Arabica coffee helps scientists absorb solar heat directly with organic colloids.

Professional coffee knowledge exchange more coffee bean information please follow the coffee workshop (Wechat official account cafe_style)

In addition to being a high-priced coffee with a supple taste and low caffeine, Arabica coffee now has new uses, and Italian scientists have successfully absorbed solar heat directly using colloids (fluids) containing Arabica coffee.

Solar energy is rich in resources, and people capture solar energy directly or indirectly, among which there are few ways to absorb solar thermal energy. at present, people mainly absorb solar thermal energy indirectly, such as using curved mirrors to concentrate solar light, and then convert solar energy into thermal energy by the principle of light and heat, but this method covers a wide area, and its efficiency will be more limited by the convective heat loss of the environment.

Although there is no way to absorb solar heat directly in the world, the current carbon-based nano-colloids have the problems of cytotoxicity (cytotoxicity) and environmental pollution. In response, Matteo Alberghini, a scientist at the National Institute of Optics in Italy, has found a solution to develop organic, pollution-free, stable and low-cost colloids.

Colloid sounds like a mysterious chemical term, which has little to do with ordinary people's daily life, but in fact, the soy milk and coffee on the table and the ink on the desk are all colloids, and different materials have different functions. Among them, the colloid surface can absorb heat, and then transferred to the internal fluid region, which can effectively prevent convection and radiation heat loss, so it is also used for solar collectors and heat carriers.

The Alberghini team made a new colloid G30 from distilled water, Arabica coffee, glycerin and copper sulfate. after further analysis of its photothermal properties, they also found that the nano-colloid could directly absorb solar heat.

They first added the coffee suspension to the water and put it into a scanning electron microscope (SEM) to assess the particle distribution, and then the scientists added glycerin and copper sulfate to reduce the freezing point and avoid the formation of algae or mold in the colloid.

In order to verify the endothermic effect of G30, scientists also carried out experiments on energy storage and optical properties according to different proportion of distilled water. Finally, it was found that coffee is behind the heat absorption of colloid. Once the proportion of distilled water is increased, the heat storage effect of colloid will be affected.

The Alberghini team also compared coffee colloids with existing solar collectors. The experimental results show that coffee colloids have shown the potential to capture solar heat directly, and the final results are consistent with the data obtained by computer models, further confirming that the photothermal properties of coffee colloids are similar to those of traditional indirect absorption techniques.

This makes it possible for scientists to use natural and organic methods to capture solar heat in the future, so that people's daily good friend Arabica coffee can help devices such as solar distillation, solar desalination, heating and sustainable solar radiation cooling, but it is unknown whether the team will use other varieties of coffee and other varieties of coffee in the future.