Why is there a smell that is difficult to deodorize?


By William Malott

Even if you try hard to get rid of clothes, stuffed animals, sofas, etc., you will probably find that 'If you move your face close, the smell still remains ...'. On the other hand, there is also a smell that disappears immediately, but the difference seems to be caused by multiple factors.

Why Are Some Smells So Hard to Get Rid of?
https://www.livescience.com/65664-why-smells-linger.html

According to Professor Christopher Kramer of the University of Minnesota chemistry department in the United States, three factors determine how much the smell remains.

The first factor is the type of odor . (PDF) According to a study in 2014, it is possible that the human nose and brain can smell 1 trillion kinds of smells, but what seems to be persistent is that “the smell of tobacco attached to the hair 'The smell of a dry dog on the sofa' has been decided to some extent. That's because, according to Professor Kramer, receptors that detect odors in the nose react strongly to specific odors.

By Markus Spiske

The second factor is ' low volatility '. Although the source of the odor is rapidly lost when the liquid that is the source of the odor is highly volatile, the source of the odor disappears quickly, but since the liquid remains as a long liquid and continues to volatilize, the odor remains forever. You Because the volatility is low, the amount of “scent” released per fixed time is small, but if it is a kind of smell to which human beings respond sensitively, the smell is felt regardless of the molecular weight reaching to the receptor It will end up.

By fotyma

The third factor is the material of the object with the smell . Hair, carpet, cement etc are porous and have micro level holes. If the source of the smell enters this hole, the volatility decreases and the smell will remain for a long time. Also, many of the unpleasant smelling molecules are hydrophobic, and entering the hydrophobic material synergetically reduces their volatility even further. The polymers contained in cloths and carpets are porous and hydrophobic, so it is likely that the unpleasant smell will last particularly long.

in Science, Posted by log1k_iy