Fatty Acid Methyl Ester Sulfonate Research Articles

Recognizing Functional Groups of MES/APG Mixed Surfactants for Enhanced Solubilization toward Benzo[a]pyrene.

Benzo[a]pyrene is difficult to remove from soil due to its high octanol/water partition coefficient. The use of mixed surfactants can increase solubility but with the risk of secondary soil contamination, and the compounding mechanism is still unclear. This study introduced a new approach using environmentally friendly fatty acid methyl ester sulfonate (MES) and alkyl polyglucoside (APG) to solubilize benzo[a]pyrene. The best result was obtained when the ratio of MES/APG was 7:1 under 6 g/L total concentration, with an apparent solubility (Sw) of 8.58 mg/L and a molar solubilization ratio (MSR) of 1.31 for benzo[a]pyrene, which is comparable to that of Tween 80 (MSR, 0.95). The mechanism indicates that the hydroxyl groups (-OH) in APG form "O-H···OSO2-" hydrogen bonding with the sulfonic acid group (-SO3-) of MES, which reduces the electrostatic repulsion between MES molecules, thus facilitating the formation of large and stable micelles. Moreover, the strong solubilizing effect on benzo[a]pyrene should be ascribed to the low polarity of ester groups (-COOCH3) in MES. Functional groups capable of forming hydrogen bonds and having low polarity are responsible for the enhanced solubilization of benzo[a]pyrene. This understanding helps choose suitable surfactants for the remediation of PAH-contaminated soils.

Molecular simulation and wetting study on the mechanism and capability of hydrophilic surfactants used as spray dust suppressants for dust reduction in coal mines

Coal dust prevention and control has always been a practical problem that needs to be solved urgently in coal mines. Based on spray technology, it has a good application prospect to achieve effective deposition of coal dust by adding surfactants. In this work, the wetting mechanism of three anionic surfactants at the water coal interface was found out from the molecular micro level and macro level through wetting angle test, sedimentation experiment, interfacial tension experiment and molecular dynamics simulation analysis. The results show that the electrostatic potential extremes of sodium sec alkyl sulfonate, sodium fatty acid methyl ester sulfonate and sodium a-alkenylsulfonate are 0.2399 a. u., 0.2430 a. u. And 0.2387 a. u. Respectively, which are greater than the electrostatic potential extremes of water 0.09157 a. u. It can be judged that the head groups of the three surfactants can produce hydrophilicity. The radial distribution function between the S atom and the O atom in the water in the hydrophilic group of the three surfactants has the same overall change trend, forming an obvious first peak and a weak second peak, with molecular diffusion coefficients of 4.633, 11.10, and 14.13 Å2/ps, respectively. The smaller diffusion coefficients correlated with stronger adsorption, which was consistent with contact angle measurements and a relative concentration analysis. The research results can provide reference for efficient evaluation of the wettability of surfactants.

Influence of process conditions on the sulfonation of methyl ester synthesized from used cooking oil: Optimization by Taguchi approach

AbstractDeveloping a robust and facile process route for fatty acid methyl ester sulfonate (MES) synthesis is of importance for industrial applications. Herein, Taguchi orthogonal array (OA) approach was used for the first time to establish the optimum process condition for the sulfonation of methyl esters (ME) with chlorosulfonic acid (CSA). According to the experimental design, the most significant parameter was sulfonation temperature, followed by CSA/ME molar ratio. Under the optimum sulfonation conditions (that is, 70°C sulfonation temperature, 2.0 h sulfonation time, 1.5:1 mol/mol CSA/ME molar ratio and 2.0 h aging time), the MES yield and the corresponding signal/noise ratio were 92.08 ± 0.28% and 39.28, respectively. The obtained FTIR and 1H NMR data revealed spectra associated with methyl (CH2 asymmetric and CH2 symmetric stretching vibrations), esters (CO, CO, and OCH3), and sulfonate (SO) groups in the MES sample synthesized under optimal conditions, thus confirming the target MES product. Surface tension measurements revealed that the optimal MES sample had a low critical miscelle concentration of 0.082 g/L at a surface tension of 51.2 mN/m, implying the possibility of better performance.

Study on the combined dust suppression effect of sodium alginate and sodium fatty acid methyl ester sulfonate

• In-depth study of coal dust wetting mechanism. • Application of molecular dynamics simulation in dust suppressants. • Study on the mechanism of dust suppression by combining different surfactants. To further improve the effect of dust control in coal mines and protect the health of workers, the effect of sodium alginate (SA) on the dust suppression ability of sodium methyl ester sulfonate (MES) was studied using molecular dynamics simulation. Scanning electron microscopy and X-ray photoelectron spectroscopy analyses were performed to compare the dust suppression effect of the SA/MES dust suppressant compound to MES by itself. The results show that when SA is present, the coal dust bonds together more, agglomerates into large particles, and settles. This finding is also consistent with the results of molecular dynamics simulations. In the analysis of relative concentrations and mean square displacement, the presence of SA can reduce the water diffusion on the coal surface, making it easier for coal dust to agglomerate. In addition, we analyzed the mode of action of SA through radial distribution and electrostatic potential, and determined that SA forms a unique networking chain structure to capture and retain water molecules. SA increases the probability of interaction between water and surfactant, thus increasing the amount of adsorption. This study provides a more in-depth understanding of the dust suppression mechanism of mixed dust suppressants.

A new method of coal fine particles humidification and agglomeration: Synergistic dust suppression with composition of soap solution

Coking plants usually use surfactants to increase the surface wettability of fine coking coal particles, promote its agglomeration, and achieve the purpose of reducing dust emission. The Soap solution as a chemical agent contains not only soap base active ingredients, but also abundant surfactants and antifouling redeposition agents. The aim of this study is to optimize the dust suppression effect by blending the chemical composition proportion of existing soap solution, and analyze the interaction mechanism of each component on the surface of fine particles, then realize the dust suppression with low cost and high dust suppressor effect. Keeping the other ingredients remain the same, the hydrophilic organosilicone and carboxymethyl starch were selected as antifouling redeposition agents; the anionic surfactant sodium fatty acid methyl ester sulfonate (MES), non-ionic surfactant fatty acid methyl ester ethoxide (FMEE) and fatty alcohol polyoxyethylene ether (AEO-9) were used to mix in different proportions. The wetting effect and adsorption rate of the compound soap solution on the surface coal were tested. Then the particle coating efficiency, size growth rate and dust removal amount during the spraying of compound soap solution were tested and mechanism analysis in the device developed by the laboratory. The result indicates the wettability and agglomeration efficiency of coal particles can be obviously improved by increasing the proportion of FMEE and AEO-9. Compared with carboxymethyl starch, using hydrophilic organosilicon as antifouling redeposition agent can increase the adsorption capacity of raw coal to surfactants by 5% and the particle growth rate by 2%.

Preparation and performance of a chelating anionic foaming agent

In this article, a chelating anionic foaming agent(SDPN) was prepared by the aminolysis reaction of sodium fatty acid methyl ester sulfonate and N, N'-Dimethyl-1,3-propyldiamine. The prepared SDPN was structurally characterized by FTIR and 1H NMR, which proved the successful preparation of the product. The critical micelle concentration of SDPN was 2.3 × 10−3mol/L and the surface tension was 30.15 mN/m. The effects of temperature, salinity, pH, etc. on the foam height and liquid carrying capacity of SDPN were studied. The results showed that the initial, 3 min and 5 min foam heights and liquid carrying capacity were used as indicators, and the foam height and liquid carrying capacity could reach 155 mm and 140 mL at a temperature of 90 °C, 200000 mg/L of sodium chloride, and 4000 mg/L of calcium chloride at a mass concentration of 0.5% SDPN. Comparing SDPN with some commonly used anionic foaming agents under the same conditions, it is concluded that SDPN is good in both foaming performance and liquid carrying performance. Finally, the effect of different concentrations and mineralization degrees on the microscopic morphology of the foam was observed by polarized light microscopy, and it was concluded that the diameter of the foam varied less and was evenly distributed and stable when the SDPN was added at a mass concentration of 0.5% and mineralization degree of 204000 mg/L.

Valorization of used cooking oil as a source of anionic surfactant fatty acid methyl ester sulfonate: process optimization and characterization studies

Valorization of used cooking oil as a source of anionic surfactant fatty acid methyl ester sulfonate: process optimization and characterization studies

Microemulsion synthesis of anhydrous calcium sulfate nanowhiskers with calcium acetate solution and its surface structure stable and crystal phase evolution after modification

Methods obtaining gypsum whiskers via calcining dihydrate or hemihydrate gypsum perform high energy consumption. It also performs potential environmental impacts. New methods with energy-saving, high-efficiency, and environmentally friendly perform great challenges, which aim at fabricating gypsum whiskers even nanowhiskers. In this study, we used high-concentration calcium acetate solution and dilute sulfuric acid to fabricate anhydrite calcium sulfate nanowhiskers with microemulsion solution at room temperature. For further research on regulation and modification of its surface, calcium sulfates were modified by silicone quaternary ammonium salt and fatty acid methyl ester sulfonate in order to study their surface structure and crystal evolution during modification. After characterization, it indicated that the phase of calcium sulfate transmitted from anhydrite phase into dihydrite phase with a slight change on the surface layers. Benefiting from stability and activity properties of calcium sulfate nanowhiskers after modified, the compressive strength of cement paste with only 1% calcium sulfates performed increased absolutely 10.1% and 4.3% at conservation age of 3 days and 28 days.

Preparation of magnetorheological fluid with excellent sedimentation stability

ABSTRACT In order to prepare magnetorheological fluid with excellent sedimentation stability, various surfactants are applied to coat carbonyl iron powder. The prepared magnetorheological fluid shows excellent sedimentation stability when the surfactants are respectively sodium lauryl alcohol phosphate, compound sodium fatty acid methyl ester sulfonate, ethylene glycol monostearate and glyceride monostearate. Orthogonal tests are carried out for the optimal combination of surfactants and thixotropic agent. The experimental results show that the optimal combination of additives for MRF is 1.5 wt% of sodium lauryl alcohol phosphate, 1.0 wt% of compound MES, 1.5 wt% of ethylene glycol monostearate, 1.5 wt% of glycerol monostearate and 1.0 wt% of hydrophobic fumed silica. Magnetorheological fluid is prepared by the compound scheme, of which the viscosity is 1.09 Pa·s at 25.9°C and the sedimentation rate is 1.61% after one-week placement. The novel MRF is in excellent sedimentation stability and fluidity.

The performance test of fatty acid methyl ester sulfonates and application in the dishwashing liquid detergent

ABSTRACTHydrolytic stability, foaming power and foam stability, calcium soap dispersing ability and stability in hard water of fatty acid methyl ester sulfonate (MES) were measured by potentiometric titration, Ross-Miles foam instrument, improved acid titration and turbidimetric test, respectively. The dishwashing detergent formulations containing MES were designed and stability and detergency of dishwashing detergents have been tested. The results showed that when storage temperature was 45°C, MES in pH 4.5 ∼ 9 was stable, disodium α-sulfonated fatty acid esters content increased at pH 10, hydrolysis rate was accelerated; foaming power of MES was lower than sodium linear alkyl benzene sulfonate (LAS) and the foam stability was equivalent to that of LAS; MES showed very excellent calcium soap dispersing ability, calcium soap dispersing amount of MES was 2.5 g calcium soap /1 g MES and LAS was 0.34 g /1 g LAS; differential stability of MES in hard water was , and LAS was ; the performance test results of dishwashing detergent products partially substituted LAS by MES can both meet the requirements of the Chinese national standard.

Synthesis and properties of α-sulfo carboxyl disodium salt

ABSTRACTThe synthesis and properties of α-sulfo carboxyl disodium salt (SCDS) were studied in detail for the first time in this paper. SCDS was synthesized via saponification reaction of fatty acid methyl ester sulfonate sodium (MES). FT-IR was used to characterize the molecular structure of target product. The yield of disodium salt was greater than 98% by two-phase titration. The performance of SCDS was studied and was compared with raw materials MES, conventional anionic surfactant AES and nonionic surfactant AEO9. The result shows SCDS can reduce the surface tension of the solution to 27.89 mN/m at critical micelle concentration (CMC). The wetting ability of SCDS was significantly enhanced with the increase of temperature. The emulsification effect of SCDS on the soybean oil is better than that on the liquid paraffin. Surprisingly, SCDS has a good foamability and foaming stability.

Experimental study on methane solubilization by organic surfactant aggregates

Seeking to enhance coal mine safety, an experimental study of a kind of water-based explosion suppression medium for the absorption of mine gas was carried out. Using methane as the model gas, solubilizing experiments with different concentrations of anionic and nonionic surfactants were carried out using headspace gas chromatography for surfactants consisting of sodium fatty alcohol polyoxyethylene ether carboxylate (AEC), fatty acid methyl ester sulfonate (MES), fatty methyl ester ethoxylate (FMEE), hexyl d-glucoside (APG06), octyl beta-d-glucopyranoside (APG08) and n-decyl glucoside (APG10). By selecting individual surfactants, the study investigated the methane solubilization performance of water mist with binary anionic–nonionic surfactants. Furthermore, the release of methane in solution was also examined. The results show that the apparent solubility of methane in solution is linearly and positively correlated with the surfactant concentration. The methane solubilization is significantly improved by the addition of anionic–nonionic surfactants. The optimal solubilizing ratio of the anionic–nonionic surfactant varies with the solution compositions. For a fixed ratio, surfactant compositions exhibit the most distinct synergistic effect and the best performance for methane solubilization. The release of methane from mixed micelles composed of the compound solution is superior to that of a single surfactant. Through the analysis of the solubilization effect and the stability of different absorbents, it is concluded that the anionic–nonionic surfactant system shows much better capability than the other selected surfactants.

Comparative study on properties, mechanisms of anionic dispersant modified nano zero-valent iron for removal of Cr(VI)

For the first time, nano zero-valent iron (NZVI) was successfully modified by an environmental friendly surfactant, fatty acid methyl ester sulfonate (MES), and at the same time the roles of a series of anionic dispersants (anionic polyacrylamide (APAM), sodium dodecylbenzene sulfonate (SDBS), and MES) in controlling the dispersity and physicochemical properties of NZVI were investigated. Results indicate that the dispersion and activity of modified NZVI were beneficially affected by the electronegativity strength of anionic dispersants according to the order of APAM > SDBS > MES. Compared with unmodified bare NZVI, the stabilization and antioxidability of anionic dispersant modified NZVI were significantly enhanced. Possible removal mechanisms associated with different anionic dispersants were proposed. A new revised kinetics model was provided for an insightful evaluation of reactive kinetics of Cr(VI) removal by anionic dispersant modified NZVI. In addition, dispersant content, initial Cr(VI) concentration, pH value and solution temperature were important parameters influencing Cr(VI) removal. Decreasing initial concentration of Cr(VI) and lower pH values were generally more favorable to accelerate the removal of Cr(VI). Moreover, the temperature will affect the surface complexation and electrostatic interaction which have a complex effect on the removal of Cr(VI).

Synthesis, Characterization and Exploratory Application of Anionic Surfactant Fatty Acid Methyl Ester Sulfonate from Waste Cooking Oil

AbstractThe environmentally friendly anionic surfactant fatty acid methyl ester sulfonate (MES) was prepared by esterification of waste cooking oil (WCO), a low‐cost raw material, followed by sulfonation with chlorosulfonic acid. MES production from WCO (W‐MES) gave yields up to 78 %. Such a value is only slightly lower than the one obtained from soybean oil (S‐MES), 82 %, and almost the same as that from reused cooking oil (R‐MES), 76 %. According to the two‐phase titration results, the content of the active component, α‐MES, in S‐MES, R‐MES and W‐MES was equal to 76.82, 69.19 and 66.60 %, respectively. The disalt, RCH(CO2Na)SO3Na, contents were instead 3.2, 3.8 and 4.7 %, respectively. As proved by the results of the FTIR and NMR characterizations, the chemical structure of W‐MES is almost the same as that of S‐MES and R‐MES. The critical micelle concentration of W‐MES is 5.38 mmol/L and the corresponding surface tension is 32.3 mN/m. The hydrophile‐lipophile balance value of W‐MES is 12.33, which indicates that it can form oil/water emulsions. The three MES demonstrated the same adsorption efficiency, yielding a pC20 value of 3.22, and similar foam stability. Their detergency can be up to 75 % at a concentration of 400 mg/kg and the tolerance to Ca2+ is higher than the one exhibited by linear alkylbenzene sulphonic acid and alpha olefin sulfonate. Additionally, W‐MES shows a considerable solubilization capacity towards polycyclic aromatic hydrocarbon as the molar solubilization ratios to pyrene, phenanthrene and acenaphthene in a 30 mmol/L solution are 1.22 × 10−3, 2.67 × 10−3 and 3.81 × 10−3, respectively.

Selective flotation of scheelite from calcite and fluorite using a collector mixture

Collector 733, a sodium soap (C12–16COONa) is widely used industrially for scheelite flotation. Low selectivity of 733 collector is always observed. In this study, a collector mixture of 733 and MES (sodium fatty acid methyl ester sulfonate) demonstrated a high selectivity for the flotation of scheelite from calcite and fluorite. An optimal mass ratio 4:1 of 733:MES was found, producing a 65.76% WO3 concentrate grade with a recovery of 66.04% from a feed material containing only 0.57% WO3. In addition, the effect of water hardness and water glass addition were studied. The results indicated that the presence of Ca2+ or Mg2+ had little effect on the adsorption of the collector mixture at the scheelite surface. Addition of water glass for depressing calcite and fluorite had no significant effect on the adsorption of the collector mixture on the scheelite surface. The advantages of this new collector mixture (733+MES) include lower cost, low dosage, high tolerance against water hardness and high selectivity, and this collector mixture has great potential for industrial application.

In vitro analysis of the effect of alkyl-chain length of anionic surfactants on the skin by using a reconstructed human epidermal model.

We investigated the effect of the alkyl-chain length of anionic surfactants on the skin using an in vitro model. The evaluated anionic surfactants were sodium alkyl sulfate (AS) and sodium fatty acid methyl ester sulfonate (MES), which had different alkyl-chain lengths (C8-C14). Skin tissue damage and permeability were examined using a reconstructed human epidermal model, LabCyte EPI-MODEL24. Skin tissue damage was examined by measuring cytotoxicity with an MTT assay. Liquid chromatography/tandem mass spectrometry (LC/MS-MS) and liquid chromatography/mass spectrometry (LC/MS) were used to detect surfactants that permeated into the assay medium through an epidermal model. To assess the permeation mechanism and cell damage caused by the surfactants through the epidermis, we evaluated the structural changes of Bovine Serum Albumin (BSA), used as a simple model protein, and the fluidity of 1,2-dipalmitoyl-sn-glycero-3-phosphpcholine (DPPC) liposome, which serves as one of the most abundant phospholipid models of living cell membranes in the epidermis. The effects of the surfactants on the proteins were measured using Circular Dichroism (CD) spectroscopy, while the effects on membrane fluidity were investigated by electron spin resonance (ESR) spectroscopy. ET50 (the 50% median effective time) increased as follows: C10 < C12 < C8 < C14 in AS and C8, C10 < C12 < C14 in MES. The order of permeation through the LabCyte EPI-MODEL24 was C10 > C12 > C14, for both AS and MES. For both AS and MES, the order parameter, which is the criteria for the microscopic viscosity of lipid bilayers, increased as follows: C10 < C12 < C14, which means the membrane fluidity is C10 > C12 > C14. It was determined that the difference in skin tissue damage in the LabCyte EPI-MODEL24 with C10 to C14 AS and MES was caused by the difference in permeation and cell membrane fluidity through the lipid bilayer path in the epidermis.

Preparation of Methyl Ester Sulfonates Based on Sulfonation in a Falling Film Microreactor from Hydrogenated Palm Oil Methyl Esters with Gaseous SO3

Fatty acid methyl ester sulfonate (MES) is an environmentally friendly anionic surfactant. It contains RCH(CO2Me)SO3Na (α-MES) as the active component and RCH(CO2Na)SO3Na (the disodium salt) whose content must be lower than 5%. In this paper, MES was prepared first in a falling film microreactor (FFMR) by sulfonation of hydrogenated palm oil methyl ester (ME) with SO3 diluted with N2, followed by aging in a tubular reactor and subsequent bleaching and neutralization with NaOH. The influences of the ME flow rate, the channel size, the N2 flow rate, the SO3-to-ME molar ratio, and the sulfonation temperature in the sulfonation step, as well as the influences of the SO3-to-ME molar ratio, the aging residence time, and the aging temperature in the aging step, were all examined. The results indicated that the ME flow rate had no evident influence on the ME conversion and the α-MES concentration both without overflow and with overflow. In the sulfonation step, the disodium salt (disalt) concentration increased w...

Rheological behavior and microstructure of an anionic surfactant micelle solution with pyroelectric nanoparticle

The rheological behavior and microstructure of anionic fatty acid methyl ester sulfonate sodium (MES) surfactant micelle solution with pyroelectric nanoparticle were investigated by dynamic light scattering (DLS), freeze-fracture transmission electron microscopy (FF-TEM) and rheological measurement. The formation of wormlike micelle due to salt addition was observed and the nanoparticle can accelerate the micelle growth and entanglement with each other. The effect of concentration of surfactant, added salt and pyroelectric barium titanate (BaTiO 3) nanoparticle were investigated, respectively. The viscosity of MES micelle solution increases with the temperature rise within a certain range because of the pyroelectric effect of nanoparticles. At low temperature (∼25 °C), the sample with 0.6 wt.% nanoparticle behaves like an elastic gel with an infinite relaxation time and viscosity. The change of microstructure and rheological properties for MES viscoelastic micelle solutions may be attributed to the electrostatic interaction and pseudo-crosslinking between micelles and nanoparticles. MES viscoelastic micelle solution can retain high viscosity at elevated temperature due to nanoparticle addition and has very attractive for reservoir stimulation and enhanced-oil-recovery in higher temperature reservoirs.

Effect of Nano-SiO&lt;sub&gt;2&lt;/sub&gt; on the Rheology of Anionic Viscoelastic Solutions Formed by the Biodegradable Surfactant Fatty Acid Methyl Ester Sulfonate

The effects of nano-SiO2 on the rheology of viscoelastic solutions formed by the bio- degradable surfactant fatty acid methyl ester sulfonate (MES) were studied. The process of MES micelles transforming from sphere or rod to wormlike was investigated with the increase in NaCl concentration by rheological measurements. The increase in η0 on the introduction of SiO2 was explained by considering the increasingly entangled wormlike micelles that were formed due to the screening of the electrostatic interactions. The results of rheological measurements show that the system of MES /NaCl can transform into wormlike micelles. MES micelle solutions without SiO2 are linear viscoelastic fluids in accord with a Maxwell model having a single relaxation time. But there is a process with some distributions of the relaxation time for MES micelle solution with SiO2.