Substrate science

Petroleum-based high polymer for cosmetics
Mechanism of salt melting



This is a property change due to osmotic pressure


Na + (sodium ion), which is formed by ionization when water enters the sodium polyacrylate molecule, is formed by ionization of salt even when salt is dissolved in water.
When salt is applied outside of the absorbed sodium polyacrylate molecule, the salt becomes a salt solution that dissolves in the water there.
The sodium + concentration inside and outside the sodium polyacrylate molecule is high outside and low inside.
In such a case, the water moves in a direction that eliminates the difference in concentration. In other words, water comes from inside to outside.
圧 力 The pressure at which water moves due to the concentration difference is called "osmotic pressure". It is also due to osmotic pressure that water comes out when salt is applied to chopped vegetables.
(Quoted http://www2.tokai.or.jp/seed/seed/minna16.htm)


Sodium polyacrylate is one of the petroleum polymer
Used in cosmetics, hairdressing products, diaper absorbers, etc.






In contrast, those with natural viscosity
Carrageenan, etc.
Carrageenan is a viscous substance of red algae
This does not dissolve even when salted
Rather, the viscosity of the gel seems to increase slightly
Seaweed is always exposed to seawater (salinity), so it is a must-have for salting!




As mentioned above
Petroleum melts when salted

The face is also salty from sweat, so if you put on a petroleum gel…
After all it is melting