- Title
- Nonionic surfactant adsorption at the ethylammonium nitrate surface: a neutron reflectivity and vibrational sum frequency spectroscopy study
- Creator
- Wakeham, Deborah; Niga, Petra; Warr, Gregory G.; Rutland, Mark W.; Atkin, Rob
- Relation
- Langmuir Vol. 26, Issue 11, p. 8313-8318
- Publisher Link
- http://dx.doi.org/10.1021/la9047243
- Publisher
- American Chemical Society
- Resource Type
- journal article
- Date
- 2010
- Description
- The adsorbed layers of polyoxyethylene n-alkyl ether surfactants C₁₂E₄, C₁₄E₄, and C₁₆E₄ at the EAN surface have a headgroup layer that is thin and compact (only~30 vol % EAN). The headgroups do not adopt a preferred orientation and are disordered within the ethylene oxide layer. Alkyl tails contain a significant number of gauche defects indicating a high degree of conformational disorder. The thickness of the tail layer increases with increasing alkyl chain length, while the headgroup layer shows little change. Lowering the C₁₂E₄ concentration from 1 to 0.1 wt % decreases the adsorbed amount, and the headgroup layer becomes thinner and less solvated, whereas C₁₄E₄ and C₁₆E₄ adsorbed layers are unaffected by dilution over the same concentration range. The C₁₆E₄ layer thickness increases and area per molecule decreases on warming to 60 °C, but the adsorbed layer structures of C₁₂E₄ and C₁₄E₄ are unchanged. Both effects are attributed to surfactant solubility.
- Subject
- nonionic surfactants; ethylammonium nitrate (EAN); neutrons; vibrational sum frequency spectroscopy (VSFS)
- Identifier
- http://hdl.handle.net/1959.13/928723
- Identifier
- uon:10421
- Identifier
- ISSN:0743-7463
- Rights
- This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/la9047243
- Language
- eng
- Full Text
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