Surfactant Adsorption at the Metal-Oil Interface
Surfactant Adsorption at the Metal-Oil Interface
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DOI：
10.1021/la200670w
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发表时间：
2011-05-17
期刊：
影响因子：
3.9
通讯作者：
Zarbakhsh, Ali
中科院分区：
文献类型：
--
作者：
Campana, Mario;Teichert, Anke;Zarbakhsh, Ali
用极化中子反射法研究了软脂酸在铁氧化物/油界面上的吸附结构。发现棕榈酸在氧化物/油界面处被强烈吸附，导致对于150和500 ppm的棕榈酸浓度，单层厚度为16 +/-4埃（对于1000 ppm的溶液，单层厚度为16 +/-5埃）。这些层厚度表明棕榈酸分子相对于界面的倾斜。该模型还需要在大量油中延伸的第二扩散层。对于150 ppm溶液，该扩散层的厚度为35 +/- 17埃，对于500和1000 ppm溶液，该扩散层的厚度为45 +/- 22埃。在界面处的组合物配置文件表明，在界面附近的油的消耗作为棕榈酸的浓度增加。
The structure of the adsorbed palmitic acid at the iron oxide/oil interface has been investigated using polarized neutron reflectometry. The palmitic acid was found to be strongly adsorbed at the oxide/oil interface resulting in a monolayer of thickness 16 +/- 4 angstrom for 150 and 500 ppm palmitic acid concentrations (16 +/- 5 angstrom for the 1000 ppm solution). These layer thicknesses suggest tilt for the palmitic acid molecules with respect to the interface. The model also requires a second diffuse layer extending in the bulk oil. The thickness of this diffuse layer was 35 +/- 17 angstrom for the 150 ppm solution and 45 +/- 22 angstrom for 500 and 1000 ppm solution. The composition profiles at the interface suggest a depletion of the oil in the vicinity of the interface as the concentration of palmitic acid increases.