Fabrication and characterization of novel macroporous cellulose–alginate hydrogels

Novel macroporous hydrogels were prepared by blending of cellulose and sodium alginate (SA) solution, and then cross-linking with epichlorohydrin. The resulting cellulose/SA hydrogels were characterized by solid-state ¹³C NMR, wide-angle X-ray diffraction (WXRD), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), rheological measurement, dynamic mechanical analysis (DMA) and swelling test to evaluate their structure, interior morphology, gelation time, compressive modulus, and equilibrium swelling ratio. Our findings revealed that the cellulose acted as backbone in the hydrogels, whereas SA contributed to the higher equilibrium swelling ratio. The combination of cellulose having semi-stiff chains and SA containing –COOH groups in the cross-linking hydrogel created the macroporous structure. This work provided a new pathway for preparation of hydrogel with large porous structure through incorporation of stiff polymer as support of pore wall and acidic polysaccharide as expander of pore size because of high water-absorbency.