Hydroxyethyl Cellulose-Based Hydrogels with Various Pore Sizes Prepared by Freeze-Drying

Porous hydrogels were prepared from hydroxyethyl cellulose (HEC) using citric acid (CA) as a cross-linker with the pores formed by a freeze-drying technique prior to the cross-linking reaction. The pore size increased with the increase of the mass ratio of water to HEC during the preparation of the hydrogels. The porous structure of the hydrogels was in favor of the protein adsorption. The results of thermogravimetry demonstrated that the thermal stability of HEC was improved by cross-linking with CA. The data of percent weight remaining in buffer solution with different pH indicated that the hydrogels were stable in both weak acid and base media. The data of the swelling ratio demonstrated a fast swelling property of the hydrogel.