Jump to main content
Jump to site search

Issue 16, 2011
Previous Article Next Article

Insight into the adsorption of humic acid/Gd3+ complex on the surface of Al2O3 studied in situ by QCM-D and ex situ by ellipsometry and XPS

Author affiliations

Abstract

The adsorption of humic acid (HA) on an Al2O3 surface in the presence of Gd3+ was studied in situ by quartz crystal microbalance with dissipation (QCM-D) and ex situ by ellipsometry and XPS. Adsorption of a HA/Gd3+ complex yielded an adlayer of a mass of 354 ng cm−2, the adlayer is characterized by a relatively high dissipation indicating a significant viscoelastic character. The viscoelasticity is enhanced by the salt and water molecules penetrating the adlayer causing it to stretch. The dry state average thickness of the adlayer is about 23 Å as measured by ellipsometry. Ellipsometry revealed a slower kinetics in the case of HA/Gd3+ adsorption than that of HA alone. XPS spectra proves the adsorption and demonstrates quantitatively that the adsorption of HA/Gd3+ and HA show the same trend, except for the higher adsorption in the case of HA/Gd3+ compared with HA. The structure of the HA/Gd3+ adlayer may be assumed according to the results of the three techniques to consist of a monolayer of HA bound directly to the surface of Al2O3 and connected via a Gd3+ bridge to a HA upper layer.

Graphical abstract: Insight into the adsorption of humic acid/Gd3+ complex on the surface of Al2O3 studied in situ by QCM-D and ex situ by ellipsometry and XPS

Back to tab navigation

Article information


Submitted
03 May 2011
Accepted
31 May 2011
First published
13 Jul 2011

Soft Matter, 2011,7, 7424-7430
Article type
Paper

Insight into the adsorption of humic acid/Gd3+ complex on the surface of Al2O3 studied in situ by QCM-D and ex situ by ellipsometry and XPS

M. Eita, Soft Matter, 2011, 7, 7424 DOI: 10.1039/C1SM05806A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements