Complexação dos íons cobre e mercúrio em quitosana natural e modificada quimicamente

Abstract

The complexation of copper and mercury with chitosan was investigated using spectrophotometric method. The study of the nature of the complexes involved demonstrated that chitosan-Cu(II) complex are different when chitosan is crosslinked with glutaraldehyde and that the complexation model chitosan-Cu(II) possibly has structures as [Cu(- NH 2)]2+ in the case of natural and epichlorohydrin-crosslinked chitosan, following mainly the “pendant model”. Glutaraldehyde-crosslinked chitosan-Hg(II) complex showed only a peak at pH = 6,0, while the natural and epichlorohydrin-crosslinked chitosan–Hg(II) presented two peaks indicating two structures that are possible (such as [Hg(-NH 2)] 2+ e [Hg(-NH 2) 2]2+ , following either “pendant” and “bridge models”).