Advances in superporous hydrogels

Superporous hydrogels (SPHs) are different from superabsorbent polymers (SAPs) in that SPHs swell fast, within minutes, to the equilibrium swollen state regardless of their size. The fast swelling property is based on water absorption through open porous structure by capillary force. The poor mechanical strength of SPHs was overcome by developing the second-generation SPH composites (SPHCs) and the third-generation SPH hybrids (SPHHs). This review examines the differences between SAPs and SPHs and describes three different generations of SPHs.