Polyampholyte/Surfactant Complexes at the Water–Air Interface: A Surface Tension Study

Langmuir ◽  
2013 ◽  
Vol 29 (25) ◽  
pp. 7600-7606 ◽  
Author(s):  
Mabya Fechner ◽  
Joachim Koetz
Keyword(s):  
Surface Tension ◽  
Air Interface ◽  
Surface Tension Study

scholarly journals Adsorption Properties of Hydrocarbon and Fluorocarbon Surfactants Ternary Mixture at the Water-Air Interface

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4313
Author(s):  
Bronisław Jańczuk ◽  
Katarzyna Szymczyk ◽  
Anna Zdziennicka
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Standard Free Energy ◽  
Ternary Mixtures ◽  
Free Energy Of Adsorption ◽  
Interface Tension ◽  
Air Interface ◽  
Surface Excess Concentration ◽  
Tail Water ◽  
Triton X

Measurements were made of the surface tension of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycols) having 10 oxyethylene groups in the molecule (Triton X-100, TX100) and cetyltrimethylammonium bromide (CTAB) with Zonyl FSN-100 (FC6EO14, FC1) as well as with Zonyl FSO-100 (FC5EO10, FC2) ternary mixtures. The obtained results were compared to those provided by the Fainerman and Miller equation and to the values of the solution surface tension calculated, based on the contribution of a particular surfactant in the mixture to the reduction of water surface tension. The changes of the aqueous solution ternary surfactants mixture surface tension at the constant concentration of TX100 and CTAB mixture at which the water surface tension was reduced to 60 and 50 mN/m as a function of fluorocarbon surfactant concentration, were considered with regard to the composition of the mixed monolayer at the water-air interface. Next, this composition was applied for the calculation of the concentration of the particular surfactants in the monolayer using the Frumkin equation. On the other hand, the Gibbs surface excess concentration was determined only for the fluorocarbon surfactants. The tendency of the particular surfactants to adsorb at the water-air interface was discussed, based on the Gibbs standard free energy of adsorption which was determined using different methods. This energy was also deduced, based on the surfactant tail surface tension and tail-water interface tension.

The Chorionic Plastron and its Role in the Eggs of the Muscinae (Diptera)

1960 ◽  
Vol s3-101 (55) ◽  
pp. 313-332
Author(s):  
H. E. HINTON
Keyword(s):  
Surface Tension ◽  
High Pressures ◽  
Middle Layer ◽  
Clean Water ◽  
Active Materials ◽  
Great Resistance ◽  
Plane Normal ◽  
Air Interface ◽  
Surface Active ◽  
Egg Shell

In flies of the subfamily Muscinae the egg-shell has both an outer and an inner meshwork layer, each of which holds a continuous film of air. Between these two meshwork layers there is a more or less thick middle layer to which the shell chiefly owes its mechanical strength. Holes or aeropyles through the middle layer effect the continuity of the outer and inner films of air. Both meshwork layers consist of struts that arise perpendicularly from the middle layer. In both layers the struts are branched at their apices in a plane normal to their long axes. These horizontal branches form a fine and open hydrofuge network that provides a large water-air interface when the egg is immersed. When it rains or when the egg is otherwise immersed in water, the film of air held in the outer meshwork layer of the shell funtions as a plastron. To be an efficient respiratory structure a plastron must resist wetting by both the hydrostatic pressures and the surface active materials to which it is normally exposed. The plastrons of all the Muscinae tested resist wetting in clean water by pressures far in excess of any they are likely to encounter in nature. The resistance of a plastron to hydrostatic pressures varies directly as the surface tension of the water, and the surface tension of water in contact with the decomposing materials in which the Muscinae lay their eggs is much lowered by surface active materials. These considerations seem to provide an explanation for the great resistance of the plastron of the Muscinae to wetting by excess pressures and for the paradox that the plastrons of these terrestrial eggs are more resistant to high pressures than are the plastrons of some aquatic insects that live in clean water.

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

scholarly journals Investigation of Interfacial Free Energy of Three-Phase Contact on a Glass Sphere in Case of Cationic-Anionic Surfactant Aqueous Mixtures

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 573
Author(s):  
Lidia A. Alexandrova ◽  
Ljudmil S. Grigorov ◽  
Nikolay A. Grozev ◽  
Stoyan I. Karakashev
Keyword(s):  
Surface Tension ◽  
Synergetic Effect ◽  
Good Method ◽  
Interfacial Free Energy ◽  
Aqueous Mixtures ◽  
Complete Wetting ◽  
Air Interface ◽  
Foam Flotation ◽  
Three Phase ◽  
Mixed Systems

The wetting of adsorbed surfactants solids is important for various technological applications in particular for the process of foam flotation. The present work aims at calculating the surface tensions of the three phase interfaces at different surfactant concentrations using the Girifalco and Good method. For this purpose, the surface tension and contact angle vs. surfactant concentration of the test substances amines and sulfonates and their mixture were measured for liquid–air interface. Calculated surface tension of solid–air interface vs. concentration for C10 amine and mixed systems are close to those for the liquid–air surface, but are slightly lower. In the case of mixed systems, the graph has a specific structure similar to that of liquid–air surface dependence. In contrast to the solid–air interface results, the solid–liquid surface tension values are significantly lower. In case of the mixed surfactant systems, C10amine/C10 sulfonate, a synergetic effect on the surface tension is observed. The specific behavior of the mixed systems is interpreted with the emergence of aggregates consisting of the anionic and cationic surfactants. It is shown that in the whole area of concentrations complete wetting does not occur.

scholarly journals The behaviour of hyaluronan solutions in the presence of Hofmeister ions: A light scattering, viscometry and surface tension study

2019 ◽  
Vol 212 ◽  
pp. 395-402 ◽  
Author(s):  
Lenka Musilová ◽  
Věra Kašpárková ◽  
Aleš Mráček ◽  
Antonín Minařík ◽  
Martin Minařík
Keyword(s):  
Surface Tension ◽  
Light Scattering ◽  
Surface Tension Study

Polymer/Surfactant Complexes at the Water/Air Interface:  A Surface Tension and X-ray Reflectivity Study

Langmuir ◽  
2000 ◽  
Vol 16 (7) ◽  
pp. 3206-3213 ◽  
Author(s):  
Cosima Stubenrauch ◽  
Pierre-Antoine Albouy ◽  
Regine v. Klitzing ◽  
Dominique Langevin
Keyword(s):  
Surface Tension ◽  
X Ray ◽  
Air Interface ◽  
Polymer Surfactant

Concentration fluctuations and surface adsorption in non-ideal binary mixtures. A light-scattering and surface tension study

2003 ◽  
Vol 5 (21) ◽  
pp. 4864-4868 ◽  
Author(s):  
Ramón G. Rubio ◽  
Ana Díez-Pascual ◽  
Baudilio Coto ◽  
A. Crespo-Colín ◽  
A. Compostizo
Keyword(s):  
Surface Tension ◽  
Light Scattering ◽  
Binary Mixtures ◽  
Surface Adsorption ◽  
Concentration Fluctuations ◽  
Surface Tension Study

Tracking of Capillary Interface in Microfluidic Channels

2011 ◽  
Author(s):  
Prashant R. Waghmare ◽  
Farhan Ahmad ◽  
David S. Nobes ◽  
Sushanta K. Mitra
Keyword(s):  
Surface Tension ◽  
Flow Regime ◽  
Fluid Transport ◽  
Capillary Flow ◽  
Laser Source ◽  
Working Fluid ◽  
Microfluidic Channels ◽  
Experimental Setup ◽  
Imaging Device ◽  
Air Interface

Capillarity is commonly used for fluid transport in microfluidic devices. The capillary flow can be divided into three different flow regimes: entry regime, Poiseuille regime, and surface tension regime as shown in Fig. 1[1]. Generally, it is anticipated that at the entrance of any narrow confinement, the flow goes through entrance flow regime. For capillary flow, this entrance regime has generally been neglected in the literature. Beyond this entrance regime, the flow attains the fully developed velocity profile across the channel, which is termed as a Poiseuille flow. Moreover, in the capillary flow, the interface is always under traction — due to the capillary forces and hence, a third flow regime needs to be considered behind the interface which is referred as the surface tension regime. These regimes are yet to be experimentally explored and analyzed. An “in-house” developed μ-PIV system is used to quantify the flow field at the liquid/air interface (surface tension regime) in a rectangular glass microchannel of dimension 1.5 mm (width) × 500 μm (depth). The magnitude of velocity and the flow front evolution along the microchannel is calculated utilizing commercially available image processing software. Figure 2 shows the μ-PIV experimental setup used here. The main components of the experimental setup include an imaging device, magnification optics, and a continuous laser source (473 nm) in back illumination mode. The fluorescent particle of 1.9 m in diameter with DI water is used as a working fluid. The concentration of the microparticles is very less which is approximately 1%, therefore the effect of microbead concentration on the wetting properties is considered to be negligible for the present study. Moreover, it is assumed that the surface properties of the particles also do not affect the fluid flow. The capillary flow interface is captured and the corresponding processed images are presented to depict the velocity field at the liquid/air interface. The enlarged view of the microchannel cross section is shown in Fig. 2. The section A-A is the location at which the images are captured for the analysis.

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