Basicity of some P1phosphazenes in water and in aqueous surfactant solution

2006 ◽  
Vol 4 (11) ◽  
pp. 2100-2105 ◽  
Author(s):  
Lilli Sooväli ◽  
Toomas Rodima ◽  
Ivari Kaljurand ◽  
Agnes Kütt ◽  
Ilmar A. Koppel ◽  
...  
Keyword(s):  
Surfactant Solution ◽  
Aqueous Surfactant Solution

Confined Swirling Flows of Aqueous Surfactant Solutions Due to a Rotating Disc in a Cylindrical Casing

2007 ◽  
Author(s):  
S. Tamano ◽  
M. Itoh ◽  
M. Yoshida ◽  
K. Yokota
Keyword(s):  
Reynolds Number ◽  
Surfactant Solution ◽  
Swirling Flows ◽  
Visualization Technique ◽  
Rotating Disc ◽  
Constant Frequency ◽  
First Normal Stress Difference ◽  
Surfactant Solutions ◽  
Aqueous Surfactant Solution ◽  
Cylindrical Casing

In this study, confined swirling flows of an aqueous surfactant solution due to a rotating disc in a cylindrical casing were investigated using a sectional flow visualization technique and a two-component laser Doppler velocimetry (LDV) system. The concentrations of aqueous surfactant solutions (C14TASal) are 0.4, 0.8, and 1.2 wt%. Rheological properties such as a shear viscosity and a first normal stress difference of the surfactant solution were measured with a rheometer. The patterns of the secondary flow were classified using the Reynolds and elastic numbers. We revealed that the projection formed near the center of the rotating disc was moving up and down at a constant frequency for C14TASal 0.8 and 1.2 wt%, which has not been reported as far as we know. The effects of the Reynolds number, elastic number, and aspect ratio on the velocity profiles were clarified. It was also found that the region of rigid body rotation existed at the higher Reynolds number tested for C14TASal 0.4 wt%.

scholarly journals Flow of Aqueous Surfactant Solution due to a Rotating Disc in a Cylindrical Casing

2005 ◽  
Vol 71 (704) ◽  
pp. 1043-1050
Author(s):  
Motoyuki ITOH ◽  
Shinji TAMANO ◽  
Mitsunori YOSHIDA ◽  
Kazuhiko YOKOTA
Keyword(s):  
Surfactant Solution ◽  
Rotating Disc ◽  
Aqueous Surfactant Solution ◽  
Cylindrical Casing

Comparative TEM of Freeze-fractured Colloidal Liquid Aphrons and Conventional Emulsions

1999 ◽  
Vol 5 (S2) ◽  
pp. 456-457
Author(s):  
P. Srivastava ◽  
J.W. Heckman ◽  
R.M. Worden
Keyword(s):  
Direct Evidence ◽  
Surfactant Solution ◽  
Lipid Phase ◽  
Residual Pressure ◽  
Aqueous Surfactant Solution ◽  
Rotary Stage ◽  
Interfacial Areas ◽  
Water Shell ◽  
Aqueous Core ◽  
Arc Evaporation

Colloidal Liquid Aphrons (CLAs) are composed of surfactant doped non-aqueous inner cores surrounded by thin surfactant films. These are created by intense stirring of the non-aqueous phase in an aqueous surfactant solution. Large interfacial areas, due to small size, and high stability (much greater than conventional emulsions) make aphron dispersions attractive for a variety of mass transfer limited processes. The unusual stability of CLA dispersions has been attributed to the multi-layered structure that includes an entrapped water shell around the non-aqueous core as postulated by Sebba. However, no direct evidence for the structure of the surfactant-stabilized interface surrounding the CLAs has been previously published.CLAs were prepared as previously reported. Comparative conventional emulsions were made similarly, with the lipid phase free of the Tergitol®(15-S-3) surfactant used in the CLAs. Aliquots (≈30 μl) of the dispersions were spread on 0.15 mm thick, 10 mm diameter copper supports These supports were ultra-rapidly frozen via plunging in liquid propane(−190°C). The frozen samples were inserted onto a pre-cooled rotary stage of a freeze-etch unit (modified Balzers BA-510) and fractured by knife at 150°C with a residual pressure of approx. 6.5 x 10−5 Pa. The replicas were shadowed with ≈2nm of Pt at 30° followed by 10-15 nm of carbon by arc evaporation. The resulting replica was washed in an 10% graded isopropanol series, rehydrated, washed in chromic acid, rinsed in de-ionized H2O, and then mounted on 300 mesh grids. TEM was performed on a JEOL 100CX operated at 120keV.

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