Abstract
The tension of the three interfaces and the dihedral angle of the lens of the air/hexadecane lens/aqueous solution of tetramethylammonium dodecyl sulfate (TMADS) system were measured as a function of the surfactant concentration. The air/water surface tension vs concentration curves both with and without an oil lens exhibited a break point corresponding to the phase transition of the adsorbed films. From the thermodynamic analysis, it was shown that the phase transition drives the spreading of hexadecane molecules into the adsorbed film. The dihedral angle decreased very rapidly from about 50° at zero concentration to about 6° at the phase transition point and then increased slowly to about 20° at the critical micelle concentration (cmc), suggesting the very drastic change in wetting properties at the phase transition point. The plausible gap was observed between the dihedral angles measured and those calculated from the interfacial tension values at the concentration range from just above the phase transition to near the cmc. This suggests a case where the Neumann relation does not hold even when a lens exists stably. One of the possibilities may be that the wetting film is rather thick just above the phase transition point.
| Original language | English |
|---|---|
| Pages (from-to) | 7344-7349 |
| Number of pages | 6 |
| Journal | Langmuir |
| Volume | 17 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - Nov 13 2001 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Surfaces and Interfaces
- Spectroscopy
- Electrochemistry
Cite this
Interfacial films and wetting behavior of the air/hexadecane/aqueous solution of a surfactant system. / Aratono, Makoto; Kawagoe, Hiroaki; Toyomasu, Takayuki; Ikeda, Norihiro; Takiue, Takanori; Matsubara, Hiroki.
In: Langmuir, Vol. 17, No. 23, 13.11.2001, p. 7344-7349.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Interfacial films and wetting behavior of the air/hexadecane/aqueous solution of a surfactant system
AU - Aratono, Makoto
AU - Kawagoe, Hiroaki
AU - Toyomasu, Takayuki
AU - Ikeda, Norihiro
AU - Takiue, Takanori
AU - Matsubara, Hiroki
PY - 2001/11/13
Y1 - 2001/11/13
N2 - The tension of the three interfaces and the dihedral angle of the lens of the air/hexadecane lens/aqueous solution of tetramethylammonium dodecyl sulfate (TMADS) system were measured as a function of the surfactant concentration. The air/water surface tension vs concentration curves both with and without an oil lens exhibited a break point corresponding to the phase transition of the adsorbed films. From the thermodynamic analysis, it was shown that the phase transition drives the spreading of hexadecane molecules into the adsorbed film. The dihedral angle decreased very rapidly from about 50° at zero concentration to about 6° at the phase transition point and then increased slowly to about 20° at the critical micelle concentration (cmc), suggesting the very drastic change in wetting properties at the phase transition point. The plausible gap was observed between the dihedral angles measured and those calculated from the interfacial tension values at the concentration range from just above the phase transition to near the cmc. This suggests a case where the Neumann relation does not hold even when a lens exists stably. One of the possibilities may be that the wetting film is rather thick just above the phase transition point.
AB - The tension of the three interfaces and the dihedral angle of the lens of the air/hexadecane lens/aqueous solution of tetramethylammonium dodecyl sulfate (TMADS) system were measured as a function of the surfactant concentration. The air/water surface tension vs concentration curves both with and without an oil lens exhibited a break point corresponding to the phase transition of the adsorbed films. From the thermodynamic analysis, it was shown that the phase transition drives the spreading of hexadecane molecules into the adsorbed film. The dihedral angle decreased very rapidly from about 50° at zero concentration to about 6° at the phase transition point and then increased slowly to about 20° at the critical micelle concentration (cmc), suggesting the very drastic change in wetting properties at the phase transition point. The plausible gap was observed between the dihedral angles measured and those calculated from the interfacial tension values at the concentration range from just above the phase transition to near the cmc. This suggests a case where the Neumann relation does not hold even when a lens exists stably. One of the possibilities may be that the wetting film is rather thick just above the phase transition point.
UR - http://www.scopus.com/inward/record.url?scp=0035856647&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035856647&partnerID=8YFLogxK
U2 - 10.1021/la0108961
DO - 10.1021/la0108961
M3 - Article
AN - SCOPUS:0035856647
VL - 17
SP - 7344
EP - 7349
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 23
ER -