The present invention features a method for the formation of superporous
hydrogels using an ion-equilibration technique. Anionic polysaccharides
are included in the hydrogel reaction mixture and cations are introduced
either during or after hydrogel formation. Properties of the resulting
hydrogel can be subsequently adjusted by treating the cation-complexed
gel with a different cation or cation mixture under equilibrating
conditions. It has been found that by properly adjusting the cations and
the sequence in which they are used in the equilibration process,
superporous hydrogels can be formed that are highly absorbent while
maintaining favorable structural properties, including strength,
ruggedness, and resiliency. It has also been found that applying
appropriate dehydration conditions to them after their formation can
further stabilize the superporous hydrogels formed by the method of the
invention.