Ethanolamine Solution Research Articles

Imaging systems by dye-sensitized photooxidation of oxazole groups attached to polymer backbones, 5. Photooxidative amplification

Copolymers of 2-(3-methacryloyloxypropyl)-4,5-diphenyl-1,3-oxazole with N-isopropylacrylamide are used as positive-working photoresists. The change of solubility is induced by the dye-sensitized photooxidation of oxazole rings into the corresponding N,N-dibenzoylcarboxamide and subsequent development in aqueous ethanolamine solution. We propose here a novel procedure to result in a marked amplification of oxazole ring photooxidation by reaching the tricarboxamide photoproduct with an ionizable amino derivative, dyeing with an ionic photosensitizer, exposing to flood light and finally developing the photo-image.

Ethanolamine injection for sclerotherapy of angiodysplasia of the colon.

Endoscopic sclerotherapy has been a very useful method for the management of bleeding vascular lesions of the gastrointestinal tract. In this report, the injection of a sclerosant agent was evaluated for the treatment of angiodysplasias of the colon. In a prospective study in eight patients an ethanolamine solution was injected under endoscopic observation directly into 15 lesions, typically angiodysplasias of the right colon at the index colonoscopy, and into another eight de novo lesions found at subsequent examinations. The needle injector was intended to be placed very carefully into the lesion, tangentially to the mucosal surface, to avoid penetrating the bowel wall. Clinical follow-up showed that in six out of the eight patients (75%) no further evidence of lower intestinal hemorrhage was registered after the sclerotherapy; follow-up ranged from 22 to 36 months. Of the four patients who needed blood transfusion before the treatment because of intestinal bleeding, only one required blood transfusion after the sclerotherapy. Neither immediate nor late complications were recorded; often light bleeding occurred immediately after the injections and stopped spontaneously, except in one case which necessitated additional injection of the sclerosant. On the other hand, only one patient had light transient right lower quadrant pain after the injection, which subsided without any medication. Our method was shown to be feasible and safe. The success of the intralesional injection of the sclerosing agent may be predicted when changes in the mucosal surface are observed: (a) immediately after the injection sufficient sclerosant is deemed to have been injected and to the proper depth in the bowel wall, if the mucosa bulges while the solution is being injected; and (b) if a shallow ulceration is seen in an early subsequent reexamination where the treated lesion was located, allowing scar tissue produced by the healing process of the ulcer to replace the former vascular lesion.

High-performance liquid chromatographic determination of primary amines in aqueous solutions after extraction and derivatization with 2,2-diphenyl-1-oxa-3-oxonia-2-boratanaphthalene (DOOB).

Aqueous solutions of tryptamine, tyramine and ethanolamine are extracted and derivatizated to azomethine chelates using a solution of DOOB in diethyl ether. The extraction takes about 2 h. Diisopropyl ether and toluol have also been tested as extractants. The separation of the azomethine chelates is realized by a gradient program on a Si 60 column using a mixture of n-heptane/tert-butyl methyl ether. UV detection is carried out at 280 nm. The concentration of these three amines has been determined in a Chianti wine sample.

Improvement in the polyethylene glycol-cibacron blue purification method

A new approach was developed for the purification of polyethylene glycol (PEG)-Cibacron synthesized from PEG 8000 and Cibacron 3G-A, using an NH 2-silica anion exchanger for separation of the unreacted PEG 8000 from the other compounds of the reaction mixture. The adsorption of PEG-Cibacron and Cibacron under acidic conditions (pH 4.7) was 22.4 mg (Cb and PEG-Cb) per gram of silica and 100% elution was achieved with 1% (v/v) ethanolamine solution at pH 9. The silica exchanger can be reused several times without loss of performance. An extraction step with chloroform was used to separate the PEG-dye from the non-bonded Cibacron, which completely partitioned into the aqueous phase. After drying, a dark-blue solid polymer with a yield of 7.6% in relation to the initial mass of PEG was obtained, which is an increase of 50% in relation to earlier work.

Electro-oxidation of ethanolamine on modified layers of CuNi alloys in alkaline environment

Investigations of ethanolamine oxidation were carried out on CuNi alloy electrodes and modified by anode-cathode cycles in an alkaline environment (1 M KOH). For comparison, investigations were also conducted on polycrystalline copper prepared similarly. The surficial thin layers obtained were subjected to phase analysis using a Philips diffractometer and Co kα radiation. Investigations of ethanolamine electro-oxidation were performed by the cyclic voltammetry and potentiostatic pulse method in 1 M KOH + 0.1 M ethanolamine solution. Characteristic kinetic parameters for the electrochemical process were calculated based on i-E curves for electro-oxidation of ethanolamine in an alkaline environment. The influence of the chemical composition of the electrode on the course of the electro-oxidation process was shown. It was ascertained that, with increasing content of copper in the CuNi alloy, the rate of electro-oxidation of ethanolamine rises and its maximal value is greater that the rate of electro-oxidation on pure copper. This shows that oxygen compounds of nickel and copper take part simultaneously in the electro-oxidation of ethanolamine.

Visible-light generation of hydrogen from hydrogen sulphide in aqueous solutions of ethanolamines containing vanadium sulphide dispersions

Hydrogen was photoproduced from dissolved hydrogen sulphide in aqueous solutions of ethanolamines (monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA)) containing vanadium sulphide suspensions. The UV-visible spectra of these photochemical mixtures, saturated with hydrogen sulphide, were examined. An iodine lamp (100 W) was used as the irradiation source. The rates of production of hydrogen were studied as a function of the irradiation time, at different vanadium sulphide concentrations for each ethanolamine at room temperature. MEA has a higher conversion value for H 2S and is more stable than the other two amines. Arrhenius activation energies were calculated for the temperature range 30–80 °C and a mechanism was suggested for this system.

Solubility of hydrogen in aqueous ethanolamine solutions at temperatures between 323 and 423 K

The solubility of hydrogen in aqueous ethanolamine solutions was measured at temperatures between 323 and 423 K at pressures up to 20 MPa. Henry's coefficients derived from the experimental results are successfully predicted by the scaled particle theory

Detection of a few picograms of DNA on polyacrylamide gels by silver staining

DNA fragments separated on polyacrylamide gels are silver stained in ethanolamine solution. The staining procedure can be completed in 3 1 2 h . Illumination of the gels on a black back-ground increases the sensitivity of detection compared with the usual transillumination. The limit level of detection is 3–5 pg per band with a cross-sectional area of 5 mm 2. Five to fifty picograms of DNA may be detected quantitatively by scanning the gels. The method will detect 0.1 to 1 ng per band of low-molecular-weight RNA components.

Influence of Contaminant Organic-Water Mixtures on Shrinkage of Impermeable Clay Soils with Regard to Hazardous Waste Landfill Liners

ABSTRACT Sedimentation volumes of montmorillonite soils in aqueous solutions of methanol, acetone, glycerol, dioxane, ethylenediamine, ethanolamine, and urea were determined. This technique was used for screening the soil shrinkage potential of waste components. The sedimentation volumes are interpreted in relation to the characteristic adsorption to the clay mineral for each organic compound. Presence of water greatly affects the clay-organic interaction. With methanol and acetone, sedimentation volumes increase as a function organic concentration up to a limit but decrease at higher organic concentrations. In contrast, the dielectric constant decreases monotonically with increasing organic concentration. Dioxane showed a decrease in sedimentation volume for increasing organic concentrations up to 1% (molar basis) with no further effect at higher organic concentrations. The other organics behaved differently, indicating the need to consider separately the response of clay to each organic-water mixture. E...

Chemical absorption of carbon dioxide into ethanolamine solutions of polar solvent

Chemical absorption of carbon dioxide into ethanolamine solutions of polar solvent

A TG study of the solvolytic breakdown of a crosslinked double base propellant

The solvolytic breakdown and dissolution of obsolete crosslinked propellants may be carried out with surprising ease with subsequent recovery of expensive constituents in high yields. An approach was adopted in which degradation was initiated in composites while they were swollen in an appropriate solvent containing additives capable of reacting with and cleaving chemical bonds located in the polymer chain. A kinetic study of the solvolysis reaction of the urethane linkages in a crosslinked double base propellant in ethanolamine solution was followed by thermogravimetry. Kinetic data were obtained using the propellant fraction reacted, which was expressed as the product of the TG fraction at 200°C and the molarity of the ethanolamine solution. First-order rate constants for the reaction were found to be higher in the mixed solvent of toluene-isopropanol compared with isopropanol probably because of their differences in swelling behavior. Activation energies for solvolysis were about 5 kcal mole −1 in toluene-isopropanol and about 8 kcal mole −1 in isopropanol. Nitroglycerin present as a plasticizer in double base propellants was extracted prior to kinetic analysis because it was found to react with the ethanolamine. The solvolytic degradation of the propellant binder with nitrocellulose was about three times as fast as the binder without nitrocellulose. A variable heating rate study showed that the binder with or without nitrocellulose had the same activation energy for thermal decomposition. Kinetic data indicates that nitrocellulose appears to catalyze the solvolytic degradation but not the thermal degradation of a crosslinked double base propellant binder.

Molar excess Gibbs free energies of mixtures of ethanolamines and water

Thermodynamic information about the vapor—liquid equilibria of systems containing water and ethanolamines is needed in the design and optimization of important industrial processes. This knowledge is also useful in the investigation of some phenomena such as the thermal conversion of ethanolamines or their complexation reactions with metals. Physico-chemical investigations involving aqueous solutions of ethanolamines are scarce, and sometimes contradictory, in the literature. It has been stated [1] that the system diethanolamine—water obeys Raoult's law. However, there have been studies [2] indicating departure from ideal behavior for this system. The purpose of this work was to determine the molar excess Gibbs free energies of the systems formed by water and the ethanolamines.

Diffusivities of mono-, di-, and triethanolamines in aqueous solutions

Aqueous solutions of ethanolamines, such as MEA (monoethanolamine), DEA (diethanolamine), or TEA (triethanolamine), are frequently used for the removal of acidic gases. Therefore, a knowledge of the diffusivities of these ethanolamines in the aqueous solutions of various concentrations is important in the rational design of absorption equipment. Thomas and Furzer (6) have measured the diffusivities of MEA, DEA, and TEA in aqueous solutions by the Gouy method up to high concentrations and found that the diffusivities of MEA and TEA follow the Stokes-Einstein relation; Le., the product Dp is constant at constant temperature, whereas the d i f f us i i of DEA shows large deviation from the Stokes-Einstein relation. They have explained that this large deviation is due to the increase in molecular weight of DEA in the solution through association and hydration. However, on the basis of the experimental results that all of the three ethanolamines are molecularly associated in aqueous solution, Ibrahim and Kuloor (2) have pointed out that the anomalous behavior in the case of DEA cannot be solely attributed to association. In this paper, new data for the diffusivities of MEA, DEA, and TEA in aqueous solutions are reported and compared with the data of Thomas and Furzer (6) and with the Stokes-Einstein relation.

Automatic collector of expired 14CO 2 for liquid scintillation counting

A filtration technique was employed to trap 14CO 2 continuously for liquid scintillation counting. Devices for delivering scintillator and ethanolamine solutions were combined symmetrically with two fritted-glass aspirators for altenating operation. The collector was regulated by a fraction collector timer. Trial and animal tests indicated that the described method was efficient, reliable, and more convenient for frequent collection over long periods than alternative methods. The automatic collector was used for metabolic studies of [1- 14C] arachidonic acid in rats kept in metabolic cages and the results were processed by multicompartmental analysis.

The measurement and prediction of the solubility of acid gases in monoethanolamine solutions at low partial pressures

AbstractAn apparatus for the determination of the solubility of hydrogen sulphide, carbon dioxide and their mixtures in ethanolamine solutions at low pressures is described. With this apparatus, the solubility of H2S, CO2 and their mixtures in aqueous solutions of monoethanolamine has been measured at partial pressures between 0.001 kPa and 9 kPa at temperatures of 80° and 100°C. The results for the mixture have been compared with two methods of prediction based on a thermodynamic model.

The absorption of carbon dioxide in solutions of monoethanolamine

Infrared, thermogravimetric and analytical results are presented that establish that the ethanolamine salt of 2-hydroxyethylcarbamic acid is formed when carbon dioxide is absorbed in solutions of ethanolamine.

Sur quelques réactions acide-base dans les solvants fortement basiques anhydres. II. Les amino-2 éthylamidures de sodium et de potassium

Solutions of sodium 2-aminoethylamide in anhydrous ethylenediamine were prepared by dissolving ammoniacal sodium amide NaNH2 in ethylenediamine and removing the ammonia formed in vacuum. When these solutions were prepared and kept under nitrogen containing not more than about 5 p.p.m. of oxygen and 1 p.p.m. of moisture, they remained colorless and stable. Upon addition of benzene to these solutions, the pure amide precipitated as fine greyish–white crystals, which were also stable under pure nitrogen. The potassium 2-aminoethylamide was prepared in a similar way from ethylenediamine and potassium hydride. Its solid product resembles that of the corresponding sodium amide, but its solutions in ethylenediamine are less stable, rapidly turning dark brown because of polymerization. The basic strengths of these two 2-aminoethylamides were compared with the corresponding lithium amide by following potentiometrically the neutralization of ethylenediamine solutions of hydrochloric acid, p-methoxyphenol, water, and ethanolamine respectively. According to the heights of the potential jumps at the equivalence points the basic strength of the amides was found to increase in the order Na < Li < K.

An experimental study of mass transfer with chemical reaction from single gast bubbles

AbstractRates of forced convection mass transfer from single bubbles of carbon dioxide reacting in aqueous ethanolamine solutions have been determined experimentally for intermediate babble Reynolds numbers.A water tunnel apparatus, and technique for measuring mass transfer rates are described.The results of the experimental study are compared with a mathematical model describing mass transfer with an accompanying second order reaction; the hydrodynamic condition of the model is described using Kawaguti type velocity profiles.The experimental data appear to confirm the model satisfactorily.

An examination of some of the factors affecting the determination of carbon dioxide by non-aqueous titrimetry

Some of the factors, including choice of absorbent, indicator and titrant, that affect the determination of carbon dioxide by non-aqueous titrimetry are examined experimentally. The results of this examination are used to give a procedure that is recommended for the determination of milligram amounts of carbon dioxide.The method involves absorption of the carbon dioxide in a 5 per cent. v/v solution of ethanolamine in formdimethylamide, followed by titration with standard tetrabutyl ammonium hydroxide in benzene-methanol solution to a visual end-point with thymolphthalein indicator.

The corrosion of mild steel by ethanolamine solutions

The corrosion of mild steel by ethanolamine solutions