Survismeter 3‐in‐1 for interfacial tension (IFT), surface tension and viscosity measurements simultaneously

Interfacial tension (IFT) (γ_ift, N m^?1) of benzene‐water; and surface tensions (γ, N m^?1) and viscosities (η, N s m^?2) of solvents methanol, ethanol, glycerol, ethyl acetate, n‐hexane, diethyl ether, chloroform, benzene, carbon tetrachloride [CCl₄], formic acid, Acetonitril, and dimethylformamide [DMF] were measured with Survismeter‐IFT. The ± 1.1 × 10^?5 N m^?1, ± 1.3 × 10^?5 N m^?1, and ± 1.1 × 10^?5 N s m^?2 deviations in respective values were noted. It has 10 times better accuracy than those of individual methods. The survismeter is inexpensive minimizing 2/3 each of consumables, human efforts, time, and infrastructure, cutting down 80% of the waste disposed the environment. Copyright © 2008 John Wiley & Sons, Ltd.     

Simultaneous study of interfacial tension,surface tension,and viscosity of few surfactant solutions with survismeter

Surfaces and interfaces are receptive valuable significant property of chemical molecules due to their potential to develop several phenomena in a self‐controlled mechanism. Science of surfaces is vast and is being used industrially since time immemorial. Their accurate and simultaneous estimation is necessary; therefore, the survismeter was used for measuring them along with viscosity. Individually tensiometers, X‐ray reflective microscope, and viscometers are used for surface tension, interfacial tension, and viscosity, respectively. These devices are sophisticated, expensive, and individually consume much time and resources with poor reproducibility in measurements. Survismeter is an alternative device for similar measurements together with higher accuracies and reproducibility. It works on a principle of capillary flow and pressure gradient (PG) inside liquid‐holding and air‐filled bulbs. Several liquids have been used for study with ± 0.01 mN/m, ± 0.01 mN/m and ± 1 × 10^?5 N s/m² accuracies in respective data. Copyright © 2008 John Wiley & Sons, Ltd.     

Survismeter Unit for Surface Tension,Viscosity, and Dipole Moment Determination for Polystyrene Interactions in Benzene

Novel instrumental set up is developed for surface tension (γ, N m^?1), viscosity (η, N s m^?2)) and dipole moment (μ/Debye) measurements. A new instrument is economic, viable and pollution free in use, the γ, η and μ from viscosities (η, N s m^?2) and surface tension (γ, N m^?1) for 0.005 to 0.125 g% polystyrene at an interval of 0.0005 g% in benzene are measured at 288.15, 293.15, and 298.15 Kelvin temperatures. The γ, η, and μ are reported stronger frictional and cohesive forces due to stronger interactions of polystyrene with benzene. The survismeter is highly accurate and mechanically operated for pulling up liquid from reservoir bulb B1 to operational bulbs B2, B3, and B4. Densities are higher than those of benzene and also infer stronger polystyrene–benzene interactions, and hydrodynamic volume (HV) calculated with intrinsic viscosity [η] is noted in 293.15 (HV) >298.15 (HV) >288.15 (HV) order with higher values at 293.15 K. Surface tension (γ) values are slightly higher than of benzene and fall in a range of 33.47 to 33.35 N m^?1.     

Study of Aqueous Biomolecules with Magnetic Flux Using Density,Viscosity, and Surface Tension Probe at 304.15 K

Doses of 0.0150 weber m^?2 magnetic flux for 30 minutes are given to four series of biomolecules in aqueous medium, densities (ρ), viscosities (η), and surface tension (γ) were measured at 304.15 K. The vitamins and carbohydrates decrease densities and viscosities and the difference of density from magnet to aqueous solution in order of dextrose (? 0.00025 kg m^?3) > fructose (? 0.00021 kg m^?3) = B6 (? 0.00021 kg m^?3) > starch (? 0.00018 kg m^?3) > B1 (? 0.0018 kg m^?3), while viscosity in order of starch (? 0.0044 kg m^?1s^?1) > fructose (? 0.0037 kg m^?1s^?1) > B1(? 0.0018 kg m^?1s^?1) > dextrose (? 0.0016 kg m^?1s^?1) > B6 (? 0.0012 kg m^?1s^?1). The surface tension also decreases in vitamin and carbohydrate. The proteins show increase in ρ, η, and γ value hence casein decrease the density and viscosity. The glutamine show increase in density and surface tension while decrease in viscosity and vice versa to alanine. These orders of the data indicate the intermolecular force between water and bimolecules in magnetic flux.     

Density,viscosity, and surface tension of binary liquid systems: Ethanoic acid,propanoic acid,and butanoic acid with nitrobenzene

Density, viscosity, and surface tension of three binary liquid systems: ethanoic acid+nitrobenzene, propanoic acid+nitrobenzene, and butanoic acid+nitrobenzene have been determined at 25, 35, and 45°C, over the whole composition range. The excess molar volumes, viscosities, Gibbs energies for the activation of flow, and surface tension were evaluated and fitted to a Redlich-Kister type of equation. The Grunberg-Nissan parameter d was also calculated. Binary viscosity data were fitted to the models of McAllister, Heric, Krishnan, and Laddha, Auslander, and Teja and Rice. Surface tension data were fitted to the models of Zihao and Jufu, Rice, and Teja, and an empirical two-constant model.     

Study of polymer-surfactant interactions via surface tension measurements

Interactions between a polymer and a surfactant were studied via surface tension measurements. Poly(ethylene glycol) and sodium dodecyl sulfate were used as a polymer and a surfactant, respectively. The addition of polymer affected the CMC value of the surfactant. The interpretations of the data and theoretical plots of polymer-surfactant interactions are discussed using a theoretical model. Received: 28 September 2000 Accepted: 3 October 2000     

Effect of solution viscosity on dynamic surface tension detection

A dynamic surface tension detector (DSTD) was used to examine the molecular diffusion and surface adsorption characteristics of surface-active analytes as a function of solution viscosity. Dynamic surface tension is determined by measuring the differential pressure across the air/liquid interface of repeatedly growing and detaching drops. Continuous surface tension measurement throughout the entire drop growth is achieved for each eluting drop (at a rate of 30 drops/min for 2 μl drops), providing insight into the kinetic behavior of molecular diffusion and orientation processes at the air/liquid interface. Three-dimensional data are obtained through a calibration procedure previously developed, but extended herein for viscous solutions, with surface tension first converted to surface pressure, which is plotted as a function of elution time axis versus drop time axis. Thus, an analyte that lowers the surface tension results in an increase in surface pressure. The calibration procedure derived for the pressure-based DSTD was successfully extended and implemented in this report to experimentally determine standard surface pressures in solutions of varied viscosity. Analysis of analytes in viscous solution was performed at low analyte concentration, where the observed analyte surface activity indicates that the surface concentration is at or near equilibrium when in a water mobile phase (viscosity of 1.0 Cp). Two surface-active analytes, sodium dodecyl sulfate (SDS) and polyethylene glycol (MW 1470 g/mol, PEG 1470), were analyzed in solutions ranging from 0 to 60% (v/v) glycerol in water, corresponding to a viscosity range of 1.0-15.0 Cp. Finally, the diffusion-limited surface activity of SDS and PEG 1470 were observed in viscous solution, whereby an increase in viscosity resulted in a decreased surface pressure early in drop growth. The dynamic surface pressure results reported for SDS and PEG 1470 are found to correlate with solution viscosity and analyte diffusion coefficient via the Stokes-Einstein equation.     

Study of molecular interactions between lipids and proteins using dynamic surface tension measurements: a review

Molecular interactions between small molecules and proteins, such as binding of lipids to proteins, are of fundamental importance in various biological processes. A recently-developed method based on dynamic surface tension measurement is efficient and versatile in detecting such molecular interactions: Axisymmetric Drop Shape Analysis (ADSA) provides a tool for measuring the surface tension (γ) response to surface area changes. Through the analysis of the γ response pattern, surface competitive adsorption between small organic molecules and protein molecules can be detected. Surface squeeze-out of small molecules by proteins can also be observed. Molecular binding of lipids to proteins manifests itself in a modification of the γ response which is not compatible with a simple superposition of the two individual patterns. The specific binding can be studied in terms of dose effects and specificity.     

Experiments and model for the surface tension of carbonated monoethanolamine aqueous solutions

The surface tension of carbonated monoethanolamine aqueous solutions from 293.15 to 323.15 K was measured by using an automatic surface tension-meter.A model applicable for the surface tension of MEA-CO2-water mixtures was proposed and the calculated results agreed well with the experiments.The influences of temperature,MEA concentration and CO2 loading were demonstrated on the basis of experiments and calculations.     

MEA-CO2-水溶液表面张力实验和模型

用全自动表面张力仪测定了293．15-323．15K温度范围内,具有不同C02载荷的乙醇胺（Monoethanolamine,MEA）水溶液的表面张力,提出了计算MEA-CO2-水体系表面张力的半经验模型,计算结果与实验值吻合良好．通过实验和计算相结合,阐明了温度、MEA浓度和C02载荷对MEA-CO2-水体系表面张力的影响规律．     

Assessment of the surface tension of various divided solids

We have attempted to calculate the surface tension of some solids using immersion calorimetry measurements along with the interfacial model of van Oss [1, 2, 3, 4].     

Surface tension measurements in the study of molecular complexes

Surface tension measurements can be used to investigate molecular complex formation in liquid solutions for strong and weak complexes. The association constant and epthalpy for triethylamine-iodine, hexamethylbenzene-tetracyanoethylene and ethanol-iodine in cyclohexane are 4·55×10³, 218 and 0.93M⁻¹ at 25° C and 12·5, 7·7 and 5·1 kcal/mol respectively. These values compare well with those reported in the literature by other methods.     

Obtaining surface tension from contact angle data by the individual representation approach

Young equation is the fundamental equation of wetting theory in which the connection among the surface tensions, \(\gamma _{{\varphi \psi }} \) and the contact angle, θ _L, are given. The surface tension of solid surfaces, however, cannot be obtained directly from the Young equation. In this paper, the application of the individual representation theory is demonstrated for the determination of surface tensions of solids (or any phase pair) using experimentally obtained contact angle data. According to this approach, the state of the interfacial layers depends upon, by definition, the properties of the bulk phases in every heterogeneous system, and thus, it complements the traditional capillary theory.     

Non-monotonic behaviour with concentration of the surface tension of certain binary liquid alloys

The surface tension σ(c) of most liquid binary alloys usually varies with concentration c in a monotonic way between the values σ₁ and σ₂ of the two pure metals, and this behaviour is well explained by current models. Some alloys show deviations from this ideal behaviour. One of those is Fe–B. The surface tension of this liquid alloy shows a minimum at 17 atomic % B, which corresponds well with the composition of the eutectic point in the phase diagram, followed by a maximum at a concentration of 24 atomic % B or higher. The usual models for the surface tension of liquid binary alloys do not explain those exceptional features, and we propose that a model involving the concentration fluctuations in the liquid alloy has the proper ingredients to account for the features in Fe–B and similar alloys.     

Prediction of the surface tension of cesium in the whole liquid range

Surface tension is an important quantity, both as physical and technological features. We applied the general form of Lennard-Jones potential model, LJ (m-n), and some thermodynamic arguments in the Kirkwood and Buff equation to calculate the surface tension of liquid cesium. To find out the surface tension in a wide temperature range, only pVT data are required. By this method, we investigated the influence of the potential model on the surface tension. For two selected potential models [LJ (6–3) and LJ (8.5–4)], the values of the calculated surface tension and the predicted surface energy agree with the experimental values.     

Comparison of the capillary wave method and pressure tensor route for calculation of interfacial tension in molecular dynamics simulations

We have studied the calculation of surface and interfacial tension for a variety of liquid–vapor and liquid–liquid interfaces using molecular dynamics (MD) simulations. Because of the inherently small scale of MD systems, large pressure fluctuations can cause imprecise calculations of surface tension using the pressure tensor route. The capillary wave method exhibited improved precision and stability throughout all of the simulated systems in this study. In order to implement this method, the interface was defined by fitting an error function to the density profile. However, full mapping of the interface from coordinate files produced enhanced accuracy. Upon increasing the system size, both methods exhibited higher precision, although the capillary wave method was still more reliable. © 2013 Wiley Periodicals, Inc.     

Adsorption isotherm for a solid electrode: The link between the differential surface tension and capacitance curves

Investigation of thermodynamically equilibrium single-component adsorption from a liquid solution on a solid electrode with allowance made for elastic deformation of its surface is continued. A full electrocapillarity equation is derived from thermodynamics equations for an interphase layer in the absence of irreversible processes. Thermodynamic aspects of the Shuttleworth equation are discussed and the equation is compared with two-dimensional Murnaghan formulas for elastic isotropic media. An adsorption isotherm equation and compatibility equations that had been derived previously are examined in a special case where the derivative of a surface concentration with respect to depends solely on (=()) and a rigorous solution of these is obtained for a deformed electrode ( 0). The effect of and dimensionless electrode potential on the extreme (at an infinitely high adsorbate concentration) value of is studied. The model of two parallel capacitors is considered in detail for a general case. Owing to the use of capacitance curves for an elastically stretched electrode, a formula that expresses the differential surface tension of a nondeformed electrode through such curves is derived for the first time ever.To the memory of my motherTranslated from Elektrokhimiya, Vol. 41, No. 1, 2005, pp. 20–34.Original Russian Text Copyright © 2005 by Podgaetskii.     

Estimation of the surface tension of liquid carbon dioxide

The surface tension of liquid carbon dioxide has practical significance in material science, environmental science and chemical engineering separation processes as well as in the secondary or tertiary recovery of petroleum. The surface tension of liquid carbon dioxide is estimated by semi-empirical and statistical formulae and the results are compared and analysed with experimental data. It is shown that the methods proposed by Brock, Hakim, Miqueua and Zuo are better methods for estimating the surface tension of liquid carbon dioxide and have relatively less percentage deviation from experimental data.