Fatty Alcohol Ethoxylates Research Articles

Gas Chromatography with Flame Ionization Detection of 1,4‐Dioxane in Palm‐Based Fatty Alcohol Ethoxylates

AbstractDuring the ethoxylation of fatty alcohol, 1,4‐dioxane, a toxic by‐product may be formed. A simple and rapid method using gas chromatography with a flame ionization detector was developed for detection of 1,4‐dioxane in commercial palm‐based fatty alcohol ethoxylate (FAEO). The method involved spiking the 1,4‐dioxane into FAEO samples, and directly injecting the spiked samples into GC with no clean‐up steps. The method was validated in terms of linearity, accuracy, intra‐day precision and inter‐day precision, selectivity, limit of detection and limit of quantification. In terms of linearity, a calibration curve with a correlation coefficient of 0.9999 was obtained. The accuracy of the method was indicated by recovery obtained for spiked 1,4‐dioxane samples at 5 levels of spiking, i.e. at 30, 60, 100, 200 and 500 μg/g, where recoveries were within 99–105 % with relative standard deviation (RSD) of <4.0 %. The RSD values of the intra‐day and inter‐day precision were <1.0 %. The limit of detection and quantification was 10 and 30 μg/g, respectively. The selectivity of the method was indicated by its ability to analyze commercial FAEO samples with different average moles of ethylene oxide (EO). The GC profiles of these FAEO with varying numbers of moles of EO were similar, and there were no other peaks interfering with the 1,4‐dioxane peak.

Synergistic Effect on Wettability of Mixtures of Amine Oxides, Alkylpolyglucosides, and Ethoxylated Fatty Alcohols

AbstractThe mixture proportions of three surfactants, i.e. an alkylpolyglucoside (APG), an ethoxylated fatty alcohol, and an amine oxide (AO), were optimized by applying Response Surface Methodology in order to achieve the surfactant ratio that produces the highest wetting power. The synergistic effect of the binary samples of AO with the other surfactants was firstly verified. An improvement in this synergistic effect on wettability was found in the ternary mixture. In the experimental range analyzed, the surfactant concentration ratio that produced the highest wettability was a composition with 19.3 % APG, 30.1 % ethoxylated alcohol, and 50.6 % lauramine oxide.

Determination of non-ionic and anionic surfactants in industrial products by separation on a weak ion-exchanger, derivatization and liquid chromatography

A method for the determination of priority surfactants, including fatty alcohol ethoxylates (FAE), alkylether sulfates (AES) and linear alkylbenzene sulfonates (LAS) is described. The samples were diluted with 50% methanol at pH 4 prior to solid-phase extraction on a weak anionic exchanger (WAX). The AES and LAS surfactant classes were retained, whereas the non-ionic components, including most FAE oligomers were eluted. After washing the WAX cartridge to remove cations, the remaining hydrophobic FAE oligomers were eluted using hot 80% methanol at pH 4 (at ca. 50°C). These two eluates were combined to constitute the non-ionic fraction. Then, AES and LAS were eluted using 80% MeOH with 3M NH3 followed by 95% methanol with 0.75M NH3. The two eluates obtained in basic media were combined to constitute the anionic fraction. The solvents were evaporated, the residues were dissolved in 1,4-dioxane, and esterification of the alcohols and transesterification of AES with phthalic anhydride was performed. Separation of the derivatized oligomers was achieved by gradient elution on a C8 column with acetonitrile/water in the presence of 0.1% acetic acid and 0.1M NaClO4. The chromatogram of the non-ionic fraction showed the peaks of the resolved FAE oligomers. The chromatogram of the anionic fraction showed the peaks of the LAS homologues well resolved from those of the AES oligomers. The method was applied to laundry and industrial cleaners, shampoos and a shower gel.

Alcohol ethoxylation kinetics: Proton transfer influence on product distribution in microchannels

The influence of the reactor type on the product distribution of the base catalyzed ethoxylation of fatty alcohols was studied.Commonly, proton exchange equilibrium is assumed when modeling this reaction to calculate the product distribution. The model is applicable for ethoxylates produced in semibatch, but cannot explain the products obtained from a continuous microstructured reactor.In this work, a non-equilibrium model is proposed to explain the observed distributions. The model is better suited to fit the distribution curves, and was used to determine the kinetic parameters of this reaction.For the propagation reaction, an activation energy EA,P= 74kJmol−1 was found, which is in good agreement to literature data. For the proton transfer, activation energies in the range of 56kJmol−1 to 68kJmol−1 were observed.

Influence of the dye transfer inhibitors for the washing of softened cotton fabric

In this, work the performance of several dye transfer inhibitors (DTI) copolymers (PVP, PVNO and PVNO with PVP) was tested for use as DTIs in washing softened undyed cotton fabric, in the presence of a direct dye in the washing bath, with and without water hardness. Three direct dyes were tested: red, blue and yellow. The detergent used was composed of an LAS anionic surfactant and a non-ionic fatty alcohol ethoxylate surfactant with 7 m. OE, both separately and in the different molar proportions anionic with non ionic, at a total concentration of 5 × 10−3 M, and in the presence of zeolite as a builder. Washing temperature was 40°C and washing time was 30 min. Staining of the softened undyed cotton fabric was assessed as the CIELAB colour differences between the original fabric and the stained fabric after washing.The different DTIs and the dye in the washing bath with and without water hardness were tested.

Optimization of Application Efficacy for POST Herbicides with Adjuvants on Three-Cornered Jack (Emex australis Steinheil) in Wheat

Field studies were conducted to evaluate POST herbicides with adjuvants for the control of three-cornered jack in winter wheat. The herbicides evaluated were fluroxypyr 9.7% w/w + MCPA 38.8% w/w (formulated mixture [450 g ai ha−1]), carfentrazone-ethyl (20 g ai ha−1), bromoxynil 26.8% w/w + MCPA 40.0% w/w (formulated mixture [450 g ai ha−1]), thifensulfuron-methyl (75 g ai ha−1), and tribenuron-methyl (75 g ai ha−1), applied alone or tank mixed with the adjuvants alkyl ether sulfate sodium salt (625 mL ha−1) or fatty alcohol ethoxylate (375 mL ha−1). The addition of adjuvants to carfentrazone-ethyl resulted in > 94% control of three-cornered jack. Both adjuvants enhanced the efficacy of all herbicides for control of three-cornered jack, except thifensulfuron-methyl. However, a maximum increase in phytotoxicity on three-cornered jack was achieved with the addition of either adjuvant to tribenuron-methyl compared with herbicides used alone. Bromoxynil + MCPA and carfentrazone-ethyl gave maximum wheat yield and yield components.

Catalyst development for the selective oxidation of ethoxylates to their corresponding ether carboxylic acids

The aerobic selective oxidation of polyethoxylates to their corresponding carboxylic acids was investigated using supported Au-based catalysts in aqueous alkaline solution. Introduction of Pt as secondary metal to the titania supported Au catalyst led to a significant boost in activity while maintaining total selectivity. A screening of different preparation methods and metal ratios led to a titania supported AuPt catalyst with a substantially reduced intermediate leaching of the catalytically active metals. A long-term stability study showed no noble metal loss of this particular catalyst after a set of repeated batches, but still revealed a distinct loss in activity due sintering of the metal nanoparticles. By switching from titania to ceria as support material, intermediate metal leaching could be prevented completely while maintaining total selectivity and further enhancing the activity. • Selective oxidation of polyethylene glycol and fatty alcohol ethoxylate was studied. • Supported Au, AuPt and AuPd catalysts were screened. • Bimetallic gold catalysts provide enhanced activity and reduced metal leaching. • Only on AuPt/CeO 2 no metal leaching can be detected.

Analytical methods for the characterization and determination of nonionic surfactants in cosmetics and environmental matrices

Nonionic synthetic surfactants, constituted of an assortment of classes, are common ingredients of industrial, household and body-care products. Alone or in combination with anionic surfactants, they perform a variety of functions including cleaning action, emulsification, skin conditioning, appearance and consistency modification, solubilization and dispersing agents. By far fatty alcohol ethoxylates (AEs) and alkylphenol ethoxylates (APEs) are more extensively used than any other nonionic surfactant class; however, works appearing in the literature making reference to the analysis of other nonionic surfactant classes have also been collected in this review. The production volume worldwide of AEs and APEs, and consequently their environmental impact, is very high. Although readily biodegraded, stable non-ethoxylated lipophilic residues remain for long periods in the aquatic environment and sediments. In addition to its harmful impact on the food chain, there is also concern on landscape spoiling, particularly in coastal areas. The analytical methods used for quality control of nonionic surfactants in industrial products and in environmental samples are revised and commented upon here. The fundamentals and characteristics of the methods, including their most relevant operative and statistical aspects, are briefly presented. Attention is also paid to the techniques used to extract and preconcentrate the analytes from liquid and solid environmental samples.

Analysis of fatty alcohol derivatives with comprehensive two-dimensional liquid chromatography coupled with mass spectrometry

A simultaneous separation of anionic (fatty alcohol sulfates, fatty alcohol ether sulfates), non-ionic (alkyl polyglucosides, fatty alcohol ethoxylates) and amphoteric (cocamidopropyl betaines) surfactants was performed by comprehensive two-dimensional liquid chromatography (LCxLC) utilizing a ZIC®-HILIC column in the first dimension, a Reprosphere 100 C8-Aqua column in the second dimension and a 10-port two position valve as the interface. The volume of the two sample loops were 25 or 50μL and allow a one or two minute modulation at a 25μL/min flow rate. In the first dimension, a gradient of acetonitrile and an ammonium acetate buffer was used to separate polyethoxylated surfactants by their degree of ethoxylation (EO number) whereas in the second dimension, a separation by alkyl chain was performed using a methanol/ammonium acetate buffer gradient. A baseline separation of the above mentioned surfactants according to both EO number and alkyl chain was achieved. The best performance was used to compare two different LCxLC–QTOF MS systems, which demonstrate that a transfer of the method from one system to a totally different system is possible. However, because of the differences in delay volume and extra-column volume between these systems the separation power is changed.

Oil Recovery from Oil Sludge through Combined Ultrasound and Thermochemical Cleaning Treatment

Oil sludge from an oil storage tank was treated using a combined ultrasound and thermochemical cleaning method. The effects of cleaning temperature, cleaning time, ultrasound frequency, ultrasound power, and other factors on the oil recovery were investigated. Experiments on the screening and remixing of reagents were conducted and indicated that the best constituents of detergent solution were sodium silicate, sodium dodecyl benzene sulfonate, and fatty alcohol ethoxylates in a ratio of 1:1:1. The optimum conditions of the combined treatment system were also determined. The results showed that, under the optimum conditions, the oil content of oil sludge dropped from 43.13% to 1.01%, 0.53% of solids remained in the separated oil layer, and 99.32% oil recovery could be achieved when the concentration of detergent solution was to 2 g/L. Compared with traditional thermochemical cleaning, the oil recovery was 17.65% higher for the combined treatment system.

Optimizing activity of herbicides at reduced rate on Emex spinosa campd. with adjuvants

In pot experiments, two adjuvants were evaluated for their efficacy in enhancing activity of five herbicides applied at reduced rates (75% of the recommended rates) on Emex spinosa at the cotyledon-leaf and at the two- to four- leaf stage. Herbicides (at recommended rates) including fluroxypyr+MCPA at 450 g a.i. ha-1, carfentrazone-ethyl at 20 g a.i. ha-1, bromoxynil+MCPA at 450 g a.i. ha-1, thifensulfuron-methyl at 75 g a.i. ha-1 and tribenuronmethyl at 75 g a.i. ha-1 alone and tank mixed at reduced rates with adjuvants, namely, alkyl ether sulphate sodium salt at 625 mL ha-1 or fatty alcohol ethoxylate at 375 mL ha-1. Addition of the adjuvants to reduced rates of fluroxypyr+MCPA and carfentrazone-ethyl, increased their efficacy with 100% mortality and biomass reduction of E. spinosa at the cotyledon- leaf stage and at the two- to four- leaf stage which was similar to their recommended rates without the adjuvants except for carfentrazone-ethyl at a reduced rate without adjuvants at the two- to four- leaf stage. Bromoxynil+MCPA at reduced rates with alkyl ether sulphate sodium salt also gave 100% control of E. spinosa over weedy check at the two- to four- leaf stage. Both the adjuvants generally increased the efficacy of tribenuron-methyl at reduced rates when sprayed at both leaf stages. These findings suggest that the use of adjuvants may increase the efficacy of the above mentioned herbicides against E. spinosa and it may be incorporated in an integrated weed management program.

A method of making an aqueous dispersion of polyaniline and inhibiting corrosion in cooling water

Abstract The present study provides a process for the dispersion of polyaniline after its synthesis, to improve the solubility of the polyaniline in an aqueous medium in the presence of nonionic surfactant (fatty alcohol ethoxylate). The surfactant selected based on their chemical composition and their Hydrophile-Lipophile-Balance and the induced steric hindrance effect. The dispersion process was developed, and the polyaniline dispersion was characterized by the electrical conductivity and in the macroscopic phase boundary. The polyaniline dispersions have been studied for their possible use in such fields as a corrosion inhibitor. In our case, the corrosion inhibitor was employed in industrial cooling water, which contains hardness and operating at temperature of 41°C and pH of 8.7. The weight-loss and corrosion polarization resistance (corrater system) methods were carried out to study the corrosion of carbon steel. Inhibition efficiencies of nearly 80% have been observed even at as low concentration o...

Analysis of Fatty Alcohol Ethoxylates Regarding Chain Length and Endgroups by MALDI‐TOF MS Using Collision‐Induced Dissociation

AbstractMALDI‐TOF MS is used to analyze the chain lengths and endgroups of fatty alcohol ethoxylates based on the fragmentation behavior in collision‐induced dissociation. MALDI‐CID‐TOF2 of the ethoxylates results in complex fragmentation patterns that mirror the fragmentation of the ethylene oxide oligomer chain and the fatty alocohol endgroups. Characteristic fragment patterns are obtained that facilitate the interpretation of the fragmentation behavior of the fatty alcohol ethoxylates. Linear and branched endgroups can be differentiated and specific fragments are identified that are characteristic for the cleavage between the polymer chain and the endgroup. These “marker” fragments are used to determine the oligomer chain length and the number of carbons per endgroup.

Determination of fatty alcohol ethoxylates and alkylether sulfates by anionic exchange separation, derivatization with a cyclic anhydride and liquid chromatography

A method for the separation, characterization and determination of fatty alcohol ethoxylates (FAE) and alkylether sulfates (AES) in industrial and environmental samples is described. Separation of the two surfactant classes was achieved in a 50:50 methanol–water medium by retaining AES on a strong anionic exchanger (SAX) whereas most FAE were eluted. After washing the SAX cartridges to remove cations, the residual hydrophobic FAE were eluted by increasing methanol to 80%. Finally, AES were eluted using 80:20 and 95:5 methanol–concentrated aqueous HCl mixtures. Methanol and water were removed from the FAE and AES fractions, and the residues were dissolved in 1,4-dioxane. In this medium, esterification of FAE and transesterification of AES with a cyclic anhydride was performed. Phthalic and diphenic anhydrides were used to derivatizate the surfactants in industrial samples and seawater extracts, respectively. Separation of the derivatized oligomers was achieved by gradient elution on a C8 column with acetonitrile/water in the presence of 0.1% acetic acid. Good resolution between both the hydrocarbon series and the successive oligomers within the series was achieved. Cross-contamination of FAE with AES and vice versa was not observed. Using dodecyl alcohol as calibration standard, and correction of the peak areas of the derivatized oligomers by their respective UV–vis response factors, both FAE and AES were evaluated. After solid-phase extraction on C18, the proposed method was successfully applied to the characterization and determination of the two surfactant classes in industrial samples and in seawater.

FATTY SOILS REMOVAL FROM HARD SURFACES IN A CLEAN‐IN‐PLACE SYSTEM

ABSTRACT The kinetics of fatty soil removal from glass surfaces using nonionic biodegradable surfactants has been investigated. For this, mathematical models have been developed, which take into account the equilibrium established between the processes of soil removal from the substrate surface and their subsequent redeposition. The washing tests have been conducted in a continuous‐flow device that simulates the conditions found in the clean‐in‐place system used in the food industry. A mixture of fatty acids (oleic, palmitic and stearic) frequently found in foods, and particularly difficult to remove, was used as the soiling agent. The experimental results show the effect of the different variables assayed (temperature, soiling‐agent concentration and surfactant concentration) on the washing process. The good agreement between the experimental detergency values and those predicted by the kinetic model indicate that this is adequate to explain the detersive process on hard surfaces. PRACTICAL APPLICATIONSIn food industry, production lines are cleaned in place every day to provide the microbial quality and safety of the products. Moreover, the effectiveness of the cleaning process depends on many factors: temperature, detergent concentrations, hydrodynamic forces, characteristics of substrate, etc. In this work, we have studied the kinetics of the washing process using alkylpolyglucosides and fatty alcohol ethoxylates, both commercial surfactants. The tests were performed in a laboratory device that simulates the clean‐in‐place processes widely used in food industries. A mixture of fatty acids commonly found in foods was used as the soiling agent. A kinetic model assuming a process combining removal and deposition during the cleaning was developed. This model, which satisfactorily predicts the detergency data obtained under different experimental conditions, could be of great practical utility since it can help develop more effective detergent formulations.

Study of Under Etching Characters of Si (100) in Surfactant Added TMAH

This work focuses on the etching characteristic of (100) silicon wafer in surfactant added tetramethyl-ammonium-hydroxide (TMAH:( CH3)4NOH) solution. The experimental result shows that under etching effect in TMAH achieves a significant reduction by adding fatty alcohol ethoxylate (R-O (CH2-CH2)n-OH) in the solution. Synperonic-A series fatty-alcohol-ethoxylate with increasing length of ethylene oxide segments are used to carry out the experiment. Comparing with the pure TMAH, the maximum under etching rate in the surfactant added TMAH is reduced to three quarters. The etching loss of convex corners is negligible for shallow to medium-deep etching (<30μm).

Some properties of an oil-soluble phosphated fatty alcohol ethoxylate.

Abstract Although phosphated hydrocarbon ethoxylates are claimed to have properties associated with the presence of both non-ionic and anionic groups in their molecules, a recent investigation of a phosphated nonylphenol ethoxylate demonstrated that the phosphate group had only a slight influence on the properties of this compound. The properties of an oil-soluble phosphated fatty alcohol ethoxylate of commercial origin has now been investigated. This material was substantially homogeneous, corresponding to a structure C9H19-(OCH2CH2)3-O-PO(OH)2—mol wt = 356 Although with considerable solubility in non-polar solvents, the compound has a slight solubility in water which is increased with increased pH, suggesting that the polar phosphate group has an influence on the properties of the compound. Measurement of the surface tension of aqueous solutions over a temperature range of 20–50° showed that there was an inflection point in the relation between cmc and temperature, behaviour typical of an anionic surfactant. As the pH is increased, the interfacial cross-sectional area of the molecule is progressively reduced at the air-water interface, but increased at the hexane-water interface. These results are discussed in terms of the orientation of the molecule at the interface, and the influence of a charged polar head group.

Phase studies of mixed phosphated surfactants, n-hexane and water.

Abstract Mixtures of phosphated nonylphenolethoxylate (PNE), phosphated fatty alcohol ethoxylate (PFE) and n-hexane form ‘oils’ which may spontaneously emulsify when added to water. However, the degree of spontaneity and the stability of the resulting dispersions vary according to the constitution of the system. Studies of the equilibrium phase diagrams suggest that the anomalies may be attributed to the presence of liquid crystalline phases of different types which are formed in the presence of water.

Measurement of the 'spontaneity' of self-emulsifiable oils.

Abstract Self-emulsifiable oils are solutions of surfactants in non-polar solvents which spontaneously form emulsions when added to water. Measurement of the degree of spontaneity has remained subjective. Accordingly, a method has been devised in which a small volume of the oil solution is injected into a flowing stream of water and carried across an intense beam of parallel light from a helium-neon laser. Light scattered from the beam by the dispersed oil droplets is collected by means of fibre optics onto an array of silicon photodiodes and the amplified output is integrated as a function of time. By varying the flow rate of the water stream it is possible to estimate the time required for an emulsifying system to come to its equilibrium state of dispersion under the conditions of the experiment, the ‘spontaneity’ of emulsion formation. Under the experimental conditions employed, systems comprising solutions of phosphated nonylphenolethoxylate (PNE) and phosphated fatty alcohol ethoxylate (PFE) in n-hexane came to equilibrium between 5 and 12 s, depending on the constitution. These times could be approximately correlated with the values for spontaneity estimated by the CPAC dilution test, although this latter test is somewhat subjective. The spontaneity appears to depend on the nature of the material existing within the phase diagram and the anomalous results obtained may be accounted for by the likely presence of a complex formed at the emulsion interface between the PNE, PFE and water during the dispersion process.

A note on the interaction between two phosphated surfactants.

Abstract Evidence of an interaction between the water-soluble phosphated nonylphenolethoxylate (PNE) and the oil-soluble phosphated fatty alcohol ethoxylate (PFE) could not be obtained when the two compounds were mixed in the anhydrous state. However, measurements of refractive index, interfacial tension, density and viscosity of aqueous solutions of the two surfactants showed anomalies which were at a maximum when they were present in an approximately equal ratio by weight. Thin-layer chromatography confirmed the anomalous properties of mixtures of the two compounds and it is suggested that these result from the formation of a complex material involving PNE, PFE and water.