Dynamic Surface Tension and Adsorption/Desorption Kinetics for Polymer Mixtures on Planar Surfaces

1999 ◽  
Vol 216 (1) ◽  
pp. 86-95
Author(s):  
Nadezhda L Filippova
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Desorption Kinetics ◽  
Polymer Mixtures ◽  
Dynamic Surface ◽  
Planar Surfaces ◽  
Adsorption Desorption

Visualization of Multiscale Processes - Bubble Dynamics in Surface Active Colloids

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
S. Manoharan ◽  
D. Kalaikadal ◽  
R. M. Manglik ◽  
E. Iskrenova-Ekiert ◽  
S. S. Patnaik
Keyword(s):  
Molecular Dynamics ◽  
Surface Tension ◽  
Pure Water ◽  
Dynamic Surface Tension ◽  
Air Flow Rate ◽  
Dynamic Surface ◽  
Multi Scale ◽  
Macro Scale ◽  
Dynamics Simulations ◽  
Adsorption Desorption

The growth dynamics of isolated gas bubbles from a submerged capillary-tube orifice in a pool of aqueous solution of Cetyl Trimethyl Ammonium Bromide (CTAB) was studied by multi-scale modeling. The macro-scale bubble ebullience is controlled by the molecular scale surfactant adsorption/desorption on the liquid-gas interface. Molecular dynamics simulations were carried out to predict the interfacial adsorption/desorption kinetics. The results of the molecular dynamics simulations were input to the volume-of-fluid based macro-scale computations. The size and shape of bubbles from incipience to departure were measured using high speed videography for model validation. Predictions of the multi-scale model agree with the experimental measurements of bubble size evolution and bubble diameter at departure. The surfactant mass transfer and adsorption on the liquid gas interface gives rise to dynamic surface tension. As a result of the surfactant presence, the bubble departure diameters were smaller in CTAB solution compared to pure water. Furthermore, dynamic surface tension behavior of CTAB makes the bubble departure diameter a function of bubble Reynolds number (Re based on the orifice diameter and air flow rate). At low flow rates or low Re, the bubble departure diameters are smaller than those in water. As the air flow rate increases, the bubble departure diameters tend towards those in pure water. The authors gratefully acknowledge funding from AFOSR Thermal Science Program and AFRL DoD Supercomputing Resource Center for computing time and resources.

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.

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
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