Adsorption mechanisms of glucose in aqueous goethite suspensions.
J Colloid Interface Sci
; 353(1): 263-8, 2011 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-20933242
ABSTRACT
The adsorption of glucose and polysaccharides onto solid surfaces is important in several areas of science and engineering including soil chemistry and mineral processing. In this work we have studied the adsorption of D-glucose at the water-goethite (α-FeOOH) interface as a function of pH using batch adsorption measurements and a simultaneous infrared and potentiometric technique. Molecular orbital calculations were also performed in order to support interpretations of the infrared spectroscopic data. Infrared spectroscopy has shown that glucose adsorbs at the water-goethite interface with an intact ring structure and that the ß-form is favored relative to the α isomer. The collective spectroscopic and macroscopic results were fully consistent with an adsorption mechanism where glucose interacts with goethite surface sites via hydrogen bonding interactions. Specific infrared peak shifts indicated that glucose primarily acts as a hydrogen bond donor and that it interacts with acceptor sites that become increasingly more prevalent as the surface is deprotonated. These results are in general agreement with the acid/base model for mono- and polysaccharide interactions at metal oxide surfaces, but contradict the inner sphere hypothesis that was proposed based on ex situ spectroscopic measurements.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Colloid Interface Sci
Ano de publicação:
2011
Tipo de documento:
Article