Polyoxyethylene Chain Length Research Articles

エマルション燃料に関する基礎研究 Ｉ Ｗ／Ｏ型エマルションの含水量および粒子径に及ぼす非イオン界面活性剤の影響

The effects of the structure of nonionic surfactant on particle size and water content in W/O type emulsions have been investigated. The changes to water content and particle size are langer for polyoxyethylene (POE) chain than for alkyl chain in surfactant molecule. The water content increases with increasing POE chain length, but does not change with alkyl chain length. The particle size of W/O type emulsion and the interfacial tension between water and oil containing nonionic surfactant decrease with increasing hydrophilic group of surfactants.This may be due to that molecules of nonionic surfactant per unit emulsion decrease and the numbers of emulsion increase.

Hemolytic activity of polyoxyethylene cholesteryl ethers

Hemolytic activity of nonionic surfactants, polyoxyethylene cholesteryl ethers, C27H45O(CH2CH2O) n H (Chol-E n ,n=, 25, 30, 50) and polyoxyethylene dihydrocholeseryl ethers, C27H47O(CH2CH2O) n H (DHChol-E n ,n=15, 30 50) were measured, changing the concentration of surfactant and erythrocyte at 37 °C. Maximum hemolytic activity was observed in these cholesteryl derivatives with 25–30 oxyethylene units. The time course of hemolysis was also measured as a function of the concentrations of surfactant and erythrocyte. Hemolysis started after a certain induction period,τ, and then apparently proceeded as a first-order reaction with respect to the erythrocyte concentration. The surfactant inducing 50% hemolysis at low concentration had a smallτ value and large rate constant. The maximum amount of adsorption without inducing hemolysis,a0, decreased with increasing polyoxyethylene chain length. Chol-E25 has the maximum activity for the solubilization of egg yolk lecithin at 37 °C. Based on these results, the mechanism of hemolysis by these surfactants was quantitatively discussed.

Changes in physico‐chemical properties during decomposition of nonionic surfactant solutions

AbstractThe decomposition and accompanying changes in surface chemical properties of nonionic surfactants were investigated. The decomposition of nonionic surfactants occurs in the polyoxyethylene and ester chains. Ester chains were susceptible to decomposition with an increase in the polyoxyethylene chain length, but polyoxyethylene chains were not. Surface chemical properties such as solubilizing power, surface tension, effective specific volume, and intrinsic viscosity also deteriorated during decomposition of the surfactants.

Solution properties of mixed surfactant system: VI. The effect of oxyethylene groups in nonionic surfactant on surface tension of anionic-nonionic surfactant systems

The effect of oxyethylene groups in a nonionic surfactant on the surface tension of anionic-nonionic systems is described; these systems are sodium 3,6,9-trioxaicosanoate (ECL)-alkyl polyoxyethylene ethers (POE n , n = 10, 20, 30, and 40). The surface tension of each mixed surfactant solution decreases with increasing mole fraction of anionic surfactant. However, these surface tension vs mole fraction curves are shifted from specific curves to monotonous curve with increasing polyoxyethylene chain length in nonionic surfactant. Moreover, in the case of the mixed systems including a nonionic surfactant which has shorter polyoxyethylene chain length, the surface tension vs total concentration curve shows only one breakpoint. In the case of systems including the nonionic surfactant which has longer polyoxyethylene chain length, that curve shows two breakpoints in the vicinity of the CMC for ECL alone and that for POE n alone. This may be attributed to the fact that the mixed micelle is formed more easily by a nonionic surfactant including shorter polyoxyethylene chain length than by one having long. Then, in the mixed surfactant systems, there are two kinds of micelles coexisting (one rich in nonionic surfactant and the other rich in nonionic one).

Effect of antituberculous calixarenes on phospholipase A2 susceptibility and on fusion of phospholipid bilayers

Some homologous calixarenes or polyoxyethylene ethers that are known to suppress or enhance experimental tuberculous infection (depending on their polyoxyethylene chain lengths) were examined for their effects on phospholipid bilayers. The effect of these solutes is seen at 0.5-50p.p.m., and their effect depends upon their structure as well as that of the phospholipid substrate. The antituberculous compound HOC-12.5 (Macrocyclon) inhibits susceptibility to pig pancreatic phospholipase A2 action and to aggregation/fusion of the ternary co-dispersions of dimyristoyl phosphatidylcholine + 1-palmitoyl lysophosphatidylcholine + palmitic acid (50:11:11 molar proportions). In contrast, the protuberculous compound HOC-60 stimulates these effects. Differential scanning calorimetry suggests that these effects are probably due to modulation of the phase equilibrium in substrate bilayers by these polyethers.

Effects of polyoxyethylene chain length on micellar structure

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffects of polyoxyethylene chain length on micellar structureYoshihiro Saito and Takatoshi SatoCite this: J. Phys. Chem. 1985, 89, 10, 2110–2112Publication Date (Print):May 1, 1985Publication History Published online1 May 2002Published inissue 1 May 1985https://doi.org/10.1021/j100256a061© American Chemical SocietyRIGHTS & PERMISSIONSArticle Views167Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (297 KB) Get e-Alerts

Interaction between anionic surfactants and oil dyes in the aqueous solutions: V. The effects of the oxyethylene chain length and/or the alkyl chain length in surfactant molecule on the tautomerism of an azo dye

The tautomerism of 4-phenylazo-1-naphthol (4-OH), which occurs between the hydrazo form and the azo form, has been studied in the aqueous solution of nonionic surfactant [alkyl poly(oxyethylene) ethers]. The tautomerism of 4-OH is dependent on the surfactant concentration and molecular properties in the solubilized solution. 4-OH exhibits only a hydrazo form and its maximal absorption appears at the 470-nm band below the CMC, while above the CMC it exhibits both hydrazo and azo forms (tautomerism) and the absorption shows two bands at 470 and 415 nm. Below the limit of solubilization, the equilibrium constant of tautomerism is independent of the increase of the surfactant concentration. It shows, however, remarkable dependence on the alkyl chain length and/or the polyoxyethylene chain length in a nonionic surfactant molecule. The determination of limits of solubilization of two chemical species showed that the hydrazo form of 4-OH is solubilized into the polyoxyethylene part of a nonionic surfactant micelle and the amount does not change with increase of the polyoxyethylene chain length, while the azo form appears to be solubilized in its alkyl part and the amount increases with increase of the alkyl chain length. Therefore, the effect on the tautomerism of 4-OH is larger for the alkyl chain length than for the oxyethylene chain length in a surfactant molecule.

Effect of Poly (vinyl alcohol) on Solubilization Behavior of Dodecyl Poly (oxyethylene) Ethers

The solubilization behavior of a series of dodecyl poly (oxyethylene) ethers (DPOE), C12H25O (CH2CH2O)nH, with oxyethylene units from 5 to 8 toward an oil-soluble dye, Oil Yellow OB, has been studied in relation to the chain length of polyoxyethylene of DPOE, the molecular weight, degree of saponification, and concentration of poly (vinyl alcohol) (PVA), and the temperature in polymer-surfactant mixed solutions. The solubilizing power (Sp) decreases with an increase in the chain length of polyoxyethylene of DPOE and the degree of saponification of PVA, but it increases with an increase in the molecular weight and concentration of partially-saponified PVA, and the temperature. The break points (Cb) in the curves of the amount of solubilized Oil Yellow OB vs. the concentration of DPOE varied in an opposite tendency from Sp. Completely-saponified PVA showed little solubilization effect. The absorption spectra of Oil Yellow OB in the solutions of n-dodecane, polyethylene glycol, and DPOE suggest that the portion of the dye solubilized in the polyoxyethylene region is larger than that in the hydrocarbon region.

Critical micelle concentration, surface, volumetric, and hydrodynamic properties of polyoxyethylenemonohexadecyl ethers

Surface, volumetric, and hydrodynamic properties of polyoxyethylenemonohexadecyl ethers at and below the critical micelle concentration were examined. The critical micelle concentration ( C 0) of the polyoxyethylene surfactants decreased as the hydrophilic chain length increased. The areas per surfactant molecules at the air/water interface increased while the free energy of adsorption decreased as the polyoxyethylene chain length increased. The packing densities of the polyoxyethylene surfactants were constant indicating the random coiling of the hydrophilic groups. The hydration of the surfactants decreased as the ethylene oxide chain length increased varying from 1.34 to 3 water molecules per ethylene oxide unit. The relationship between intrinsic viscosity and molecular configuration below C 0 was examined in terms of the Debye-Bueche, Kirkwood-Riseman, Flory-Fox, and Peterlin hydrodynamic theories. The results show that polyoxyethylene surfactants are randomly coiled in aqueous solution.

Non-ionic surfactants and the membrane transport of barbiturates in goldfish

The effect of a series of polyoxyethylene non-ionic surfactants on the membrane transport of barbiturates in goldfish has been assessed using the overturn time technique. The surfactants, ranging in polyoxyethylene chain length from 2 to 60 and alkyl chain length from 4 to 18, were used at concentrations ranging from 0.001 to 0.1% w/v. Presence of the surfactants in the bathing medium caused a concentration-dependent alteration in the absorption of secobarbitone and thiopentone. The greatest enhancement of absorption for each barbiturate occurred with surfactants with 10 to 20 ethylene oxide moieties, alkyi chain lengths of C 12-C 16 and molecular areas of between 1.00 and 1.60 nm 2. The results are comparable with data obtained with the same surfactants using other epithelial membranes.

Activities of cell fusion and lysis of the hybrid type of chemical fusogens (I) structure and function of the promotor of cell fusion

Summary Monomeric lipids, for example, oleic acid, stearic acid, lauric acid, oleyl alcohol and p-isooctyl phenol, were introduced through ester or ether bonds to oligoethylene glycol with various molecular weights. The activities of hemolysis and fusion of these oligomeric lipids were examined using human erythrocytes in the presence or absence of high molecular weight of water-soluble polymers such as polyethylene glycol (Mw=6,000) or dextran (Mw=70,000). When the chain length of polyoxyethylene of the oligomeric lipids was less than 20, the activities of hemolysis and fusion were both enhanced. On the other hand, when the chain length was more than 20, the two activities were reduced to a different degree for each other.

THE EFFECTIVE HYDROPHILE - LIPOPH1LE BALANCE OP NONIONIC SURFACTANT MIXTURES

Abstract In the phenol index method, forces between water and the hydrophilic groups of the mixed micelles decrease with increasing phenol concentration. This results in a depression of the cloud point with substantial changes in the micellar structure and decrease of the hydrophilic properties of the mixed micelles. The effective HLB of the mixtures of nonionic surfactants is thus also altered and in the case of surfactants differing remarkably in the polyoxyethylene chain length is higher than the calculated ones. Deviation from additivity in HLB values are explained on the basis of hydration change of the polyoxyethylene shell with the change in composition of mixed micelles.

Effect of polyoxyethylene chain length upon mixed surfactant solutions and temperature dependence on the surface tension

The surface tensions of a series of polyethylene glycol- n-dodecyl ethers ( nED) were measured by the Wilhelmy plate method in the presence of constant 6.3 m M sodium dodecyl sulfate (SDS) at temperature of 15, 25, and 40°C, respectively. The surface tension curves for the mixed system of SDS and nonionic surfactants showed a flat portion in the range of which the mixed micelles in the solution and the two-dimensional ones on the water surface occur, respectively. The width of this flat portion decreased with shortening of the polyoxyethylene chain length, and when the unit of ethylene oxide in the chain reached 3ED, the flat portion disappeared. This limiting length in the ethylene oxide chain required for the disappearance of the flat portion, that is, the so-called critical length of the ethylene oxide chain, can be considered to be one of the critical values for the existence of mixed micelles and below the critical value only excess micelles of the nonionic surfactant exist in all ranges of the mixed concentration of the SDS and nonionic surfactants. Furthermore, the effects of temperature on the flat portion were investigated on the assumption that the rise in temperature rendered a similar effect with respect to the length of the flat portion to that of reducing the length of the polyoxyethylene chain.

高速液体クロマトグラフィーによるポリオキシエチレン系非イオン界面活性剤の分析

The mutual separation of non-ionic surfactants containing polyoxyethylene (POE) chain was accomplished by high-performance liquid chromatography (HPLC) by using a UV detector after the esterification with 3, 5-dinitrobenzoyl chloride. The molar absorption coefficients (ε) at 254nm of the benzoylates of these materials having different POE chain length are confirmed to be practically identical (1.1×104) by measurments of ε of the homogeneous polyethylenglycol monododecyl ethers, and following conclusion can be established that these chromatograms should give the molar distribution of POE chain length directly.Further, the statistical treatment of the chromatograms has been studied and then concluded that this HPLC analysis is one of the most convenient method for routin analysis of nonionic surfactants containing POE chain. Two typical molar distribution of POE chain length (We-ibull Nycander and Poisson distribution) were analyzed precisely by this HPLC method.

The Determination of the Effective HLB of Nonionic Surfactants by a Phenol Titration I: Relation to Cloud Point

AbstractThe qualitative similarities in two various methods of the HLB (Hydrophile‐Lipophile Balance) determination based on the cloud point and so called phenol index measurements are demonstrated. The effects of polyoxyethylene chain length, surfactant concentration and the presence of additives on the cloud point and phenol index values have been compared. The results are interpreted as the change of the effective HLB of polyoxyethylene nonionic surfactants.

Cloud Point and Emulsion Inversion Point

AbstractThe effects of some hydrophilic additives on the cloud point and, emulsion inversion point have been studied. Hydrophilic additives cause an increase in the effective HLB of the surfactants as was indicated by raise of the cloud point and decrease of the emulsion inversion point value, depending on the nature of additive, its concentration and polyoxyethylene chain length. In conclusion it may be stated and emphasized that it is necessary to take into account the HLB value correction in order to select an emulsifier blend for a given system.

Surface properties and micelle formation of long-chain polyoxyethylene nonionic surfactants

Air/water interfacial adsorption parameters and CMC values were determined for C 16 polyoxyethylene nonionic surfactants from surface tension data. Temperature (10–40°C) and polyoxyethylene chain length (EO = 17–63) effects were studied. Surface activity increased with temperature but decreased with hydrophilic chain length. The areas per surfactant molecules at the air/water interface increased with temperature and hydrophilic chain length. Thermodynamic parameters for adsorption and micellization were calculated at different temperatures. Adsorption occurred with positive entropic and enthalpic changes. Free energy of the process decreased with temperature but increased with polyoxyethylene chain length. Free energy of micellization was resolved into hydrophobic and hydrophilic components to study the effect of the polyoxyethylene chain length.

Micellar size, shape, and hydration of long-chain polyoxyethylene nonionic surfactants

Light scattering and hydrodynamic measurements determined the weight average micellar weights, aggregation numbers, and extent of hydration of C 16 polyoxyethylene nonionic surfactant micelles in aqueous solution at 25°C. Micellar size decreased with polyoxyethylene chain length, the aggregation number varying from 99 for EO = 17 to 25 for EO = 63; micelles were spherical or nearly spherical. Micellar hydration was estimated from the difference in volumes between hydrated and anhydrous micelles obtained from light scattering and molecular models. Hydration was extensive and varied from 5.2 to 10.5 water molecules per ethylene oxide unit as the hydrophilic chain length increased; most of the water was mechanically trapped in the polyoxyethylene chains.

Studies on Adsorption of Surfactants on Activated Carbons. I.

The relationship between the molecular structure of nonionic surfactants and their adsorptivities on activated carbons was investigated. The adsorption isotherms for all water-soluble nonionic surfactants used in this study were Langmuir type and the adsorptivities were higher than ordinary organic compounds. With the increase in the length of polyoxyethylene chain of polyoxyethylene nonylphenyl ether (NP), activated carbons were saturated by NP in lower concentrations, and both the adsorption rate and the amount of adsorbed NP at saturation decreased. For the surfactants with a fixed length of polyoxyethylene chain, the adsorption was favored by the increase in the length of the alkyl chain. An unsaturated bond in the alkyl chain depressed the adsorption. The carbon activated with zinc chloride had large surface area and pores, and was effective for the adsorption of nonionic surfactants. When an aqueous solution of NP was passed through the column of activated carbon under certain conditions, the adsorption efficiency was 90.6%. These results suggest that the use of activated carbon may be very effective for the treatment of wastewater containing nonionic surfactants.

Structural Effects on the Properties of Nonionic Surfactants. VII.

Di-n-hexyl- or tri-n-butyl-carbinyl ethylene glycol monoethers were prepared from 2-n-hexyl-or 2, 2-di-n-butyl-l, 3-dioxolane and appropriate Grignard reagents. These were converted into nonionic surfactants containing two or three alkyl chains in the hydrophobe, (n-C6H13) 2CHO (C2H4O) mH (DC series), (n-C4H9) 3CO (C2H4O) mH (TC series), by the reaction with ethylene oxide (EO). Some surface active properties of these nonionics were examined in comparison with those of tridecanol-EO addcts (S series) and with other conventional nonionics in order to clarify the effects of the multi-chain type hydrophobe. For the same length of polyoxyethylene chain (m), the cloud point decreased in the order; S>TC>DC. Aqueous surface tension of DC- and TC-series was lower than that of S-series. No significant difference in molecular area on adsorbed film was observed between DC, TC and S having comparable m. A linear relation was found for m dependence of cmc in DC-, TC- and S-series. The cmc values markedly increased with increase of the number of alkyl chains in the hydrophobe, being consistent with “Hartleys' principle”. Some gross effects such as wetting efficiency, suspending and emulsifying powers were enhanced by the introduction of multi-chain structure to the hydrophobe, while the foaming properties reduced.These results were discussed from a viewpoint of the hydration of polyoxyethylene chain and the arrangement of adsorbed surfactant molecules.