Analysis of ethylene oxide and propylene oxide adducts of alkylphenols or alcohols by nuclear magnetic resonance, gas-liquid chromatography, and thin-layer chromatography procedures

Ludwig, F. John.

doi:10.1021/ac60267a018

Cited by 24 publications

(6 citation statements)

References 18 publications

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“…BRIJ 96, a polyoxyethylene oleylether with a specified average number of 10 EO units per molecule was a gift form Atlas Chemie (Essen, FRG). The products were investigated with HPLC [6] and 1H NMR [7] to check the average EO-length and the EO-length distribution. Averages are shown in Table l and distributions are shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

Mesophases in mixtures of water and polyoxyethylene surfactant: Variations of repeat spacing with temperature and composition

Jousma

Joosten

Junginger

1988

Colloid & Polymer Sci

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Abstract." Lamellar (L~) and hexagonal (Hi) mesophases, formed in mixtures of water and polyethylene oxide (PEO) oleylethers (average EO-numbers 5 (a), 8.5 (b) and 14 (c)) and pure hexaoxyethylene dodecylether (d), were investigated with small-an~e X-ray diffraction. Analysis of repeat spacings shows a deviation from linear one-and two-dimensional swelling of L~ and P/l, respectively, when a transition to a mesophase with a larger curvature of the interface is approached. With regard to L~, in this respect similar behaviour is observed for a pure surfactant (d) and a surfactant with an EO-length distribution (b). It is proposed that, through the formation of aggregates of limited extent, water filled pores in the mesophases arise. This is confirmed by analysis of the intensity ratio of diffraction maxima of first and second order in L~. Models for finite aggregates are introduced. These consist of (1) lamellae, infinite in one direction and with variable length L in a direction perpendicular to the first, with cylindrical edges and (2) cylinders with variable length L bounded by spherical caps. According to these models, under certain conditions, finite aggregates may be formed without an increase of the interfadal area per surfactant molecule. Applying the models to the regions where non-linear swelling is observed, reasonable values for L are found, which decrease progressively when the phase transition is approached.

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Section: Methodsmentioning

confidence: 99%

Mesophases in mixtures of water and polyoxyethylene surfactant: Variations of repeat spacing with temperature and composition

Jousma

Joosten

Junginger

1988

Colloid & Polymer Sci

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“…Earlier NMR studies of the PEO-PPO-PEO block copolymers have mainly focused on the assignments of 1 H and 13 C chemical shifts. [20][21][22] The temperature dependence of the chemical shifts and the line shape of the 13 C resonance of the methyl groups in the PPO block were used to probe the hydrophobic region of the copolymer during the micellization processes. Slight variations in the line position and broadening of the line width of the methyl resonance were attributed to a dehydration process which induces a conformational change involving alternations in the orientations and steric crowding of the methyl groups.…”

Section: Introductionmentioning

confidence: 99%

H NMR Relaxation Studies of the Micellization of a Poly(ethylene oxide)−Poly(propylene oxide)−Poly(ethylene oxide) Triblock Copolymer in Aqueous Solution

1996

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1H nuclear magnetic resonance (NMR) relaxation studies of the temperature-induced micellization of a poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide), PEO−PPO−PEO, block copolymer in aqueous solution were performed in the range 280−345 K. 1H NMR spectra of the block copolymer were well resolved, thus allowing us to probe specifically the methyl and methylene relaxation processes in the PPO and PEO blocks, respectively. Interpretation of the relaxation data in terms of the Hall−Helfand correlation function leads to four distinct correlation times for the PPO and PEO blocks. The slower correlation time in the PPO block was identified as the Zimm−Rouse first normal mode of the copolymer and served to determine the hydrodynamic radius, R H, of the unimers and the micelles. On a more local scale, the behavior of the correlation time for segmental motions in the PPO block indicates an extension of the PPO chains in micelles relative to the unimers. This conformational change is related to the formation of a water insoluble liquid-like core created by the PPO chains in the micelle where the trans isomers are favored. The rotational isomeric states model used to interpret the faster correlation time in the PEO chains yields an activation energy of 14.6 kJ/mol for the correlated transitions in the PEO blocks, in agreement with previous theoretical calculations. The slower correlation time in the PEO blocks shows a marked increase upon micellization attributed in part to the polymer−polymer interactions between the different PEO blocks constituting the hydrophilic moiety of the micelles. A power law relating this relaxation time to the micelle hydrodynamic radius is predicted and observed experimentally. The concentration dependence of the critical micellization temperature, inferred from the methyl spin−lattice relaxation time in the PPO block, was found to be adequately described by a closed association model. The standard free energy, enthalpy, and entropy of micellization obtained by NMR are in close agreement with the recent experimental thermodynamic studies of P. Alexandridis et al. (Macromolecules 1994, 27, 2414).

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“…Other mixtures of ¿-octane and CC14 could also be used as mobile phases to achieve the desired separation for a given sample. Thus by optimizing column LC, more compounds ( 19) can be separated in less time (13,14,(16)(17)(18).…”

Section: Resultsmentioning

confidence: 99%

“…Planar chromatographic methods (thin layer and paper) have become widely used (9-14) although they suffer from the inherent difficulties in quanbtation. Gas chromatographic methods can be used with the short chain lengths (13,15) but the formation of volatile derivatives is usually required. Most of the separations by liquid-solid (14,16) and gel permeation (13,17,18) chromatography have been slow.…”

mentioning

confidence: 99%

“…Gas chromatographic methods can be used with the short chain lengths (13,15) but the formation of volatile derivatives is usually required. Most of the separations by liquid-solid (14,16) and gel permeation (13,17,18) chromatography have been slow. Only the recent work of Bombaugh et al (19) realizes the fast speed of modern high pressure liquid chromatography (LC).…”

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confidence: 99%

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Rapid separation and determination of nonionic surfactants of the polyethylene glycol-monoalkyl phenyl ether-type by column liquid chromatography

Huber¹,

Kolder²,

Miller³

1972

Anal. Chem.

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The purpose of this work was to develop a fast method of analysis for nonionic surfactants which could be used in routine analysis and water pollution studies. This has been achieved for a series of nonylphenolethylene oxide adducts by column liquid-liquid chromatography using a 23-cm column and ultraviolet detection. Adducts varying in chain length from 1 to 20 ethylene oxide units have been separated and a series of commercial products has been characterized. Typical separations take 5 to 30 minutes depending on the resolution desired and the number of components in the sample. The relative precision is 0.4% and the limit of detection is estimated to be about 0.2 Mg. Nonionic surfactants are the second largest group of surfactants produced in the United States (1). They are used as laundry detergents as well as emulsifying agents in products like cosmetics and paints. The main types are polyoxyethylene and polyoxypropylene adducts such as the alkyl phenol ethyoxylates: R-((Z))-O-(CH -CH,-O), HIn the manufacture of these products the alkyl phenol is reacted with an excess of ethylene oxide (EO) and a mixture of oligomers of varying chain length (*) is produced. The distribution of chain lengths should be Poisson (2) and there is some evidence to support this prediction (2-6). Commercial products are mixtures of oligomers which are conveniently denoted by the number of moles of ethylene oxide reacted with one mole of phenol, e.g., 5 EO.A fast and simple method of analysis does not exist for nonionic surfactants at the present time (1). Fast, sensitive methods would be useful in biodegradation studies and water pollution analysis as well as routine quality control. Analysis methods have been reviewed in the book edited by Shick (7), and several papers are included in the proceedings of a 1964 International Congress (8) also published in 1967.

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Analysis of ethylene oxide and propylene oxide adducts of alkylphenols or alcohols by nuclear magnetic resonance, gas-liquid chromatography, and thin-layer chromatography procedures

Cited by 24 publications

References 18 publications

Mesophases in mixtures of water and polyoxyethylene surfactant: Variations of repeat spacing with temperature and composition

Mesophases in mixtures of water and polyoxyethylene surfactant: Variations of repeat spacing with temperature and composition

H NMR Relaxation Studies of the Micellization of a Poly(ethylene oxide)−Poly(propylene oxide)−Poly(ethylene oxide) Triblock Copolymer in Aqueous Solution

Rapid separation and determination of nonionic surfactants of the polyethylene glycol-monoalkyl phenyl ether-type by column liquid chromatography

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