Surface Tension Meter Research Articles

A Low-Cost Dynamic Surface Tension Meter with a LabVIEW Interface and Its Usefulness in Understanding Foam Formation

Using standard chemical laboratory equipment, it is possible to construct a low-cost dynamic surface tension meter. The concept of the experiment seemed very appropriate to demonstrate a broad range of dynamic effects on surface tension. Everyday samples such as beer and cola revealed that the dynamic surface tension data are a very useful aid to understanding the foaming characteristics of these liquids. Further experiments into foam formation demonstrated that static surface tension data are useless in explaining such dynamic processes; on the other hand, a very nice correlation between dynamic surface tension and foam volume clearly indicated that the experimental setup presented in this paper is well suited to explaining the phenomena occurring at the surface of liquids during foam formation.

Strength of CO2 Hydrate Membrane in Sea Water at 40 MPa

Abstract: The strength of the CO2 hydrate membrane that forms at the interface between liquid CO2 and artificial sea water at 40–45 MPa was measured with Du‐Nouy type surface tension meter. At low temperatures with a subcooling greater than 5 K, the membrane strength, initially abut 0.1 N/m, decreased with increasing temperature. However, it increased sharply and reached a peak of about 0.9 N/m just below the dissociation temperature and abruptly drops to zero at the dissociation temperature. This abnormal tendency of the membrane strength was previously observed by the authors in an experiment with fresh water. The temperature of the abnormality, however, shifts to lower temperatures and the peak decreases with increasing salinity. This new phenomenon could exert major influences on the various CO2 ocean sequestration methods that have been proposed to mitigate global warming. It can be explained in terms of a model in which the dissociation process of hydrate that occurs near the dissociation temperature enhances the diffusion of water molecules in the hydrate membrane and makes the membrane thicker.

Interaction between Liposomes as a Model of Biomembrane and Nonionic Surfactants

The degree of lytic action due to interactions between nonionic surfactants and liposomes was determined in terms of affinity for lipid membranes. The solubilization potential of some surfactants toward liposome membranes was estimated based on physicochemical measurements such as fluorometry to detect the release of fluorescent markers (calcein) from liposomes, turbidimetry in suspensions and surface tensiometry. The lytic action of the alkyl poly (oxyethylene) ether (POE) toward lipid membranes was greatest when the alkyl and ethylene oxide chain lengths were 12 and 8, respectively. The lytic action of nonionic surfactants with various hydrophobic portions (hydrogenated caster oil POE ethers, cholesteryl POE ethers, nonylphenyl POE ethers and POE stearate) was found to depend on structure. Maximum activity in each homologous series was 1.2 I.O.B. (Inorganic Organic Balance).The critical micelle concentrations (cmc) of dodecyl POE (5) and POE (10) ether in the absence and presence of liposomes were determined using a surface tension meter. Addition of liposomes caused cmc of the surfactants to increase. Dodecyl POE (5) ether causes marker release at lower concentration than cmc without change in turbidity. Dodecyl POE (5) ether concentration increase further, marker release from liposomes greatly increase minor change in turbidity. For dodecyl POE (10) ether, marker release started from cmc with decrease in turbidity. The lytic action of nonionic surfactants on liposomes would thus appear related to their capacity formixed micelle formation with phospholipids.

Effect of alkyl‐2‐pyrrolidone‐5‐carboxylate as an additive on emulsion stability

AbstractAlkyl‐2‐pyrrolidone‐5‐carboxylates (R‐PCA), the derivatives of higher alcohols, were prepared and their properties as emulsion stabilizers were estimated using surface tension meter and Multiple Drop methods in the presence of sodium dodecyl sulfate (SDS) and were compare to those of another system containing a series of edly reduced the interfacial tension compared to a higher alcohol system, and the interfacial tensions for both R‐PCA and higher alcohol systems decreased with the increase of carbon chain length. The stability of oil drops increased greatly by addition of R‐PCA compared to higher alcohol system. In the higher alcohol system, the stability of oil drop showed the minimum at carbon 12. In the R‐PCA system, the stability of oil drops increased greatly with the increase of carbon chain length. A series of R‐PCA was found to be useful as emulsion stabilizers.

Effect of polyethylene glycol-n-dodecyl-ether-2-pyrrolidone-5-carboxylate as additive on stability of emulsion

Ester derivatives (PCA-nED) of dodecyl alcohol, ethyleneglycol dodecyl ether, and diethyleneglycol dodecyl ether with DL-2-pyrrolidone-5-carboxylic acid were prepared, and their properties as emulsion stabilizer were estimated by using a surface-tension meter and multiple drop method in the presence of SDS and compared to those of a series of the corresponding polyethyleneglycol dodecyl ether (nED) as stabilizers. PCA-nED system remarkably reduced the interfacial tension compared tonED system, and the interfacial tension for both PCA-nED andnED systems decreased with the increase of ethylene oxide chain length. The stability of oil drop remarkably increased by addition of PCA-nED compared tonED system, and increased with the increase of ethylene oxide chain length. A series of PCA-nED was found to be utilized as emulsion stabilizers.

Studies on the Surface Tension of Lower Polyoxyethylene Ethers of Lauryl-, Cetyl-, Oleyl-Alcohol and Nonylphenol

Author investigated the surface activities of the polyoxyethylene ethers which have the oxyethylene chains of definite lengths. Mono, di, tri, tetra and penta oxyethylene ethers of lauryl, cetyl, oleyl alcohols and nonylphenol, synthesized in our labolatory, were dissolved or suspended in water and the surface tension of the solutions was measured by using du Nouy's surface tension meter. With the exception of cetyl ethers and mono and di oxyethylene lauryl ethers, the surface tensionconcentration curves of the solutions showed same characteristics as those of ordinary surface active agents. Namely, change in the surface tension is little at higher concentration, while it increases rapidly as the concentration decreases for the range below c.m.c.Furthermore, it was observed that the surface tension of the solutions of paired ethers containing lauryl-oleyl, oleyl-nonylphenyl, and nonylphenyl-lauryl, having tetraoxyethylene chain respectively, was in a range between those of individuals of the pair ethers. Exploratory experiments were also carried out with other combinations and the effect was studied.