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Additional Support for a Revised Gibbs Analysis

delete2009-12-04
delete57
PRE
AI
F
Fredric M. Menger *
史雷 (Lei Shi)
S
Syed A. A. Rizvi
DOI:10.1021/la9043914delete
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Abstract

Abstract

En 中文
Gibbs-determined areas of >60 angstrom(2)/molecule for many common surfactants cause rather small surface tension reductions when measured on a Langmuir Film balance. This is inconsistent with ail air/water interface being saturated throughout the steep linear decline in plots of surface tension versus In [surfactant]. In support for a gradually populating interface in the linear re,ion, we have found that sodium docosanyl sulfate lowers the surface tension by only 7 mN/m when compressed to 50 angstrom(2)/molecule. When docosanyltrimnethylmmonium bromide is compressed to 65 angstrom(2)/molecule, the surface tension is lowered about 15 mN/m as compared to a 30-40 mN/m drop occurring within the range of typical Gibbs analysis. Saturation of the interface is often obscured by competitive micelle formation that levels the surface tension versus in [surfactant] plot before saturation has it chance to do so.
Keywords:
INTERFACE

Journal

Langmuir cover
Langmuir
IF:
3.9
Papers:
5.4W
Citations:
10.6W

Organization

E
Emory University
Scholars:
5.0W
Papers: 4.2W
Citations: 5.7W