polymer tech

Superabsorbent polymer  (also called  slush powder ) can absorb and retain extremely large amounts of a liquid relative to their own mass. [1] Water-absorbing  polymers , which are classified as  hydrogels  when cross-linked, [2]  absorb aqueous solutions through hydrogen bonding with water molecules. A SAP's ability to absorb water depends on the ionic concentration of the aqueous solution. In deionized and distilled  water , a SAP may absorb 300 times its weight (from 30 to 60 times its own volume) and can become up to 99.9% liquid, but when put into a 0.9% saline solution, the absorbency drops to approximately 50 times its weight [ citation needed ] . The presence of valence cations in the solution impedes the polymer's ability to bond with the water molecule. The total absorbency and  swelling capacity  are controlled by the type and degree of cross-linkers used to make the  gel . Low-density cross-linked SAPs generally have a ...