Alkyl Ether Carboxylate Research Articles

Preparation and performance evaluation of a novel temperature-resistant anionic/nonionic surfactant

Aiming at oil extraction from a tight reservoir, the Jilin oil field was selected as the research object of this study. Based on the molecular structures of conventional long-chain alkyl anionic surfactants, a new temperature-resistant anionic/nonionic surfactant (C8P10E5C) was prepared by introducing polyoxyethylene and polyoxypropylene units into double-chain alcohols. The resulting structures were characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (1H-NMR), and electrospray ionization mass spectrometry (ESI–MS). Then, based on surface tension, interfacial tension, adsorption resistance, wettability, and emulsification performance tests, the performance of C8P10E5C was evaluated. The FT-IR, ESI–MS, and NMR spectra confirmed that C8P10E5C was successfully prepared. The critical micelle concentration (CMC) of C8P10E5C in water was 2.9510 × 10−4 mol/L (the corresponding mass concentration is 0.26%), and the surface tension of the aqueous C8P10E5C solution at this concentration was 30.5728 mN/m. At 0.3% concentration, the contact angle of the C8P10E5C solution was 31.4°, which is 60.75% lower than the initial contact angle. Under high-temperature conditions, C8P10E5C can still reduce the oil–water interfacial tension to 10−2 mN/m, exhibiting good temperature resistance. At 110 °C, upon adsorption to oil sand, the C8P10E5C solution could reduce the oil–water interfacial tension to 0.0276 mN/m, and the interfacial tension can still reach the order of 10−2 mN/m, indicating that C8P10E5C has strong anti-adsorption capability. Additionally, it has good emulsifying performance; upon forming an emulsion with crude oil, the highest drainage rate was only 50%. The forced imbibition oil recovery of C8P10E5C is 65.8%, which is 38.54, 24.22, and 27.25% higher than those of sodium dodecyl benzene sulfonate, alkyl polyoxyethylene ether carboxylate, and alkyl ether carboxylate, respectively.

Rock–Fluid Interactions of Alkyl Ether Carboxylate Surfactants with Carbonates: Wettability Alteration, ζ-Potential, and Adsorption

This work evaluated the rock–fluid interactions of two linear alkyl ether carboxylate (AEC) surfactants C11E11A and C12E7A in carbonates: wetting ability, ζ-potential, and adsorption capacity. Contact angle measurements showed that the ability of AECs to hydrophilize the surface is strongly affected by the ethylene oxide (EO) chain length and the presence of electrolytes. An AEC with a shorter EO chain C12E7A demonstrated a better wetting ability and decreased the contact angle value on the limestone surface from 113 to 27 ± 11° in deionized (DI) water and until 17 ± 5° in 5 wt % NaCl. The mechanism of surfactant action was assessed through thermodesorbed hydrocarbon analysis and organic matter characterization with the help of the Rock-Eval (RE) pyrolysis technique for the first time. The analysis results revealed that all surfactant compositions partially removed free oil and heavy oil components from limestone samples. Also, the presence of C12E7A molecules was detected in the samples after surfactant treatment that indicates that a better wetting ability is achieved by the combination of washing hydrocarbons and adsorption of surfactants on clean sites. The combination of ζ-potential measurements and static adsorption test on crushed limestone demonstrated that the adsorption of AECs in deionized water is not governed by electrostatic interactions and mainly occurs due to hydrogen bonding. Salinity has a significant effect on the adsorption behavior of AECs and leads to the partial destruction of hydrogen bonds and the shift from monomolecular adsorption in DI water to polymolecular adsorption in brines. The adsorption of C11E11A achieved ∼9 mg/g-rock and was higher than that of C12E7A, showing a maximum value of ∼4 mg/g-rock. This work provides a set of experiments that characterize the behavior of AECs during interactions with carbonate rock and describes a novel approach of the wettability shift mechanism assessment through RE pyrolysis.

Impact of the molecular structural variation of alkyl ether carboxylate surfactant on IFT reduction and wettability alteration capabilities in carbonates

This paper features an experimental investigation of the effect of single and mixed alkyl ether carboxylate (AEC) surfactants having different molecular structure in altering the wettability of oil-wet carbonate and reducing the interfacial tension (IFT) between oil and brine. All tests were performed at a representative carbonate reservoir conditions; at brine salinity of 196 g/L and temperature of 75 °C. Preliminary compatibility tests revealed that only AEC surfactants having high hydrophilicity; molecular weight ratio of hydrophilic to hydrophobic groups ≥1, were compatible at reservoir harsh conditions and were considered for further analysis. IFT measurements showed that better IFT reduction could be achieved with surfactants having longer branched alkyl chain. Interestingly, inclusion of polypropylene oxide (PO) groups was found to reduce the IFT reduction performances. Only AEC surfactant with branched alkyl chain was able to generate microemulsion Winsor type III. Contact angle measurements using calcite surfaces showed that wettability alteration from strong oil-wet state toward strong water-wet state was obtained with surfactant having the shortest alkyl chain and, correspondingly, highest hydrophilicity. Moreover, this surfactant exhibited the lowest adsorption level on calcite. Adsorption results were further confirmed with thermogravimetric analysis (TGA). Mixing of AEC surfactants resulted in synergistic effect and ultra-low IFT in the order of 10−4 mN/m was obtained. While, no improvement in wettability alteration was observed for the mixed surfactants system. Overall, selection of proper surfactant type is crucial to maximize oil recovery. The novelty of this work resides in quantifying the effect that a particular structural difference could have on the surfactant capabilities in IFT reduction and wettability alteration, which could provide flexibility of tailoring the structure of the surfactant to meet the different reservoir conditions.

The effect of the molecular structure of alkyl ether carboxylate surfactants on the oil–water interfacial tension

• OPLS-AA is not applicable to study surfactants at the alkane-water interface. • Trappe-UA and OPLS-AA underestimate the effect of surfactants on the IFT. • The adsorption limit decreases with the increase in the surfactant headgroup length. • Doubling the tailgroup length leads to a small decrease in the adsorption limit. • The effect of a surfactant molecule size on the adsorption limit is asymptotical. Alkyl ether carboxylate surfactants at the alkane–water interface are explored experimentally through interfacial tension measurements with the spinning drop method and molecular dynamics simulations. The experimental interfacial tension dependence on bulk surfactant concentration is interpreted with the Redlich-Peterson adsorption model, which fits the experiments well. The critical micelle concentrations obtained from the experimental isotherms agree reasonably with published data on other surfactants of the same class. The length of the ethylene oxide hydrophilic segment significantly influences the dependence of the CMC and the interfacial tension at CMC on temperature. The excess surface density of the surfactant at the decane-water interface is calculated with the Redlich-Peterson model and compared with the molecular dynamics simulations, which are performed with two different forcefields. The simulations showed only semiquantitative agreement with the experiments: surfactants interfacial concentrations corresponding to a particular value of tension are systematically higher than the values derived from the experiments, for both forcefields by a certain factor that appears constant. Simulations of surfactants with different lengths of the alkyl tail and ethylene oxide head segments revealed general tendencies related to the surfactants interactions in the layer. Initially, the ethylene oxide segment elongation decreases the monolayer density and increases the effective elasticity. However, as the number of ethylene oxide monomers exceeds approximately eight, the density and compressibility become invariant of the length, which is likely explained by the dominance of electrostatic forces between the charged carboxylate groups that decay with the distance slower than the steric repulsion between the ethylene oxide chains.

Effect of temperature and salinity on interfacial behavior of alkyl ether carboxylate surfactants

This work investigates the interfacial behavior of alkyl ether carboxylate (AEC) surfactants in examples of sodium laureth-11 carboxylate and sodium trideceth-7 carboxylate. AECs have two hydrophilic groups and demonstrate both anionic and nonionic properties, displaying stability under harsh reservoir conditions during surfactant flooding. The interfacial tension measurements were conducted with a spinning drop tensiometer; n-decane, and oil were used as the hydrocarbon phase. The influence of surfactant concentration, temperature (25 °C and 70 °C), and various ions (Na+, Ca2+, Mg2+, Cl−, SO4 −, and HCO3 −) were evaluated. It was found that the temperature increase has no significant effect on critical micelle concentration (CMC) for both surfactants but influences interfacial tension values in pre-CMC and post-CMC regions. According to data obtained, the temperature rise has a stronger impact on a surfactant with a longer oxyethylene chain sodium laureth-11 carboxylate. In contrast, brine salinity has a more substantial effect on sodium trideceth-7 carboxylate interfacial behavior.

Eco-conception of Highly Salt-Tolerant Alkyl Ether Carboxylate Hydrotropes with a Glyceryl Spacer.

New alkyl ether carboxylates with a glyceryl spacer instead of ethylene glycol units have been synthesised using environmentally friendly methodology. A cascade synthesis of acetalisation and hydrogenolysis was developed to obtain products containing an alkyl chain linked to a glycerol unit bearing a polar carboxylate head. These products were methylated by using trimethyl phosphate to observe the influence of a free or methoxylated alcohol on the physicochemical properties. Finally, saponification gave the carboxylate anionic group of the new hydrotropes. Studying the amphiphilicity, the tolerance to sodium and calcium ions, and the solubilising power of these bio-based ionic/nonionic hydrotropes has shown that they exhibit significantly improved application properties compared to similar petro-based hydrotropes.

Static Adsorption Evaluation for Anionic-Nonionic Surfactant Mixture on Sandstone in the Presence of Crude Oil at High Reservoir Temperature Condition

Summary The application of surfactants in enhanced oil recovery (EOR) has revealed over the years various challenges that impose limitations on the successful implementation of surfactant flooding. Surfactant adsorption is one of the most important aspects that strongly dictates the feasibility of surfactant-based EOR. The effect of the presence of crude oil on surfactant adsorption and the influence of surfactant partitioning on the adsorption quantification are presented in this paper. Static adsorption experiments were conducted in this study for a surfactant mixture [alkyl ether carboxylate (AEC):alkylpolyglucoside (APG)] on sandstone rock samples in the absence and presence of crude oil. Partitioning experiments were carried out to evaluate the surfactant partitioning between the aqueous surfactant solution and the crude oil to determine the partitioning influence on the adsorption results in the presence of crude oil. The mixture’s adsorption and partitioning behaviors were studied at a fixed salinity of 32 k ppm and temperatures of 80 and 106°C. High-performance liquid chromatography (HPLC) was used in measuring the surfactant concentration throughout adsorption and partitioning tests. Rock characterization was also performed in this study using X-ray diffraction (XRD) as well as X-ray photoelectron spectroscopy (XPS) before and after adsorption with and without crude oil being present. Static adsorption outcomes displayed the adsorption of APG, AEC, and the overall mixture with and without crude oil being present, because all are having a similar increasing trend when concentration increases. However, the adsorption values were much higher when crude oil was present as compared with the adsorption values when crude oil was absent; this is because of not considering the impact of surfactant partitioning. The adsorption values (i.e., at 0.2 wt%) for both temperatures were below 2.5 mg/g in the absence of crude oil and rose to around 3.5 mg/g in the presence of crude oil. A significant amount of what was adsorbed belongs to AEC because of its increased chain-chain interactions with APG, which was evidenced experimentally in our previous work; hence, AEC is the greatest contributor to the overall surfactant mixture’s adsorption. Also, temperature had an impact on the adsorption capacity of the AEC:APG mixture, showing that APG has a greater sensitivity to temperature in comparison to AEC. The adsorption behavior of APG was found to be the opposite of AEC, where the adsorption capacity at 106°C was lower for AEC than its adsorption capacity at 80°C and vice versa for APG. The surfactant partitioning results were used to validate the surfactant adsorption outcomes in the presence of crude oil. After eliminating the partitioning effect, the surfactant adsorption isotherms in both cases of the presence and the absence of crude oil were almost identical. The results highlighted the importance of measuring surfactant partitioning, and the impact that partitioning has on the total surfactant losses during the surfactant flooding process. XRD and XPS results indicated that the change of the rock structure after adsorption when crude oil was present was attributed to the rock dissolution phenomena. It was concluded that adsorption and partitioning take place in the water/oil/rock system simultaneously and taking that into account allows for the improved and proper designing of the surfactant flooding.

Newly synthesized Ionic Liquids as potent lubricants and additives to existing lubricant oils

Ionic Liquids are promising candidates for next generation green lubricants. We have synthesized 39 Tetraalkylammonium Alkyl Ether Carboxylate Ionic Liquids and tested them for their lubricant capabilities. We measured friction coefficient to assess the transition from the boundary to the hydrodynamic lubrication, the hydrodynamic area and the minimum friction value. Some Ionic Liquids are capable of forming a hydrodynamic layer fully separating two specimens. Compounds with short C-chain of the cationic part show poor tribological behaviour. Similarly, increasing the PO-degree of the anionic part lowers the lubrication power. An increase of the C-chain length improves the tribological behaviour, i.e. the minimum friction value becomes lower. This is due to the formation of a uniform tribolayer of the long-chain carboxylic acids. Higher viscosity of the Ionic Liquids results in low friction coefficients and the development of a hydrodynamic layer. This is due to a strong hydrodynamic pressure, which is formed by the more viscous compound. Addition of small amounts of Ionic Liquids to low performance oils increases their capability to from tribolayers and thus improves their lubricant capability.

Direct Organometallic Synthesis of Carboxylate Intercalated Layered Zinc Hydroxides for Fully Exfoliated Functional Nanosheets

AbstractIntercalation of organic anions into 2D materials can enable exfoliation, improve dispersion stability, increase surface area, and provide useful functional groups. In layered metal hydroxides, intercalation of bulk structures is commonly achieved by cumbersome and typically incomplete anion exchange reactions. In contrast, here, a series of carboxylate‐intercalated layered zinc hydroxides (LZH‐R) are synthesized directly, at room temperature, by reacting an organozinc reagent with a precise sub‐stoichiometric quantity of the desired carboxylic acid and water. A range of carboxylic acids are used to make new LZH‐R materials which are crystalline, soluble, and functionalized, as established by X‐ray diffraction, spectroscopic, and microscopy techniques. When R is an alkyl ether carboxylate, this direct synthesis method results in the spontaneous exfoliation of the LZH‐R into monolayer nanosheets with high yields (70–80%) and high solubilities in alcohols and water of up to 180 mg mL−1. By altering the carboxylate ligand, functional groups suitable for post‐synthetic modification or for detection by fluorescence are also introduced. These examples demonstrate a versatile synthetic route for functional exfoliated nanosheets.

Physical-chemical properties of newly synthesized tetraalkylammonium alkyl ether carboxylate ionic liquids

Thirty-nine different Ionic Liquids were synthesized, with symmetric quaternary ammonium cations and alkylethercarboxylates as anions. Similar to the recently published Concept of Melting Point Lowering due to Ethoxylation, here propoxyethylene groups, PO groups, in the anions allow a wide range of salts being liquid at or close to room temperature. The physical chemical properties, density, viscosity, conductivity, thermal stability, melting behaviour and hygroscopy of such Ionic Liquids were determined. Density was linearly dependent on the temperature and was affected by the molecular weight of the Ionic Liquid. Higher viscosity of longer carbon chains resulted from stronger intermolecular Van der Waals forces. Viscosity of the Ionic Liquids was lowered by shorter carbon chains in the anions, bulkier cations or lower propoxyethylene degrees. The conductivity of the Ionic Liquids ranged from 1 to 3000 μS/cm and was dependent on the structure of the compound. Melting points of Ionic Liquids were dependent on the length of the carbon chain. At high temperatures, they decomposed in a two-step mechanism. First, the cationic part decomposed, and, at a higher temperature, the anionic part of the Ionic Liquid. Moreover, the Ionic Liquids showed a strong hygroscopic behaviour that was observed for an extended time range up to 5 days.

Feasibility Study of Dual-Function Chemical in Reducing Surfactant Adsorption and Interfacial Tension for Chemical Enhanced Oil Recovery Application

Summary The performance of a low-cost and biodegradable dual-function chemical was evaluated based on its attainment in reducing the interfacial tension (IFT) and surfactant adsorption in synthetic seawater at a temperature of more than 90°C. The phase behavior, interfacial tension, and static adsorption tests were conducted for the feasibility study of a dual-function chemical for a chemical enhanced oil recovery application. The experimental matrices were constructed using Design Expert (Stat-Ease, Minneapolis, Minnesota, USA). Alkyl ether carboxylate (AEC) and amido propyl betaine (APB) were identified for the study to be tested with the dual-function chemical at a temperature of more than 90°C in synthetic seawater. In the phase behavior study, the volume ratio of the aqueous phase to the Malaysian crude oil was kept 1:1. The interfacial tension between the surfactant and dual-function chemical system against the crude oil was performed by using a spinning drop method. Meanwhile, the static adsorption was conducted by using the crushed core at room temperature for up to 30 days, and the analysis was conducted using a high-performance liquid chromatography method. In comparison with two types of surfactants, the dual-function chemical works best with the AEC surfactant in order to reach an ultralow interfacial tension (less than 10−3 mN/m) within 60 minutes. An ultralow interfacial tension for APB surfactant can only be obtained at an earlier time. In contrast, the phase behavior study for AEC and APB surfactants and dual-function chemical obtained was a Type II(−) microemulsion. In the static adsorption study, the dual-function chemical (>0.5 wt%) significantly helped in reducing the adsorption of AEC and APB surfactants by up to 73%. Based on the obtained results, the dual-function chemical worked more efficiently when compounded with AEC than APB surfactant at the same surfactant concentration and reservoir conditions. The findings of this feasibility study are worthwhile for the potential application of dual-function chemical for chemical enhanced oil recovery.

Experimental investigation, binary modelling and artificial neural network prediction of surfactant adsorption for enhanced oil recovery application

Throughout the application of enhanced oil recovery (EOR), surfactant adsorption is considered the leading constraint on both the successful implementation and economic viability of the process. In this study, a comprehensive investigation on the adsorption behaviour of nonionic and anionic individual surfactants; namely, alkyl polyglucoside (APG) and alkyl ether carboxylate (AEC) was performed using static adsorption experiments, isotherm modelling using (Langmuir, Freundlich, Sips, and Temkin models), adsorption simulation using a state-of-the-art method, binary mixture prediction using the modified extended Langmuir (MEL) model, and artificial neural network (ANN) prediction. Static adsorption experiments revealed higher adsorption capacity of APG as compared to AEC, with sips being the most fitted model with R2 (0.9915 and 0.9926, for APG and AEC respectively). It was indicated that both monolayer and multilayer adsorption took place in a heterogeneous adsorption system with non-uniform surfactant molecules distribution, which was in remarkable agreement with the simulation results. The (APG/AEC) binary mixture prediction depicted contradictory results to the experimental individual behaviour, showing that AEC had more affinity to adsorb in competition with APG for the adsorption sites on the rock surface. The adopted ANN model showed good agreement with the experimental data and the simulated adsorption values for APG and AEC showed a decreasing trend as temperature increases. Simulating the impact of binary surfactant adsorption can provide a tremendous advantage of demonstrating the binary system behaviour with less experimental data. The utilization of ANN for such prediction procedure can minimize the experimental time, operating cost and give feasible predictions compared to other computational methods. The integrated workflow followed in this study is quite innovative as it has not been employed before for surfactant adsorption studies.

THE EFFECT OF HARDNESS AND TEMPERATURE ON INTERFACIAL TENSION OF INDIVIDUAL AND MIXED SURFACTANT SYSTEM

Surfactant flooding is one of the chemical enhanced oil recovery (CEOR) techniques that can be used to improve oil recovery. The surfactant injection reduces the oil-water interfacial tension and mobilizes residual oil towards the producing well. In this paper, the performance of alkyl ether carboxylate (AEC) and calcium lignosulfonate (CLS) in individual and mixed surfactant systems were investigated based on their ability to reduce the interfacial tension through a spinning drop method. The interfacial tensions of individual and mixed surfactant systems in different brine systems were measured against decane at 25°C and 98°C. The results show that the individual and mixed surfactant systems in 3.5 wt.% NaCl brine has a significant reduction in interfacial tension at 98°C. In contrast, the presence of hardness in 2.5 wt.% NaCl and 1.0 wt.% MgCl2 brine reduces the interfacial tension of the individual AEC surfactant system and mixed surfactant system significantly at 98°C except for the individual CLS system. Meanwhile, the interfacial tension of mixed surfactant system decreases with increasing surfactant concentration in two brine systems and at 98°C. The findings show the significant application of the AEC and CLS surfactant mixture considering the harsh reservoir conditions for the chemical enhanced oil recovery application.

Partitioning behaviour of novel surfactant mixture for high reservoir temperature and high salinity conditions

Investigating the use of surfactants in high temperature and high salinity conditions can assist expanding the application of surfactant-based enhanced oil recovery (EOR) to more challenging environments. In the present work, compatibility and thermal stability for alkyl ether carboxylate (AEC) and alkylpolyglucoside (APG) were investigated at anaerobic conditions. The most suitable surfactant formulation was selected after passing the screening criteria of compatibility and thermal stability for the studied offshore field. Interfacial tension (IFT) and partitioning of the selected surfactant formulation were then studied at different surfactant concentrations, brine/oil ratios, temperatures, and salinities. The partitioning behaviour of the AEC:APG mixture was comprehensively examined under the before mentioned conditions. The screening experiments for the individual surfactant AEC have shown poor compatibility and thermal stability. Whereas, a 50:50 ratio of the anionic-nonionic (AEC:APG) mixture has passed the compatibility test criteria. For 90 days, the mixture demonstrated remarkable compatibility and thermal stability at high water salinity (32k ppm) and high temperature (106 °C). The IFT of the AEC:APG mixture was significantly affected by the increase of surfactant concentration, temperature and salinity. The proposed mechanism, through the experimental results, illustrated that as surfactant mixture concentration gradually increased, additional molecules of AEC occupied the interface whereas the APG molecules tend to attach to the existed APG molecules at the interface via hydrogen bonds and they both formed a new interface. The formed interface caused the increment of the IFT values. The outcomes proved that APG was the most dominant surfactant as it had the highest impact on the mixture behaviour. It is believed that the outcomes of this work are expected to provide a better fundamental understanding of the surfactant partitioning behaviour in high temperature and high salinity conditions, as well as providing a basic guideline to design efficient surfactant flooding slugs.

A cleanser formulated with Tris (hydroxymethyl) aminomethane and l-arginine significantly improves facial acne in male Thai subjects.

Acne is one of the most common skin problems among human populations. A facial cleanser formulated with alkyl ether carboxylate (AEC) and alkyl carboxylate (AC) can improve acne by cleansing sebum on facial skin but cannot effectively remove keratotic plugs in the skin pores. Recently, we confirmed that Tris (hydroxymethyl) aminomethane and L-arginine (Tris/Arg) is able to reduce sebum levels, disrupt keratotic plugs in vitro and decrease pore size on facial skin. To compare the efficacy of the Tris/Arg-formulated cleanser with the AEC/AC cleanser in Thai subjects with acne. We designed a randomized, double-blind, controlled, parallel trial. Thirty-four male Thai subjects with mild to moderate acne were assigned to one of two groups: one group used the Tris/Arg cleanser while the other used the AEC/AC-based cleanser twice a day for 4 weeks. After 4 weeks, significant decreases in noninflammatory acne were observed in both groups, yet significant decreases in inflammatory acne were only observed in the Tris/Arg cleanser group. The sebum level prior to and 30 minutes after facial washing showed no change in either group. The average pore size with keratotic plugs on the cheeks was significantly decreased in the Tris/Arg group. More than half of subjects in both groups observed acne improvement but more subjects in the Tris/Arg group noted pore size improvement. The Tris/Arg formulated cleanser has a high efficacy for significantly reducing both noninflammatory and inflammatory acne accompanied by decreases in pore size with keratotic plugs in male Thai subjects.

Evaluation of new surfactants for enhanced oil recovery applications in high-temperature reservoirs

Surfactants have been successfully used for enhanced or improved oil recovery in reservoirs having mild conditions (low temperature, low salinity). Reservoirs having harsh conditions, however, offer unique challenges in that most surfactants precipitate and chemically degrade due to a combined effect of high temperature and hardness salinity. Industry’s efforts are continuing to develop or formulate surfactants for oil recovery applications to high temperature and salinity. The aim of this study was to evaluate several modified anionic surfactants/formulations that were claimed to be able to overcome the unfavorably high-salinity brine (sea water) and high temperature and to understand the impact of high temperature to surfactant adsorption. A series of experiments were conducted to characterize and quantify the effects of aging time in high temperature (106 °C) and seawater salinity (32,000 ppm with 1600 hardness) on surfactant performance. Results for both sulfate- and sulfonate-based surfactants were deemed not to be satisfactory. Sulfate-based surfactants encountered hydrolysis problem at high temperature, whereas sulfonate-based surfactants precipitated in the presence of divalent ions. This study then focused on alkyl ether carboxylate (AEC) as the main surfactant, and blends of AEC with alkyl polyglucoside (APG). To find the optimum conditions, phase behavior tests were performed with a fixed seawater salinity but with different blending ratios of surfactant and co-surfactant, as well as overall surfactant concentrations, similar to the salinity scan. Type III microemulsion was observed for both surfactant solutions of AEC and AEC–APG blend with IFT of 10−3 mN/m (millinewton/meter). Surfactant adsorption resulted in lower adsorption in the high-temperature region. The results of this project are urgently needed by the industry for future screening in order to find suitable surfactants for applying to reservoirs with harsh conditions. The study also intends to provide an understanding of adsorption relationship to high temperature, as a guideline in addressing surfactant losses due to adsorption at high-temperature field application.

Aggregation behaviors of alkyl ether carboxylate surfactants in water

Two fatty alcohol polyoxyethylene ether carboxylate surfactants (NEX-n) with different oxyethylene units have been employed to investigate the effect of headgroup on their aggregation behaviors in water. Surface tension and electrical conductivity measurements were conducted to characterize the surface activities and micelle formation in NEX-n/water systems. Different from nonionic surfactant systems, the critical micelle concentration of NEX-7 surfactant with more oxyethylene units is a little lower than that of NEX-4. The thermodynamic parameters obtained on surface tension measurements suggest a stronger hydrophobic interaction in NEX-7 aqueous solution, and disclose the driving forces for micelle formation. In addition, the liquid crystalline (LC) phase behaviors have been studied by polarized optical microscopy and small angle X-ray scattering techniques. With increasing NEX-4 concentration, the hexagonal, lamellar, sponge, and reverse cubic phases have been observed to appear in sequence, whereas only hexagonal and lamellar are formed in NEX-7/H2O system. Comparison with sodium myristate and C12E4 systems further reveals that the electrostatic interaction combining with the hydrogen bonding should be the main driving forces for the LC phase formation.

An Alkyl Ether Carboxylate and Alkyl Carboxylate Formulated Cleanser Decreases Facial Sebum and Inflammatory Acne Without Inducing Dry Xerotic Skin in Thai Females

An Alkyl Ether Carboxylate and Alkyl Carboxylate Formulated Cleanser Decreases Facial Sebum and Inflammatory Acne Without Inducing Dry Xerotic Skin in Thai Females

Effect of Electrolytes on Interfacial Tensions of Alkyl Ether Carboxylate Solutions

Alkyl ether carboxylate is one type of surfactant that can produce ultralow interfacial tension (IFT) under high-salinity and high-temperature conditions. In this paper, the influence of counterion...

Physico-Chemical Property and Performance of Detergent Containing Sodium Poly (oxyethylene) Alkyl Ether Carboxylate

Physico-Chemical Property and Performance of Detergent Containing Sodium Poly (oxyethylene) Alkyl Ether Carboxylate