| Adsorption of fatty acids on iron (hydr)oxides from aqueous solutions. | |
| | |
MedLine Citation:
|
PMID: 21711036 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
The interaction of iron (hydr)oxides with fatty acids is related to many industrial and natural processes. To resolve current controversies about the adsorption configurations of fatty acids and the conditions of the maximum hydrophobicity of the minerals, we perform a detailed study of the adsorption of sodium laurate (dodecanoate) on 150-nm hematite (a-Fe2O3) particles as a model system. The methods used include in situ FTIR spectroscopy, ex situ X-ray photoelectron spectroscopy (XPS), measurements of the adsorption isotherm and contact angle as well as the density functional theory (DFT) calculations. We found that the laurate adlayer is present as a mixture of inner-sphere monodentate mononuclear (ISMM) and outer-sphere (OS) hydration-shared complexes independent of the solution pH. Protonation of the OS complexes does not influence the conformational order of the surfactant tails. One monolayer, which is filled through the growth of domains and is reached at the micellization/precipitation edge of laurate, makes the particles superhydrophobic. These results contradict previous models of the fatty acid adsorption and suggest new interpretation of literature data. Finally, we discovered that the fractions of both the OS laurate and its molecular form increase in D2O, which can be used for interpreting complex spectra. We discuss shortcomings of vibrational spectroscopy in determining the interfacial coordination of carboxylate groups. This work advances the current understanding of the oxide-carboxylate interactions and the research toward improving performance of fatty acids as surfactants, dispersants, lubricants, and anti-corrosion reagents. |
| | |
Authors:
|
Irina Chernyshova; Sathish Ponnurangam; Ponisseril Somasundaran |
Related Documents
:
|
9481876 - Cytochrome c potentiates fatty acid-induced cyclosporin a-sensitive permeability transi... 8120676 - Evidence of docosahexaenoic acid synthesis and predominant existence of arachidonic aci... 21959336 - Micellar system in copper-catalysed hydroxylation of arylboronic acids: facile access t... 2442046 - Variation of incorporation of [3h]orotic acid into the nucleotide and rna fractions of ... 21871076 - Treatment of an adrenomyeloneuropathy patient with lorenzo's oil and supplementation wi... 10572856 - Detection of mycobacterium avium subspecies avium in formalin-fixed, paraffin-embedded ... |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2011-6-28 |
Journal Detail:
|
Title: Langmuir : the ACS journal of surfaces and colloids Volume: - ISSN: 1520-5827 ISO Abbreviation: - Publication Date: 2011 Jun |
Date Detail:
|
Created Date: 2011-6-29 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 9882736 Medline TA: Langmuir Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: An Examination of the Ternary Methane + Carbon Dioxide + Water Phase Diagram Using the SAFT-VR Appro...
Next Document: Magnetic Nanoparticle-Enhanced Biosensor Based On Grating-Coupled Surface Plasmon Resonance.