Ethylene Oxide Number Research Articles

Degradation of alkylphenol ethoxylates by Pseudomonas sp. strain TR01.

An alkylphenol ethoxylate-degrading bacterium was isolated from activated sludge of a municipal sewage treatment plant by enrichment culture. This organism was found to belong to the genus Pseudomonas; since no corresponding species was identified, we designated it as Pseudomonas sp. strain TR01. This strain had an optimal temperature and pH of 30 degrees C and 7, respectively, for both growth and the degradation of Triton N-101 (a nonylphenol ethoxylate in which the average number of ethylene oxide [EO] units is 9.5). The strain was unable to mineralize Triton N-101 but was able to degrade its EO chain exclusively. The resulting dominant intermediate was identified by normal-phase high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry as a nonylphenol ethoxylate with 2 mol of EO units. A carboxylated metabolite, [(nonylphenoxy)ethoxy]acetic acid, was detected by gas chromatography-mass spectrometry. This bacterium also metabolized alcohol ethoxylates with various numbers of EO units but not polyethylene glycols whatever their degree of polymerization. By oxygen consumption assay, the alkyl group or arene corresponding to the hydrophobic part of alcohol ethoxylates or alkylphenol ethoxylates was shown to contribute to the induction of the metabolic system of the EO chain of Triton N-101, instead of the EO chain itself, which corresponds to its hydrophilic part. Thus, the isolated pseudomonad bacterium has unique substrate assimilability: it metabolizes the EO chain only when the chain linked to bulky hydrophobic groups.

Optimization of HPLC Conditions to Analyze Widely Distributed Ethoxylated Alkylphenol Surfactants

Abstract Commercial ethoxylated alkylphenol surfactants are always a mixture of oligomers with different ethylene oxide number (EON). The different oligomers can be separated by various HPLC techniques. Isocratic mode with mixed solvent on silica column allows to separate oligomers up to EON = 10; gradient programming moves the limit up to EON = 15. For higher EON values (up to 25) a NH2 column has to be used, either with isocratic or gradient mode. Applications to the analysis of microemulsion systems and to the separation of tributyl phenol ethoxylates are discussed. Extreme separation of wide range EON distribution is attained with two columns (Si and NH2) in series, and a solvent programming.

Analytical study of polyoxyethylene surfactants of high degree of condensation by normal-phase liquid chromatography on p-nitrophenyl-bonded silica

Polyoxyethylene-based non-ionic surfactants resulting from the condensation of ethylene oxide with fatty alcohol cuts have been widely studied by high-performance liquid chromatography. Even though satisfactory analyses are obtained in normal-phase partition liquid chromatography ( e.g., using a diol stationary phase) and in reversed-phase partition liquid chromatography ( e.g., using C 8 bonded silica) for polyoxyethylenic (POE) surfactants with an average ethylene oxide (EO) number lower than 20 ( n <20 EO), the analysis of the total distribution of the whole EO oligomers is impossible with more condensed POE surfactants ( n > 20 EO on C 16 and C 18 alcohols). In order to establish the total distribution of such surfactants, the potential offered by stationary phases with electron-acceptor characteristics used in normal-phase liquid chromatography was studied. The stationary phase selected was a p-nitrophenyl-bonded silica with an n-propyl spacer. Different mobile phases were tested. The results obtained indicated the possibility of determining the total distribution of polyoxyethylenic oligomers from 1 to more than 80 EO units with baseline resolution using this stationary phase and n-heptane—dichloromethane—methanol as the mobile phase, with either UV detection after derivatization of compounds that do not possess chromophoric groups or light-scattering detection, the latter technique having the great advantage of not requiring any derivatization.

Effect of secondary alcohol ethoxylates on behavior of triolein‐water‐surfactant systems

AbstractStudy of the equilibrium phase behavior of systems containing water, triolein and secondary alcohol ethoxylates showed that a D or microemulsion phase, which solubilized significant amounts of triolein, formed at temperatures as low as 25°C when the surfactant was a suitable mixture of TERGITOL 15‐S‐3 and 15‐S‐5 (Union Carbide, Charleston, WV) with average ethylene oxide numbers of 3 and 5, respectively. In previous work with pure C12 linear ethoxylates and triolein, the D phase had formed only at temperatures above about 55°C. Based on the earlier studies, formation of the D phase would be expected to improve soil removal from synthetic fabrics by a solubilization‐emulsification mechanism. When sufficient oleyl alcohol was mixed with triolein, the D phase was observed at 25°C with Tergitol 15‐S‐5 alone. Observation of dynamic behavior in this system for triolein‐oleyl alcohol drops injected into surfactant‐water mixtures revealed that intermediate phases frequently formed near the drop surfaces and that considerable spontaneous emulsification of triolein occurred for appropriate drop compositions. Experiments with drops initially attached to individual polyester fibers confirmed that little oil remained on the fibers when emulsification was extensive. This mechanism involving spontaneous emulsification provides a means for soil removal different from that found previously in other systems, where the soil was solubilized into an intermediate phase, and this phase was emulsified by externally imposed agitation.

Experimental Conditions for HPLC Analysis of Ethoxylated Alkyl Phenol Surfactants in Microemulsion Systems. Part II. Gradient Mode for Extended EON Range as Found in the Analysis of Oligomer Fractionation

Abstract The different oligomers of ethoxylated nonylphenols present in commercial surfactants can be separated by HPLC. While low ethylene oxide number (EON) species may be separated by isocratic HPLC on silica, intermediate EONs require gradient elution HPLC. The separation of higher oligomers can be carried out with an intermediate polarity column of the NH2 type and a solvent gradient. The suggested experimental conditions allow a satisfactory single run separation of a complex mixture with EONs ranging from 1 to 25 by using a linear gradient from 100% less polar solvent (n-heptane—chloroform—methanol 90/5/5) to its mixture with up to 20% of a more polar solvent made of chloroform—methanol (50/50). This method is used to analyze the EON distribution resulting from the mixing of different commercial surfactants. When two surfactants with very different EON distributions are mixed to produce a formulation scan, the occurrence of three-phase behavior at the optimum formulation of the surfactant—oil—water...

Quantitative analysis of polyethoxylated octylphenol by capillary supercritical fluid chromatography

The rapid separation and quantitative determination of oligomers of polyethoxylated octylphenol surfactants was achieved using capillary supercritical fluid CO 2 chromatography. The oligomer distribution of all surfactants studied was graphically depicted, and the average ethylene oxide number of each individual surfactant was calculated. Temperature programming was investigated in combination with linear pressure programming to enhance long-chain surfactant analysis. The effect of the variable chromatographic parameters, including temperature, pressure programming ramp rate, and solvents used to prepare surfactant solutions, on the separation of polyethoxylated octylphenols are discussed. The capillary supercritical fluid chromatographic analysis results were validated by comparing them to the values obtained from C1 reversed-phase HPLC analyses.

C OF ULTRALOW INTERFACIAL TENSION SYSTEMS FORMULATED WITH CARBOXYMETHYL ETHOXYLATES UNDER EXTREMELY HIGH CALCIUM ION CONCENTRATION

ABSTRACT Physicochemical measurements have been applied to study the micellar properties of some commercial surfactant systems exhibiting ultralow interfacial tension under extremely high calcium ion concentration (0.5-1.5 M). These surfactant systems were prepared from Hills B433 surfactant sample containing carboxy-methyl ethoxylated anionic and ethoxylated nonionic surfactant with an average ethylene oxide number of 4.5. Micellar dissociation concentration (mdc) values were determined by turbidity and surface tension methods at different CaCl2- concentrations. The mdc value decreases with the increase of Cacl2- concentration. UV absorption measurements were also performed in these surfactant systems by varying the surfactant and CaCl2- concentrations. The absorption peak around 277 nm has an absorbance proportional to the surfactant concentration. This peak may be useful for quantitative determination of the surfactant. Other peaks in the spectrum seem to be related with surfactant association and coul...

Use and mode of action of adjuvants for herbicides: A review of some current work

AbstractThe use of surfactants, mineral and vegetable oils, emulsifiers and fertiliser salts, such as ammonium sulfate, can greatly enhance the activity of foliage‐applied herbicides. Adjuvant‐herbicide interactions are reviewed with particular reference to the benefits, including dose reduction, enhanced and more consistent herbicide activity, and the nature of underlying mechanisms; the use and role of surfactants receive particular attention. Surfactants are used as activators in commercial formulations of many herbicides to improve their foliar absorption and ultimate biological activity. Current views on their influence are considered in relation to surface phenomena, solubilisation of non‐polar active ingredients, wax dissolution, cuticle penetration, preferential sites of penetration, membrane permeability and possible systemicity. The importance of a number of moderating factors (plant, chemical and environmental) is discussed in the light of current work, with particular regard to herbicide polarity, surfactant type, Hydrophile‐Lipophile Balance and critical micelle concentration. Current studies on the influence of nonionic polyoxyethylene surfactants of differing ethylene oxide (EO) content have underlined the importance of EO number to their activity.

Optimal Surfactant Structures for Cosurfactant-Free Microemulston Systems I. C16and C14Guerbet Alcohol Hydrophobes

ABSTRACT In most surfactant formulations involving microemulsions, a cosurfactant is generally required in combination with a primary surfactant for several purposes; however, it has previously been shown not to be an absolute requirement and moreover surfactant hydrophobe structure has a profound effect on such requirements. After examining the phase behavior of several industrially feasible surfactants using oil phase composition, temperature, salinity, cosurfactant concentration, ethylene oxide number (EON), and propylene oxide number (PON) as variables, ethoxylated or propoxylated C14 Guerbet alcohol sulfates are often found to form cosurfactant-free microemulsion systems with acceptable solubilization parameters (σ∗) over a wide variety of system conditions. The C16 Guerbet alcohol sulfates are much more restricted in application, thus often requiring cosurfactant.

Mixed adsorption of sodium dodecyl sulfate and ethoxylated nonylphenols on carbon black and the stability of carbon black dispersions in mixed solutions of sodium dodecyl sulfate and ethoxylated nonylphenols

Adsorption of sodium dodecyl sulfate (SDS) and ethoxylated nonylphenols (NP-12, NP-40 and NP-100) from their mixed solutions on carbon black and the stability of carbon black dispersions in SDS—NP mixed solutions have been investigated. The adsorption isotherms of either SDS or NP alone on the surface of carbon black are shown to be of the Langmuir type, and the amount of NP adsorbed decreased with increasing number of ethylene oxide (EO) units in the NP molecules. In the mixed solutions of SDS and NP, the adsorption of both SDS and NP on carbon black decreased in the presence of the other component, and the amount of one component adsorbed varied in an inverse-linear relationship with that of the other, indicating a displacement mechanism of adsorption for the two surfactants on carbon black. The stability of carbon black dispersions in mixed solutions of SDS and NP was demonstrated to be consistent with the displacement mechanism of the mixed adsorption.

Solubilization of synthetic perfumes by nonionic surfactants

The solubilization of synthetic perfumes (eugenol, linalool, benzyl acetate, α-Ionone, α-hexylcinnamaldehyde, and d-limonene) by hexadecyl polyoxyethylene ethers (C 16POE n , n = 10, 20, 30, and 40) has been studied in terms of cloud point, maximum additive concentration, solubilizing capacities, distribution coefficient, and micellar size. The greater the hydrophilic properties of synthetic perfumes, the more the cloud points of C 16POE 10 solution are decreased. The maximum additive concentration and solubilizing power are increased with decreasing polyoxyethylene chain length, except for eugenol and linalool. The distribution coefficients of eugenol, linalool, and benzyl acetate between micelle and bulk phase are increased as the number of ethylene oxides in C 16POE n decreases. The diameters of micelles containing solubilized synthetic perfumes are increased with increasing concentration of synthetic perfumes dissolved. Furthermore, for C 16POE 10 solution, the diameters of micelles solubilizing eugenol and linalool are increased substantially in the vicinity of each maximum additive concentration.

Vesicle to Micelle Transitions of Egg Phosphatidylcholine Liposomes Induced by Nonionic Surfactants, Poly(oxyethylene) Cetyl Ethers1

Vesicle to micelle transitions of sonicated liposomes of egg yolk phosphatidylcholine (EPC) induced by a homologous series of nonionic surfactants, poly(oxyethylene) cetyl ethers [POE(n) cetyl ether], were investigated by using the method of turbidity titrations. The turbidities of the mixed dispersions of sonicated vesicles and surfactant were systematically measured as a function of the surfactant added for a wide range of lipid concentrations (from 0.51 to 6.35 mM EPC). From the titration curves, two threshold points representing onset and complete solubilization of liposomal membranes were determined as a probe for the effect of the length of ethylene oxide (EO) moiety on the phase behavior of ternary system of POE(n) cetyl ethers-EPC-excess water. Patterns of turbidity curves and the surfactant concentrations at two threshold points as well as widths of region between two transitions, where lamellar sheets and mixed micelles may coexist, mainly depended on the length of EO head group. With changing the lengths, solubilization of liposomes and phase diagram showed optimal behavior. That is, in the middle range of EO numbers, it resulted in narrowest coexistence region between onset and complete solubilization. Assuming the equilibrium partitioning model, critical effective molar ratios of surfactant to lipid, Rsat, free surfactant concentrations, Dw, and the partition coefficient of surfactant between bilayer and aqueous phase, K, in surfactant-saturated liposomes were quantitatively determined as a function of EO number. Effective ratios, Rsol, and free surfactant concentration in mixed micelles were also determined. In addition, the effects of CMC and HLB of surfactants on the solubilization of liposome were discussed.

Polymeric surfactants for enhanced oil recovery. Part V: Prediction models for the effect of temperature and length of polyoxyethylene chain or hlb on surface and thermodynamic properties of some ethoxylated polymeric nonionics

AbstractSeveral equation models were investigated to find the relationship between temperature (T). number of ethylene oxide (EO) units (n) or the hydrophile‐lipophile balance (HLB) and the surface and thermodynamic properties of some ethoxylated alkylphenol‐formaldehyde polymeric nonionic surfactants. These properties include critical micelle concentration (CMC), free energy of micellization (ΔGmic), surface tension at CMC (7CMC), effectiveness (γCMC) and efficiency (pC20) of surfactant to reduce the surface tension of water. The values of the ratio CMC/C2(π = 20) were also considered.The linear multiple regression technique was employed to determine the parameters of the equations and to choose the best forms with the highest values of R2 and F‐ratio which reflect the goodness and the reliability of the fit.

Viscosities of anionic—nonionic mixed surfactant systems

The viscous property of anionic-nonionic mixed surfactant systems in aqueous solutions is described. The systems studied are sodium dodecyl sulfate (SDS)-alkyl poly(oxyethylene) ethers (C m POE n ; m = 12, 14, 16, and 18, n = 10, 20, 30, and 40). In the single system, the relative viscosity of the nonionic surfactant is larger than that of SDS and increases with increasing number of ethylene oxide. In mixed systems the relative viscosity shows maximum at the mixed molar ratio of SDS around 0.3, except for the SDS-C 16POE 40 system. The mixed systems having longer alkyl and/or polyoxyethylene chain lengths in the nonionic surfactant have a larger relative viscosity at any mixed ratio. The system in which the mixed micelle forms easily has a positive deviation from the ideal value. The relative viscosities of the surfactants in 0.1 M NaCl solution decrease linearly with an increase in the mixed molar ratio of SDS. It is considered that the relative viscosities in the mixed solutions show a maximum due to the electroviscous effect of a mixed solution being larger than that of a single solution.

Refractive index of nonionic surfactant solutions containing polyoxyethylene mono-n-alkylether

The refractive index of nonionic surfactant solutions containing polyoxyethylene mono-n-decylether and dodecylether was measured at 25.0°C with an Abbé refractometer as a function of surfactant concentration up to 1% (wt). This series of surfactants has an ethylene oxide number ranging from 1 to 8. The refractive-index increment is constant under our experimental conditions and shows a linear dependence on the ethylene oxide number.

The micelle size distribution of nonionic surfactants determined by ultrafiltration

The micelle size distribution of two poly (oxyethylene) nonylphenol nonionic surfactants with mean ethylene oxide numbers of 9 and 30 has been investigated using a new development of the ultrafiltration technique. Fractionation of the micellar solution by various membranes reveals details of the distribution of micelle sizes present at any given concentration. Results are compared with light scattering measurements from which concentration dependent mean aggregation numbers are derived. The results are discussed in terms of several current models of micelle formation.

Thin-layer chromatographic separation of some tributylphenyl ethylene oxide oligomers according to the length of the ethylene oxide chain

The separation of non-ionic surfactants such as tributylphenyl ethylene oxide oligomers according to the length of the ethylene oxide chain was carried out on precoated alumina thin-layer plates using various carbon tetrachloride-acetonitrile mixtures as the eluent. The optimum separation of surfactant oligomer pairs with longer ethylene oxide chains requires a higher eluent strength (higher acetonitrile concentration). The results suggest that at a maximum of thirteen fractions can be separated on a plate with a given eluent composition. Because of the possible folding of longer ethylene oxide chains in the eluent, oligomers with higher ethylene oxide numbers could not be separated under the conditions applied.

Microanalysis of Alkyl Poly (oxyethylene) Ethers by HPLC

Analysis of alkyl poly (oxyethylene) ethers was carried out by HPLC. Nonionic surfactants were well separated regardless of the distribution of the adducted number of ethylene oxides to give chromatographic peaks according to alkyl chain length under certain rigidly controlled eluent conditions. Moreover, the analytical sensitivity of nonionic surfactants with solvent extraction became 20 times without solvent extraction. This method should thus prove particularly suited for the analysis of nonionic surfactants in aqueous solution because in view of its simplicity and rapidity of performances.

Effect of Some Nonionic Tenzides on Potassium Influx in Roots of Wheat Seedlings

Summary Polyethoxylated nonionic tenzides containing nonyl-phenyl and tributyl-phenyl groups as hydrophobic parts decreased considerably the net potassium influx in roots of wheat seedlings. Their effect depended quadratically on the number of ethyleneoxide groups per molecule and on the molecular lipophilicity determined by reversed-phase thinlayer chromatography. The optimum range of biological effectivity was 6–13 ethyleneoxide groups per molecule. Besides lipophilicity and ethyleneoxide number steric parameter (width of hydrophobic part) also influenced significantly potassium influx. These variables explained about 78 % of total variance. Polyethoxylated sorbitane derivatives had no effect on the potassium influx.

HPLC determination of non-ionic surfactants used in tertiary oil recovery

Having developed a chromatographic technique with a diol bonded phase for the study of the distribution versus ethylene oxide number (E.O.) for various non-ionic polyoxyethylated surfactants used in enhanced oil recovery (KL 6,\(\bar n = 6 E.O\); KM 11,\(\bar n = 11 E.O.\) and KM 20,\(\bar n = 20 E.O.\)) we report here the titration of one of these surfactants (KL 6) in the presence of an ionic surfactant (S 385, sulfonated petroleum fraction) and other non-ionic surfactants (KM 11 and/or KM 20) which are the conditions found in enhanced oil recovery. This work has been carried out in brine and in n-decane, as a model for the petroleum phase.