ABSTRACT
Hydrophilic gels, also called “hydrogels,” are hydrophilic polymer networks swollen in water. Water inside the hydrogel allows free diffusion of some solute molecules, while the polymer serves as a matrix to hold water together. Hydrogels are mainly prepared by free-radical cross-linking copolymerization of acrylamide-based monomers with a divinyl monomer (cross-linker) in aqueous solutions. To increase their swelling capacity, an ionic co-monomer is also included in the monomer mixture. The desired properties of
hydrogels-increased swelling capacity, modulus of elasticity, and degree of heterogeneity-are obtained by adjusting both the concentration and the composition of the initial monomer mixture.
