Sodium Oleate Solution Research Articles

Oleochemicals and the processing of polymeric resins — Part 5

Polymers which do not normally dissolve in water can usually be dispersed in sodium oleate solutions, the polymer adsorbing surfactant to give a complex similar to polymer electrolytes. Molten palmitic acid will serve as a solvent in which to polymerise acrylic compounds, and benzyl butyrate has been examined as a solvent in which to polymerise benzyl methacrylate. Ethyl palmitate has been applied to aid the reduction of the carbon tetrachloride content of solutions of chlorinated polyisoprene, when this is removed from the polymer by steam or hot water.

Multicomponent diffusion in dialysis membranes

Multicomponent diffusion through porous media is usually described by an effective diffusivity for each component. In such a diffusivity many different effects are lumped together, which makes its behaviour very difficult to understand. In this study we use a different approach in which each species has a driving force which is counteracted by friction due to its motion relative to the surroundings. The resulting equation is a difference form of what is known as the generalized Maxwell—Stefan equation (GMS). We apply this to describe transport through cellulose dialysis membranes. Friction between water and the membrane matrix is determined by isobaric dialysis experiments in mixtures with methanol, ethanol and 2-propanol. The water—membrane friction strongly depends on the water content. The friction of methanol or ethanol with the membrane is almost constant, while that of 2-propanol decreases with an increase in the 2-propanol concentration. The resulting friction coefficients give a quantitative description of transport of a ternary liquid mixture through the membrane. Using similar mixtures with a hollow fibre device shows that only the external area of the fibre bundle is effectively used. Apparently there is insufficient flow of the external phase between the fibres. In a second set of experiments a multicomponent system is studied. At the feed side of the membrane a solution of water, 2-propanol and sodium oleate is applied; on the permeate side a NaCl solution. A small pressure gradient from feed to permeate is applied. Initially a mass flux against the pressure gradient is observed. After some time the flux changes direction and becomes two to ten times larger than the permeation rate would be for the feed solution alone with the same applied pressure. These effects cannot be explained using effective diffusivities, but they can be understood qualitatively from the GMS equations.

Residue Analysis of Oleic Acid in Cucumber Fruits after Spraying Sodium Oleate Solution

アブラムシ防除剤として開発中のオレイン酸ナトリウム液剤 (主成分としてシス-9-オクタデセン酸ナトリウムを20%含む) のキュウリ散布後のシス-9-オクタデセン酸 (ODA) の残留量を調べるため, ガスクロマトグラフによる分析を行なった. 二品種のキュウリ中の内因性ODA量は, それぞれ0.33, 0.37ppmであった. 二品種のキュウリ中のODA残留量は, 最終散布後1日目はそれぞれ1.81, 3.57ppmであり, 3日目においては, それぞれ0.88, 1.01ppmへと減少した. 未処理のキュウリにODAを2.5ppm添加し回収率試験を行なったところ, 回収率は102.0～108.4%の範囲にあった.

Oscillatory behavior of a water/oil interface system in response to current-clamp and voltage-clamp stimulation

Oscillatory behavior in response to current-clamp and voltage-clamp stimulation was examined on a water/oil/water system consisting of an aqueous solution of sodium oleate as surfactant, a solution of 2,2'-bipyridine in nitrobenzene and an aqueous solution of sodium chloride. Stable oscillation was observed only when the strength of the stimulation lay within a specific range of values.

Characteristic response to taste stimuli of the intensities of higher harmonics in an electrochemical oscillatory system.

In general, the electrochemical characteristics of solid/liquid or liquid/liquid interfaces are highly nonlinear, i.e., the capacitance changes markedly according to the applied voltage. In this paper, we propose a novel method for evaluating these nonlinear characteristics quantitatively. That is, a sinusoidal voltage source is applied to a test solution and the waveform of the output current is analyzed by Fourier transformation. It is shown theoretically that higher harmonic components in the Fourier transformation afford us useful information on nonlinear behavior. It is stressed that our technique is entirely different from the classical impedance method, i.e., nonlinear components of the impedance can be evaluated in our method, having been ignored previously in the classical impedance measurement. As an application of this method, we have studied the effect of taste compounds on the intensities of the higher harmonics, using an electrochemical cell containing an aqueous solution of sodium oleate. It has been found that the intensities of the higher harmonics exhibit characteristic changes upon the addition of taste compounds, the change being dependent upon the taste category. The characteristic response to taste compounds in the electrochemical nonlinearity is discussed in relation to the experimental trend of the dynamic isotherm for oleic acid at an air/water interface.

Meal-induced peptide tyrosine tyrosine inhibition of pancreatic secretion in the rat.

In the present studies we examined the distribution, release, and biological actions of peptide tyrosine tyrosine (PYY) in the rat. The concentration and distribution of PYY was highest in the ileum and colon as determined by both radioimmunoassay of rat tissue extracts and immunocytochemistry. An ultrastructural comparison of rat and dog colonic PYY cells revealed a bipolar distribution of peptide-containing secretory granules in both species. Serum PYY and pancreatic exocrine secretory responses were monitored after presentation of a meal to meal-trained rats (n = 12). A significant increase in PYY concentrations was not observed until 120 min after meal presentation, a delayed response similar to that previously observed in the dog. PYY responses were also observed in rats after perfusion of the intestine at the level of the duodenum and ileum with an 80 mOsm micellar solution of sodium oleate. Duodenal instillations of the fatty acids resulted in a maximum PYY response after 120 min, whereas rats subject to ileal perfusion of fat exhibited maximum PYY release within the first hour. In other experiments, infusion of exogenous PYY at 100 pmol.kg-1.h-1, which reproduced plasma PYY levels observed after a meal and perfusion of the gut with fat, significantly inhibited CCK-stimulated bile pancreatic volume (P less than 0.02), protein (P less than 0.01), and amylase (P less than 0.01) output. These studies demonstrate a bipolar distribution of PYY-containing secretory granules in cells of the jejunal, ileal, and colonic mucosa, and show that PYY is released in response to a meal in amounts sufficient to inhibit cholecystokinin-stimulated pancreatic secretion. Evidence is presented that PYY may mediate the delayed inhibition of pancreatic secretion that is observed in the rat after ingestion of a meal.

In vitro detachment of bacteria from ruminal digesta by buffered sodium oleate solutions

The effectiveness of a buffered sodium oleate solution was evaluated for detaching bacteria from ruminal digesta samples. A response surface derived from an octagonal design was used to determine the pH and concentration combination for maximum detachment of total and cellulolytic bacteria. The total number of bacteria detached increased up to 81% over control with treatment of a pH 8.8 and 1.5% sodium oleate solution. The recovery of cellulolytic bacteria was decreased to 35% of control with treatment of a pH 9.0 and 0.1% sodium oleate solution. Attempts to improve the recovery of viable bacteria exposed to sodium oleate solutions were unsuccessful. This response surface design identified an optimal pH and concentration that were consistent with existing information regarding detachment of total bacteria, and suggested that sodium oleate, at the concentrations tested, was toxic to the cellulolytic population of the rumen.

He(I) photoelectron studies of mixed surfactant films on liquid surfaces

By means of He(I) photoelectron spectroscopy, the surface compositions of mixed solutions of sodium oleate and dimethyldioctadecylammonium bromide in hydroxypropionitrile solution have been measured.

Thyroid hormone metabolism in nonthyroidal illnesses. II. A new method for measuring serum thyroid hormone binding inhibitor and its clinical application

It is well known that serum T3 and T4 concentrations are often decreased in patients with nonthyroidal illnesses (NTI). The purpose of this study was to elucidate the possible role of serum thyroid hormone binding inhibitor (THBI) in lowering serum T4 in patients with NTI using the originally developed method for measuring THBI. 125I.T4 and 0.05 micromilligram of pooled normal serum was applied to the Sephadex G.25 column equilibrated in advance by 0.1N NaOH, and 4 micromilligram of 0.075M veronal buffer, pH 8.6 (Buffer) was added. 125I.T4 thus adsorbed on the column was then eluted by adding the charcoal treated thyroxine-free serum (used as thyroxine binding protein (TBP) solution) with THBI which had been extracted from the serum by diethyl ether or standard sodium oleate solution (0.125 approximately 1.0 mumol/column). When the radioactivity of the eluate was counted, the gradual decrease in radioactivity was observed with increase in sodium oleate due to the inhibition of 125I.T4 and TBP binding. Thus, THBI in serum could be expressed as mumol sodium oleate equivalent from the dose response curve for binding inhibition. Coefficients of intrassay and interassay variations in this assay were 6 and 17%, respectively when sera from patients with acute myocardial infarction (AMI) were measured. THBI from 15 normal controls ranged from 0 to 0.27 (mean +/- SD: 0.11 +/- 0.08) mumol sodium oleate equivalent, the normal range being less than 0.27 mumoles. In 12 patients with AMI and 12 with end-stage malignancy (cancer), serum T4 levels were below the normal range in 9 and 8 cases, respectively. In these patients, serum THBI was positive in as many as 10 (83%) and 11 (92%) cases, respectively. Serum T4 and THBI were serially measured after admission in patients with AMI. Serum T4 concentrations showed their lowest values on the first, second or third hospital day and they gradually increased to the normal range by the seventh day. On the other hand, serum THBI showed their highest value on the first hospital day in 8 cases of AMI, and they gradually decreased thereafter. A statistically significant negative correlation was observed between serum T4 and THBI in these patients (r = -0.63, p less than 0.01). Moreover, statistically significant positive correlations were observed between serum THBI and FFA in both AMI and cancer patients (r = 0.89, p less than 0.01; r = 0.88, p less than 0.01, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Photon correlation spectroscopy in micellar solutions of sodium and potassium oleate

Photon correlation spectroscopy was applied to concentrated micellar solutions of sodium and potassium oleate. In rod-like micellar phases the relaxation times of the concentration fluctuation were measured as a function of temperature. A remarkable temperature dependence of the relaxation time was found in the isotropic phase of rod-like micelles. This suggests that the rotational diffusion is strongly reduced by the entanglement effect. The thermal expansion coefficient of rod-like micelles was determined.

Preconcentration of humic acid in water by coprecipitation/flotation with iron(III) hydroxide followed by ultrafiltration.

To 1 liter of water containing humic acid was added 1 ml of iron(III) solution (10 mg Fe/ml) and the pH was adjusted to 7 to collect the humic acid on iron(III) hydroxide precipitates. Three ml of 70% ethanol solution of sodium oleate (0.2 mg/ml) and sodium dodecyl sulfate (0.6 mg/ml) was added to render the precipitate surfaces hydrophobic. The precipitates were rapidly floated with numerous nitrogen bubbles (0.10.5 mmin diam.), collected and then dissolved in 10 ml of 2 M hydrochloric acid. Humic acid was filtered off on an ultrafilter (molecular weight cut-off, 10000) and ultrasonically dissolved in 10 ml of 0.1 M potassium hydroxide solution for the spectrophotometric determination. Within 1 h of the entire procedure, 0.015 mg/l of humic acid was recovered at more than 92%.

Floc-size distribution of scheelite treated by shear-flocculation

The size distributions of flocculated pulps as observed in the shear-flocculation of scheelite suspended in sodium oleate solution were approximately bimodal. The behaviour of the fine and coarse fractions was separately analyzed. For the fine fraction, an empirical second-order rate equation was used to describe the mass-rate of disappearance. For the coarse fraction, a self-preserving distribution of log-normal form dependent only on the stirring geometry and stirring speed was obtained. Correlations obtained from experimental results in a series of small tanks were used to predict flocculation behaviour in a larger tank of similar geometry.

Oscillating pendant drop: A method for the measurement of dynamic surface and interface tension

A method is described for measuring dynamic surface and interface tension. The technique is essentially a variation of the pendant drop method in which the drop is allowed to oscillate after sudden formation at the tip of a syringe. Immediately after the oscillation stops but before the drop detaches, there is an instant of rest. At this moment, the profile of the drop is obtained using high-speed photography. The boundary tension is then calculated from the profile using established methods. The technique is demonstrated on systems consisting of aqueous solutions of sodium stearate or oleate on one hand and mineral oil or air on the other hand. Surface or interface tensions may be obtained within 0.25 to 5 s after surface formation.

Solution chemistry studies and flotation behaviour of apatite, calcite and fluorite minerals with sodium oleate collector

The maximum flotation response for three naturally occurring calcium minerals, apatite, calcite and fluorite with sodium oleate collector correlated directly with the minimum interfacial tension of the air/solution interface. For fluorite and apatite the minimum surface tension occurred about the mid-pH region and was attributed to the formation of pre-micellar associated species in solution. In the case of calcite the minimum was observed at high pH since the presence of high concentrations of calcium ions in solution appeared to reduce the concentration of amphililic species in the low and mid-pH regions. Microelectrophoresis data demonstrated that the three minerals acquired a negative charge in sodium oleate solution, resulting from adsorption of oleate species on the mineral surfaces. The flotation behaviour of the systems were shown to be related to the species distribution diagrams suggesting that the role of the acid soap dimer, soap dimer, molecular and lattice species could make a significant contribution to the character and composition of the interfacial films. High flotation response was explained by strong adhesion between the hydrophobic particle and bubble. It was suggested that the reduction in surface tension may not be the major factor contributing to the flotation efficiency but indicated the presence of associated surfactant species in solution which could also synergistically adsorb at the solid/liquid interface, increasing the hydrophobic character of the mineral surface. This would maximize the magnitude of the contact angle and hence the strength of the adhesion between particle and bubble. This adsorption behaviour is not in general agreement with conventionally non-hydrolyzable collector theory which is usually based on electrostatic models.

Potentiometric titration of sodium oleate in dilute aqueous solutions

Acidification of sodium oleate aqueous solutions creates an oil phase which exists in the form of droplets 0.2-0.3 μm in diameter. On the basis of the thermodynamic solubility diagram for oleic acid it was assumed that the created oleic phase consisted of pure oleic acid molecules. The surface area of the oleic acid droplets was determined by utilizing light transmittance measurements of the emulsions and the Mie theory. The concentration of surface oleate species at the oil-water interface was calculated from pH-metric titration data for 5 × 10 −4, 10 −3, 5 × 10 −3, and 10 −2 M sodium oleate solutions. It was found that the electrical charge at the oleic acid droplets-aqueous solution interface estimated from the above data increased with pH up to 800 μC/cm 2 significantly exceeding the theoretical maximum value 128 μC/cm 2. Therefore, the assumed model in which only surface oleate anion and simple oleate species such as Ol aq −, HOl · Ol aq −, Ol 2aq 2− are present in the sodium oleate-HCl-H 2O system is useless for the interpretation of sodium oleate titration curves.

Interaction of sodium oleate with the surface of aluminum

1. The adsorption of sodium oleate on an oxidized aluminum surface is of an irreversible chemical type and decreases the work function by 0.05–0.06 eV. In the complex formed on the surface, the axis of the carboxyl group is oriented perpendicular to the surface. 2. Increasing the time of exposure of aluminum to the sodium oleate solution leads to the formation of polylayers of aluminum oleate on its surface, tightly bonded to the substrate. In this case the work function decreases by an additional 0.10–0.13 eV, while the orientation of the carboxyl groups is disrupted. 3. After the exposure of aluminum to concentrated nitric acid, a layer consisting of oxides, nitrogen-containing salts, and aluminum hydroxides is formed on its surface. 4. Modification of the surface acclerates the chemisorption of sodium oleate and the ion-exchange reaction in solution. In this case the chemisorption of sodium oleate increases the work function by 0.3 eV, while the formation of phase layers of aluminum oleate decreases it by 0.25 eV. In the case of analogous exposures in solution, the thickness of the aluminum oleate layers formed is greater on a modified surface.

Infrared spectrophotometric analysis of acidified aqueous sodium oleate solutions

Infrared spectroscopy was applied to the analysis of 10 −3 M aqueous sodium oleate solutions titrated with 0.2 M HCl. From characteristic absorption bands of sodium oleate at 1560 cm −1 and oleic acid at 1710 cm −1 the degree of oleate ion neutralization in the titrated system at varying pH was calculated.It was found that the pH-metric titration curve of oleate ions differs considerably from the theoretical curve calculated for the reaction Ol − aq + H + = HOl liq, taking the solubility product of oleic acid equal to 12.5. Most likely aggregates of oleate ons (micelles) are formed during titration and account for the deviation of the titration curves from theory.

Pressure effects on the Raman spectra of micelles: Pressure induced phase transition and structural changes in aqueous sodium oleatea)

The Raman spectrum of an aqueous micellar solution of sodium oleate has been studied at pressures up to 5.05 kbar. It is shown that the acyl chain interactions are enhanced by pressure and that the number of gauche bonds in the micellar phase increases with increasing pressure. A first-order phase transition, from the micellar isotropic phase to a solidlike coagel phase was found to occur at 1.7 kbar. This phase transition has a very high pressure hysteresis. Significant differences were observed between the pressure and temperature effects on many structural properties of this aqueous sytem.

Temperature-induced phase transition and structural changes in micellar solutions of sodium oleate observed by Raman scattering

Temperature-induced phase transition and structural changes in micellar solutions of sodium oleate observed by Raman scattering

Liquid Crystal Solubilization of Cholesterol: Potential Method for Gallstone Dissolution

□ Solubilization rate and phase equilibrium studies were conducted for cholesterol in aqueous sodium oleate solutions. The components interacted to form a lamellar liquid crystalline phase, and this phenomenon was investigated as a potential method for cholesterol gallstone dissolution. Phase equilibria data for cholesterol-sodium oleate–water showed that the mesophase contained approximately equimolar amounts of cholesterol and oleate with large amounts of water. The cholesterol solubilization rate from a static pellet in sodium oleate solutions was much faster than dissolution in sodium cholate solutions and was independent of oleate concentration from 2.5 to 10%. In these experiments, the medium became a cloudy disperson of liquid crystalline phase in the micellar solutions. The rate-limiting step in the solubilization process appears to be dispersion of fragments from the liquid crystalline layer on the cholesterol surface. This hypothesis was consistent with the kinetic effects of viscosity, stirring rate, and oleate concentration. By converting cholesterol to a liquid crystalline phase, the solubilization process avoids the limitations of micellar solubility and interfacial resistance which control cholesterol dissolution in bile salt-containing media.