Sulfonate Gemini Surfactants Research Articles

Synthesis and surfactant properties of sulfonate Gemini surfactants

Abstract In this study, a novel high salinity resistant, high temperature tolerant sulfonate Gemini surfactant (CK-3) for enhanced oil recovery was synthesized and is described. The critical micelle concentration (CMC) of CK-3 is 7.3 × 10−5 mol L−1 with a surface tension at CMC, γ CMC, of 30.88 mN m−1, and a pC20 value of 4.80. Moreover, increasing temperature led to delayed micellization, indicating the superior surface activity inherent in Gemini surfactants. When CK-3 was evaluated as an imbibing agent, an interfacial tension of 8.3 × 10−2 mN m−1 was observed between a 0.3 wt% CK-3 solution and crude oil, facilitated by hydrophobic group interactions which allow crude oil detachment. Finally, CK-3 molecules exhibited stable adsorption on rock walls, influencing wetting reversal. Zeta potential measurements exceeding 30 mV indicated stability. In aged capillary tubes, a 0.3 wt% CK-3 solution exhibited a rise height of 2.9 cm. Imbibition experiments on natural core samples showed a water imbibition efficiency of 8.73 %, compared to a significantly improved efficiency of 50.78 % with a 0.3 wt% CK-3 solution. This study also demonstrated the imbibition process and mechanisms of the CK-3, providing novel insights for the efficient development of unconventional oil reservoirs and the enhancement of crude oil recovery rates.

Interfacial properties of cationic and anionic Gemini surfactant mixtures

AbstractThe possibility and the prospect of cationic/anionic (“catanionic”) surfactant mixtures based on sulfonate Gemini surfactant (SGS) and bisquaternary ammonium salt (BQAS) in the field of enhanced oil recovery was investigated. The critical micelle concentration (CMC) of SGS/BQAS surfactant mixtures was 5.0 × 10−6 mol/L, 1–2 orders of magnitude lower than neat BQAS or SGS. A solution of either neat SGS or BQAS, could not reach an ultra‐low interfacial tension (IFT); but 1:1 mol/mol mixtures of SGS/BQAS reduced the IFT to 1.0 × 10−3 mN/m at 100 mg/L. For the studied surfactant concentrations, all mixtures exhibited the lowest IFT when the molar fraction of SGS among the surfactant equaled 0.5, indicating optimal conditions for interfacial activity. The IFT between the 1:1 mol/mol SGS/BQAS mixtures and crude oil decreased and then increased with the NaCl and CaCl2 concentrations. When the total surfactant concentration was above 50 mg/L, the IFT of SGS/BQAS mixtures was below 0.01 mN/m at the studied NaCl concentrations. Adding inorganic salt reduced the charges of hydrophilic head groups, thereby making the interfacial arrangement more compact. At the NaCl concentration was above 40,000 mg/L, surfactant molecules moved from the liquid–liquid interface to the oil phase, thus resulting in low interfacial activity. In addition, inorganic salts decreased the attractive interactions of the SGS/BQAS micelles that form in water, decreasing the apparent hydrodynamic radius (DH, app) of surfactant aggregates. When the total concentration of surfactants was above 50 mg/L, the IFT between the SGS/BQAS mixtures and crude oil decreased first and then increased with time. At different surfactant concentrations, the IFT of the SGS/BQAS mixtures attained the lowest values at different times. A high surfactant concentration helped surfactant molecules diffuse from the water phase to the interfacial layer, rapidly reducing the IFT. In conclusion, the cationic‐anionic Gemini surfactant mixtures exhibit superior interfacial activity, which may promote the application of Gemini surfactant.

Effect of a newly synthesized anionic Gemini surfactant composite fracturing system on the wettability of coking coal

To improve the wetting effect of the fracturing fluid on coal, a sulfonate Gemini surfactant (Gemini-3OH) was synthesized from nonyl phenol through a double ether and sulfonation reaction. It was mixed with an appropriate amount of cationic cellulose (JR400) to form a fracturing fluid composite system (Gemini-3OH/JR400). The optimum concentration ratio of the composite system was determined using a surface tension test. The mechanism of action of water, Gemini-3OH and Gemini-3OH/JR400 composite system on the coal surface was analyzed by means of FTIR, XPS, industrial analysis, and SEM, along with microscopic observations, contact angle measurements, and molecular dynamics simulations. The results showed that Gemini-3OH/JR400 had a lower critical micelle concentration and surface tension, and had the greatest impact on the coal structure and functional group content. The contact angles of Gemini-3OH/JR400 at the moment of contact with coal and at 60 s were 33.12° and 19.76°, respectively. Finally, molecular dynamics simulations further verified that Gemini-3OH/JR400 had a better wetting effect on coal. This study provides a new concept for wetting coal bodies by water injection and fracturing in coal seams, and hence, can help in the prevention and control of mining accidents and disasters.

Renewable dissymmetric sulfonate gemini surfactants from addition of sodium hydrogensulfite to alkyl linoleate

AbstractA new series of bio‐based sulfonate gemini surfactants was synthesized through esterification of renewable linoleic acid with various alcohols and subsequent sulfonation with readily available sodium hydrogensulfite (NaHSO3). Organocatalytic sulfonation of methyl linoleate with NaHSO3 by the triethylamine and tert‐butyl peroxybenzoate catalyst system was investigated, where a methyl linoleate conversion of 96.4% could be achieved while generating high purity product without tedious purification. Three resulting sodium alkyl linoleate disulfonates (SALDs) have been characterized by Fourier transform infrared, high‐performance liquid chromatography, LC–MS, high‐resolution mass spectrometry (HR–MS), nuclear magnetic resonance techniques, and thermogravimetric analysis. The physicochemical properties and surface properties of the SALDs at various concentrations were investigated. The results showed that the SALDs exhibited low Krafft temperature, high water solubility, foam stability (foam half‐life time could reach 15 min), emulsifying ability (emulsification time of 2.0 g/L is 192 s), and good thermal stability. This study enriches the family of anionic gemini surfactants and provides reference data for facile preparation of gemini surfactants.

Effect of Gemini surfactant structure on water/oil interfacial properties: A dissipative particle dynamics study

Understanding the structural effects of Gemini surfactants on interfacial properties is pivotal towards the rational design of efficient Gemini surfactants. Herein, a series of alkylbenzene sulfonate Gemini surfactants have been constructed, and their influences on the interfacial properties of dodecane/water systems are systematically explored by using dissipative particle dynamics simulation. The Gemini surfactants are modeled as ‘π-shaped’ coarse-grained molecules, and their spacer lengths and hydrophobic chain lengths are varied for examining the properties including radial distribution functions, interfacial tension and thickness, and self-assembly morphologies. We find that when increasing the hydrophobic chain length, the critical micelle concentration decreases, and the oil molecules tend to penetrate into the space between two hydrophobic chains, causing nano-mixing phenomenon. This phenomenon is further enhanced when increasing the spacer length, and consequently, the oil–water interface gradually becomes curved and blurred due to the enhanced surfactant efficiency, and the system evolves from the lamellar interface state to micelle state. This work provides a theoretical basis for rational designing efficient Gemini surfactants.

Study on Adsorption Characteristics of Sulfonate Gemini Surfactant on Lignite Surface

In order to explore the adsorption characteristics of sulfonate gemini surfactants on the surface of lignite, the molecular dynamics simulation method was used, and A kind of sulfonic acid bis sodium salt (S2) and the sodium dodecyl sulfate (SDS) were selected. A binary model of surfactant/lignite adsorption system and a ternary model of water/surfactant/lignite system were constructed, and a series of properties such as adsorption configuration, interaction energy, order parameters, relative concentration distribution, number of hydrogen bonds, etc., were analyzed. The results showed that the adsorption strength of S2 on the surface of lignite was higher than that of SDS. The results indicated that the large-angle molecular chain in S2 tended to become smaller, the small-angle molecular chain tended to become larger, and the angle between the molecular chains and the Z axis tended to be concentrated, making the formed network structure denser during the adsorption process. The number of hydrogen bonds in the water-coal system was 42, and the number of hydrogen bonds in the system after S2 adsorption was 15, which was much lower than the 23 hydrogen bonds in the system after SDS adsorption, and S2 could better adsorb and wrap the oxygen-containing groups on the surface of the lignite. The comparative study of the adsorption characteristics of the two surfactants on the surface of lignite can help us better understand the influence of the surfactant structure on the adsorption strength. The research results have important theoretical and practical significance for developing new surfactants, and enriching and developing the basic theory of coal wettability.

Study on the structure–activity relationship between the molecular structure of anionic Gemini surfactants and the rheological properties of their micelle solutions

In this study, the viscosity and viscoelasticity of Gemini surfactant solutions with different molecular structures were measured, and the micelle structure formed by self-assembly in the solution was observed and measured using FESEM and DLS. The effect of the molecular structure of anionic Gemini surfactants on the rheological properties of the solution was studied systematically. The experimental results showed that the carboxylate Gemini surfactants with long hydrophobic carbon chains and a moderate spacer group have better rheological properties in aqueous solution. The carboxylate Gemini surfactant solution aggregated to form more densely, larger-sized micelle structures than the sulfonate Gemini surfactant, so its viscosity and viscoelasticity are greater. When the carbon number of the spacer group was the same (s = 2), as the carbon number of the hydrophobic chain increased (m = 14,16,18), the hydrodynamic diameter increased, the size of the micelle structures formed by self-assembly in the solution increased, the micelles aggregated more tightly, and the solution viscosity and viscoelasticity increased. When the carbon number of the hydrophobic chain was the same (m = 18), as the carbon number of the spacer group increased (s = 2,3,4), the hydrodynamic diameter first increased and then decreased, the micelle structures exhibited the phenomenon of aggregation first and then disintegration, and the solution viscosity and viscoelasticity also increased first and then later decreased. These phenomena indicated that the change of Gemini surfactant molecular structure would lead to the change of its micelle microstructure and eventually lead to the change of solution rheological properties.

Studies on the surface properties and microaggregates of cationic/anionic surfactant mixtures based on sulfonate gemini surfactant

The surface properties and the microaggregates of a sulfonate gemini surfactant 1,2-bis(N-dodecyl-N-propane sulfonate sodium)-ethane (SGS12) and conventional cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) mixtures were studied. The critical micelle concentration (CMC) values of SGS12, CTAB, and SGS12/CTAB mixtures (1:1) were 0.0045, 0.89 and 0.0031 mmol·dm‐3, respectively. By changing the molar ratios of SGS12 to CTAB, the transitions between micelles and vesicles were observed. When nSGS12:nCTAB = 4:6, the size of surfactant aggregates increased abruptly to 68.06 nm, and a pale blue opalescence appeared, which was consistent with the size and optical characteristics of the vesicles. The hydrodynamic diameter (DH) of all surfactant aggregates increases with the increase of temperature from 35 °C to 50 °C. Especially at nSGS12:nCTAB = 6:4, we observed a temperature-induced transition from micelles to vesicles. We also investigated the effects of 1-propanol on the SGS12/CTAB precipitate. At nSGS12:nCTAB = 4:6, the addition of 1-propanol led to the precipitate → vesicles → micelles transition. Moreover, the addition of NaCl increased the aggregate size of the SGS12/CTAB mixtures, and we observed the light blue opalescence. The addition of NaCl induced the formation of vesicles. As a result, the SGS12/CTAB mixtures have more excellent surface activity than either component. By changing the composition, temperature, the concentration of salt, and the volume fraction of alcohol, the transition of precipitation → vesicles → micelles can be achieved.

Surface properties and microemulsion of anionic/nonionic mixtures based on sulfonate Gemini surfactant in the presence of NaCl

The mixing properties of anionic/nonionic surfactant mixtures in the presence of inorganic salts are essential to the industrial application. The equilibrium and dynamic surface tension of the sulfonate Gemini surfactant (SGS12) and alkyl glycoside (APG0810) mixtures were examined using the plate method and drop-shape analysis. Moreover, the Winsor phase diagram and solubility properties of the microemulsion were studied using the salinity scan. Results show that the critical micelle concentration (cmc) of the SGS12/APG0810 mixtures was intermediate between those of the two single surfactants in the presence of NaCl. For the SGS12/APG0810 mixtures, the absolute value of interaction parameters increased as the APG0810 content increased at cNaCl = 0.01 or 0.1 mol/L. The formation of the mixed micelles was spontaneous. At cNaCl = 0.01 mol/L, the initial adsorption (t → 0) of surfactant molecules from the bulk phase to the surface was diffusion-controlled. The salinity scan experiments showed that the optimal solubilization parameters of the SGS12/APG0810 microemulsion decrease with the decrease of the molar fraction of SGS12. However, the concentration range of inorganic salt between the formation and disappearance of Winsor III broadened with the decline in SGS12 content. The impact of temperature on the volume fraction of the middle-phase microemulsion (MPM) was ignorable, indicating the high stability of MPM at the temperature range of 30.0 °C ~ 80.0 °C. At 30.0 ± 0.1 °C, the hydrodynamic diameter of the SGS12/APG0810 MPM was about 28.0 nm, and the number of microemulsion droplets decreased with the increase of APG0810 content. When the total mass fraction of surfactant and cosurfactant was 15%, wNaCl = 5% (brine), Km = 1:3 and Vo/Vw = 1, the interfacial tension between crude oil and the SGS12/APG0810 MPM reached the order of 10−3mN/m. At nSGS12:nAPG0810 = 7:3, the lowest interfacial tension was 9 × 10−4 mN/m. For the SGS12/APG0810 (7:3) mixture, the addition of n-butanol induced the formation of MPM. The concentration range of n-butanol between the formation and the disappearance of Winsor III first increased and then decreased with the increase of surfactant concentration.

Synthesis and Study of 4, 4-12-12 Alkyl Phenol Polyoxyethylene Sulfonate Gemini Surfactant

Background: Gemini surfactants have good prospect of application development in various fields for their superior performance in foaming, wettability, and emulsification with lower critical micelle concentration (CMC) than conventional mono-surfactants. Objective: The purpose of this study was to synthesize an ionic sulfonate Gemini surfactant, which is mainly used as an oil flooding agent, to improve oil recovery and reduce oil production cost. Methods: With 4-dodecyl phenol, diethylene glycol and triethylene glycol as the raw materials to synthesize two sulfonate Gemini surfactants. The single factor experiment combined with Box-Behnken center composite experimental design, the optimum reaction conditions were determined. The optimal reaction condition of sulfonation was determined by orthogonal test. The product structure was characterized by nuclear magnetic resonance and infrared. Results: The mass fraction of sodium hydroxide ω(NaOH), temperature and the quality ratio of hexadecyl trimethyl ammonium bromide to dodecyl phenol were 18%, 93.5°C and 14.2%, respectively. Under the condition of ice bath, the molar ratio of chlorosulfonic acid to 4, 4- 12-12 alkyl phenol polyoxyethylene ether was 2.02:1 and reaction for 5h. The critical micelle concentration was determined to be 2×10-4, 1.05×10-4, respectively. Conclusion: Two sulfonate Gemini surfactants, namely 5, 5-dilauryl alkyl-2,2'-(diethylene glycol oxygen base) sodium diphenyl sulfonate and 5,5-dilauryl alkyl-2,2'-(triethylene glycol oxygen base) sodium diphenyl sulfonate (recorded as III and IV, respectively) were synthesized. The synthesized surfactants have excellent emulsification ability.

New sulfonate Gemini surfactants: synthesis and evaluation for enhanced oil recovery applications

In this work, a series of new sulfonate Gemini surfactants (abbreviated as m-3-m) were studied as an attempt to develop a single surfactant that can effectively reduce the oil-water interfacial tension to ultralow values. The novel surfactants were synthesized and characterized by 1HNMR and 13CNMR spectroscopies. The surface activeness of those surfactants at the air-water interface and thermodynamic properties in the bulk aqueous phase were investigated. The oil-water interfacial tension, viscous and viscoelastic properties of solutions were studied. The results showed that the novel surfactants exhibit fascinating surface activeness and low values of CMC; spontaneously formed micelles and adsorbed at the air-water interface. They can substantially reduce the oil-water interfacial tension to ultralow values () when the surfactant concentration is less than 0.5 wt%. The surfactants possess attractive viscous and viscoelastic properties towards EOR applications through flooding methods. In accordance with the experimental studies, the surfactants are promising in formulating fluid systems with ultralow interfacial tension.

Surface Properties and Solubility Enhancement of Anionic/Nonionic Surfactant Mixtures Based on Sulfonate Gemini Surfactants

AbstractAs a class of novel surfactants, Gemini surfactants usually exhibit fairly excellent interfacial properties in aqueous solutions on account of the unique structure. They have significant application and development potential for industrial production. However, the mixing properties of Gemini surfactants with conventional surfactants are the key to their application. The equilibrium surface tension curves of anionic/nonionic surfactant mixtures based on the sulfonate Gemini surfactant (SGS‐12) were measured using the Wilhelmy Plate method. The parameters of surface adsorption, the interaction parameters between anionic and nonionic surfactants, and the thermodynamic parameters of micelle formation were calculated from the corresponding equations. In addition, the dynamic surface tension (DST) curves of anionic/nonionic surfactant mixtures were examined through bubble profile analysis, and the diffusion performance parameters were acquired from empirical formulas. The solubilization of pyrene in micelle solutions was studied using UV–vis absorption spectroscopy. The results show that the interaction parameters of all anionic/nonionic surfactants are negative, indicating that there is a synergistic effect on reducing the surface tension. For the SGS‐12/OP‐10, SGS‐12/Tween 80, SGS‐12/AEO9, and SGS‐12/APG0810 mixtures, the optimum mixing ratios are 6:4, 7:3, 7:3, and 8:2, respectively. The thermodynamic data of micelles show that the formation of mixed micelles for SGS‐12/APG0810 mixtures is an enthalpy‐driven process. The tendency of DST curves of the SGS‐12/APG0810 mixture is similar to that of SGS‐12. In comparison with single‐surfactant solutions, the anionic/nonionic surfactant mixtures show stronger solubilization capacity toward pyrene.

A novel fluorometric assay for trypsin on the basis of a gemini anionic surfactant/BSA/NR supramolecular assembly system with favorable salt resistance

A novel label-free fluorometric assay for trypsin detection was successfully established on the basis of an anionic sulfonate gemini surfactant C12C3C12(SO3)2/bovine serum albumin (BSA)/nile red (NR) supramolecular assembly system.

Surface properties and solubility enhancement of Gemini/conventional surfactant mixtures based on sulfonate Gemini surfactant

The synergistic effect of sulfonate Gemini surfactant (SGS12) with different kinds of conventional surfactants on surface properties and solubility enhancement was investigated. Results indicated that the absolute values of βm were in the following order: SGS12/BQAS > SGS12/DTAB > SGS12/rhamnolipid > SGS12/SDS > SGS12/Triton X-100. The cationic/anionic surfactant mixtures formed micelles at a low concentration, which resulted from the strong attraction among different charged hydrophilic headgroups. Moreover, the molar solubilization ratio and lnKm values indicated that the solubility of SGS12/BQAS, SGS12/Triton X-100, and SGS12/DTAB mixtures toward pyrene was higher than that of either component. The micelle's hydrodynamic sizes of cationic/anionic surfactant mixtures were larger than that of either component, so the hydrophobic space to dissolve additional pyrene was large. Furthermore, dynamic surface tension determination suggested that cationic/anionic surfactant mixtures had a relatively short induction period, and the n values for SGS12/BQAS and SGS12/DTAB mixtures were slightly larger than those for either component. At the total surfactant concentration of 1 μmol·L−1, the plots of γt versus t1/2 for all surfactant mixtures were linear, indicating that the initial adsorption was controlled by diffusion. The values of Dt→0 for SGS12/BQAS, SGS12/DTAB, and SGS12/rhamnolipid mixtures were higher than those of either pure component. Therefore, the mixture of these surfactants accelerated the adsorption process and lowered the adsorption energy barrier, and the mixing of cationic and anionic surfactants was beneficial for dynamic surface activity. In conclusion, the cationic/anionic surfactant mixtures demonstrated good potential for the remediation of polycyclic aromatic hydrocarbon-contaminated soils from equilibrium and dynamic viewpoints.

Experimental Study of Sulfonate Gemini Surfactants as Thickeners for Clean Fracturing Fluids

Hydraulic fracturing is one of the important methods to improve oil and gas production. The performance of the fracturing fluid directly affects the success of hydraulic fracturing. The traditional cross-linked polymer fracturing fluid can cause secondary damage to oil and gas reservoirs due to the poor flow-back of the fracturing fluid, and existing conventional cleaning fracturing fluids have poor performance in high temperature. Therefore, this paper has carried out research on novel sulfonate Gemini surfactant cleaning fracturing fluids. The rheological properties of a series of sulfonate Gemini surfactant (DSm-s-m) solutions at different temperatures and constant shear rate (170 s−1) were tested for optimizing the temperature-resistance and thickening properties of anionic Gemini surfactants in clean fracturing fluid. At the same time, the microstructures of solutions were investigated by scanning electron microscope (SEM). The experimental results showed that the viscosity of the sulfonate Gemini surfactant solution varied with the spacer group and the hydrophobic chain at 65 °C and 170 s−1, wherein DS18-3-18 had excellent viscosity-increasing properties. Furthermore, the microstructure of 4 wt.% DS18-3-18 solution demonstrated that DS18-3-18 self-assembled into dense layered micelles, and the micelles intertwined with each other to form the network structure, promoting the increase in solution viscosity. Adding nano-MgO can increase the temperature-resistance of 4 wt.% DS18-3-18 solution, which indicated that the rod-like and close-packed layered micelles were beneficial to the improvement of the temperature-resistance and thickening performances of the DS18-3-18 solution. DS18-3-18 was not only easy to formulate, but also stable in all aspects. Due to its low molecular weight, the damage to the formation was close to zero and the insoluble residue was almost zero because of the absence of breaker, so it could be used as a thickener for clean fracturing fluids in tight reservoirs.

Effect of Micelle Structure on the Viscosity of Sulfonate Gemini Surfactant Solution

In order to optimize the thickening performance of clean fracturing fluid, a series of sulfonate Gemini surfactants (DSm-s-m) were synthesized and identified by FTIR, $$^{1}\hbox {HNMR}$$ , and $$^{13}\hbox {CNMR}$$ . The surface tension curve was obtained by testing the surface tension of the surfactant at different concentrations, and the viscosity of sulfonate Gemini surfactant solution was measured by rheometer and investigated through changing the molecular structure. The microstructures of the solution were studied by SEM. The experimental results indicated that the CMC of the surfactant decreased with increasing the length of the hydrophobic chain. Moreover, the viscosity of sulfonate Gemini surfactant changed with the carbon number (s or m) of spacer group and hydrophobic chain, and the DS18-3-18 had superior viscosity behavior. The viscosity of the DS18-3-18 solution decreased with the temperature increase but was still $$13.25 \hbox { mPa}\cdot \hbox {s}$$ at $$90\,{^{\circ }}\hbox {C}$$ . The microstructures of DS18-s-18 solution demonstrated that the micelles of the DS18-s-18 solution changed from spherical to layer like and finally to commixture of spherical/layer like with increasing the carbon number of spacer group ( $$s=2,3,4$$ ), and the viscosity of the solution increased firstly and then decreased correspondingly. The number of sheet micelles and bulk density in DS18-3-18 solution decreased with the increase of temperature, causing the decrease of the viscosity in solution. However, the intact sheet micelles still existing in solution at $$90\,{^{\circ }}\hbox {C}$$ meant that the DS18-3-18 had prominent temperature-resistant viscosity behavior. These phenomena illustrated that changing the molecular structure of surfactants could cause changes in their microstructure and finally lead to a change in the viscosity of the solution.

Self-assembled structure of sulfonic gemini surfactant solution

Sulfonate gemini surfactant is a new type of anionic gemini surfactant. The unique structure of double sulfonate endows the sulfonate gemini surfactant with superior surfactant properties, including lower critical micelle concentration (CMC), unusual decontamination ability, excellent stability in strong acid/alkali solution. In this paper, the self-assembled structure of gemini dodecyl sulfonate sodium, abbreviated as 12-2-12(SO3Na)2, is studied by using of dissipative particle dynamics (DPD) method. We have constructed a spring structure model of surfactant molecules, and the effect of length hydrophobic chain, the concentration of surfactants, ethanol addictive on the self-assembly behavior and critical micelle concentration (CMC) was investigated. The results show that with the increase of the concentration of surfactants in aqueous solution, spherical, wormlike and layered micelles appear in turn. With the increase of the length of the hydrophobic chain, the clusters of the surfactants become tighter and the larger clusters are presented at the lower concentration. It was found that the addition of ethanol molecule can enhance the solubility of hydrophobic group and thus inhibit the formation of the micelles.

Study on Variation of Physicochemical Parameters of the Polymer/Surfactant Binary Multisystem in Porous Media

The sulfonate Gemini surfactant and hydrophobic associating polymers were prepared with different ratio in multisystem, and we measured viscosity and interfacial tension of the solution before pour it into the core. The multisystem with different ratio was poured into the core, we measured the produced liquid viscosity, interfacial tension, the concentration of polymer and surfactant at core outlet with different injection stage and at different locations after stable, calculated the dynamic adsorption capacity of the binary multisystem, and measured the static adsorption capacity of binary multisystem with different ratio on natural oil sand in Suizhong 36-1 Oilfield. Experimental results show that the stable viscosity of the produced liquid of multisystem increased with increase of polymer concentration, and decreased with the increase of the distance flowed through the core, and these changes concentrated on the first 1/3 of core; the interfacial tension decreased with the increase of mass fraction of surfactant, the stable interfacial tension value after passed through the core was about 7-10 times before solution injected; Multisystem has the chromatographic fractionation in rock.

Recent Advances in the Synthesis of Sulfonate Gemini Surfactants

AbstractSulfonated Gemini surfactants are a relatively new class of anion surfactants, composed of 2 or more sulfonated surfactant monomers connected by a spacer at or near the head groups through a covalent bond. In general, the sulfonated Gemini surfactants show better properties compared to conventional anionic surfactants including better surface activity, a lower critical micelle concentration, enhanced detergency, excellent compatibility with other surfactants, and better solubility in high ionic strength systems. This article reviews the synthesis of the sulfonated Gemini surfactants using different raw materials. Based on the existing information in the literature, new ideas are proposed for the synthesis and application of the sulfonated Gemini surfactants.

Micellization of Anionic Sulfonate Gemini Surfactants and Their Interactions With Anionic Polyacrylamide

AbstractAnionic sulfonate gemini surfactants 8‐s‐8(SO3)2 and 12‐s‐12(SO3)2 (s = 3, 6) were synthesized, and their micellization in aqueous solution at 25.0 °C and pH 9 was investigated. The results show that the critical micelle concentrations (CMC) of 8‐s‐8(SO3)2 are more than 2 orders of magnitude larger than those of 12‐s‐12(SO3)2, but the spacer length has a relatively small impact on the CMC. Moreover, the interactions of n‐s‐n(SO3)2 (n = 8, 12; s = 3, 6) with anionic polyacrylamide (PAM) at 25.0 °C and pH 9 were investigated using surface tensiometry, rheolgy, and scanning electron microscopy (SEM). The results indicate that the surface tension and rheological properties of PAM depend on the concentration of n‐s‐n(SO3)2. Below the critical aggregation concentration of C1, surface tension is sharply reduced, the surface tension of n‐s‐n(SO3)2/PAM is lower than n‐s‐n(SO3)2 alone, but viscosity is almost unchanged with increasing Cn‐s‐n(SO3)2. Above C1, surface tension reduces very slowly until the saturated concentration of C2 is reached. Above C2, surface tension rapidly reduces until CM is attained, suggesting free n‐s‐n(SO3)2 micelles begin to form. In the region of C1–CM, the viscosity significantly increases. Above CM, surface tension is basically unchanged and these curves coincide with those of the single surfactant system. Moreover, the viscosity is almost constant. The SEM images indicate that fibrous aggregates are formed below C1, then transformed into multilayer fibrous aggregates above C1, and further into fiber‐braided‐structured and spider‐web‐structured aggregates above CM. The variation of viscosity is closely associated with the transformation of aggregates.