Lignocellulose fibers elaborating super-swollen three-dimensional cellulose hydrogels from solution in N,N-dimethylacetamide/lithium chloride

摘要

Super-swollen hydrogels were prepared in vitro from lignocelluloses of various origins via direct dissolving in N,N-dimethylacetamide/ lithium chloride (DMAc/LiCl) followed by regeneration from solutions. The hydrogels retained a large amount of water (up to 2500 wt%) and had high porosity and specific surface areas. Superabsorbance of the hydrogels was confirmed with a wide angle X-ray scattering method. The hydrogels seem to be smart matters due to PH-dependent behavior by swelling and pH change experiments. The gelation mechanism includes spontaneous self-assembly from the solutions in DMAc/LiCl, due to the reconstruction of new hydrogen bond webs between lignocellulose chains and water. The hydrogels exhibited high stability but their morphology changed while drying due to water removal and the collapse of the H-bonds.