Spectroscopic investigation of the adsorption mechanisms of polyacrylamide polymers onto iron oxide particles
Date
2006
Authors
McGuire, Melanie Jane
Addai-Mensah, Jonas
Bremmell, Kristin Elizabeth
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Journal of Colloid and Interface Science, 2006; 299 (2):547-555
Statement of Responsibility
Melanie J. McGuire, Jonas Addai-Mensah and Kristen E. Bremmell
Conference Name
Abstract
The mechanisms of high-molecular-weight polyacrylamide nonionic homopolymer and 25 mol% anionic acrylate-substituted copolymer adsorption onto iron oxide particles were investigated via DRIFT and UV–vis spectroscopies at three pH values (6, 8.5, and 11). While electrostatic interactions play an important role in charged polymer adsorption, this information is not spectroscopically available. At pH values above and below pH 8.5 (the isoelectric point for the anionic polymer), bidentate chelation and hydrogen bonding were the main adsorption mechanisms. At the isoelectric point, monodentate chelation was observed to be the main mode of adsorption, along with hydrogen bonding. For the nonionic polymer, in all cases, hydrogen bonding through the carbonyl group was the main mode of adsorption. The adsorption of both polymers conformed well to the Freundlich model, suggesting that the adsorbed polymer amount increases with increasing polymer concentration up to 7500 g/t solid, rather than approaching monolayer coverage. Spectroscopic evidence was found to suggest that hydrolysis of nonionic polyacrylamide occurs at high pH.
School/Discipline
School of Chemical Engineering