Researchers create biodegradable aerogel with more than 100 per cent solar reflectivity

A team of researchers from Sichuan University in China has developed an aerogel that has a reflectivity of 104 per cent.

Made up of gelatine and DNA, the aerogel has attractive radiative cooling properties. The layered design of the cooling material allows it to absorb and reflect sunlight. The material achieves a high reflectivity because it develops a unique glow during the photoluminescence effect.

The new development comes as scientists around the world are trying to develop environmentally sustainable methods for heating and cooling, and this cooling material could tick most of the boxes.

A biodegradable solution

The research team, led by Jian-Wen Ma, created the aerogel via “a freeze-drying process to obtain structurally homogeneous aerogels using gelatine and DNA”. Because it is created with DNA and gelatine, it is recyclable and biodegradable.

Ma told Interesting Engineering the multi-stage layered structure of the aerogel allows for multiple scattering/reflection of sunlight, which effectively improves solar reflectivity.

“The reflectivity is obtained by testing with a post-spectroscopic UV/VIS/NIR device,” he said. “The luminescence of the aerogel originates from the tightly cross-linked network formed by gelatine and DNA, which allows the chromophores to come together and inhibit the non-radiative leaps of the system.”

The material has been successfully tested in different weather conditions and was able to cool ambient temperatures by 16ºC under high solar irradiance. The researchers estimate the material could lower the energy required to cool buildings by 69 per cent when applied to the outside.

The full paper is available to read here.

Feature image provided by Interesting Engineering.