Water Absorption

Water Absorption

Here’s the interesting science behind water absorption by polymers found in diapers to satisfy your #ScienceSunday  curiosity!

Originally shared by Aida Hazlan

Sodium polyacrylate: The fluff that absorbs water!

❅ Sodium polyacrylate is an example of a super-absorbing polymer. It is a cross-linked (network) polymer that contains sodium atoms. It absorbs water by a process called osmosis. 

❅ Explanation from; http://goo.gl/IPzPU2 (h/t Rajini Rao)

The white powder is a polymer of sodium polyacrylate. The particles have a membrane of the polyacrylate which surrounds the sodium ions. By the process of osmosis, the water is attracted to the sodium polyacrylate because it contains sodium ions (an ion that you would find in table salt).

It expands the crystals of the powder and makes it into solid like gel. This is an example of an osmosis process reaction involving a polymer. Sodium polyacrylate contains a high number of sodium ions within each particle. Water is highly attracted to sodium ions. So when the water is poured into the beaker containing the sodium polyacrylate, it moves into the individual powder particles and expands the polymer particles to become a solid like gel.

❄  Sodium polyacrylate can absorb 800 times its weight in distilled water, but only 300 times its weight in tap water, since tap water contains some sodium, calcium and other mineral salts.

Source : http://goo.gl/PwVwUT   #sciencesunday   #scienceeveryday   #chemistry