Enhanced Swelling, Mechanical and Thermal Properties of Cellulose Nanofibrils (CNF)/Poly(vinyl alcohol) (PVA) Hydrogels with Controlled Porous Structure

In this work, novel porous cellulose nanofibrils (CNF)/poly(vinyl alcohol) (PVA) hydrogels were prepared using the hybrid solvent of dimethyl sulfoxide (DMSO)/water, followed by freezing/thawing process. Structure, swelling, mechanical and thermal properties of CNF/PVA were explored. The results revealed that porous hydrogels were formed by using the hybrid solvent of DMSO/water, and the pore sizes of hydrogels were controlled by the concentration of CNF. The porous structure of the composite hydrogels can strongly enhance the swelling properties as expected. Compared with pure PVA hydrogels, a 150% improvement in compressive strength were achieved by the hybrid solvent. And the increment of compressive strength depended on the concentration of the CNF. Moreover, the addition of CNF improved the thermal stability of the PVA hydrogels significantly. The low cost, nontoxic and high-performance nanoreinforced hydrogels may have a promising application in tissue engineering fields.