scholarly journals Equilibrium Surface Tension, Dynamic Surface Tension, and Micellization Properties of Lactobionamide-Type Sugar-Based Gemini Surfactants

2013 ◽  
Vol 62 (6) ◽  
pp. 353-362 ◽  
Author(s):  
Tomokazu Yoshimura ◽  
Shin Umezawa ◽  
Akihiko Fujino ◽  
Kanjiro Torigoe ◽  
Kenichi Sakai ◽  
...  
Keyword(s):  
Surface Tension ◽  
Gemini Surfactants ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Equilibrium Surface ◽  
Equilibrium Surface Tension

Adsorption of C14EO8 at the interface between its aqueous solution drop and air saturated by different alkanes vapor

2017 ◽  
Vol 19 (3) ◽  
pp. 2193-2200 ◽  
Author(s):  
R. Miller ◽  
E. V. Aksenenko ◽  
V. I. Kovalchuk ◽  
V. B. Fainerman
Keyword(s):  
Aqueous Solution ◽  
Surface Tension ◽  
Pure Water ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Equilibrium Surface ◽  
Equilibrium Surface Tension

The dynamic and equilibrium surface tension for drops of aqueous C14EO8 solutions at the interface to pure air or pentane, hexane, heptane and toluene saturated air, and the dynamic surface tension of pure water at these interfaces are presented.

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.

Influence of Surfactants and Plant Species on Leaf Retention of Spray Solutions

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 567-572 ◽  
Author(s):  
Hans De Ruiter ◽  
André J.M. Uffing ◽  
Esther Meinen ◽  
Albertus Prins
Keyword(s):  
Surface Tension ◽  
Winter Wheat ◽  
Plant Species ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Black Nightshade ◽  
Equilibrium Surface Tension ◽  
Spray Solution ◽  
Determining Factor ◽  
Cuticular Surface

Spray solutions containing a cationic or a nonionic surfactant were applied to six plant species at a broad range of concentrations. The species investigated were three weeds (black nightshade, chamomile, and quackgrass) and three crops (winter wheat, pea, and tomato). The microroughness of the leaf surface as revealed by scanning electron microscopy appeared to be a relevant retention-determining factor. Plant species with crystalline epicuticular waxes (winter wheat, pea, and quackgrass) retained much less spray solution than the other species, which are characterized by a smooth cuticular surface. The two surfactants enhanced retention on species with a reflective surface, whereas retention on black nightshade, chamomile, and tomato was hardly influenced by addition of surfactants. The two surfactants had a similar influence on the retention. Surfactant at 1% (wt/v) enhanced retention on pea, winter wheat, and quackgrass by factors of twenty, six, and four, respectively, compared with retention without surfactant. A linear relation between retention and logarithm of surfactant concentration was observed. Retention of spray drops was related not to equilibrium surface tension of the spray solution but rather to dynamic surface tension.

Dynamic surface tension of xylem sap lipids

2020 ◽  
Vol 40 (4) ◽  
pp. 433-444 ◽  
Author(s):  
Jinlong Yang ◽  
Joseph M Michaud ◽  
Steven Jansen ◽  
H Jochen Schenk ◽  
Yi Y Zuo
Keyword(s):  
Surface Tension ◽  
Surface Area ◽  
Xylem Sap ◽  
Dynamic Surface Tension ◽  
Liquid Interfaces ◽  
Surface Tensions ◽  
Local Surface ◽  
Dynamic Surface ◽  
Equilibrium Surface ◽  
Pit Membrane

Abstract The surface tension of xylem sap has been traditionally assumed to be close to that of the pure water because decreasing surface tension is thought to increase vulnerability to air seeding and embolism. However, xylem sap contains insoluble lipid-based surfactants, which also coat vessel and pit membrane surfaces, where gas bubbles can enter xylem under negative pressure in the process known as air seeding. Because of the insolubility of amphiphilic lipids, the surface tension influencing air seeding in pit pores is not the equilibrium surface tension of extracted bulk sap but the local surface tension at gas–liquid interfaces, which depends dynamically on the local concentration of lipids per surface area. To estimate the dynamic surface tension in lipid layers that line surfaces in the xylem apoplast, we studied the time-dependent and surface area-regulated surface tensions of apoplastic lipids extracted from xylem sap of four woody angiosperm plants using constrained drop surfactometry. Xylem lipids were found to demonstrate potent surface activity, with surface tensions reaching an equilibrium at ~25 mN m-1 and varying between a minimum of 19 mN m-1 and a maximum of 68 mN m-1 when changing the surface area between 50 and 160% around the equilibrium surface area. It is concluded that xylem lipid films in natural conditions most likely range from nonequilibrium metastable conditions of a supersaturated compression state to an undersaturated expansion state, depending on the local surface areas of gas–liquid interfaces. Together with findings that maximum pore constrictions in angiosperm pit membranes are much smaller than previously assumed, low dynamic surface tension in xylem turns out to be entirely compatible with the cohesion–tension and air-seeding theories, as well as with the existence of lipid-coated nanobubbles in xylem sap, and with the range of vulnerabilities to embolism observed in plants.

Dynamic surface tension of xylem sap at the air-water interface

2021 ◽  
Author(s):  
Reddy Prasanna Duggireddy ◽  
Eran Raveh ◽  
Gilboa Arye
Keyword(s):  
Surface Tension ◽  
Surface Activity ◽  
Pure Water ◽  
Xylem Sap ◽  
Dynamic Surface Tension ◽  
Bulk Solution ◽  
Diffusion Control ◽  
Dynamic Surface ◽  
Equilibrium Surface Tension ◽  
Air Interface

<p>The surface tension (ST) of xylem sap at the water-air interface is a crucial phenomenon, influencing many physiological events such as air seeding and embolism, by which xylem vessels become air-filled and cease to function. Refilling of embolized, may relies on sap’s surface activity at the interface. It is commonly assumed that the ST of xylem sap is equal to the ST of pure water (72 mN/m). However, xylem sap is a complex solution and consists of surface-active molecules that may adsorb and accumulate at the water-air interface and thereby reduce the ST of water as a function of their aqueous concentration. However, when a new water-air interface is formed, equilibrium ST is not reached instantaneously. Specifically, amphiphilic molecules are kinetically adsorbed and undergo orientation at the interface following diffusion from the bulk solution. Dynamic ST of xylem sap and liquid-solid interactions, describing the surface phenomena of the xylem of vascular plants is currently not fully understood. This is mainly due to a lack of quantitative knowledge on the rate and extent of dynamic and equilibrium ST of sap. In this regard, the main objective of this study is to quantify the dynamic and equilibrium ST of xylem sap as a function of their aqueous concentration. We extracted xylem sap from lemon trees and measured ST as a function of time using the pendant drop technique. The dynamic ST data were analyzed using empirical and diffusion-control mathematical models which adequately described the exponential-like decay of the ST as a function of time. The results showed reduced ST of water in the xylem sap, indicating significant surface activity, reaching equilibrium ST values as low as 42 mN/m. The rate of ST decay was higher in high sap concentration and reduced in diluted one. The results of dynamic and equilibrium ST and the corresponding model will be presented and their implications for xylem hydraulic functioning will be discussed.</p><p> </p><p>Keywords: Dynamic surface tension, Equilibrium surface tension, Diffusion, Xylem sap.</p><p> </p>

Effect of Oxyethylene Groups of Fatty Alcohol Polyoxyethylene Ether Sodium Sulfates on Equilibrium and Dynamic Surface Tension in Relation to Wetting Properties

2021 ◽  
Vol 58 (5) ◽  
pp. 394-400
Author(s):  
Xiaodan Ren ◽  
Ping Li ◽  
Jianbo Li ◽  
Xiaoyi Yang ◽  
Chaohua Guo ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Fatty Alcohol ◽  
Dynamic Surface Tension ◽  
Dynamic Surface ◽  
Polyoxyethylene Ether ◽  
Wetting Properties ◽  
Equilibrium Surface Tension ◽  
Fatty Alcohol Polyoxyethylene Ether ◽  
Air Liquid Interface

Abstract The effect of hydrophilic chain of surfactants fatty alcohol polyoxyethylene ether sodium sulphates (AEnS, n = 2, 3, 7) on surface properties and wetting properties was investigated by the measurement of equilibrium surface tension, dynamic surface tension and dynamic contact angle. The fatty alcohol polyoxyethylene ether sodium sulphates with different head group sizes were used. From the results of equilibrium surface tension measurements, we could obtain the critical micellisation concentration, adsorption efficiency, maximum surface excess concentration and Langmuir equilibrium adsorption constant at air/liquid interface. The dynamic surface tension results showed that the adsorption of aqueous solutions at the air/liquid interface follows a mixed-diffusion kinetic adsorption mechanism. In conclusion, for both studied surfactant, the longer the oxyethylene chains, the higher the maximum rate of surface tension reduction, the higher the diffusivity and wetting properties in terms of contact angle.

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