Enhanced Swelling Rate of Poly(ethylene glycol)-Grafted Superporous Hydrogels

Hydrophilic poly(ethylene glycol) (PEG) grafts were introduced into superporous hydrogels (SPHs) to enhance the water absorption rate and swelling kinetics. PEG-grafted SPHs were prepared by copolymerization of acrylic acid and acrylamide monomers in the presence of PEG acrylate accompanied by a gas blowing foaming process to create superporous structures. PEG-grafted SPHs swelled 3 6 times faster than the control SPHs. The equilibrium swelling time was significantly reduced by introduction of hydrophilic PEG grafts and was further shortened by moisture. PEG-grafted SPHs containing 28wt% of moisture reached their equilibrium swelling within 20s. These PEG-grafted SPHs with fast swelling and superabsorbent properties may be useful for bioapplications where fast swelling kinetics is critical.