Adsorption of Model Perfumes at the Air鈥揝olution Interface by Coadsorption with an Anionic Surfactant

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• 作者：Robert Bradbury ; Jeffrey Penfold ; Robert K. Thomas ; Ian M. Tucker ; Jordan T. Petkov ; Craig Jones
• 刊名：Langmuir
• 出版年：2013
• 出版时间：March 12, 2013
• 年：2013
• 卷：29
• 期：10
• 页码：3361-3369
• 全文大小：392K
• 年卷期：v.29,no.10(March 12, 2013)
• ISSN：1520-5827

文摘

The adsorption of the model perfumes phenyl ethanol, PE, and linalool, LL, at the air鈥搒olution interface by coadsorption with the anionic surfactant sodium dodecyl 6-benezene sulfonate, LAS-6, has been studied primarily by neutron reflectivity, NR. The variation in the mixed surface adsorption with solution composition is highly nonideal, and the more hydrophobic LL is more surface active. At a LAS-6 concentration of 0.5 mM the adsorption of PE and LL is broadly similar but with the LL systematically more surface active, and at 2 mM the LL completes more effectively for the surface than the PE. The variation in surface composition with solution composition and concentration reflect the greater hydrophobicity and hence surface activity of LL, and the greater solubility of PE in aqueous solution. Changing the geometry of the LAS isomer, from the symmetrical LAS-6 geometry to the more asymmetrical LAS-4, results in the LL competing more effectively for the surface due to changes in the packing constraints associated with the hydrophobic region. The results provide insights into the factors that affect coadsorption that can be more broadly applied to the surface delivery of a wide range of molecules other than perfumes.