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1.
R. A. Greff E. A. Setzkorn W. D. Leslie 《Journal of the American Oil Chemists' Society》1965,42(3):180-185
A method for the determination of nonionics in low concn (0–20 ppm) has been developed. This method is based on the formation
of a blue complex between ammonium cobaltothiocyanate reagent and a polyethoxylated compound. This complex is extracted into
benzene from a saturated salt solution and measured with a spectrophotometer at 320 mμ. The absorbance reading is compared
to a standard.
The method requires only a single extraction and no preliminary concn step is necessary. It is sensitive to polyethoxylated
compounds containing three or more moles of ethylene oxide. We have used this method to detect as little as 0.01 mg of nonionic
in 100 ml of sample (0.1 ppm). Reaction conditions, sensitivity differences between compounds, interferences and suitability
for use in biodegradation studies have been investigated. The accuracy and repeatability of this method is ±3% relative at
20 ppm concn. 相似文献
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4.
Robert Aveyard Bernard P. Binks Paul D. I. Fletcher Xilin Ye 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1992,54(3):231-236
Nonionic surfactants are frequently used as emulsifiers in nonpolar oil + water systems and as solubilisation agents for oil in water, or vice versa. In the latter application the amount of, say, water that can be solubilised in nonpolar oil (to give microemulsion droplets) depends on: (a) the capacity of the micelles to incorporate water; and (b) the fraction of surfactant originally present as micelles. This paper is concerned with the single-phase water-in-oil (W/O) microemulsion regions enclosed by the haze and solubilisation boundaries at the oil-rich end of Shinoda-type phase diagrams. The systems studied contain the nonionic surfactant C12H25(OCH2CH2)5OH (C12E5), normal alkane (heptane, decane or tetradecane) and water. Critical microemulsion concentrations (cμc) and droplet compositions for w/o microemulsions formed from C12E5 in alkane have been determined at phase boundaries over a range of temperatures. The results show how the maximum extent of water solubilisation is determined jointly by the cμc and the maximum droplet size for a given temperature. It appears that for larger (microemulsion) droplets, the cμc is determined by temperature rather than by droplet size. However, along part of the haze curves, aggregates form with only small amounts of water (less than four molecules per ethyleneoxy group on the surfactant head groups). For a given temperature, in the small range where either micelles or microemulsion droplets can exist, reverse hydrated micelles have much higher critical micelle concentrations (cmc) than the cμc of the larger microemulsion droplets. 相似文献
5.
Hydrophilic lipophilic balance (HLB) values for various commercial nonionic surfactants have been determined by means of high
resolution NMR. The results are in good agreement with given HLB values. The method is rapid, nondestructive and requires
only small samples. 相似文献
6.
The methods currently reported in the literature for the characterization of nonionic surfactants are usually applied to one
portion of the molecule and require a knowledge of the other portion for complete identification. This indirect approach leaves
much to be desired. A simple, rapid, and more direct method of characterization is to measure the proton signal intensity
in high resolution nuclear magnetic resonance (NMR) spectra. This method determines the hydrophile to hydrophobe ratio without
requiring standard samples for calibration or a prior knowledge of the hydrophobe. In addition, this method will frequently
give much valuable information about the identity of the hydrophobe, such as the average chain length, the degree of branching,
and the type of aromatic substitution, if any. This method has been applied to the characterization of the common types of
commercial polyethylene oxide condensates. The application of NMR to the analysis of formulated detergent products is also
discussed.
Presented at the AOCS meeting in New Orleans, La., 1962. 相似文献
7.
针对已合成的含缩醛结构的环保型非离子表面活性剂香兰素辛二醇缩醛聚氧乙烯醚(VAEO),研究不同乙氧基链长的VAEO_n(n=6~24)的表面活性及乳化性,并与壬基酚聚氧乙烯醚(NPEO_(10))的表面活性及乳化性作比较。结果表明,随EO聚合度(n)增大,VAEO_n降低表面张力和油/水界面张力的能力下降,对石蜡乳化能力减弱。EO聚合度为6~10的VAEO_n与NPEO_(10)降低表面张力的能力相近,乳化性能也相当。VAEO_n降低油/水界面张力的能力较NPEO_(10)差。采用Material Studio软件模拟分析VAEO_n和NPEO_(10)乳化石蜡的能力,结果表明VAEO_n乙氧基链越长,乳化石蜡重新聚集的速度越快,即乳化性能越差,模拟结果与乳化石蜡分相法的实验结果相吻合。 相似文献
8.
M. Mausner J. H. Benedict K. A. Booman T. E. Brenner R. A. Conway J. R. Duthie L. J. Garrison C. D. Hendrix J. E. Shewmaker 《Journal of the American Oil Chemists' Society》1969,46(9):432-440
A wide range of nonionic surfactants was studied in an extensive inter-laboratory biodegradability testing program carried
out by member companies of The Soap and Detergent Association over a three year period. The objectives were to determine the
biodegradability of a variety of nonionic surfactants, and to develop a reliable laboratory scale test method which could
be used to evaluate the biodegradability of new candidate materials. The results of this research and testing confirm that
the primary and secondary alcohol ethoxylates, the alkyl alkanolamides, and the alkyl amine oxides are all highly biodegradable.
These materials represent the important classes of nonionics used in household and institutional synthetic detergents. The
removal of these materials under conditions of normal secondary wastewater treatment can be anticipated. The diversity of
structures represented in the complete nonionic surfactant spectrum, and the problems of residue analysis imposed serious
obstacles in the development of a single standard laboratory procedure which will correlate well with the limited field data
presently available. The objective of establishing a standard test for all nonionics was not achieved. Residues of nonionic
surfactants from household and institutional synthetic detergents do not appear to contribute to esthetic water pollution
or to interfere with waste treatment processes. A variety of biodegradability assessment procedures, applicable to specific
nonionics or nonionic groups are currently available and should assure that their residues will not adversely affect the quality
of receiving waters. The Subcommittee plans to maintain a program for continued research in nonionic biodegradability testing.
Prepared under the auspices of The Subcommittee on Biodegradation Test Methods of The Soap and Detergent Association. 相似文献
9.
L. P. Turner D. McCullough A. Jackewitz 《Journal of the American Oil Chemists' Society》1976,53(11):691-694
A method employing high pressure liquid chromatography has been developed for the quantitative determination of polyethylene
glycols in ethoxylated fatty alcohols and alkylphenols. This technique overcomes many of the limitations encountered in previously-reported
methods. The polyethylene glycols are separated from the ethoxylated product and other sample components using a 65/35 acetonitrile/water
mobile phase and a Bondapak C18/Corasil reversephase column system. The response factor of the differential refractometer detector is determined using Carbowax
standards of appropriate molecular weights. The molecular weight of the polyethylene glycols in each sample is approximated
using thin layer chromatography prior to the high pressure liquid chromatography calibration and analysis. The precision of
this method for the determination of polyethylene glycols is ± 4% relative or better, and the recovery of added polyethylene
glycols is quantitative. Application of this method to a wide variety of commercial ethoxylated fatty alcohols and alkylphenols
is presented.
Presented at the Meeting of the American Oil Chemists’ Society, April 1976, New Orleans. 相似文献
10.
The crystallization behavior of calcium carbonate in ethanol/water solution containing mixed nonionic/anionic surfactants 总被引:1,自引:0,他引:1
Crystallization of CaCO3 was performed in an ethanol/water solution containing Pluronic F127 (EO97PO68EO97) and sodium dodecyl sulfate (SDS). The effects of the ethanol/water volume ratio, concentration of surfactants, and aging temperature (30-90 °C) on the morphology and polymorphs of CaCO3 were investigated using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The presence of both F127 and SDS in solution favored the vaterite phase of CaCO3. A binary calcite-vaterite mixture and a ternary calcite-vaterite-aragonite mixture were produced at low (< 60 °C) and high temperatures, respectively. Spherical, plate-like, flower-like, and rod-like crystals were obtained at different ethanol/water volume ratios. Controllable synthesis of nearly pure flower-like vaterite and rod-like aragonite can be realized by adjusting the ethanol/water volume ratio. The formation mechanism of flower-like CaCO3 crystals is discussed. 相似文献
11.
Synthesis of surfactants with Narrow-range distribution of the polyoxyethylene chain 总被引:10,自引:0,他引:10
Ethoxylation of alcohols, alkylphenols, and alkylamines has been studied in the presence of a few catalytic systems. Distribution
constants were computed. Broad-range distributed ethoxylates are formed in the presence of NaOH, and the distribution constants
increase up to the homologue containing six oxyethylene units. Narrow-range distributed ethoxylates are formed in the presence
of calcium-based catalysts. It is reflected in the values of the distribution constants because an increase with the growing
number of oxyethylene units in successive homologue is not observed. 相似文献
12.
Gemini表面活性剂具有的优良表面活性,使之有望作为三次采油用的表面活性剂。用界面张力仪及HAAKERS600流变仪研究了非离子型Gemini表面活性剂的表面活性及流变特性。结果表明,25℃下,氧乙基数(EO数)分别为8,10,12的3种非离子型Gemini表面活性剂8-NP-8、10-NP-10及12-NP-12的临界胶束浓度(cmc)值分别为:0.99,0.15和0.032 mmol/L;非离子型Gemini表面活性剂的表面活性及cmc值受电解质的影响较小;氧乙基数为12的非离子型Gemini表面活性剂可以使亲水及亲油固体表面的接触角明显降低,水润湿性增强;非离子型Gemini表面活性剂溶液的粘度随剪切速率增加基本保持不变,呈现出牛顿流体的特性。 相似文献
13.
The highest effectiveness of detergency for nonionic surfactants is observed in the proximity of the cloud point. This phenomenon is primarily influenced by surfactant molecular structure, such as carbon chain length and type of the hydrophilic components. Target of this investigation is to identify a relationship between the cloud point and the structure of nonionic surfactants based on ethoxylated (CnEm), ethoxylated-propoxylated (CnEmPp) and propoxylated-ethoxylated (CnPpEm) fatty alcohols. Three hundred and fifty nonionic surfactants have been prepared for this purpose. These surfactants differ in the C-chain lengths, C4/C6 to C20/C22, and the amount of ethylene oxide (EO range [n] 2–22 ethoxylation) and propylene oxide (PO range [p] 0–12 propoxylation) moieties. Mapping the differences in the performance allows us to propose a high-accuracy topological model describing the structure influence on the cloud point. 相似文献
14.
S. T. Dubey L. Kravetz J. P. Salanitro 《Journal of the American Oil Chemists' Society》1995,72(1):23-30
The effluents and activated sludges used in benchscale biotreater units have been analyzed for nonionic alcohol ethoxylates
and their residues. Separate bench-scale units were fed linear alcohol ethoxylates (AE), highly branched and branched nonylphenol
ethoxylates. Effluents and sludges were first pretreated by a foam sublation technique to provide a gross separation of surfactants
from the environmental matrix. This step was followed by normal-phase high-performance liquid chromatography (HPLC) with either
fluorescence detection (FD) or evaporative light-scattering detection (ESLD). The AEs were derivatized with phenylisocyanate
and analyzed by normal-phase HPLC coupled with FD. At extremely low surfactant levels, pretreatment of large sample volumes
resulted in interferences on derivatization. Hence, a normal-phase HPLC method with ELSD was developed. Although some interferences
do appear using ELSD, this method appears to be a more viable alternative to derivatization/FD for very low levels of AE.
HPLC with FD and ELSD detection methods are more quantitative and provide information on the polyoxyethylene chain than is
possible with traditional methods like cobalt-thiocyanate active substance.
Presented at the 82nd AOCS Annual Meeting & Expo, May 1991, Chicago, Illinois. 相似文献
15.
简要介绍了非离子表面活性剂的分类,较详细地叙述了常用非离子表面活性剂的乳化性能、润湿性能和配伍性能等相关性能,综述了非离子表面活性剂在制革工业准备工序、鞣制工序以及整饰工序中的作用与功能。 相似文献
16.
V. Mohan Rao S. Uma C. G. Gajelli Ravi Y. Kelkar 《Journal of surfactants and detergents》1998,1(4):515-517
Low-temperature differential scanning calorimetry studies on ethoxylates of hydrogenated castor oil and 12-hydroxystearic acid show endothermic transformations that could be ascribed to melting of ethylene oxide (EO) components of the surfactant molecule. The ethoxylation process also results in formation of free polyethylene glycol (PEG). Separation of free PEG followed by area under the curve measurements enabled estimation of EO content of the product formed during manufacture. The melting endotherm provided additional information on the chain-length distribution of polyoxyethylene units in the surfactant. 相似文献
17.
K. Giribabu 《Chemical engineering science》2007,62(11):3057-3067
Major industrial applications of surfactants are related to the stability of emulsions and foams, which is directly dependent on the rate of coalescence of drops and bubbles. Surfactant molecules adsorb at the liquid-liquid and gas-liquid interfaces and prevent the drops and bubbles from coalescing with one another. Therefore, it is important to correlate the adsorption of surfactant with the time required for coalescence. In this work, we have studied the adsorption of three nonionic surfactants, Tween 20, Triton X-100 and Span 80 at air-water and water-toluene interfaces. The variation of surface and interfacial tension with the concentration of surfactant was studied and the data were fitted using a surface equation of state derived from the Langmuir adsorption isotherm. We have studied binary coalescence of water drops in toluene in presence of these three surfactants. Coalescence of air bubbles at flat air-water interface was studied in presence of the water-soluble surfactants, Tween 20 and Triton X-100. A stochastic model for coalescence was used to fit the coalescence time distributions. The significance of the model parameters was discussed. 相似文献
18.
Phase diagrams in which water was combined with sodium dodecyl sulfate, plus one of four nonionic surfactants, as well as
an aliphatic oil, were determined by visual observation and low-angle X-ray diffractometry. The results agreed with earlier
investigations on specially synthesized polyethyleneglycol alkyl ether surfactants, except that the extended water-in-oil
microemulsion areas were not found with the commercial surfactants. 相似文献
19.
Parameters concerning the microemulsion phase behavior of nonionic surfactants of the alkyl polyglycol ether type have extensively been investigated in the last years. By studying these, essential parameters for future applications can be determined. Especially in the field of enhanced oil recovery, lubricants, and cosmetic applications these parameters are of special interest. In this work, the influence of technical grade nonionic surfactants on the phase behavior and the resulting surfactant efficiency has been studied. For this, the alkyl chain length, the degree, type, and order of alkoxylation of the surfactant have been varied. The investigation of these parameters has been conducted by measuring the phase behavior via the Kahlweit fish diagram. It has been found that varying the C-chain length has a great impact on the efficiency, whereas the influence of the ethoxylation degree is minor. By the introduction of propylene oxide, the efficiency has been improved significantly. Additionally, it is important to have the right order of alkoxylation. If the fatty alcohol is first ethoxylated and afterwards propoxylated the efficiency is significantly decreased. 相似文献
20.
概述了阴离子表面活性剂给水环境带来的危害,深入分析了目前阴离子表面活性剂的主要测定方法以及各优缺点,并对今后检测方法的改进方向进行了介绍,指出联用技术将成为未来水环境中阴离子表面活性剂检测的主要技术。 相似文献