Climate change and recent heat waves in Europe and North America are forcing the world to think about how to adjust to a new reality. online blackjack. The solution could be materials that passively heat or cool the environment and make the environment more comfortable. Technologies today change our world and ourselves. Until you don’t buy such material and are sitting under an air conditioner check the link https://bitcoincasinos-au.com/ and test your luck there. Digitalization is already everywhere.
Researchers from Nankai University have proposed their own version. A multilayer material that combines both properties. In a cool environment, it twists and absorbs light. In a warm environment, it stretches and reflects it.
Another Way of Thinking
As a rule, when designing passive materials, casino joka casino en ligne you have to choose between properties – they cannot easily switch from absorbing sunlight to reflecting. It’s usually best to be able to turn this feature on or off. But it takes energy to transition between states .
A team from Nankai University in China has created another mimosa-inspired solution. The idea was created by nature. The Chinese scientists decided to create the material according to the plant.
To bring this idea to life, they used a polymer that changes its shape depending on temperature. The polymer consisted of three different subunits that could assume different conformations when subjected to loading.
How Does It Work?
As an experiment, polymer sheets were stretched at high temperatures (90°C). Then they expanded and contracted at temperatures typical of the internal environment. This temperature-sensitive sheet was then combined with a transparent sheet that is not temperature sensitive. The temperature is changing. The resulting two-layer sheet experiences uneven stress. As a result, when cooled, it collapses, and when heated, it flattens again.
As the heat-sensitive sheet would lose its usefulness, the scientists have decided to change it. Basically, they combined two different materials to get the unique one. With the right proportions, the material started to absorb the visible light and radiate the heat.
At low temperatures, the heat-sensitive sheet rolls up, revealing a dark base that absorbs sunlight, causing objects to heat up.
However, as soon as the temperature rises, the leaf will open. Instead of an absorbent surface, the surface becomes reflective, preventing the environment from heating up. Researchers creatively refer to these two states as heating and cooling modes.
At first, about 73% of the incident sunlight is absorbed in heating mode. And the second in the cooling mode reflects 67%. The resulting material looks thin and brittle but has withstood over 500 twisting cycles without visible problems.
The only problem the team had was that in advanced mode, the reflective layer did not come into close contact with the non-reflective layer, which limited the amount of heat that could be transferred between them and the efficiency of the system as a whole. In addition, this material requires space to work, as it rolls up into a tube. This obstacle must be overcome before it can be used in practice.