Interfacial tension pendant drop method

Interfacial tension, V12- Drop retraction method (DDRM) 310-312, 314, 317, 456, 495 Interfacial tension, Pendant drop method 310-312, 314, 317, 456, 495... 

Interfacial Tension of Aqueous Surfactant Solutions by the Pendant Drop Method... 

The low interfacial tensions between two liquids have been measured for different systems by using the pendant drop method. In the case of the quaternary system Ci2ll25S 3 tNa+H20+n-Butanol+Toluene, the interfacial data as measured by pendant drop method are compared with reported literature data, using other methods (with varying NaCl concentration). In order to understand the role of co-surfactant, ternary systems were also investigated. The pendant drop method was also used for measuring the interfacial tension between surfactant-H20/n-alcohol (with number of carbon atoms in alcohol varying from 4-10). The interfacial tension variation was dependent on both the surfactant and alcohol. 

BIRDl AND STENBY Interfacial Tension by the Pendant Drop Method 331... 

These studies, carried out by measuring interfacial tensions, Yq , between aqueous and oil phases, by using the pendant drop method, show that this method is very useful for ternary and quaternary systems. In one system (A), NaDDS + H2O + n-butanol + Toluene... 

The interfacial tension was measured by the pendant drop method. Detailed description of the apparatus and the method was given previously (3 ). ... 

The energy associated with the interfaces between phases plays an important part in certain aspects of the migration of petroleum in underground reservoirs. For this reason there has long been interest in the interfacial tension between the phases of petroleum. The work of Swartz (71) was one of the early efforts to determine the effect of changes in pressure and composition upon the interfacial tension between the liquid and gas phases of petroleum. The methods of determining the interfacial tension between phases have been improved and the pendant drop method (16, 25) appears to be one of the more useful approaches to such measurements, particularly at elevated pressures. 

The pendant drop method has been used to measure the interfacial tension at the surface between mercury and cyclohexane solutions of stearic acid at 30 and 50°C. 

The pendant drop method (Fig. 4.16) measures the contact angle 6 and drop radius R to determine the surface tension for any liquid surrounded by gas, or the interfacial tension between any two liquids A drop is hung from a syringe tip in air, and the interfacial surface tension J gl is... 

The pendant drop method was applied in order to determine interfacial tension and was carried out by photographing the drop in a high pressure optical cell evaluating the contour... 

The interfacial tension of the binary system a-tocopherol/carbon dioxide was measured using the pendant drop method in the pressure range between 10 and 37 MPa at nine different temperatures 313, 333, 343, 353, 363, 373, 383, 393 and 402 K. The interfacial tension decreases with rising pressure at a constant temperature and increases with increasing temperature at a constant pressure. The interfacial tension was found to be mainly a function of the mutual solubility of the two system components and of the density of pure carbon dioxide. 

Interfacial tension of the water/oil system, determined by a pendant drop method. 

Methods used to measure interfacial tension are reviewed by Drelich, Fang, and White [ Measurement of Interfacial Tension in Fluid-Fluid Systems, in Encyclopedia of Surface and Colloid Science (Dekker, 2003), pp. 3152-3156]. Also see Megias-Alguacil, Fischer, and Windhab, Chem. Eng. Sci., 61, pp. 1386-1394 (2006). One class of methods derives intertacial tension values from measurement of the shape, contact angle, or volume of a drop suspended in a second liquid. These metho(Js include the pendant drop method (a drop of heavy liquid hangs from a vertically mounted capillary tube immersed... 

In theory, every surface tension measurement method can be used to determine the interfacial tension between two liquids. However, the accuracy of these methods is reduced when applied to liquid-liquid interfaces, or when one or both of the liquids is viscous. In practice, the maximum bubble pressure and pendant drop methods are the most suitable, giving consistent and reliable values for interfacial tensions, although there is sometimes the... 

Pendant Drop Method A method for determining surface or interfacial tension based on measuring the shape of a droplet hanging from the tip of a capillary (in interfacial tension the droplet may alternatively hang upward from the tip of an inverted capillary). Also termed the hanging drop (or bubble) method. 

Figure 4.7. Schematic representation of the interfacial tension measurements by the pendant drop method d is the maximum drop diameter, and d is the diameter located at the distance d from the drop apex.

Recently, the effect of a reactively formed compatibilizer on Vj2 was smdied using the pendant drop method [Garmabi and Kamal, 1998]. Their results are shown in Figure 4.16. A small quantity of MAH drastically reduced the interfacial tension coefficient, but the amount of formed graft was not determined. 

It came to be realized that interfaces between low molecular weight liquids in immiscible liquid mixtures possess an interfacial tension. Experimental measurements of interfacial tension between low molecular weight liquids were first made in the nineteenth century (59,60). Various experimental techniques have been developed to measure interfacial tensions. A popular method has been the pendant drop measurement, which was originally developed by Andreas et al. (61)... 

Measurements of interfacial tensions of polymer melts were reviewed by Wu (55), Koberstein (65), and Demarquette (66). The measurements usually need long equilibrium time because of the high viscosities of polymer melts. The measurements can be divided into two groups static methods in which interfacial tension is calculated based on the equilibrium profile of the drops and dynamic methods that study the evolution of fiber or drop profiles with time. Static methods include pendant drop method, sessile drop method, and rotating drop method. Dynamic methods include breaking thread method, imbedded fiber method, and deformed drop retraction method. 

The pendant drop method and the sessile drop methods for surface tension appear quite different, but are similar in principle. In each case, a drop is formed which either sits on a plane surface (sessile, see Figure 3.11) or hangs as a pendant drop (each can be formed rightside-up or upside-down depending on Ap). In zero gravity, each would form a sphere due to surface or interfacial tension. In the gravitational field, the drop becomes distorted until the gravitational and surface tension forces equal. 

Surface and interfacial tensions of the two liquids were measured with a Kruss DSA 100 drop analyser system by the pendant drop method. The liquid was injected... 

The interfacial tensions of water and two ionic liquids in silicone oil are measured by the ECD method and also by the pendant drop method for comparison. As shown in Fig. 7, the measurement results by the two different methods are not significantly different and show consistent value with the literatures. The consistent measurement results by... 

Kakiuchi, T., M. Nakanishi, and M. Senda (1988). The electrocapillary curves of a phosphatidylcholine monolayer at a polarized oil-water interface. I. Measurement of interfacial tension using a computer-aided pendant-drop method. Bull. Chem. Soc. Jpn 61, 1845-1851. 

Interfacial tension measurement Interfacial tensions were measured using the pendant drop method (19), and by use of a Wilhelmy plate in conjunction with an interfacial film balance (20). 

For each of the three surfactant systems, the interfacial tension values calculated from the I.D.T. traces are higher than their equilibrium counterparts as measured by the pendant drop method. This holds true even when the interface is subject only to displacement, rather than expansion or compression this is shown in Figures 6, 8 and 10, where steady state dynamical interfacial tension values are shown. These values are obtained from the constant linear parts of the I.D.T. traces, or from the last part of the central (small capillary) section of the trace in those cases where it is not certain that the trace had yet reached its plateau (steady state) value. 

Abstract The interfacial properties of tracheal aspirate from infants with untreated neonatal respiratory distress syndrome (NRDS), and NRDS infants after therapy with the exogenous surfactant Curosurf were assessed. The interfacial characteristics of the aspirate (equilibrium surface tension, maximal and minimal surface tension during lateral compression-decompression cycles) were determined with the pendant drop method. Our results show that the tracheal aspirate of infants with untreated NRDS had high equilibrium, maximal and minimal surface tension values. In contrast, the samples from infants, treated with Curosurf , showed lower surface tension values, suggesting that the application of Curosurf improves the composition and the properties of the pulmonary surfactant in the infant lung. 

The shape adopted by a drop stems from a compromise between the effect of surface tension, which favors a sphere, and gravity (or any other force field), which will cause distortions. For any given situation, analyzing the shape of the drop ought to make it possible to extract the surface tension. Several methods currently used to measure surface (or interfacial) tensions are based on this principle, such as the sessile drop method or the pendant drop method. The latter is the most commonly used. ... 

As preliminary tests to show surfactant properties of asphaltenes were performed interfacial tension measures in a Kriiss Tensiometer DSAIOO using the pendant drop method. The analysis time was 90min and a needle with a diameter of 1.463 mm and a 500pL syringe used. 

Only methods based on drop profiles are suitable for both surface and interfacial tension measurements. These include the pendant drop method [125-127], the sessile bubble or drop method [128, 129], and the rotating drop or bubble method [130, 131]. These methods are independent of the solid-Uquid contact angle but require accurate knowledge of the density difference across the interface. The demand of accurate density data becomes even greater when the two phases have similar densities. The rotating drop or bubble method is particularly suited for the determination of very low surface and interfacial tensions. 

The most versatile, convenient, and reliable technique for determining the surface and interfacial tension of polymer melts is the pendant drop method [19, 20, 45, 54, 56, 122, 126, 127, 152-155]. The results obtained by the pendant drop method constitute the bulk of the available data [10, 120]. The method is... 

Determinations by Roe [154] and Wu [127, 152, 153] using the pendant drop method and by Hata and coworkers [128, 175] using the sessile bubble technique have yielded values for a number of polymer pairs as a function of temperature. Gaines [ 174] and Wu [ 10,120,176] provided extensive reviews of the early work in the area of surface and interfacial tension of polymer liquids and melts. 

Anastasiadis et al. [45] investigated the compatibilizing effect of an anionically synthesized model FS-b-FYE diblock copolymer on the interfacial tension between PS and PVE model polymers as a function of the concentration of the copolymer additive. They utilized the pendant drop method [155] to measure the interfacial tension between the immiscible polymer fluids. A sharp decrease in interfacial tension was observed with the addition of small amounts of copolymer (Fig. 24),... 

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