Igepal CO-630 Research Articles

Effect of β-cyclodextrin on the aggregation of the non-ionic surfactant Igepal CO-630 in water as studied by 1D and 2D NMR spectroscopy

The micellization process of the non-ionic surfactant, Igepal CO-630, and its inclusion complexes with β-cyclodextrin (β-CD) have been investigated by NMR spectroscopy. The critical micelle concentration of Igepal was determined by measuring the chemical shifts of different resonances. The structure and binding of the inclusion complexes between the Igepal and the β-CD have been studied by 1D proton NMR and ROESY experiments. The stoichiometry of the inclusion complex is mainly 1:1, with a slight contribution of 2:1. At high concentrations of surfactant, the plots of the chemical shifts in the absence and presence of β-CD coalesce, which indicates that the complexes do not take part into the micelles. The ROESY spectrum displays strong correlations between the internal cavity protons of the CD and the aromatic and aliphatic regions of the Igepal, suggesting the formation of a 2:1 primary face-to-face inclusion complex at high concentrations of β-CD.

Physical and metabolic interactions of Pseudomonas sp. strain JA5-B45 and Rhodococcus sp. strain F9-D79 during growth on crude oil and effect of a chemical surfactant on them.

Methods to enhance crude oil biodegradation by mixed bacterial cultures, for example, (bio)surfactant addition, are complicated by the diversity of microbial populations within a given culture. The physical and metabolic interactions between Rhodococcus sp. strain F9-D79 and Pseudomonas sp. strain JA5-B45 were examined during growth on Bow River crude oil. The effects of a nonionic chemical surfactant, Igepal CO-630 (nonylphenol ethoxylate), also were evaluated. Strain F9-D79 grew attached to the oil-water interface and produced a mycolic acid-containing capsule. Crude oil emulsification and surface activity were associated with the cellular fraction. Strain JA5-B45 grew in the aqueous phase and was unable to emulsify oil, but cell-free supernatants mediated kerosene-water emulsion formation. In coculture, stable emulsions were formed and strain JA5-B45 had an affinity for the capsule produced by strain F9-D79. Igepal CO-630 inhibited F9-D79 cells from adhering to the interface, and cells grew dispersed in the aqueous phase as 0.5-microm cocci rather than 2.5-microm rods. The surfactant increased total petroleum hydrocarbon removal by strain JA5-B45 from 4 to 22% and included both saturated compounds and aromatics. In coculture, TPH removal increased from 13 to 40% following surfactant addition. The culture pH normally increased from 7.0 to between 7.5 and 8.5, although addition of Igepal CO-630 to F9-D79 cultures resulted in a drop to pH 5.5. We suggest a dual role for the nonylphenol ethoxylate surfactant in the coculture: (i) to improve hydrocarbon uptake by strain JA5-B45 through emulsification and (ii) to prevent strain F9-D79 from adhering to the oil-water interface, indirectly increasing hydrocarbon availability. These varied effects on hydrocarbon biodegradation could explain some of the known diversity of surfactant effects.

Community dynamics of a mixed-bacterial culture growing on petroleum hydrocarbons in batch culture

The effects of various hydrocarbon substrates, and a chemical surfactant capable of enhancing crude-oil biodegradation, on the community structure of a mixed-bacterial inoculum were examined in batch culture. Of 1000 TSA-culturable isolates, 68.6% were identified at the genus level or better by phospholipid fatty acid analysis over 7-day time course experiments. Cultures were exposed to 20 g/L Bow River crude oil with and without 0.625 g/L Igepal CO-630 (a nonylphenol ethoxylate surfactant), 5 g/L saturates, 5 g/L aromatics, or 125 g/L refinery sludge. A group of six genera dominated the cultures: Acinetobacter, Alcaligenes, Ochrobactrum, Pseudomonas/Flavimonas, Stenotrophomonas, and Yersinia. Species from four of the genera were shown to be capable of hydrocarbon degradation, and counts of hydrocarbon degrading and total heterotrophic bacteria over time were nearly identical. Pseudomonas/Flavimonas and Stenotrophomonas normally dominated during the early portions of cultures, although the lag phase of Stenotrophomonas appears to have been increased by surfactant addition. Acinetobacter calcoaceticus was the most frequently isolated microorganism during exposure to the saturate fraction of crude oil. Regardless of substrate, the culture medium supported a greater variety of organisms during the latter portions of cultures. Understanding the community structure and dynamics of mixed bacterial cultures involved in treatment of heterogeneous waste substrates may assist in process development and optimization studies.Key words: mixed culture, phospholipid fatty acid analysis, petroleum hydrocarbons, community structure.

Stability and film properties of tung oil modified soybean alkyd emulsion

A series of tung oil modified soybean alkyd emulsions are prepared by an inversion emulsified technique. In these alkyd resins, the tung oil contents are about 0, 12.5, and 25.0 wt % (based on the total oil). Using IGEPAL CO-630 as the surfactant, a very stable alkyd emulsion can be obtained. With the increase of the tung oil contents in alkyd emulsions, the initial droplet sizes of the emulsions increase dramatically. Aging under 50°C can eliminate the difference in droplet sizes; the final droplet sizes of the emulsions are about 50 nm. The alkyd resins also have good hydrolytic stability. The tung oil contents in the alkyd resins also strongly influences the film properties; suitable tung oil content improves the film gloss. An atomic force microscopy investigation shows that the film from the alkyd emulsion is more water sensitive; after a 50-h deionized water immersion, the film surface appears to have a lot of dents. This indicates that the film surface may be very rich in surfactant species. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1698–1706, 2000

Community dynamics of a mixed-bacterial culture growing on petroleum hydrocarbons in batch culture

The effects of various hydrocarbon substrates, and a chemical surfactant capable of enhancing crude-oil biodegradation, on the community structure of a mixed-bacterial inoculum were examined in batch culture. Of 1000 TSA-culturable isolates, 68.6% were identified at the genus level or better by phospholipid fatty acid analysis over 7-day time course experiments. Cultures were exposed to 20 g/L Bow River crude oil with and without 0.625 g/L Igepal CO-630 (a nonylphenol ethoxylate surfactant), 5 g/L saturates, 5 g/L aromatics, or 125 g/L refinery sludge. A group of six genera dominated the cultures: Acinetobacter, Alcaligenes, Ochrobactrum, Pseudomonas/Flavimonas, Stenotrophomonas, and Yersinia. Species from four of the genera were shown to be capable of hydrocarbon degradation, and counts of hydrocarbon degrading and total heterotrophic bacteria over time were nearly identical. Pseudomonas/Flavimonas and Stenotrophomonas normally dominated during the early portions of cultures, although the lag phase of Stenotrophomonas appears to have been increased by surfactant addition. Acinetobacter calcoaceticus was the most frequently isolated microorganism during exposure to the saturate fraction of crude oil. Regardless of substrate, the culture medium supported a greater variety of organisms during the latter portions of cultures. Understanding the community structure and dynamics of mixed bacterial cultures involved in treatment of heterogeneous waste substrates may assist in process development and optimization studies.

Influence of chemical surfactants on the biodegradation of crude oil by a mixed bacterial culture

The effects of surfactant physicochemical properties, such as the hydrophile-lipophile balance (HLB) and molecular structure, on the biodegradation of 2% w/v Bow River crude oil by a mixed-bacterial culture were examined. Viable counts increased 4.6-fold and total petroleum hydrocarbon (TPH) biodegradation increased 57% in the presence of Igepal CO-630, a nonylphenol ethoxylate (HLB 13, 0.625 g/L). Only the nonylphenol ethoxylate with an HLB value of 13 substantially enhanced biodegradation. The surfactants from other chemical classes with HLB values of 13 (0.625 g/L) had no effect or were inhibitory. TPH biodegradation enhancement by Igepal CO-630 occurred at concentrations above the critical micelle concentration. When the effect of surfactant on individual oil fractions was examined, the biodegradation enhancement for the saturate and aromatic fractions was the same. In all cases, biodegradation resulted in increased resin and asphaltene concentrations. Optimal surfactant concentrations for TPH biodegradation reduced resin and asphaltene formation. Chemical surfactants have the potential to improve crude oil biodegradation in complex microbial systems, and surfactant selection should consider factors such as molecular structure, HLB, and surfactant concentration.

Micellar Fluidity and Preclouding in Mixed Surfactant Solutions

The fluorescence anisotropy of perylene and the native fluorescence of Igepal CO-630 and Triton X-114 were used to study the intramicellar fluidity of mixed micellar solutions containing these noni...

Surfactant fluorescence in the study of aggregation and clouding

The intrinsic fluorescence of Triton X-114 and Igepal CO-630 was used to monitor the aggregation behavior of micellar solutions of these surfactants. The response to changes in surfactant concentration, increases in temperature up to and beyond the cloud point, and addition of an ionic surfactant (SDS) was monitored. The intrinsic fluorescence was used to measure aggregate anisotropy as a function of SDS concentration and temperature. Relative aggregate abundance showed a minimum at the CMC, confirming the existence of premicellar assemblies. Structural differences in the hydrophobic portions of the two nonionic surfactants led to vastly different packing in their aggregates. The addition of SDS produced smaller, more closely packed micelles.

The effect of concentration of an environmental stress cracking agent on slow crack growth in polyethylenes

Slow crack growth was measured in three polyethylene copolymers by a notch tensile test at 50°C in Igepal Co-630. The concentration of Igepal was varied from 0 to 100%. The largest reduction in time to failure occurred in the concentration range between 0% and 0.1%. From 0.1 to 20% concentration, the additional effect was much less. A minimum in time to failure occurred at ∼ 50% concentration. There is a significant increase in failure time when the concentration is increased from 50 to 100%. If the failure time is <10 3 min in air, Igepal has practically no effect.

In vitro BALB/3T3 cell transformation assay of nonoxynol-9 and 1,4-dioxane.

The spermicidal surfactant nonoxynol-9 (Igepal CO-630, GAF Corp.) and a potential impurity, 1,4-dioxane, were tested in the in vitro cell transformation assay using BALB/3T3 cells. Two treatment periods, 48 hr and 13 days, were used. Nonoxynol-9, tested at levels up to 10 micrograms/ml, did not induce transformation, whereas dioxane was very active in the induction of type III foci in the cultured BALB/3T3 cells.

Effects of detergent concentration and ethylene oxide chain length of the detergent molecule on stress-cracking of low-density polyethylene

Stress-cracking behaviour of low-density polyethylene is investigated using a fracture mechanics approach. It is experimentally observed thatK l independent crack speed is directly proportional to the concentration of Igepal CO-630 up to 25% concentration.K ISCC is found to increase with detergent concentration; and the increase inK ISCC is attributed to the larger amounts of detergent absorption in the higher concentrations, which decreases the strain localization at the crack tip. Micelle formation of detergents in water is thought to enhance the rate of cracking because of their ability to increase plasticization efficiency at the local area because the micelles contain larger amounts of aggressive molecules. In contrast to Williams' model, the cracking behaviour in the constant crack speed region is found to be not controlled by the flow properties of the environment.

The role of crazes in the crack growth of polyethylene

Brittle slow crack growth, or stress cracking, is a major concern in many applications of polyethylene materials. Using a constant tensile load test and removing specimens prior to complete failure, details of the crack tip region can be discerned in both butene and hexene copolymerized polyethylene. In both the presence and absence of an accelerating environment (Igepal CO-630), it was found that crazes formed at the crack tip, although secondary crazes were also evident in the specimens removed from the Igepal. Multiple crack arrest lines were clearly evident, suggesting a stick-slip mechanism under static load. The appearance of the craze zone at the crack tip can be explained through invoking an interlamellar failure model.

Studies on nonoxynol-9. II. Intravaginal absorption, distribution, metabolism and excretion in rats and rabbits

Some pharmacological aspects of Igepal CO-630, used by some pharmaceutical companies as the source of nonylphenoxypoly(ethyleneoxy)ethanol (Nonoxynol-9, N-9) in various spermicidal formulations, were studied. It was found that Igepal CO-630 contains at least 13 components, 70% having molecular weights near that of N-9. After intravaginal administration, the detergent is rapidly and quantitatively absorbed through the vaginal wall into the systemic circulation. The rate of vaginal absorption of N-9 depends on the vehicle in which the detergent is carried. Once in the blood, N-9 is excreted by liver-bile-feces and the kidney-urine routes, the first being more effective in rats, the latter in rabbits. Following intravaginal or intraperitoneal injection of radio-active N-9, the highest content of radioactivity was found in the liver and kidney. The detergent was detected in the milk of lactating rats and the serum of their pups within two hours after the intravaginal dose.

Interfacial Tension and Behavior of Nonionic Surfactants

Abstract Low interfacial tensions are possible with nonionic surfactants. The effects of several solution variables (e.g., salinity and alcohol) on low-tension behavior have been determined for some nonionic surfactants. Nonionics have been found to be much less sensitive to changes in solution conditions than anionics (sulfonates) studied to date. Introduction A survey of the literature reveals very few examples of low interfacial tension (IFT) with nonionic surfactants and few systematic studies of the IFT behavior of nonionics. Youngs examined the tension behavior of some aminimides; Shinoda et al. investigated the emulsion phase-inversion temperatures of ethoxylated nonionic surfactants and stated that the IFT between the oil and aqueous phases approaches zero at the phase-inversion phases approaches zero at the phase-inversion temperatures.It has been shown that it is possible to achieve ultralow; (10 dyne/cm) IFT's using pure hydrocarbons as the oil phase. Subsequent work has proved the feasibility of attaining low IFT's between pure hydrocarbons and pure alkylbenzene sulfonates. In this paper, nonionic surfactants are similarly shown to be capable of giving IFT'S. Further, the low-tension state is associated with the three-phase (microemulsion) region of the ternary phase diagram, but the presence of a "middle" phase is not a sufficient condition for low IFT's.The effects of several solution variables on low IFT behavior have been determined for some nonionic surfactants. Comparison of these results with those of similar studies of anionics (sulfonates) shows that nonionics' behavior is (1) much less sensitive to hydrophobe structure; (2) less sensitive to salinity changes; (3) more tolerant to divalent cations (i.e., Ca+ +); (4) less dependent on alcohol concentration; and that (5) for some nonionics, pH can be an important factor.Obviously, the first four of these could be of considerable significance from a practical standpoint, as they all represent improvement over the behavior usually exhibited by sulfonate surfactants. Materials and Experiment The ethoxylated aliphatic primary alcohols and the five ethoxylated dinol phenols (DNP) are commercial samples provided by Witco Chemical Corp. These samples are described in Table 1. Witco also supplied a commercial coconut diethanolamide [R-CON(CH CH OH), R C,]. Other alkyl variants of the diethanolamides were synthesized in this laboratory.The ethoxylated nonylphenols (IGEPAL CO) were supplied by GAF Corp. and were 100% active materials. We had at our disposal products with 4, 6, 7.5, 9, and 10.5 moles of ethylene oxide per mole of hydrophobe - IGEPAL CO430, CO530, CO610, CO630, and CO710, respectively. To obtain products containing intermediate values of ethylene oxide, mole-fraction weighted mixtures of these materials were prepared.The Klearfac AA-270 phosphate ester was provided by BASF Wyandotte. Steven McGuire of provided by BASF Wyandotte. Steven McGuire of Conoco Inc. ethoxylated samples of 6-undecanol and 7-tridecanol prepared in this laboratory. DNP-M1 is an experimental ethoxylated dinonyl phenol of somewhat narrowed molecular weight distribution provided by Milliken Chemical Co. provided by Milliken Chemical Co. SPEJ P. 349

The conformational state of surfactants in the solid state and in micellar form. A laser-excited Raman scattering study

The Raman spectra of a series of cationic, anionic, and nonionic surfactants have been examined as pure solids or liquids, and in aqueous micellar solutions. The spectra show that cationic surfactants such as hexadecyltrimethylammonium bromide (CTAB), dodecylammonium chloride (DAC), and decyltrimethylammonium bromide (DeTAB), along with anionic surfactants such as sodium laurate (NaL) and sodium lauryl sulfate (NaLS) exist in all-trans structures in the crystalline state. Aqueous micellar solution of these surfactants show additional Raman lines which correspond to a liquidlike nature of the micellar core. Raman spectral studies indicate that the ethylene oxide chains in nonionic surfactant such as Igepal CO-880 and Brij 35 assume dihedral helical structures. Nonionic liquid surfactants with shorter ethylene oxide chains such as Triton X-100 and Igepal CO-630 have a major part of the ethylene oxide chain in an open coil form. No significant differences are observed in Brij 35 in H/sub 2/O. However, micellization of Igepal CO-630 shows spectra which indicate a partial ordering of the ethylene oxide chains. The phase changes associated with the electrolyte-induced sphere-rod transition in micellar systems have also been examined by Raman spectroscopy. These studies show a greater ordering of the hydrocarbon chain in the rod-shaped compared to themore » sphere-shaped aggregates.« less

Adsorbed layer of protein II. Film hysteresis and stress relaxation

Studies of hysteresis and stress relaxation in vertically suspended liquid laminae are reported. A model consisting of two Maxwell units in parallel is proposed to describe the phenomena. Based upon the model, elastic and viscous parameters are calculated. The stabilizing surface films studied were protein, e.g., hemoglobin, ovalbumin, lysozyme, egg yolk lipoportein, or other surface-active materials, e.g., saponin, Alipa CO-436, Igepal CO-630, or Igepal CO-880.

Time-Temperature Strain and Molecular Weight Effects in the Environmental Stress Cracking of 0.95 Density Polyethylene

Reduced variables of time-temperature and molecular weight are used to describe the stress relaxation failure of 0.95 density polyethylene in a stress cracking agent, Igepal CO-630. This method was previously shown to work for 0.96 density linear polyethylene. The 0.95 density polyethylene has an apparent activation energy of 38 kcal for stress cracking. This is appreciably higher than the 22 kcal found for 0.96 density linear polyethylene. A much higher dependence on molecular weight was also found. The 0.95 density polyethylene has a lifetime that is proportional to Mv5.8 while the 0.96 density polyethylene has a lifetime proportional to Mv3.4. Some data are also shown which indicate a difference in the sensitivity to strain for the two materials. This can lead to appreciably longer lifetimes for the 0.95 density polyethylene at low strain.

Control of the Alfalfa Weevil, Hypera postica, in New York

Experiments were conducted to determine the effectiveness of experimental, labeled, and mixtures of various insecticides for controlling the alfalfa weevil, Hypera postica (Gyllenhal), on fall, first-, and second-crop alfalfa. Fall-applied methoxychlor and a mixture of Guthion M-E® (O,O-diethyl S-(4-oxo-1,2,3-benzotriazin-3(4H)-yl-methyl) phosphorodithioate) and 3% Igepal CO-630® (nonylphenoxypoly(ethyleneoxy)ethanol 9–10 ethyleneoxy per mole of nonylphenol) did not give adequate control and both were below the normal performance of the standard fall-applied heptachlor. None of the stubble sprays, except HRS 1671 (heptachlorohexahydroketomethanophthalan), gave better control than lindane and few were more effective than the already recommended materials that were tested. Of the experimental insecticides tested, HRS 1671, Bayer 41831 (O,O-dimethyl O-(4-nitro-m-tolyl)phosphorothioate), AC 47031 (2-(diethoxyphosphinylimino)-1,3-dithiolane), AC47772 (2-(dimethoxyphosphinylimino)- 4-methyl-1,3-dithiolane), and R.P. 11974 (0,0-diethyl dithiophosphoryl methyl-3-chloro-6-benzoxazolone) showed the most promise.

Speaking of Quality IGEPAL CO-630

Speaking of Quality IGEPAL CO-630