Spinning Drop Method Research Articles

Synthesis, surface and interface tension of N-lauroyl-L-Valine sodium

N-lauroyl-L-Valine sodium (NLLVS) was synthesized and characterized by FT-IR, 1H-NMR spectrometry. Surface and interface tension were measured by wilhelmy plate and spinning drop method. The effects of surfactant concentration, salt, polymer and mixed surfactant on interfacial tension were studied in detail. The critical micelle concentration (cmc) was 6 × 10−3 mol/L and cmc oil was 8 × 10−3 mol/L. The equilibrium interfacial tension (IFTequ) first decreased and then increased with NLLVS increasing. Mixed salts were less effective at reducing interfacial tension than NaCl and CaCl2, while the higher concentration of NaCl was needed to obtain the same IFT as added CaCl2 and NaCl/CaCl2. The lowest IFTequ obtained at the NaCl concentration of 10% when the ratio of NLLVS and Alkyl polyoxypropylene polyoxyethylene ether sulfate (P12) was 2:8. Polyacrylamide was disadvantage to reduce IFT, while polyacrylamide was arranged more tightly by NLLVS.

Prediction of phase equilibrium and interfacial properties in the quaternary system water + 1-hexanol + hexylacetate + acetic acid

The knowledge of the liquid-liquid phase equilibrium and the corresponding interfacial properties of quaternary liquid mixtures can be used for the optimization of extraction processes relevant for industrial application. The purpose of this work is the theoretical prediction of the above mentioned interfacial properties for the quaternary mixtures water + 1-hexanol + hexylacetate + acetic acid using the incompressible version of the density gradient theory in combination with the NRTL activity coefficient model. The prediction is based on phase equilibria data including vapor-liquid and liquid-liquid equilibria of the corresponding binary and ternary subsystems and binary experimental interfacial tension data of the two binary subsystems water + 1-hexanol and water + hexylacetate forming a miscibility gap. The predicted interfacial tensions of the quaternary were verified by new measurements utilizing the spinning drop method and an excellent agreement was achieved. Additionally, for the first time, the simultaneous enrichment of two different components inside the liquid-liquid interfacial layer could be observed.

Comparison of Vegetable Oil-Silicone Oil Interfacial Tension Data from the du NoüyRing and the Spinning Drop Methods

Liquid-liquid interfacial tension is very important in colloid and surface chemistry as it detects the amount of energy required to create a new interface. This makes its measurement very crucial. There are different techniques for measuring it, with the common ones being the du Noüy ring and spinning drop methods. The aim of this work is to compare the low interfacial tension values obtained from the du Noüy ring method with those obtained using the spinning drop method in vegetable oil-silicone oil systems. Low interfacial tension values of various vegetable oil-silicone oil systems were measured with the du Noüy ring and spinning drop methods. The interfacial tension values range from 2.1 to 2.8 mN m‒1 for the du Noüy ring method and 1.0 to 2.7 mN m‒1 for the spinning drop method. These values agree closely)05.0(=p. This shows that both methods can be used for measuring interfacial tension with high accuracy in vegetable oil-silicone oil systems.

An Experimental Approach to Formulate Lignin-Based Surfactant for Enhanced Oil Recovery

The higher cost of chemical surfactants has been one of the main reasons for their limited used in enhanced oil recovery (EOR) process. Hence, the reason for developing lignin-based surfactant is to lower the cost of chemicals as it does not tie to the price of crude oil as compared to petroleum-based surfactants. Besides, lignin is biodegradable and easily extracted from plant waste. The objectives of this study are to determine the formulations of the lignin-based surfactant for EOR applications and to determine the oil recovery performance of the formulated surfactants through surfactant flooding. The lignin-based surfactants were formulated by mixing the lignin with the amine (polyacrylamide or hexamethylenetetramine) and the surfactant sodium dodecylbenzenesulfonate in a 20,000 ppm NaCl brine. Interfacial tension (IFT) of the formulated lignin-based surfactant is measured at ambient temperature using the spinning drop method. The displacement experiments were conducted at room temperature in glass beads pack holders filled with glass beads, saturated with paraffin and brine. The results of the study showed that the best formulation of lignin-based surfactant is using hexamethylenetetramine as the amine, lignin, and sodium dodecylbenzenesulfonate at 2% total active concentration. The oil recovery and interfacial tension using the lignin amine system is comparable with the commercial petroleum sulfonate system.

Studies on Interfacial Tensions of Ionic Surfactant and Alkyl Sulfobetaine Mixed Solutions

To expound the mechanisms responsible for reducing interfacial tensions (IFTs) in amphoteric and ionic surfactant mixed systems, the IFTs of mixed solutions containing alkyl sulfobetaine (ASB) and different ionic surfactants against hydrocarbons with different carbon numbers have been investigated by the spinning drop method. For cationic surfactants, the antagonistic effect for reducing IFT appears between cationic and ASB molecules because of electrostatic repulsion, which results in competitive adsorption. On the other hand, the synergistic effect will be observed in ionic and ASB mixed systems as a result of the mixed adsorption caused by the electrostatic attraction. The “chain length compatibility” between the anionic surfactant and ASB molecules leads to a stronger synergistic effect and further reduces IFT. However, “size compatibility” plays the crucial role, and only mixed solutions containing an anionic surfactant with a larger hydrophobic group can produce ultralow IFT against hydrocarbons. Th...

SFTA3 \u2013 a novel surfactant protein of the ocular surface and its role in corneal wound healing and tear film surface tension

The study aimed to characterize the expression and function of SFTA3 at the ocular surface and in tears. Ocular tissues, conjunctival (HCjE) and human corneal (HCE) epithelial cell lines as well as tearfilm of patients suffering from different forms of dry eye disease (DED) were analyzed by means of RT-PCR, western blot, immunohistochemistry, and ELISA. A possible role of recombinant SFTA3 in corneal wound healing was investigated performing in vitro scratch assays. Tear film regulatory properties were analyzed with the spinning drop method and the regulation of SFTA3 transcripts was studied in HCE and HCjE after incubation with proinflammatory cytokines as well as typical ocular pathogens by real-time RT-PCR and ELISA. The results reveal that human ocular tissue as well as tears of healthy volunteers express SFTA3 whereas tears from patients with DED showed significantly increased SFTA3 levels. In vitro wounding of HCE cell cultures that had been treated with recombinant SFTA3 demonstrated a significantly increased wound closure rate and rSFTA3 reduced the surface tension of tear fluid. The results indicate that SFTA3 at the ocular surface seemed to be involved in wound healing and the reduction of surface tension.

Ultra-Low Interfacial Tension of a Surfactant under a Wide Range of Temperature and Salinity Conditions for Chemical Enhanced Oil Recovery

AbstractUltra-low interfacial tension (IFT) is an important parameter for selecting surfactants to apply in chemical enhanced oil recovery (CEOR). In this study, the IFT between the solution of the surfactant ANSM and Dagang crude oil was measured using the spinning drop method. The effects of the surfactant concentration, temperature, salt types and aging time on the IFT were investigated in detail. The results showed that ANSM effectively reduced the IFT without alkali. Ultra-low IFT was formed in a wide range of surfactant concentrations from 0.05∼ 0.5 wt.% and a wide range of temperatures from 20∼80°C. In addition, ANSM also showed great NaCl tolerance, with a maximum NaCl concentration of 130000 mg · L−1. Furthermore, 0.1 wt.% ANSM maintained an ultra-low IFT, even with 900 mg · L−1 CaCl2 or 1300 mg · L−1 MgCl2, in the presence of 10000 mg · L−1 NaCl. ANSM also had an excellent stability; the solution maintained the ultra-low IFT for 60 days at 90°C. Thus, ANSM proved itself as a potential candidate for CEOR.

Interfacial Behavior of Aqueous Two-Phase Systems Based on Linear and Hyperbranched Polymers

In this work, the interfacial behavior of two different aqueous two-phase systems (ATPSs) was analyzed. One ATPS is formed by the dissolution of polyethylene glycol (PEG) and dextran T40 in water, and the second ATPS is formed by a hyperbranched polyesteramide (HB) and dextran T40. The interfacial behavior of both ATPSs was investigated experimentally and theoretically. As a thermodynamic model, the lattice cluster theory combined with a lattice Wertheim model was used. This thermodynamic model was combined with density gradient theory to model the interfacial properties. It was found that the interfacial tension, which was measured by the spinning drop method, of the ATPS containing the HB was lower than the interfacial tension of the ATPS containing the PEG. Moreover, the mass transfer of the phase forming components across the interface was measured and modeled. To measure the mass transfer, a Nitsch cell was used. The mass transfer was modeled by the instationary density gradient theory. It was found ...

Preparation and Characterization of Chemical Agents for Augmenting Injectivity in Low Permeability Reservoirs

In this paper, experimental techniques have been developed to prepare and characterize chemical agents for augmenting injectivity in low permeability reservoirs. First, chemical agents are selected, formulated, and optimized on the basis of interfacial tension (IFT), scale inhibition ratio, and clay particle size distribution and specific surface area. The spinning drop method is utilized to measure the IFT between crude oil and the formulated solution, while contact angle between brine and rock surface is measured to examine effect of the chemical agents on the rock wettability. Also, scale inhibition ratio and antiswelling ratio are, respectively, measured by performing static-state scale inhibition experiments and centrifugation experiments. Then, displacement experiments are conducted to evaluate injectivity improvement after one pore volume (PV) of such formulated chemical agents has been injected into a core plug. It is found that the optimized solution consists of 0.15 wt % fluorocarbon surfactant FC-117, 4.00 wt % isopropanol, 1.20 × 10−3 wt % scale inhibitor 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), and 1.50 wt % clay stabilizer diallyl dimethyl ammonium chloride (DMDAAC). The IFT between crude oil and the optimized solution can be reduced to 5.36 × 10−3 mN/m within a short time, while the scale inhibition ratio and antiswelling ratio are measured to be 94.83% and 86.96%, respectively. It is found from comprehensive evaluation experiments that such a formulated and optimized solution can not only alter the rock surface from oil-wet to water-wet but also reduce the scale formation of the reservoir brine. In addition, it is shown from displacement experiments that the pressure is decreased by 34.67% after the injection of such formulated solution. When the formulated solution contains 0–300,000 mg/L sodium chloride (NaCl) and 0–5000 mg/L calcium chloride (CaCl2) at 50–90 °C, the IFT between crude oil and the formulated solution can be reduced to lower than 10−2 mN/m.

Dual Action of Hydrotropes at the Water/Oil Interface

Hydrotropes are substances containing small amphiphilic molecules, which increase solubility of nonpolar (hydrophobic) substances in water. Hydrotropes may form dynamic clusters (less or about 1 ns lifetime) with water molecules; such clusters can be viewed as “pre-micelles” or as “micellar-like” structural fluctuations. We present the results of experimental and molecular dynamics (MD) simulation studies of interfacial phenomena and liquid–liquid equilibrium in the mixtures of water and cyclohexane with the addition of a typical nonionic hydrotrope, tertiary butanol. The interfacial tension between the aqueous and oil phases was measured by Wilhelmy plate and spinning drop methods with overlapping conditions in excellent agreement between techniques. The correlation length of the concentration fluctuations, which is proportional to the thickness of the interface near the liquid–liquid critical point, was measured by dynamic light scattering. In addition, we studied the interfacial tension and water–oil i...

METROLOGICAL ANALYSIS OF DIFFERENT TECHNIQUES FOR MEASURING INTERFACE TENSION BETWEEN TWO FLUIDS BASED ON SPINNING DROP METHOD

METROLOGICAL ANALYSIS OF DIFFERENT TECHNIQUES FOR MEASURING INTERFACE TENSION BETWEEN TWO FLUIDS BASED ON SPINNING DROP METHOD

Investigation on Physical Properties and Morphologies of Microemulsions formed with Sodium Dodecyl Benzenesulfonate, Isobutanol, Brine, and Decane, Using Several Experimental Techniques

In the context of chemical enhanced oil recovery (EOR), there is no well-established way to characterize and understand the physical properties and structures of microemulsions composed of crude oil and industrial surfactants due to their complexity. Making a comparison to a well-studied model system is a simple and effective way to investigate the complex microemulsions. The purpose of this study is to provide and complete experimental characteristic data of model-microemulsions as a basis of analysis of the complex system. Types of microemulsions studied in the present work were oil in water (O/W), bicontinuous, and water in oil (W/O). The system was composed of water, sodium dodecyl benzenesulfonate (SDBS), isobutanol, sodium chloride (NaCl), and decane. We performed several experiments at room temperature such as spinning drop method, differential scanning calorimetry (DSC), Karl Fischer titration, Hyamine titration, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and electron cry...

Performance of alkali‐free natural petroleum sulfonates: Ultra‐low interfacial tension on oil/water interface

Ultra‐low interfacial tension (IFT) is one of the most important conditions relating to surfactant flooding for enhanced oil recovery. In this paper, the dynamic interfacial tension (DIT) of an alkali‐free petroleum sulfonate surfactant was studied with the spinning drop method aimed at the Daqing oil/water system. The effects of various experimental conditions, such as surfactant concentration, inorganic salt concentration, polar organic compounds, oil‐soluble sulfonates, and time stability were investigated. It was shown that the aqueous phase has little effect on DIT. The high molecular weight petroleum sulfonates play an important role in the lowering of oil/water IFT. The non‐uniform changes of the oil droplets in DIT measurements were also discussed from the aspects of petroleum sulfonate composition and diffusion rate. The increase of aqueous phase viscosity could only ease the rebound phenomenon, while the increase of heavy components of petroleum sulfonates could both eliminate the non‐uniform changes of the oil droplets and reduce the values of the IFT. These results may be helpful in explaining the reasons behind producing ultra‐low interfacial tension and the preparation of formulations for practical applications.

DEVICE FOR STUDY OF DYNAMIC SURFACE TENSION OF AQUEOUS SURFACTANT SOLUTIONS

Theoretical bases of fixed spinning drop method for the study of dynamic interfacial tension of aqueous surfactant solutions on the border with other immiscible liquids in water are considered. The block diagram and appearance of the device, which implements the method of fixed spinning drop are given. There are provided the results of research of the dynamic interfacial tension between the base oil and aqueous solutions of surfactants Tipol and Savenol of different concentrations used for intensification of oil and gas extraction.

Interfacial Tension between Low Salinity Solutions of Sulfonate Surfactants and Crude and Model Oils

Interfacial tensions (IFT) between low salinity surfactant solutions of sodium dodecylbenzenesulfonate (SDBS) and sodium dioctylsulfosuccinate (Aerosol OT or AOT) and different oil phases were measured using the spinning drop method. The oil phases were either n-heptane, a 1:1 mixture of n-heptane and toluene or crude oils. The IFT was strongly affected by variation of the salinity and especially by the presence of calcium. IFT values between SDBS solutions and heptane, as well as all four crude oils, decreased when adding sodium and calcium. IFTs down to 32 μN/m for crude oil were measured in the presence of AOT solutions with low salinity electrolyte. In the IFT region below 1 mN/m the presence of small amounts of calcium could lower the IFT by more than 1 order of magnitude compared to solutions containing only sodium chloride with the same ion strength.

Influence of polymer on dynamic interfacial tensions of EOR surfactant solutions

ABSTRACTThe effects of different types of polymers, partially hydrolyzed polyacrylamide (HPAM) and hydrophobically modified polyacrylamide (HMPAM), on dynamic interfacial tensions (IFTs) of surfactant/model oil systems have been investigated by the spinning drop method in this article. Two anionic surfactants, 1,2‐dihexyl‐4‐propylbenzene sulfonate (366), 1,4‐dibutyl‐2‐nonylbenzene sulfonate (494) and an anionic–nonionic surfactant octyl‐[ω‐alkyloxy‐poly(oxyethylene)]yl‐benzene sulfonates (828) with high purity were selected as model surfactants. The influences of polymer concentration on IFT were expounded. It was found that the addition of polymer mostly results in increasing IFT because the interfacial molecular arrangement is modified owing to the interaction between polymer and surfactants. For HPAM, the polymer chains will enter the surfactant adsorption layer to form mixed‐adsorption layer. Therefore, HPAM shows strong effect on surfactant molecules with large size, such as 366. Conversely, surfactants can interact with the hydrophobic blocks of HMPAM and form mixed micelle‐like associations at interface. As a result, HMPAM shows more impact on IFT of 494 due to small steric hindrance for the formation of interfacial associations. This mechanism has been ensured by 828 molecules with two long alkyl chains. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40562.

Interfacial Tensions for System of n-Heptane + Water with Quaternary Ammonium Surfactants and Additives of NaCl or C2–C4 Alcohols

Interfacial tensions of the oil–water interface versus surfactant concentration for n-heptane + water system with each of six single chain quaternary ammonium surfactants, and six Gemini quaternary ammonium surfactants around their critical micelle concentrations (CMC) have been measured by using the spinning drop method. The influences of additives (NaCl, ethanol, n-propanol, and n-butanol) on the interfacial tensions have also been investigated. It is observed that all of the surfactants can significantly lower the interfacial tensions of the n-heptane + water system. The required concentrations to reach the lowest interfacial tensions for Gemini surfactants with C12 and C14 alkyl chains are less than 10 % of those values for the corresponding single chain surfactants. For the n-heptane + water + Gemini surfactant systems, the addition of NaCl can lower the required surfactant concentrations to obtain the lowest interfacial tensions; however, the addition of C2–C4 alcohols has no evident effects but leads to a slight decrease of the values of these interfacial tensions.

Dynamic Interfacial Tensions Between Offshore Crude Oil and Enhanced Oil Recovery Surfactants

The dynamic interfacial tensions between offshore crude oil and different types of EOR surfactants were investigated by spinning drop method at 65 degree under the condition of weak base (pH ∼ 8) in the present work. Effects of surfactant concentration on the dynamic interfacial tension were investigated. In the presence of weak alkali, the active components of crude oil can react at the interface to produce surface-active species in situ. The interactions among the added surfactants, the petroleum active components and in situ produced surface-active species together determine the dynamic interfacial tension behaviors, whose curves show “L”, “V,” and “W” shapes, respectively. Surfactant type and concentration play the crucial roles on dynamic interfacial tension behaviors.

Adsorption kinetics of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride at oil–water interface

Dynamic interfacial tension (DIT) between aqueous solution of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride (RnHTAC) and n-octane was measured using spinning drop method. The effects of RnHTAC concentration (the concentration below the CMC) and temperature on DIT have been investigated. The cause of the change of DIT with time has been discussed. The effective diffusion coefficient, Da, and the adsorption barrier, ɛa, have been obtained with extended Word–Tordai equation. The results show that the higher the concentration of the surfactant is, the smaller the DIT will be and the lower the curve of the DIT, and the aqueous RnHTAC solutions follow a mixed diffusion–activation adsorption mechanism. With increase of RnHTAC concentration in the bulk solution, Da decreases and ɛa increases. Da of aqueous R14HTAC solution decreases from 0.090×10−13m2s−1 to 0.081×10−13m2s−1 and ɛa increases from 10.12kJmol−1 to 11.89kJmol−1, with the temperature increasing from 30°C to 50°C. This phenomenon indicates that the diffusion tendency becomes weak with the strengthening of the interaction between the surfactant molecules and that the thermo-motion of molecules benefits interface adsorption.

Considerations when determining low interfacial tensions

Surfactants are often used to create low or “ultralow” oil–water interfacial tensions (IFTs). These molecules, in some cases, may also lead to the inadvertent formation of microemulsion phases which can obscure IFT measurements. Here, we present a case study of such an issue. We also introduce a little-known micropipette technique which has many advantages over the more common spinning drop method for determining low/ultralow IFTs.