FTIR spectroscopic studies on the adsorption of an oxidized starch on some oxide minerals

Abstract

Fourier-transformed IR spectroscopy was used to study the adsorption of oxidized starch on hematite, corundum, and quartz substrates in relation to their flotation. The difference spectrum of the adsorbed starch on hematite indicates surface reactions involving -CH₂OH and -COH groups and shows similarities with that of the ferric-starch system and suggests chemical interaction between the Fe of hematite and starch adsorbate. The IR spectra of starch adsorbed on corundum and quartz show no evidence of chem. interaction, although H bonding is apparent. The extent of adsorption of starch on hematite, corundum, and quartz decreases in the indicated order. The evidence for chem. interaction of starch with hematite is further obtained by XPS of starch adsorbed on hematite and shoewd a noticeable decrease in peak positions of O(1s) and C(1s) of free starch. The Moessbauer spectrum of hematite with starch adsorbed on it complements these findings.