Dynamic surface tension and Gibbs elasticity of perfluoropolyether surfactant films

2004 ◽  
pp. 51-54
Author(s):  
R. Pieri ◽  
A. Chittofrati ◽  
P. Baglioni
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Gibbs Elasticity

Marangoni effects on the motion of an expanding or contracting bubble pinned at a submerged tube tip

1999 ◽  
Vol 379 ◽  
pp. 279-302 ◽  
Author(s):  
HARRIS WONG ◽  
DAVID RUMSCHITZKI ◽  
CHARLES MALDARELLI
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Bond Number ◽  
Boundary Integral ◽  
Dynamic Surface ◽  
Constant Flow Rate ◽  
Tangential Flow ◽  
Marangoni Effects ◽  
Gibbs Elasticity ◽  
Made In

This work studies the motion of an expanding or contracting bubble pinned at a submerged tube tip and covered with an insoluble Volmer surfactant. The motion is driven by constant flow rate Q into or out of the tube tip. The purpose is to examine two central assumptions commonly made in the bubble and drop methods for measuring dynamic surface tension, those of uniform surfactant concentration and of purely radial flow. Asymptotic solutions are obtained in the limit of the capillary number Ca→0 with the Reynolds number Re=o(Ca−1, non-zero Gibbs elasticity (G), and arbitrary Bond number (Bo). (Ca=μQ/a2σc, where μ is the liquid viscosity, a is the tube radius, and σc is the clean surface tension.) This limit is relevant to dynamic-tension experiments, and gives M→∞, where M=G/Ca is the Marangoni number. We find that in this limit the deforming bubble at each instant in time takes the static shape. The surfactant distribution is uniform, but its value varies with time as the bubble area changes. To maintain a uniform distribution at all times, a tangential flow is induced, the magnitude of which is more than twice that in the clean case. This is in contrast to the surface-immobilizing effect of surfactant on an isolated translating bubble. These conclusions are confirmed by a boundary integral solution of Stokes flow valid for arbitrary Ca, G and Bo. The uniformity in surfactant distribution validates the first assumption in the bubble and drop methods, but the enhanced tangential flow contradicts the second.

scholarly journals A pH-Responsive Foam Formulated with PAA/Gemini 12-2-12 Complexes

2021 ◽  
Vol 5 (3) ◽  
pp. 37
Author(s):  
Hernán Martinelli ◽  
Claudia Domínguez ◽  
Marcos Fernández Leyes ◽  
Sergio Moya ◽  
Hernán Ritacco
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Foam Formation ◽  
Ph Responsive ◽  
Dynamic Surface ◽  
X Ray ◽  
Equilibrium Surface Tension ◽  
Potential Applications ◽  
The Stability ◽  
Air Interfaces

In the search for responsive complexes with potential applications in the formulation of smart dispersed systems such as foams, we hypothesized that a pH-responsive system could be formulated with polyacrylic acid (PAA) mixed with a cationic surfactant, Gemini 12-2-12 (G12). We studied PAA-G12 complexes at liquid–air interfaces by equilibrium and dynamic surface tension, surface rheology, and X-ray reflectometry (XRR). We found that complexes adsorb at the interfaces synergistically, lowering the equilibrium surface tension at surfactant concentrations well below the critical micelle concentration (cmc) of the surfactant. We studied the stability of foams formulated with the complexes as a function of pH. The foams respond reversibly to pH changes: at pH 3.5, they are very stable; at pH > 6, the complexes do not form foams at all. The data presented here demonstrate that foam formation and its pH responsiveness are due to interfacial dynamics.

Laser-based dynamic surface tension detection for liquid chromatography by probing a repeating drop radius

1995 ◽  
Vol 691 (1-2) ◽  
pp. 195-204 ◽  
Author(s):  
Lawrence R. Lima ◽  
Robert E. Synovec
Keyword(s):  
Surface Tension ◽  
Liquid Chromatography ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Drop Radius

An axisymmetric model for the analysis of dynamic surface tension

RSC Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 7921-7931 ◽  
Author(s):  
S. I. Arias ◽  
J. R. Fernández ◽  
L. García-Rio ◽  
J. C. Mejuto ◽  
M. C. Muñiz ◽  
...  
Keyword(s):  
Surface Tension ◽  
Diffusion Length ◽  
Dynamic Surface Tension ◽  
Ionic Surfactants ◽  
Adsorption Behaviour ◽  
Dynamic Surface ◽  
Axisymmetric Model

An axisymmetric model accounts for dynamic surface tension of non-ionic surfactants under consideration of diffusive adsorption behaviour with a finite diffusion length.

Effect of plasticizer on the dynamic surface tension and the free volume of Eudragit systems

2002 ◽  
Vol 244 (1-2) ◽  
pp. 81-86 ◽  
Author(s):  
Romána Zelkó ◽  
Á Orbán ◽  
K Süvegh ◽  
Z Riedl ◽  
I Rácz
Keyword(s):  
Surface Tension ◽  
Free Volume ◽  
Dynamic Surface Tension ◽  
Dynamic Surface

Determination of albumin content in blood serum based on the results of dynamic surface tension

2021 ◽  
Vol 1 (6) ◽  
pp. 68-73
Author(s):  
M. S. Tsarkova ◽  
◽  
I. V. Milaeva ◽  
S. Yu. Zaytsev ◽  
◽  
...  
Keyword(s):  
Surface Tension ◽  
Blood Serum ◽  
Objective Assessment ◽  
Dynamic Surface Tension ◽  
The Body ◽  
Maximum Pressure ◽  
Dynamic Surface ◽  
Good Convergence ◽  
Albumin Content

The blood test allows you to give an objective assessment of the state of health of animals and timely identify changes occurring in the body. To assess the content of albumins in the blood serum, the method of measuring the dynamic surface tension on the VRA-1P device, which works according to the method of maximum pressure in the bubble, was used. Based on the results of the measurements, a mathematical model was proposed, and using the regression analysis method, formulas for determining the concentration of albumins were developed, which showed good convergence with other measurement methods.

scholarly journals Properties of the seawater-air interface. Dynamic surface tension studies1

1979 ◽  
Vol 24 (6) ◽  
pp. 1022-1030 ◽  
Author(s):  
Dj. Dragcevic ◽  
M. Vukovic ◽  
D. Cukman ◽  
V. Pravdic
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Air Interface ◽  
Interface Dynamic

Dynamic surface tension of natural surfactant extract under superimposed oscillations

2011 ◽  
Vol 44 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Prasika I. Reddy ◽  
Ahmed M. Al-Jumaily ◽  
Geoff T. Bold
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Natural Surfactant
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