Preparation and characterization of chitin hydrogels by water vapor induced gelation route

A novel method of chitin hydrogel preparation, called vapor induced gelation, using exposure of chitin/N-methyl-pyrrolidone/LiCl solution to water vapors is presented. Compared to gelation induced by direct immersion in water, hydrogels are characterized by smaller deformation during gelation (area shrinkage is 20% instead of 65%), larger water volume fraction (75 instead of 62%, v/v) and 10 times higher apparent compression moduli. Their nanostructure consists of thicker and larger crystalline platelets network (thickness = 37 angstrom, apparent coherent crystalline size L-020 = 145 angstrom) comparatively to direct immersion gels (25 angstrom and L-020 = 95 angstrom). Drug delivery potential of chitin hydrogels was determined for non-interactive low molecular molecules. (C) 2012 Elsevier B.V. All rights reserved.