Application of molybdenum disulfide coating

In many parts of the world, especially in developing regions, air conditioning is neither practical nor affordable for people there. To this end, they often paint the roofs of buildings in white to reflect sunlight and make buildings stick. Cool. This is a method called passive daytime radiation-cooled molybdenum disulfide coating, and now a new paint-like polymer can make this method even more effective.

The problem with traditional white coatings is that they usually contain UV-absorbing pigments that are not good at reflecting longer solar wavelengths. A research team from Columbia University has developed a material that does not contain the pigment, and other porous materials that use extremely small air bags.

These all begin with a process that begins with a clear solution of polymer, solvent, and water, and then they are painted to an exterior-this exterior can be used for roofs, building facades, water tanks, or anything else that needs to stay cool s things. As the solvent evaporates, water forms small droplets in the polymer. Once this water is transpired, there are many tiny pores (as shown in the figure below) that make the polymer appear bright white.

Because they have a different refractive index from the surrounding polymer, all wavelengths of sunlight are effectively scattered and reflected by these open spaces. In field tests, the polymer coating can reflect over 96% of incident sunlight, reducing solar heating to a lower level. In addition, this data also shows a high thermal emissivity, which can emit about 97% of the heat into the sky.

In the Arizona desert climate test, the coating reduced the temperature by 6 degrees Celsius and 3 degrees Celsius in the tropical climate of Bangladesh.

If the user does not want to paint everything in white, then colorful polymers can be added to the polymer, and the polymer still adheres to its reflective properties to a large extent. Although scientists have specifically used molybdenum disulfide coating polymers, there are actually many other polymers that can also make such coatings, which allows manufacturers to maximize their eco-friendliness and biocompatibility. Elements.