Developing a technology that keeps off air pollutants with one puff!

Who doesn't look forward to the end of a cold winter and the beginning of spring with its warmer days and brighter mood? In fact, quite a few people are apprehensive about the season change... That’s because early spring means hay fever for some. More than that, did you know that the concentration of air pollutants, such as fine particles less than 2.5 μm in diameter (PM2.5), also grows with spring in the recent years? And these are said to increase the risk of respiratory and cardiovascular diseases.
These tiny particles suspended in the air are invisible to the naked eye, but cause considerable damage to human health. Isn’t there an easy way to protect our health from such risks and deliver better quality of life and lifestyles of greater beauty? This question was the starting point of this award-winning research.

If you look at a pollen grain or a PM2.5 particle under an electron microscope, you will notice that they have a rough surface. Objects “stick together” exactly when the bumps on their surfaces get caught with each other. As the surface of our skin, hair, and clothes also has innumerable micro-level bumps, they are easy to adhere to. Based on this fact, we thought of a way to reduce roughness and smooth the surface of skin and hair.

We looked for a substance that could be used for coating the surface and came up with phosphorylcholine, which is a key component of human cell membrane. Therefore, it is extremely biocompatible and puts no stress on human skin or body. We processed this substance into chain-like compounds, so-called polymers, and succeeded in smoothing the surface of skin and hair with these phosphorylcholine-based polymers.

Meanwhile, there is another major factor that causes the adhesion of pollen or PM2.5: static electricity. It is generated due to friction between objects, thus our skin, hair, and clothes are also charged, and small particles like pollen or PM2.5 are easily attracted by this static electricity charge.
In other words, if the generation of static electricity on object surfaces could be suppressed, it would prevent the adhesion of airborne pollutants. Further research showed that the above-mentioned phosphorylcholine-based polymer, which we used for surface coating, also possessed an antistatic effect. Phosphorylcholine was found to have an extremely high electrical conductivity, which means that the substance easily conducts electric current. So, it is effective in suppressing the electrical charge of a surface.

As a result, we have found a safe and easy method to protect human health from air pollutants. Shiseido will continue this research to develop products that would help people enjoy comfortable daily lives in a simple way.