کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9567056 1388384 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Properties of Langmuir monolayers from semifluorinated alkanes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Properties of Langmuir monolayers from semifluorinated alkanes
چکیده انگلیسی
The aim of this study was to characterize several semifluorinated alkanes (SFA), of the general formula F(CF2)m(CH2)nH (in short FmHn), containing 25 carbon atoms in total (pentacosanes) differing in the m/n ratio, as Langmuir monolayers at the free water surface. The following compounds have been studied: F6H19, F8H17, F10H15 and F12H13. Surface pressure (π) and electric surface potential (ΔV) isotherms were recorded in addition to quantitative Brewster angle microscopy results. The negative sign of ΔV evidenced for the orientation of all the investigated semifluorinated pentacosanes, regardless the length of the hydrogenated segment, with their perfluorinated parts directed towards the air. As inferred from apparent dipole moment values and relative reflectivity results, the fluorinated pentacosanes with shorter perfluorinated fragment (F6H19 and F8H17) were found to be vertically oriented at the air/water interface, while those with longer perfluorinated moiety (F10H15 and F12H13) remain titled even in the vicinity of the film collapse.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 246, Issue 4, 30 June 2005, Pages 342-347
نویسندگان
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