Scientists at the National University of Singapore were extremely frustrated by the fact that only 40% of used tires go to recycling - so they set out to find an alternative solution to this problem. There was no clear plan, only an idea - to isolate rubber from the tire material and give it a new shape. For example, turn it into a porous airgel base - a cellular structure in which the cells are filled with gas.
During the experiments, the scientists soaked thin fragments of tires in a mixture of "environmentally friendly" solvents and water to clean the rubber from impurities. Then the solution was digested until a uniform mass was formed, cooled to -50 ° C and lyophilized in a vacuum chamber for 12 hours. The output was a dense and lightweight airgel.
Unlike other types of aerogels, the rubber-based version turned out to be many times stronger. And after coating with methoxytrimethylsilane, it also became water-resistant, which immediately determined its promising field of application - as a sorbent for oil spill response. Yesterday's trash will help you get rid of another type of waste and pollution.
But most of all, Singaporean scientists are pleased with the economic side of the invention. Creation of a sheet of rubber airgel with an area of 1 sq. M. and 1 cm thick takes 12-13 hours and costs $ 7. The process can be easily scaled up and turned into a commercially attractive business. Especially, given the enormous reserves and the cheapness of the source material.