Ordered structures of dichain cationic surfactants at interfaces
We have observed stable layered structures adsorbed at the silicon-water and air-water interfaces from N,N-didodecyl-N,N-dimethylammonium bromide surfactant (DDAB) and the corresponding diundecyl compound (DUDAB). The structures were studied by neutron reflection at the wet hydrophilic silicon inter...
| Asıl Yazarlar: | , , , , |
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| Materyal Türü: | Conference item |
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2003
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| _version_ | 1826289837025525760 |
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| author | McGillivray, D Thomas, R Rennie, A Penfold, J Sivia, D |
| author_facet | McGillivray, D Thomas, R Rennie, A Penfold, J Sivia, D |
| author_sort | McGillivray, D |
| collection | OXFORD |
| description | We have observed stable layered structures adsorbed at the silicon-water and air-water interfaces from N,N-didodecyl-N,N-dimethylammonium bromide surfactant (DDAB) and the corresponding diundecyl compound (DUDAB). The structures were studied by neutron reflection at the wet hydrophilic silicon interface, and at the air-water interface, at concentrations of 0.2-2% w/w. The structures formed are found to have a high sensitivity to temperature, with the repeat spacing decreasing approximately reversibly by about 50% with an increase of temperature of about 40°C. Associated with the specular scattering there is pronounced off-specular scattering, indicative of a degree of lateral structure or dynamic fluctuation. The observations are consistent with two to four correlated layers which could arise from adsorbed monodisperse unilamellar vesicles, a lamellar phase, or a structured bicontinuous phase. Studies of the bulk solutions with X-ray scattering and cryo transmission electron microscopy show only coexisting unilamellar vesicles and lamellar phase. |
| first_indexed | 2024-03-07T02:34:59Z |
| format | Conference item |
| id | oxford-uuid:a87d543b-bc8f-4406-840b-eb6aa8be73c8 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T02:34:59Z |
| publishDate | 2003 |
| record_format | dspace |
| spelling | oxford-uuid:a87d543b-bc8f-4406-840b-eb6aa8be73c82022-03-27T03:01:52ZOrdered structures of dichain cationic surfactants at interfacesConference itemhttp://purl.org/coar/resource_type/c_5794uuid:a87d543b-bc8f-4406-840b-eb6aa8be73c8Symplectic Elements at Oxford2003McGillivray, DThomas, RRennie, APenfold, JSivia, DWe have observed stable layered structures adsorbed at the silicon-water and air-water interfaces from N,N-didodecyl-N,N-dimethylammonium bromide surfactant (DDAB) and the corresponding diundecyl compound (DUDAB). The structures were studied by neutron reflection at the wet hydrophilic silicon interface, and at the air-water interface, at concentrations of 0.2-2% w/w. The structures formed are found to have a high sensitivity to temperature, with the repeat spacing decreasing approximately reversibly by about 50% with an increase of temperature of about 40°C. Associated with the specular scattering there is pronounced off-specular scattering, indicative of a degree of lateral structure or dynamic fluctuation. The observations are consistent with two to four correlated layers which could arise from adsorbed monodisperse unilamellar vesicles, a lamellar phase, or a structured bicontinuous phase. Studies of the bulk solutions with X-ray scattering and cryo transmission electron microscopy show only coexisting unilamellar vesicles and lamellar phase. |
| spellingShingle | McGillivray, D Thomas, R Rennie, A Penfold, J Sivia, D Ordered structures of dichain cationic surfactants at interfaces |
| title | Ordered structures of dichain cationic surfactants at interfaces |
| title_full | Ordered structures of dichain cationic surfactants at interfaces |
| title_fullStr | Ordered structures of dichain cationic surfactants at interfaces |
| title_full_unstemmed | Ordered structures of dichain cationic surfactants at interfaces |
| title_short | Ordered structures of dichain cationic surfactants at interfaces |
| title_sort | ordered structures of dichain cationic surfactants at interfaces |
| work_keys_str_mv | AT mcgillivrayd orderedstructuresofdichaincationicsurfactantsatinterfaces AT thomasr orderedstructuresofdichaincationicsurfactantsatinterfaces AT renniea orderedstructuresofdichaincationicsurfactantsatinterfaces AT penfoldj orderedstructuresofdichaincationicsurfactantsatinterfaces AT siviad orderedstructuresofdichaincationicsurfactantsatinterfaces |