کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10375024 | 880029 | 2005 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Properties of two-component Langmuir monolayer of single chain perfluorinated carboxylic acids with dipalmitoylphosphatidylcholine (DPPC)
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کلمات کلیدی
ΔV–A isothermPerfluorocarboxylic acid - اسید Perfluorocarboxylicπ–A isotherm - ایزوترم π-ADipalmitoylphosphatidylcholine (DPPC) - دیپالمیتویف فسفاتیدیل کولین (DPPC)Langmuir monolayer - لانگموری یکنواختFluorescence microscopy - میکروسکوپ فلورسانسatomic force microscopy - میکروسکوپ نیروی اتمیTwo-dimensional phase diagram - نمودار فاز دو بعدیSurface potential - پتانسیل سطح
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The surface pressure (Ï)- and the surface potential (ÎV)-area (A) isotherms were obtained for two-component monolayers of four different perfluorocarboxylic acids (FCns; perfluorododecanoic acid: FC12, perfluorotetradecanoic acid: FC14, perfluorohexadecanoic acid: FC16, perfluorooctadecanoic acid: FC18) with dipalmitoylphosphatidylcholine (DPPC) on substrate solution of 0.15 M NaCl (pH 2.0) at 298.2 K as a function of compositions in the mixtures by employing the Wilhelmy method, the ionizing electrode method, the fluorescence microscopy, and the atomic force microscopy. The data for the two-component monolayers on these systems were analyzed in terms of the additivity rule. Assuming a regular surface mixture, the Joos equation which allows one to describe the collapse pressure of a two-component monolayer with miscible components was used to declare the miscibility of the monolayer state, and an interaction parameter and an interaction energy were calculated. The new finding was that FCns and DPPC are miscible or immiscible depending on chain length increment of fluorocarbon part. That is, FC12/DPPC monolayer was perfectly miscible, and FC14/DPPC, and FC16/DPPC (0 ⤠XFC16 ⤠0.3) monolayers were partially miscible. While FC16/DPPC (0.3 < XFC16 < 1) and FC18/DPPC systems are immiscible in the monolayer state. Furthermore, the mean molecular area, the surface dipole moment, and the phase diagrams enabled us to estimate the molecular orientation of four different perfluorocarboxylic acids/DPPC in the two-component monolayer state. One type of phase diagrams was obtained and classified into the positive azeotropic type. The miscibility of FCns and DPPC in the monolayer was also supported by fluorescence microscopy and atomic force microscopy. FC12/DPPC, FC14/DPPC and FC16/DPPC (0 ⤠XFC16 ⤠0.3) two-component monolayers on 0.15 M NaCl (pH 2) showed that FC12, FC14 and FC16 (0 ⤠XFC16 ⤠0.3) can dissolve or partially dissolve the ordered solid DPPC domains formed upon compression. This indicates that these fluorinated amphiphiles soften or harden the lipid depending on their chain length.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces B: Biointerfaces - Volume 41, Issue 4, 10 April 2005, Pages 285-298
Journal: Colloids and Surfaces B: Biointerfaces - Volume 41, Issue 4, 10 April 2005, Pages 285-298
نویسندگان
Hiromichi Nakahara, Shohei Nakamura, Hideya Kawasaki, Osamu Shibata,