Crystalline Structure of Chitosan Microgranules Cross-Linked with Cu2+ and Ag+ Ions

Granules with different degrees of chelating with Cu2+ and Ag+ ions were a subject of structural studies related to crystallinity. The degree of ordering of selected samples was described by the X-ray method. The WAXS diffraction patterns are presented as three bands corresponding to the crystalline phase (2θ = 10, 20, and 22°) and two broad ones that correspond to the amorphous phase (2θ = 20 and 40°). In diffraction patterns of pure chitosan granules there are mainly two peaks 2θ = 10 and 20°, which according to literature might indicate crystalline form II. From the X-ray analysis, it follows that after adsorption of both metal ions, the degree of ordering of the tested sample is reduced. This can provide an evidence of a dependence of the ordering degree, i.e., supramolecular structure of chitosan on the adsorption of both metal ions.