- Previous Article
- Next Article
- Table of Contents
Journal of Colloid and Interface Science, Vol.200, No.1, 1-6, 1998
Complexation mechanism of dextrin with metal hydroxides
The complexation of dextrin with metal hydroxides was studied quantitatively by FT-IR and UV-visible reflectance spectroscopic techniques. Though three hydroxyl groups are present in each dextrin molecule, complexation involving only two hydroxyl groups situated at the C-2 and C-3 positions has been studied by many investigators. Involvement of a third hydroxyl group situated at the C-6 position was examined in the present study. Since metal hydroxy sites were found to play a key role in the complexation, precipitates of Ca(OH)(2) and Pb(OH)(2) were separately mixed with dextrin solutions at different ratios. Complexes with a stoichiometry of 2:3 (dextrin:metal ion) were identified, indicating the involvement of a third hydroxyl group. However, the ratio of metal ions to hydroxyl groups of dextrin remained as 1:2. Complexation between dextrin and metal hydroxide via a condensation mechanism is proposed.