Fatty Alcohol Ethoxylates Research Articles

Polyoxyethylene alkyl and nonyl phenol ethers complexation with potato starch

Starchy soil removal efficiency when cleaning food industry equipment can be affected by surfactant–starch complexes. Polyoxyethylene alkyl and nonyl phenol ethers complexation with potato starch has been studied by surface tension measurements. All surfactants assayed yield inclusion complexes with starch after a critical concentration of association was achieved. No starch saturation was observed throughout complexation until micellization, with bound surfactant being proportional to the total added surfactant. This bound/total surfactant ratio and the critical concentration of association seemed to depend mainly on the surfactant alkyl chain length. Unlike fatty alcohol ethoxylates, the nonyl phenol ethoxylate was feebly bound likely caused by its aromatic moiety. Binding isotherms and Scatchard plots suggested surfactants positive cooperative and non-cooperative binding with amylose and amylopectin respectively. Phosphate buffer raised surfactants binding capacity, ascribed either to an increase in cooperativity or to a reduction in the number of glucose units required to bind a surfactant molecule.

Kinetics and Modeling of Fatty Alcohol Ethoxylation in an Industrial Spray Loop Reactor

AbstractThe kinetics of the ethoxylation of fatty alcohols catalyzed by potassium hydroxide was studied to obtain the rate constants for modeling of the industrial process. Experimental data obtained in a lab‐scale semibatch autoclave reactor were used to evaluate kinetic and equilibrium parameters. The kinetic model was employed to model the performance of an industrial‐scale spray tower reactor for fatty alcohol ethoxylation. The reactor model considers that mass transfer and reaction occur independently in two distinct zones of the reactor. Good agreement between the model predictions and real data was found. These findings confirm the reliability of the kinetic and reactor model for simulating fatty alcohol ethoxylation processes under industrial conditions.

Partitioning behavior of an acid-cleavable, 1,3-dioxolane alkyl ethoxylate, surfactant in single and binary surfactant mixtures for 2- and 3-phase microemulsion systems according to ethoxylate head group size

Partition coefficients for a pH-degradable 1,3-dioxolane alkyl ethoxylate surfactant, 4-CH(3)O (CH(2)CH(2)O)(5.6)-CH(2), 2,2-(CH(2))(12)CH(3), 2-(CH(2)) CH(3), 1,3-dioxolane or "cyclic ketal" surfactant, CK-2,13-E(5.6,ave), between isooctane- and water-rich phases of 2- and 3-phase microemulsion systems (K(n)) were determined as functions of the ethoxylate size, n, and temperature for the neat surfactant and its binary surfactant mixtures, to understand the partitioning of alkyl ethoxylates possessing a broad distribution of ethoxylate size and to determine conditions required for formation of 3-phase microemulsion systems at an optimal temperature where phase separation occurs rapidly, important for protein purification via proteins' selective partitioning to the middle phase, driven by affinity to the second surfactant of the binary mixture. A semi-empirical thermodynamic mathematical model described the partitioning data well, provided optimal temperature values consistent with phase diagrams and theory, and demonstrated that the tail region of CK-2,13-E(5.6,ave) is more polar than the hydrophobes of fatty alcohol ethoxylates. The addition of Aerosol-OT (AOT) removed the temperature sensitivity of CK-2,13-E(5.6,ave)s partitioning, producing 3-phase microemulsion systems between 20 °C and 40 °C. Analysis of the bottom phases of the 2- and 3-phase microemulsion systems formed by CK-2,13-E(5.6,ave) via small-angle neutron scattering demonstrated the presence of spherical, monodisperse oil-in-water microemulsions.

Chemical Clustering for Risk Assessment: Fatty Alcohol Alkoxylates

Abstract Fatty alcohol alkoxylates are non-ionic surface active compounds comprised of a hydrophobic fatty alcohol moiety of variable chain length linked to a hydrophilic polyalkoxylate chain of repeating alkylene oxide subunits containing ethylene and propylene oxides. Materials falling inside this group that are derived from a fatty alcohol and ethylene oxide alone are referred to as fatty alcohol ethoxylates. The unifying features of this class include (1) the use of fatty alcohol fractions drawn from alkyl chains between 4 and 100 carbons in length, each with deliberately wide or narrow ranges and falling within or across specific groups, and (2) the chemical addition to these fractions of specific numbers of repeating structural units of an alkylene oxide in molar ratios ranging from 2 to 100 for ethylene oxide and from 0 to 30 for propylene oxide. A useful rationale establishing the cohesiveness of grouping, or “clustering,” of this family of chemistry is described based on a comparison of similarities across chemical structures contained in the cluster, the continuum of predictable change in associated physiochemical properties, and the accompanying consistency in underlying biological data. A semiquantitative approach is described using the accessible non-confidential information.

Single‐pump bi‐dimensional LC applied to the characterization of derivatized fatty alcohol ethoxylates

A column selection valve and a 6-port 2-position injection valve were combined to implement bi-dimensional LC in a system driven by a single pump. The system was applied to the separation of linear fatty alcohol ethoxylates with 12-18 carbon atoms in the hydrocarbon moiety, previous derivatization with diphenic anhydride. Separation on the first separation dimension (C(1)) was carried out with a propyl-diol column and an acetonitrile/aqueous ammonium acetate gradient. Fatty alcohol ethoxylate hydrocarbon series (oligomers with the same number of carbon atoms in the alkyl chain but differing in the number of ethylene oxide units) were resolved without distinguishing the oligomers within the series. Selected segments of the eluate of C(1) were transferred to the second column (C(2)), where the successive oligomers within the isolated series were resolved by using either an octyl-silica or a pentafluoro-phenyl-propyl column and an acetonitrile/water gradient. Flow stopping at C(1) during system re-conditioning and elution along the second dimension did not produce any noticeable band broadening. Overlapping of the non-ethoxylated and mono-ethoxylated oligomers with other oligomers within the series was avoided by eluting the pentafluoro-phenyl-propyl column at low temperatures (3 degrees C).

Two‐dimensional chromatography of complex polymers, 8. Separation of fatty alcohol ethoxylates simultaneously by end group and chain length

A comprehensive two-dimensional liquid chromatography system was developed to precisely describe the molecular heterogeneity of fatty alcohol ethoxylates. The end-group functionality was analyzed by gradient HPLC while ethylene oxide oligomer distributions were characterized by liquid adsorption chromatography. A baseline separation of all functionality fractions irrespective of the ethylene oxide oligomer chain length was achieved on nonpolar X-Terra C(18) with a methanol-water gradient, whereas an isocratic flow of isopropanol-water on a polar Chromolith Si column gave a separation according to the oligomer chain length without interference of the end-group distribution. The combination of these two methods to conduct online two-dimensional liquid chromatography experiments resulted in a comprehensive two-dimensional picture on the molecular heterogeneity of the sample.

Derivatization of fatty alcohol ethoxylate non‐ionic surfactants using 2‐sulfobenzoic anhydride for characterization by liquid chromatography/mass spectrometry

A derivatization procedure has been developed for the improved characterization of fatty alcohol ethoxylate non-ionic surfactants by liquid chromatography/mass spectrometry. The end hydroxyl group of each surfactant species was converted into an oxycarbonylbenzene-2-sulfonic acid group with 2-sulfobenzoic anhydride under mild conditions. The produced sulfonic acid group allows all species, including fatty alcohols and those with less than three ethoxylates, to be uniformly ionized by electrospray ionization (ESI) mass spectrometry. Both acid and base can be used as a mobile phase additive for liquid chromatography without affecting M(n) and average ethoxylate values, although ion intensities are suppressed during the ESI process. The method was used to analyze seven commercial fatty alcohol ethoxylate non-ionic surfactants, and the determined M(n) and EO values were comparable with the results obtained by NMR. The relative ratio of different fatty alcohol based ethoxylates in a sample can also be determined using the summed mass spectral data.

Acute toxicity and relationship between metabolites and ecotoxicity during the biodegradation process of non-ionic surfactants: fatty-alcohol ethoxylates, nonylphenol polyethoxylate and alkylpolyglucosides

The toxicity values of fatty-alcohol ethoxylates, nonylphenol polyethoxylate, and alkylpolyglucosides have been determined by applying assays with luminescent bacteria. Also, the relation between metabolites and ecotoxicity during the biodegradation process has been determined. The biodegradation tests were carried out according to the OECD 301 E test for ready biodegradability. In these tests a solution of the surfactant, representing the sole carbon source for the microorganisms, was tested in a mineral medium, inoculated and incubated under aerobic conditions in the dark. The toxicity of surfactants is related to their molecular structure (Quantitative Structure Activity Relationships, QSAR). For the alkylpolyglucosides, toxicity expressed as EC(50) is related with the critical micelle concentration (CMC), the hydrophilic-lipophilic balance (HLB) of the surfactant, and the hydrophobic alkyl chain (R). The results indicate that toxicity increased as the CMC decreased and as the hydrophobicity increased and R rose. For fatty-alcohol ethoxylates, parameters characteristic studied have been HLB, number of units of ethylene oxide and the alkyl chain length. Relationships found are in agreement with the fact that increasing the alkyl chain length leads to a lower EC(50), whereas increasing ethoxylation leads to a lower toxicity. An analysis of the behaviour of the toxicity and HLB again indicates that the toxicity was greater for surfactants with a smaller HLB. The evolution of the toxicity was studied over the biodegradation process, expressed as a percentage of inhibition. For all the non-ionic surfactants assayed, except for the nonylphenol polyethoxylate, a major decline was found in toxicity during the first days of the biodegradation assay and at all the concentrations tested.

Identification and quantitation of trace impurities in fatty alcohol ethoxylates using HPLC and MALDI-TOF mass spectrometry

A two-step HPLC separation that combines isocratic and gradient elution has been developed for the analysis of trace impurities in fatty alcohol ethoxylates (FAEs). Quantitative estimates of the early eluting impurities were obtained from a calibration curve based on the responses of an evaporative light scattering detector (ELSD). Isocratic conditions were used to elute the impurities and gradient conditions for the main FAE components. In this manner, an acceptable compromise was obtained between resolution and analysis time. Fractions were collected and the impurities identified using MALDI-TOF mass spectrometry.

Determination of fatty alcohol ethoxylates with diphenic anhydride derivatization and liquid chromatography with spectrophotometric detection: A comparative study with other anhydrides

A method for the determination of fatty alcohol ethoxylates (FAEs) using diphenic anhydride as derivatization reagent and RP-HPLC separation with UV–vis detection is presented and compared to derivatization with maleic, phthalic, and other cyclic anhydrides. With these anhydrides, the reaction rates increased when urea was added to the reaction medium, and the yields did not decrease when the samples contained moderate amounts of water. Gradient elution on a C8 column was performed with water/acetonitrile in the presence of 0.1% acetic acid. The use of diphenic anhydride was advantageous for both the chromatographic separation and the detection. Specifically, sensitivity at 200 and 220 nm was significantly better for the FAE diphenates, resulting in lower limits of detection at both wavelengths for the diphenates than for the maleates and phthalates (up to 30 and 4.3 times lower at 220 nm, respectively). Response factors for the diphenates decreased less than those of the phthalates when the number of ethylene oxide units, m, increased, reaching a constant value of ca. 0.62 when m > 3. Peak symmetries and efficiencies were also better than those found for the other anhydrides. The optimized procedure was applied to the characterization and determination of FAEs in the effluent of a wastewater treatment plant and in sea water.

Development and application of kinetic models for the primary biodegradation of non-ionic surfactants

The growing concern for the environment is promoting the use of surfactant products from renewable sources such as fatty alcohol ethoxylates. The high production and use of these products implies the need to develop models that enable predictions of their behaviour in biodegradation processes. The biodegradation tests were carried out according to the OECD 301 E test for ready biodegradability. In this work, kinetic models of general application to surfactant biodegradation are developed, both for substrates that do not support growth and for those that do, considering a residual substrate concentration as not being biodegraded. The models were applied to three commercial non-ionic surfactants, fatty alcohol ethoxylates with different carbon-chain lengths and degrees of ethoxylation, also analysing the initial surfactant concentration.

Separation of fatty alcohol ethoxylates by capillary zone electrophoresis and micellar electrokinetic chromatography

Separation methods based on capillary zone electrophoresis and micellar electrokinetic chromatography were developed to characterize the distribution of ethylene oxide (EO) homologues in the fatty alcohol ethoxylates (FAEs). Prior to the separation, the FAEs were derivatized with 2-fluoro-1-methylpyridinium p-toluenesulfonate (FMPTS) to allow CZE separation and UV detection. To prevent adsorption of cationic analytes onto the inner surface of the capillary and formation of micelles in CZE analysis, a lower pH background solution (BGS) containing a high concentration of acetonitrile was employed. Under optimal conditions, FMPTS-derivatized FAEs with an average EO number of 6 were completely separated within 11 min. For MEKC analysis of the FAEs, dodecyltrimethylammonium chloride (DTAC) was added to the BGS. In the presence of 30 mM DTAC in 10 mM phosphate buffer (pH 2.5) containing 20% (v/v) acetonitrile, superior oligomer separation of the FAEs containing up to 50 EO groups was achieved within 30 min with good analytical reproducibilities. Furthermore, the developed method was applied to the analysis of the FAEs in commercial products such as laundry detergent and fabric softener.

1,2 Hexanediol as an Alternative Cosurfactant for Preparing Palm-Based Microemulsions for Practical Applications

Microemulsions (µE) were prepared with palm fatty acid esters (PFAME) as solvents stabilised by fatty alcohol ethoxylates (hydrophilic-lipophilic balance, HLB value ∼12.8), and 1,2 hexanediol as a co-surfactant. The effects of co-surfactant on the ternary phase systems were studied only at 10, 15, 20, 25, and 30% (w/w) of surfactant concentrations. The ratio of PFAME/water was chosen at 30:70 only. The mixtures were mixed vigorously and then kept at ambient temperature (25°C) for few days. The emulsions (two-phase), µE and liquid crystalline phases were observed using the polarised light. In addition, the physical stability (accelerated test/month at 45°C),conductivity and viscosity for µE solutions were measured. The effects of co-surfactant on the ternary phase systems for PFAME/non-ionic surfactant/water were constructed at 25 and 45°C. The result showed that larger µE region was formed with PFAME 1 than the PFAME 2 at 30:70 ratio of oil to water. The minimum concentration of surfactant for producing clear, low viscosity and thermodynamically stable µE solutions was 10% (w/w) for both PFAME 1 and PFAME 2 at 25°C. However, the concentration of co-surfactant used to produce µE solutions was 12.5% for PFAME 1 but was 30% (w/w) for PFAME 2. Furthermore, the conductivity and viscosity measurements indicated types of µE, that is, O/W or W/O formed.

Simultaneous elimination of dissolved and dispersed pollutants from cutting oil wastes using two aqueous phase extraction methods

Oily wastewater experimental study has been accomplished using two aqueous phases extraction methods on the basis of phase separation properties of non-ionic surfactants above the so-called cloud point curve and the solubilization phenomena of coacervate micelles (surfactant rich phase). Two commercial ethoxylate fatty alcohol surfactants (Oxo-C(10)E(3), Oxo-C(15)E(7)) were employed to treat three kinds of cutting oil wastewater, in order to define the conditions promoting cutting oils emulsions destabilization and cloud point extraction possesses simultaneously. Before extraction test, the phase diagrams of binary water/surfactants systems were drawn and the effect of some cutting oil additives on water-surfactant systems was, therefore studied. The results of oily wastewater extraction with respect to wt.% surfactant and temperature were expressed in terms of chemical oxygen demand (COD) of the dilute phase before and after extraction, residual chemical oxygen demand (COD(R)), residual concentrations of surfactant in the dilute phase (X(t,w)) converted to chemical oxygen demand (COD(T)) and the volume fraction of coacervate (phi(c)) at the equilibrium. The results obtained for each parameter which were also represented on three dimensional diagrams using an empirical smoothing method were in agreement with the experimental ones, where the COD(R) was reduced from 55 to 1.1 g O(2)l(-1).

Determination of fatty alcohol ethoxylates by derivatization with phthalic anhydride followed by liquid chromatography with UV–vis detection

The esterification of fatty alcohol ethoxylates (FAEs) with phthalic anhydride in 1,4-dioxane was studied. At 110 °C and in the presence of urea, which increased the reaction rate, esterification was completed in 60 min. The reaction yield did not decrease when the sample contained up to 50% water. For the non-ethoxylated alcohols, the UV–vis response factors of the derivatives were not significantly different from each other ( f = 1 for C12E0 as reference). The response factors decreased when the number of ethylene oxide units, m, increased, reaching constant values of ca. 0.40 and 0.65 for the n = 8 and 18 series, respectively, when m ≥ 3. Using a C8 column and gradient elution with acetonitrile/water plus 0.1% acetic acid, FAEs in industrial mixtures and cleaning products were characterized. At column temperatures of 25 and 35 °C, homologous series with even values of n from 8 up to 20, were resolved up to m = 14 and 18, respectively, and at 25 °C, series with consecutive even and odd values of n were resolved up to m = 7. Within the series, superior resolution of the ethoxymers with large values of m was achieved; however, the elution order was reversed for the m = 1 and 0 ethoxymers, which produced overlapping of a few peaks within the series. A simple procedure for the accurate prediction of the concentrations of all the ethoxymers in industrial samples was described. After preconcentration with C18 solid-phase extraction cartridges, FAEs were also characterized and quantified in environmental samples (river and sea water). The LODs were ca. 2 μM ( S/ N = 3) in the injected solutions.

Rapid characterization of fatty alcohol ethoxylates by non‐aqueous capillary electrophoresis

Fatty alcohol ethoxylates (FAE) (a mixture of nonionic surfactants) have been characterized using NACE with UV detection. Phenyl polyurethane derivatives of these compounds were previously obtained by reaction with phenyl isocyanate. The derivatization reaction only requires microwave irradiation for 30 s (600 W). Phenyl polyurethanes were separated and characterized using a BGE containing a mixture of ammonium nitrate (15 mM), acetic acid (1.5%) and 9:1 v/v methanol/ACN. After optimization of the instrumental conditions for the separation, phenyl polyurethane compounds (formed from the corresponding FAE) with ethylene oxide numbers (EON) of 6 (certified standard and industrial samples), 7 and 10 (both as industrial samples), and 5.5 (microemulsion phase) were successfully separated and characterized. The properties of these FAE nonionic surfactants are very important in the petroleum industry, which requires characterization of the quality of the purchased materials as well as the final products in the microemulsion-oil-water stream process. This analytical objective has been achieved by the proposed NACE methods, allowing FAE to be distinguished from 5.5 to 10 EON with errors below 4%, and shows advantages against to HPLC methods.

Foaming Power and Foam Stability of Several Alkyl Polyglycosides

Abstract The foaming power and foam stability of three commercial alkyl polyglycosides (APG), Glucopon 215, 600 and 650, have been studied using a modified Ross Miles method. The effects of APG concentration (0.1–4.0 g/L) and temperature (30–60°C) on foam level have been analysed, determining the volume of air in the foam and the foaming power at different times (0–300 s). Furthermore, the foaminess was determined over time until 300 s, registering values from 0.95 or 0.96 to 0.98 or 0.99. Finally, different binary mixtures of surfactants have been assayed at 40°C. To prepare these mixtures Glucopon 650 was mixed with one of the following surfactants: two commercial fatty alcohol ethoxylates, Findet 1214N/23 and Findet 10/18, and a control foaming surfactant, Triton CF:32.

Investigation into the effect of detergents on disinfectant susceptibility of attachedEscherichia coliandListeria monocytogenes

Investigate the effect of detergent treatment on susceptibility of attached Escherichia coli and Listeria monocytogenes to subsequent disinfectant treatment. Plate counts show that E. coli attached to stainless steel surfaces became significantly more susceptible to benzalkonium chloride (BAC) after treatment with sodium alkyl sulfate (SAS) and fatty alcohol ethoxylate (FAE). No change in susceptibility was observed with Sodium dodecyl sulfate (SDS). L. monocytogenes became significantly less susceptible to BAC after treatment with SAS and SDS yet no change in susceptibility was observed with FAE. Flow cytometry using the fluoresceine propidium iodide revealed significant increases in cell membrane permeability of both organisms by SAS and FAE, although the effect was much greater in E. coli. No change was observed with SDS. Hydrophobic interaction chromatography showed that both organisms became less hydrophobic following treatment with SAS and SDS but FAE had no effect. In E. coli, detergents that increase susceptibility to BAC increase membrane permeability. In L. monocytogenes, detergents that reduce susceptibility to BAC lower cell surface hydrophobicity. Detergents can influence the sensitivity of pathogenic food borne micro-organisms to BAC.

Determination of fatty alcohol ethoxylates by derivatisation with maleic anhydride followed by liquid chromatography with UV–vis detection

The esterification of fatty alcohol ethoxylates (FAEs) by melting with maleic anhydride has been studied in the presence of urea. The reaction rate and yield of non-ethoxylated and ethoxylated alcohols increase largely when grinded urea is suspended in the reaction medium, a 100% yield being achieved at 80 °C in 15 min. The procedure is tolerant to the presence of large amounts of water. The UV–vis response factors of the derivatives of individual FAE oligomers vary little with the number of carbon atoms in the alkyl chain, n, and the number of ethylene oxide units, m. Derivatised samples of industrial FAE mixtures, cleaning products and river and sea waters were chromatographed on a C8 column of the fused-core type using gradient elution with acetonitrile/water mixtures plus 0.1% acetic acid. The hydrocarbon series with even values of n from 8 up to 20, were well resolved using column temperatures in the 15–30 °C range. Superior resolution between the consecutive oligomers within the series was also obtained at large values of m; however, reversion of the elution order for the derivatives with m = 1 and 0 hindered direct quantitation of a few oligomers at low m values. Full resolution of all the oligomers was achieved by deconvolution with a genetic algorithm assisted by the unconstrained local method of Powell. After preconcentration with C18 solid-phase extraction cartridges, both river and sea water samples also showed the signature of the FAE oligomers. The evaluation of total FAEs in these samples was demonstrated.

Separation of Neutral Red and Methylene Blue from Wastewater using Two Aqueous Phase Extraction Methods

The aim of this work was the two‐aqueous phase extraction of neutral red and methylene blue from wastewater. This has been achieved on the basis of phase separation properties of non‐ionic surfactants above the so‐called cloud point curve and the solubilization phenomena of coacervate micelles (surfactant rich phase). Three commercial surfactants were used in this work; the Oxo‐C15E7 which is an ethoxylate fatty alcohol (Dehydol LT 7), Triton X‐114 (iso‐C8H17‐C6H4‐(OCH2CH2)7,5OH), and Triton X‐100 (iso‐C8H17‐C6H4‐(OCH2CH2)9,5OH) which are alkyl phenol ethoxylate surfactants. The phase diagrams of binary water/surfactants systems were drawn and the effect of sodium sulphate on water‐surfactant systems was therefore studied. Oxo‐C15E7 and Triton X‐114 were used for the cloud point extraction of neutral red and methylene blue from their aqueous solutions at 100 mg/L and 7 mg/L, respectively. The experimental extraction results were expressed by the following three responses: percentage of the extracted dye (E), residual concentrations of dye in the dilute phase (Xs,w), and the volume fraction of coacervate (φC) at the equilibrium. The results obtained for each parameter were also represented on three‐dimensional diagrams using an empirical smoothing method. The empirical modelling data were in agreement with the experimental ones. The main advantage was sought between E, which has reached 99% in the case of neutral red, whereas in the case of mehtylene blue 92% was obtained with respect to (φC), which should have a minimum value. At the optimal conditions, neutral red and methylene blue concentrations in the effluent were reduced to about 500 times and 7 times, respectively.