from an aerogel and knit a sweater from it. Tests have shown that such clothing allows you to keep warm better than sweaters made of traditional materials.
An aerogel is a special type of gel of various materials in which the liquid has been replaced by air. They were invented in the 1930s and used for various purposes, from thermal insulation and collection of dangerous spilled chemicals to creating traps for space dust on NASA’s Stardust interplanetary station. At the same time, the aerogel weighs a few grams and is the size of a palm.
Given the thermal insulation capabilities of aerogels, the creation of clothing from them has long attracted scientists. But it is difficult to turn aerogel into fiber due to insufficient moisture resistance and strength. But Chinese scientists managed to deal with both flaws.
We turned to polar bear fur for inspiration. The researchers noted that the animals are able to keep warm at extremely low temperatures thanks to their wool, which is porous inside but dense outside. To recreate these properties, they made encapsulated aerogel fibers – they took the starting material, rotated it in frozen form, and then ran the sol-gel process to make the actual aerogel. It was subjected to freeze-drying and covered with a semi-hard shell.
The result is thin, round fibers that can be adjusted in length. These fibers did not require further processing: they can be immediately knitted into a sweater, which is what the authors did.
The finished sweater was tested at -20°C. The thermal insulation properties turned out to be higher than those of wool, down and cotton. The results also showed that aerogel fiber garments can be stretched and dyed without compromising shape and properties. To test its durability, the sweater was stretched 10 thousand times and it was noted that it was practically unharmed.
The use of such fibers in mass-produced clothing has not yet been reported, but it is possible that in a few years, along with wool sweaters, aerogel ones will be available in stores.
