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Sample records for 2-propanol

  1. Partial oxidation of 2-propanol on perovskites

    Sumathi, R.; Viswanathan, B.; Varadarajan, T.K. [Indian Inst. of Tech., Madras (India). Dept. of Chemistry

    1998-12-31

    Partial oxidation of 2-propanol was carried out on AB{sub 1-x}B`{sub x}O{sub 3} (A=Ba, B=Pb, Ce, Ti; B`=Bi, Sb and Cu) type perovskite oxides. Acetone was the major product observed on all the catalysts. All the catalysts underwent partial reduction during the reaction depending on the composition of the reactant, nature of the B site cation and the extent of substitution at B site. The catalytic activity has been correlated with the reducibility of the perovskite oxides determined from Temperature Programmed Reduction (TPR) studies. (orig.)

  2. Partial ionisation cross-sections of 2-propanol and ethanal

    Electron impact ionisation of 2-propanol and ethanal is studied using mass spectrometry. Cross-sections of the formation of molecular ions and ionic fragments are measured between 14 and 86eV. Free energy changes are evaluated using ab initio calculations. For 2-propanol, two ions, identified as CH3CHOH+ (45amu) and CH3CHCH3+ (43amu), contribute more than 75% to the total cross-section over the whole range of electron energies and are produced by simple bond cleavage in the molecular ion. Both processes occur spontaneously, leaving the molecular ion as a minority species. For ethanal, two ions, identified as HCO+ (29amu) and CH3CO+ (43amu), and the molecular ion (44amu) contribute more than 80% to the total cross-section. The ions of 29 and 43amu result from a simple bond cleavage in the molecular ion. These sprocesses are not spontaneous and the contribution of the molecular ion becomes predominant at 15eV and is therefore significant over the whole range of ionisation energies

  3. Performance analysis for direct 2-propanol fuel-cell based on Pt containing anode electrocatalysts

    TAPAN, Niyazi Alper; ÖZTÜRK, Ezgi

    2009-01-01

    Direct 2-propanol cell performance based on Pt containing anode electrocatalyst was evaluated. Cell performance, open circuit voltage, maximum current density, and maximum power density were measured at various alcohol concentrations and cell temperatures. 2-propanol fuel cell shows the highest performance at 1 M concentration and 80 °C operating temperature. The highest practical efficiency (at the maximum power density) was found at 2 M 2-propanol concentration and 60 °C operating ...

  4. Effect of γ-irradiation on the catalytic decomposition of 2-propanol

    70 kGy of γ-irradiation enhances the catalytic transformation of 2-propanol into acetone and propylene on transition metal oxides. Fragment products are formed and for TiO2, V2O5 and Fe2O3 the selectivity of 2-propanol decomposition is shifted towards dehydration by the irradiation. Both catalytic and radiocatalytic transformation of 2-propanol correlate with the adsorption capacity of metal oxides, which suggests that irradiation acts mainly on the adsorbed 2-propanol. Possible changes in the catalyst's chemical properties due to the irradiation are discussed. (author)

  5. (3-Aminophenyldiphenylphosphine oxide–2-propanol (1/1

    Jafar Attar Gharamaleki

    2008-03-01

    Full Text Available The title compound, C18H16NOP·C3H8O, was synthesized by the reduction of (3-nitrophenyldiphenylphosphine oxide in the presence of 2-propanol as recrystallization solvent. There are two molecules in the asymmetric unit. Each P atom is tetracoordinated by three C and one O atom from two phenyl fragments, one aniline group and one double-bonded O atom in a distorted tetrahedral geometry. C—H...π and N—H...π interactions are present. In the crystal structure, a wide range of non-covalent interactions consisting of hydrogen bonding [of the types of O—H...O, N—H...O and C—H...O, with D...A distances ranging from 2.680 (3 to 3.478 (3 Å] and π–π [centroid–centroid distance of 3.7720 (15 Å] stacking interactions connect the various components into a supramolecular structure.

  6. Sex differences in the toxicokinetics of inhaled solvent vapors in humans 2. 2-propanol

    The aim of this study was to evaluate possible sex differences in the inhalation toxicokinetics of 2-propanol vapor. Nine women and eight men were exposed on different occasions for 2 h during light physical exercise (50 W) to 2-propanol (350 mg/m3) and to clean air (control exposure). The level corresponds to the Swedish occupational exposure limit. 2-Propanol and its metabolite acetone were monitored up to 24 h after exposure in exhaled air, blood, saliva, and urine by headspace gas chromatography. Body fat and lean body mass were estimated from sex-specific equations using bioelectrical impedance, body weight, height, and age. Genotypes were determined by PCR-based assays for alcohol dehydrogenase and cytochrome P450 2E1 (CYP2E1). The CYP2E1 phenotype was assessed by the 2-h plasma 6-hydroxychlorzoxazone/chlorzoxazone metabolic ratio in vivo. The toxicokinetic profile in blood was analyzed using a one-compartment population model. The following sex differences were significant at the p 0.05 level (Student's t test). The respiratory uptake was lower and the volume of distribution smaller in females. The women had a slightly shorter half-time of 2-propanol in blood and a higher apparent total clearance when corrected for body composition. However, women reached approximately four times higher 2-propanol levels in exhaled air at 10-min postexposure and onward. Acetone in blood was markedly higher in females than in males in the control experiment and slightly higher following exposure to 2-propanol. A marked sex difference was that of a 10-fold higher in vivo blood:breath ratio in men, suggesting sex differences in the lung metabolism of 2-propanol. The most marked sex difference was that of salivary acetone, for which an approximately 100-fold increase was seen in women, but no increase in men, after exposure to 2-propanol compared to clean air. The toxicokinetic analysis revealed no significant differences in toxicokinetics between subjects of different metabolic

  7. Molecular conformation and liquid structure of 2-propanol through neutron diffraction

    A Sahoo; S Sarkar; P S R Krishna; R N Joarder

    2010-05-01

    The neutron diffraction data analysis of deuterated liquid 2-propanol at room temperature to define its molecular conformation is presented. 2-Propanol being a large molecule with twelve atomic sites, the conformation analysis is tricky and an improved method of data analysis is given. The intermolecular structural correlations, i.e., hydrogen-bonded liquid structure, can be modelled accurately to extract the nature of the average hydrogen-bonded molecular association in liquid state at room temperature. Like other alcohols these are mostly hexamer ring chain (HRC) clusters. The cluster analysis of recent X-ray data available in the literature also support the same liquid structure.

  8. Kinetics of the γ-radiation-initiated reaction of 2-propanol with tri- and hexafluoropropylene

    The initiation of telomerization reactions by ionizing radiation provides good opportunities for studying the kinetics of free radical reactions. The fluoroalcohols and their derivatives prepared using fluoroolefins and aliphatic alcohols find wide practical application. The object of this exercise was to study the reactivity of trifluoropropylene and hexafluoropropylene with 2-propanol. The reaction products were analyzed gas chromatographically

  9. Solvation thermodynamics of ammonium iodide ions in 2-propanol and its mixtures with water

    The electrometric method using chains without transfer has been applied to determine total thermodynamic characteristics of ammonium iodide ions salvation in 2-propanol and its mixtures with water at 278.15-308.15 K.Regularities of their changes with temperature and composition of a mixed solvent are considered

  10. Photodissociation dynamics of 1-propanol and 2-propanol at 193.3 nm

    193.3-nm photodissociation dynamics of jet-cooled 1-propanol and 2-propanol and their partially deuterated variants are examined by using the high-n Rydberg-atom time-of-flight technique. Isotope labeling studies show that O-H bond fission is the primary H-atom production channel in the ultraviolet photodissociation of both 1-propanol and 2-propanol. Center-of-mass (c.m.) product translational energy release of the RO-H dissociation channel is large, with T>=0.78 for H+1-propoxy (n-propoxy) and 0.79 for H+2-propoxy (isoproxy). Maximum c.m. translational energy release yields an upper limit of the O-H bond dissociation energy: 433±2 kJ/mol in 1-propanol and 435±2 kJ/mol in 2-propanol. H-atom product angular distribution is anisotropic (with β≅-0.79 for 1-propanol and -0.77 for 2-propanol), suggesting an electronic transition moment perpendicular to the H-O-C plane and a short excited-state dissociation lifetime (less than a rotational period). Information about photodissociation dynamics and bond energies of the partially deuterated propanols are also obtained. The 193.3-nm photodissociation dynamics of 1-propanol and 2-propanol are nearly identical to each other and are similar to those of methanol and ethanol. This indicates a common RO-H dissociation mechanism: after the nO→σ*(O-H)/3s excitation localized on the H-O-C moiety, the H atom is ejected promptly in the H-O-C plane in a time scale shorter than a rotational period of the parent molecule, and it dissociates along the O-H coordinate on the repulsive excited-state potential-energy surface with a large translational energy release

  11. Characterization of the products formed by the reaction of trichlorocyanuric acid with 2-propanol.

    Sandercock, P Mark L; Barnett, Julie S

    2009-11-01

    We report a recent investigation into the death of a cat that was initially thought to involve intentionally burning the animal via the use of an ignitable liquid. The exposure of the animal to flame was ruled out. Instead, forensic investigation revealed the intentional mixing together of a common outdoor swimming pool chlorinator, trichlorocyanuric acid (TCCA), and 2-propanol (aka, isopropyl alcohol or rubbing alcohol). The reaction of these two chemicals resulted in the formation of cyanuric acid residue, hydrochloric acid, and the evolution of a significant volume of chlorine gas. Further alpha-chlorination side reactions also occurred between 2-propanol and TCCA to produce a variety of chlorinated 2-propanone species that were detected on the submitted evidence. The identification of the products of both the main reaction and the side reactions allowed the authors to determine what chemicals were originally mixed together by the culprit. PMID:19818110

  12. Electrooxidation of 2-propanol and 2-butanol on the Pt–Ni alloy nanoparticles in acidic media

    Graphical abstract: Schematic representation of 2-propanol electrooxidation on the Pt–Ni alloy. Highlights: ► Electrocatalytic oxidation of 2-propanol and 2-butanol on the Pt–Ni nanoparticles. ► High stability and reproducibility of the Pt–Ni nanoparticles at the CCE. ► Pt–Ni/CCE as a potent electrocatalyst in the oxidation of alcohols in DAFCs. -- Abstract: The platinum–nickel nanoparticles carbon-ceramic modified electrode (Pt–Ni/CCE) was used as a potent electrocatalyst for the electrooxidation of 2-propanol and 2-butanol in a mixture of 0.15 M 2-propanol (or 0.15 M 2-butanol) and 0.1 M H2SO4 solutions. The Pt–Ni/CCE catalyst shows excellent electrocatalytic activity for electrooxidation of these fuels in comparison with platinum nanoparticles of carbon-ceramic modified (Pt/CCE) and smooth Pt electrodes due to the presence of Ni atoms in the alloy which enhances the electrocatalytic activity of Pt toward the oxidation of 2-propanol and 2-butanol and reduces the amount of Pt in the anodic material of direct 2-propanol and 2-butanol fuel cells. Furthermore, the Pt–Ni/CCE catalyst has satisfactory stability and reproducibility for the electrooxidation of 2-propanol and 2-butanol in acidic media when stored in ambient conditions or when used in constant potential applying (chronoamperometry) and continuous potential cycling (cyclic voltammetry) which makes it more attractive for alcohol-based fuel cell applications

  13. UNIQUAC activity coefficient model for the systems of 1-propanol + water and 2-propanol + water

    Numuang, C.; Kaewsichan, L.

    2005-01-01

    Predictions of vapor liquid equilibria and azeotrope conditions of binary systems of 1-propanol+ water and 2-propanol+water at 30, 60, and 100 kPa were conducted in this work. UNIQUAC activity coefficient and ideal gas models represented behavior of the systems in liquid phase and vapor phase respectively. Experimental data collected from the literature (Gobaldon et al., 1996 and Marzal et al., 1996) were used to calculate energy interaction parameters of the UNIQUAC activity coefficient mode...

  14. Gas Chromatography Method of Cleaning Validation Process for 2-Propanol Residue Determination in Pharmaceutical Manufacturing Equipment

    Łukasz Czubak

    2014-07-01

    Full Text Available Cleaning validation is an integral operation of good manufacturing practice in pharmaceutical industry. The aim of this study was to validate simple analytical method for detection of 2-propanol residue in equipment, which is likely contaminated with 2-propanol, usually used in the production area. The gas chromatography with flame ionization detection (GC-FID method was validated on a GC system using DB-FFAP capillary column at the flow rate of 4.9 mL/min. The calibration curve was linear over concentration range from 2.8µg/mL to 110.7µg/mL with a correlation coefficient equal to 0.99981. The detection limit (LOD and quantitation limit (LOQ were 1.1µg/mL and 2.8µg/mL, respectively. The simplicity of gas chromatography method makes it useful for routine analysis of 2-propanol residue and is an alternative to corresponding methods.

  15. Structure Chemical Composition And Reactivity Correlations during the In Situ Oxidation of 2-Propanol

    K Paredis; L Ono; S Mostafa; L Li; Z Zhang; J Yang; L Barrio; A Frenkel; B Roldan Cuenya

    2011-12-31

    Unraveling the complex interaction between catalysts and reactants under operando conditions is a key step toward gaining fundamental insight in catalysis. We report the evolution of the structure and chemical composition of size-selected micellar Pt nanoparticles ({approx}1 nm) supported on nanocrystalline {gamma}-Al{sub 2}O{sub 3} during the catalytic oxidation of 2-propanol using X-ray absorption fine-structure spectroscopy. Platinum oxides were found to be the active species for the partial oxidation of 2-propanol (<140 C), while the complete oxidation (>140 C) is initially catalyzed by oxygen-covered metallic Pt nanoparticles, which were found to regrow a thin surface oxide layer above 200 C. The intermediate reaction regime, where the partial and complete oxidation pathways coexist, is characterized by the decomposition of the Pt oxide species due to the production of reducing intermediates and the blocking of O{sub 2} adsorption sites on the nanoparticle surface. The high catalytic activity and low onset reaction temperature displayed by our small Pt particles for the oxidation of 2-propanol is attributed to the large amount of edge and corner sites available, which facilitate the formation of reactive surface oxides. Our findings highlight the decisive role of the nanoparticle structure and chemical state in oxidation catalytic reactions.

  16. An investigation into the electro-oxidation of ethanol and 2-propanol for application in direct alcohol fuel cells (DAFCs)

    Sagar Sen Gupta; Jayati Datta

    2005-07-01

    A comparative study of the electro-oxidation of ethanol and 2-propanol was carried out on carbon-supported platinum particles. Cyclic voltammetry, steady state polarisation, and electrochemical impedance spectroscopy were used to investigate the oxidation reactions. A difference in the mechanistic behaviour of the oxidation of ethanol and 2-propanol on Pt was observed, thereby highlighting the fact that the molecular structure of the alcohol has great influence on its electroreactivity. The study emphasizes the fact that 2-propanol is a promising fuel candidate for a direct alcohol fuel cell.

  17. APPLICATION OF RESPONSE SURFACE METHOD ON PURIFICATION OF GLUCOMANNAN FROM AMORPHOPHALLUS ONCOPHYLLUS BY USING 2-PROPANOL

    DYAH H. WARDHANI

    2016-04-01

    Full Text Available Glucomannan purification methods affect the properties of mannan and have influence to the scope of glucomannan applications. Combination between ethanol solution and thermal treatment is commonly method applied to purify glucomannan obtained from Amorphophallus sp. However, 2-propanol was reported to be more effective in removing glucomannan impurities including the starch and the carotenes. The objective of this research was to study the effect of 2-propanol concentration, temperature and time as well as their interaction on purification of glucomannan obtained from Amorphophallus oncophyllus by using response surface methods. The relevant parameters (glucomannan content, starch content, degree of whiteness, yield were investigated in order to establish mathematical model. The results showed that the linear models were reliable to predict the responses (R2 ≥ 0.926. Temperature was a significant variable for the all responses. This purification method improved the absorbance of the functional groups at ~2900 cm-1 of stretching of C-H vibration and ~1730 cm-1 of acetyl group which is responsible on glucomannan solubility. However, this method reduced the absorbance of the functional groups at ~1650, ~1070, ~1020 and 900 - 800 cm-1 of absorbed water or protein, C-O alcohol and -glucosidic and -mannosidic linkages, respectively. The morphology observation revealed that this purification method achieves separation and removal of impurities which encapsulated the glucomannan and subsequently released the glucomannan granules. The highest content of glucomannan obtained in this study was 72.30 % when 90 % 2-propanol at 75 °C for 180 min was used for purification.

  18. UNIQUAC activity coefficient model for the systems of 1-propanol + water and 2-propanol + water

    Numuang, C.

    2005-12-01

    Full Text Available Predictions of vapor liquid equilibria and azeotrope conditions of binary systems of 1-propanol+ water and 2-propanol+water at 30, 60, and 100 kPa were conducted in this work. UNIQUAC activity coefficient and ideal gas models represented behavior of the systems in liquid phase and vapor phase respectively. Experimental data collected from the literature (Gobaldon et al., 1996 and Marzal et al., 1996 were used to calculate energy interaction parameters of the UNIQUAC activity coefficient model by non-linear regression method. The obtained parameters were not dependent on temperature and mole fraction; however, those parameters were dependent on pressure of the system. The mean absolute error of vapor mole fraction of alcohol and water were in the range 3.86-4.65% and 2.33-3.28% respectively for the binary system of 1-propanol +water. The mean absolute error of vapor mole fraction of alcohol and water were in the range 1.93-2.06% and 1.47-1.94% respectively for the binary system of 2-propanol+water. The thermodynamics consistency test proved that the UNIQUAC activity coefficient model was satisfied very well with Gibbs- Duhem equation.

  19. Formation of 2-propanol in condensed molecular films of acetaldehyde following electron impact ionisation-induced proton transfer*

    Borrmann, Tobias; Swiderek, Petra

    2016-06-01

    Experimental studies on thin condensed layers of acetaldehyde have previously revealed that electron exposure at an energy above the ionisation threshold leads to formation of 2-propanol. However, the mechanism of this reaction remained unclear. Therefore, a computational approach is used to explore the electron-induced reactions of acetaldehyde yielding 2-propanol. Starting from hydrogen-bonded dimers of acetaldehyde we show that the initial ionisation event triggers proton transfer between the two acetaldehyde moieties resulting in a hydrogen-bonded complex of a [OCCH3] radical and a protonated acetaldehyde cation. Given an excess energy of up to 0.75 eV and a favourable arrangement, a methyl radical released upon dissociation of the CC bond within the [OCCH3] radical can migrate to the carbonyl carbon of the protonated acetaldehyde cation. This produces a 2-propanol radical cation and CO. Neutral 2-propanol is then obtained by recombination with a second electron. A mechanism involving ionisation-driven proton transfer is thus proposed as pathway to the formation of 2-propanol during electron exposure of condensed layers of acetaldehyde.

  20. The buffering-out effect and phase separation in aqueous solutions of EPPS buffer with 1-propanol, 2-propanol, or 2-methyl-2-propanol at T = 298.15 K

    Highlights: ► Buffering-out is a new liquid–liquid phase separation containing biological buffer. ► EPPS buffer-induced phase separation of aqueous solutions of aliphatic alcohols. ► Phase diagrams of EPPS + water + 1-propanol/2-propanol/2-methyl-2-propanol are studied. ► EPPS breaks the 1-propanol + water and 2-methyl-2-propanol + water azeotropes. ► The (liquid + liquid) equilibria can be well correlated by the NRTL model. - Abstract: Buffering-out is a new liquid–liquid phase separation phenomenon observed in mixtures containing a buffer as a mass separating agent. The (liquid + liquid) equilibrium (LLE) and (solid + liquid + liquid) equilibrium (SLLE) data were measured for the ternary systems {3-[4-(2-hydroxyethyl)piperazin-1-yl]propanesulfonic acid (EPPS) buffer + 1-propanol, 2-propanol, or 2-methyl-2-propanol + water} at T = 298.15 K under atmospheric pressure. The phase boundary data were fitted to an empirical equation relating to the concentrations of organic solvent and buffer. The effective excluded volume (EEV) values of EPPS were obtained from the phase boundary data. The phase-separation abilities of the investigated aliphatic alcohols were discussed. The reliability of the experimental tie-lines was satisfactorily confirmed by the Othmer–Tobias correlation. The experimental tie-lines data for the ternary systems have been correlated using the NRTL activity coefficient model. The separation of these aliphatic alcohols from their azeotropic aqueous mixtures is of particular interest to industrial process. The addition of the EPPS as an auxiliary agent breaks the (1-propanol + water) and (2-methyl-2-propanol + water) azeotropes. The possibility of using the new phase separation systems in the extraction process is demonstrated by using different dyestuffs.

  1. Crystallization of 2-propanol studied by neutron diffraction and dielectric spectroscopy in real-time

    The crystallization of 2-propanol was investigated in order to monitor the change of the molecular dynamics with increasing crystallinity by means of real-time dielectric spectroscopy and neutron-diffraction experiments. Both experiments were performed during isothermal crystallization at 135.5 K, above the glass-transition temperature (Tg=115 K). In the dielectric spectrum was observed a moderate shift of the peak of the α-relaxation and a broadening of the spectrum. The crystallization at that temperature is explained with a simple model of the transformed volume fraction based on steady-state homogeneous nucleation of crystallites which grow at a constant rate. Although no direct information about the morphology of the sample is available, the indirect measurements by means of neutron diffraction indicate a three-dimensional crystal growth. (orig.)

  2. Solid-liquid interface of a 2-propanol-perfluoromethylcyclohexane mixture: From adsorption to wetting

    The liquid-solid interface between a silicon substrate and the binary mixture perfluoromethylcyclohexane (PFMC) and 2-propanol (IP) is examined by x-ray specular reflectivity and diffuse scattering under grazing angles. The wetting films between the PFMC-rich phase and the substrate are characterized with respect to the density profile and lateral fluctuations. We find that the liquid-liquid interface of the film is anomalously broadened as compared to capillary wave theory. This broadening is caused by a locally slow variation of the density between the liquid phases and marks an adsorption profile that does not reflect the bulk properties of the film phase. Essentially the same behavior is present for a fused silica substrate

  3. Adsorption of 2-propanol on MgO surface: A combined experimental and theoretical study

    Fuente, Silvia A.; Ferretti, Cristián A.; Domancich, Nicolás F.; Díez, Verónica K.; Apesteguía, Carlos R.; Di Cosimo, J. Isabel; Ferullo, Ricardo M.; Castellani, Norberto J.

    2015-02-01

    The adsorption of 2-propanol (or isopropanol) on MgO was studied using infrared (IR) spectroscopy and density functional theory (DFT) simulations. The analysis of IR spectra indicates that the molecule can adsorb either molecularly or dissociatively. DFT calculations show that the adsorption mode depends on the active site of the catalyst. While on perfect terrace it adsorbs non-dissociatively, on edge and on threefold coordinated O anion (O-corner sites) the adsorption occurs dissociatively by breaking the Osbnd H bond without activation barrier giving 2-propoxide and a surface hydroxyl group. Calculations also suggest that vacant oxygen centers on terrace, edge and corner are also possible sites for non-dissociative adsorption. On Mg ions located at corners the adsorption is strong but non-dissociative, while on a Mg vacancy at the same position the molecule easily dissociates. Frequency modes are also calculated and compared in detail with experimental IR spectra.

  4. Isopropylation of benzene with 2-propanol over substituted large pore aluminophosphate-based molecular sieves

    K Joseph Antony Raj; V R Vijayaraghavan

    2004-03-01

    Large pore aluminophosphate-based molecular sieves like AlPO4-5, MAPO-5, MnAPO-5 and ZAPO-5 were synthesised hydrothermally using triethylamine as a structure directing agent. These materials were characterised by X-ray diffraction (XRD), 27Al and 31P MAS-NMR, ICP-MS, -butylamine- TPD, BET and SEM. The catalytic performance of these materials was tested for isopropylation of benzene with 2-propanol at 250, 300, 350 and 400°C. The products were cumene, -DIPB (-diisopropylbenzene) and -DIPB (-diisopropylbenzene). MnAPO-5 was found to be more active than the other catalysts. Maximum conversion (20%) was noted at 350°C over MnAPO-5. The selectivity to DIPB was found to decrease with time on stream but the selectivity to cumene showed an increase after 3 h of time on stream.

  5. Vapour pressures and vapour-liquid equilibria of propyl acetate and isobutyl acetate with ethanol or 2-propanol at 0.15 MPa. Binary systems

    Susial Pedro

    2012-01-01

    Full Text Available Vapour pressures of propyl acetate, isobutyl acetate and 2-propanol from 0.004 to 1.6 MPa absolute pressure and VLE data for the binary systems propyl acetate+ethanol, propyl acetate+2-propanol, isobutyl acetate+ethanol and isobutyl acetate+2-propanol at 0.15 MPa have been determined. The experimental VLE data were verified with the test of van Ness and the Fredenslund criterion. The propyl acetate+ethanol or +2-propanol binary systems have an azeotropic point at 0.15 MPa. The different versions of the UNIFAC and ASOG group contribution models were applied.

  6. Study on Salt-Containing Extractive Distillation for the 2-Propanol/Water System

    Fu Jiquan

    2008-01-01

    The salt-containing extractive distillation column and the salt-containing agent recovery column for the 2-propanol/water/ethanediol/KAc system were simulated by the NRTL model and the modified Rose Relaxation method. The simulation results showed that prediction of the salt effect in vapor-liquid equilib-rium and the correlation method (TDCM) of NRTL parameters were suitable for the said system. Four different distillation technology processes were investigated; the results showed that the salt-containing extractive distillation process was the best one. The simulating design of the extractive distillation column was performed under the conditions of different total stage number, feeding location, reflux ratio, amount of mixed agent and concentration of KAc. The results showed that such factors as 17 stages, a feeding location at the 9th stage, a reflux ratio of 1.2, and a mixed agent feeding rate of 1.141 kmol/h, might be the best suited operating conditions. The simulating design was also done for the column for recovering the salt-containing agent. The simulation method of the salt-containing extractive distillation is simple and effective in this work.

  7. Sub- and supercritical liquefaction of rice straw in the presence of ethanol-water and 2-propanol-water mixture

    The critical liquefaction of rice straw to bio-oil with sub- and supercritical mixtures (ethanol-water and 2-propanol-water mixture) was studied in a 1000 ml autoclave at 533-623 K, 6-18 MPa, respectively. The results showed that the maximum yield of bio-oil was 39.7% for the 2-propanol:water volume ratio of 5:5 at 573 K, while the higher heating value (HHV) of bio-oil increased with the reaction temperature and solvent volume ratio. The formation of low-boiling-point materials was reduced by a mixture. Using a mixture could inhibit the formation of residue and then promote the conversion of rice straw with the ratio of 1:9-5:5. The bio-oil was analyzed by GC/MS and Elemental Analyzer, while the morphological changes of residue were observed by a scanning electron microscope (SEM)

  8. Effect of ionic liquids on (vapor + liquid) equilibrium behavior of (water + 2-methyl-2-propanol)

    Isobaric T, x, y data were reported for ternary systems of {water + 2-methyl-2-propanol (tert-butyl alcohol, TBA) + ionic liquid (IL)} at p = 100 kPa. When the mole fraction of TBA on IL-free basis was fixed at 0.95, measurements were performed at IL mass fractions from 0.6 down to 0.05, in a way of repeated synthesis. The vapor-phase compositions were obtained by analytical methods and the liquid-phase compositions were calculated with the aid of mass balances. Activity coefficients of water and TBA were obtained without the need of a thermodynamic model of the liquid-phase. Six ILs, composed of an anion chosen from [OAc]- or [Cl]-, and a cation from [emim]+, or [bmim]+, or [hmim]+, were studied. Relative volatility and activity coefficients were presented in relation with the IL mole fraction, showing the effect of the ILs on a molar basis. The effect of the ILs on relative volatility of TBA to water was depicted by the effect of anions and cations on, respectively, the activity coefficients of water and TBA. The results indicated that, among the six ILs studied, [emim][Cl] has the most significant effect on enhancement of the relative volatility, which reaches a value of 7.2 at an IL mass fraction of 0.58. Another IL, [emim][OAc], has also significant effect, with an appreciable value of 5.2 for the relative volatility when the IL mass fraction is 0.6. Considering the relatively low viscosity and melting point of [emim][OAc], it might be a favorable candidate as solvent for the separation of water and TBA by extractive distillation. Simultaneous correlation by the NRTL model was presented for both systems of (water + ethanol + IL) and (water + TBA + IL), using consistent binary parameters for water and IL

  9. Conductometric studies of dissociation constants of benzoic acid in water and 2-propanol mixtures at different temperatures

    The molar conductance of dilute solutions of benzoic acid in binary mixtures of water and 2-propanol has been measured at temperatures ranging from 298.15 K to 313.15 K. The experimental data were analyzed by means of the Fuoss-Kraus equation (1933) for the derivation of the thermodynamic dissociation constants and limiting molar conductance. The results were compared with those available in literature pertaining to analogue media. (author)

  10. Inhibition of alcohol dehydrogenase after 2-propanol exposure in different geographic races of Drosophila mojavensis: lack of evidence for selection at the Adh-2 locus.

    Pfeiler, Edward; Reed, Laura K; Markow, Therese A

    2005-03-15

    High frequencies of the fast allele of alcohol dehydrogenase-2 (Adh-2F) are found in populations of Drosophila mojavensis that inhabit the Baja California peninsula (race BII) whereas the slow allele (Adh-2S) predominates at most other localities within the species' geographic range. Race BII flies utilize necrotic tissue of pitaya agria cactus (Stenocereus gummosus) which contains high levels of 2-propanol, whereas flies from most other localities utilize different cactus hosts in which 2-propanol levels are low. To test if 2-propanol acts as a selective force on Adh-2 genotype, or whether some other yet undetermined genetic factor is responsible, mature males of D. mojavensis lines derived from the Grand Canyon (race A) and Santa Catalina Island (race C), each with individuals homozygous for Adh-2F and Adh-2S, were exposed to 2-propanol for 24 h and ADH-2 specific activity was then determined on each genotype. Flies from five other localities homozygous for either the fast or slow allele also were examined. Results for all reported races of D. mojavensis were obtained. 2-propanol exposure inhibited ADH-2 specific activity in both genotypes from all localities, but inhibition was significantly less in two populations of race BII flies homozygous for Adh-2F. When F/F and S/S genotypes in flies from the same locality were compared, both genotypes showed high 2-propanol inhibition that was not statistically different, indicating that the F/F genotype alone does not provide a benefit against the inhibitory effects of 2-propanol. ADH-1 activity in female ovaries was inhibited less by 2-propanol than ADH-2. These results do not support the hypothesis that 2-propanol acts as a selective factor favoring the Adh-2F allele. PMID:15726639

  11. Oxidation of 2-propanol ligands during collision-induced dissociation of a gas-phase uranyl complex

    van Stipdonk, Michael J.; Chien, Winnie; Anbalagan, Victor; Gresham, Garold L.; Groenewold, Gary S.

    2004-10-01

    We demonstrate, by way of multi-stage tandem mass spectrometry and extensive deuterium labeling, that 2-propanol is converted to acetone, and 2-propoxide to acetaldehyde, when monopositive 2-propanol-coordinated uranyl-ligand cations are subjected to collision-induced dissociation in the gas-phase environment of an ion trap mass spectrometer. A species with formula [(UO2OCH(CH3)2)(HOCH(CH3)2)]+, derived from dissociation of the gas-phase precursor [(UO2NO3)(HOCH(CH3)2)3]+ eliminates two H atoms and CH3 in consecutive stages to generate a monopositive complex composed of the U(V) species UO2+ coordinated by acetone and acetaldehyde, i.e. [UO2+(OC(CH3)2)(OC(H)CH3)]. Dissociation of this latter ion resulted in elimination of the two coordinating carbonyl ligands in two consecutive dissociation stages to leave UO2+. Analogous reactions were not observed for uranyl complexes containing 1-propanol or 2-methyl-2-propanol, or for cationic complexes with divalent metals such as Ni2+, Co2+, Pb2+ and Ca2+. One explanation for these reactions is bond insertion by the metal center in the bis-ligated uranyl complex, which would be expected to have an LUMO consisting of unoccupied 6d-orbitals that would confer transition metal-like behavior on the complex.

  12. Studies on Dechlorination of DDT with Alkaline 2-propanol and Iron-Nickel (Fe-Ni) Catalyst.

    Shareef, A.; Zaman, S. U.

    2009-05-01

    The Persistent Organic Pollutants (POPs) pesticides were previously extensively used in the cotton production and other agricultural activities in Pakistan and at least three thousand metric tons of obsolete pesticides have been stored under extreme hazardous conditions in more than thousand sites. Locally banned or severely restricted pesticides are easily available and DDT is continuously illegally imported and use in our country. Elimination of organochlorine pesticides (OCPs) waste has received considerable attention over the past two decades. Existing catalytic hydrodechlorinated techniques for disposing of OCPs are very costly due to the use of noble metals as catalysts. The aim of our study is to develop the cost effective and efficient method for the safe disposal of OCPs. This study is in continuation work on dechlorination of organochlorine pesticides with Fe-Ni catalyst in alkaline 2-propanol media. We turned our attention to the development of DDT disposal method for the third world countries. Herein, we report our first finding that in alkaline 2-propanol with Fe-Ni catalyst is an effective method for dechlorination of DDT. Catalytic dechlorination of DDT was carried out in an alkaline solution of NaOH and 2-propanol in the presence of catalyst at the temperature below 82 oC and end products were analyzed by using Gas Chromatography (GC-ECD) and Ion Chromatography (IC) techniques. Results obtained with initial concentration of DDT ranging between 10-100 μg/ml showed conversion of DDT to chlorine free product within 4 hrs.

  13. Role of mitogen-activated protein kinases and nuclear factor-kappa B in 1,3-dichloro-2-propanol-induced hepatic injury

    Lee, In-Chul; Lee, Sang-Min; Ko, Je-Won; Park, Sung-Hyeuk; Shin, In-Sik; Moon, Changjong; Kim, Sung-Ho; Kim, Jong-Choon

    2016-01-01

    In this study, the potential hepatotoxicity of 1,3-dichloro-2-propanol and its hepatotoxic mechanisms in rats was investigated. The test chemical was administered orally to male rats at 0, 27.5, 55, and 110 mg/kg body weight. 1,3-Dichloro-2-propanol administration caused acute hepatotoxicity, as evidenced by an increase in serum aminotransferases, total cholesterol, and total bilirubin levels and a decrease in serum glucose concentration in a dose-dependent manner with corresponding histopath...

  14. The electro-oxidation of the mixture of formaldehyde and 2-propanol on gold (100) and (111) single crystal planes in alkaline medium

    BRANISLAV Z. NIKOLIC; MILKA L. AVRAMOV-IVIC; TANJA R. VIDAKOVIC

    2000-01-01

    The effect of formaldehyde on the oxidation of 2-propanol and vice versa on gold single crystal planes (100 and 111) was studied. An activating effect in the reaction of the simultaneous oxidation of 2-propanol and formaldehyde was obtained on a gold (100) plane. In the case of a gold (111) electrode, the activation effect was not obtained. It was concluded that the adsorption of formaldehyde on the electrode surface prevents the adsorption of poisoning species formed during the electro-oxida...

  15. Electrochemical oxidation of 2-propanol over platinum and palladium electrodes in alkaline media studied by in situ attenuated total reflection infrared spectroscopy.

    Okanishi, Takeou; Katayama, Yu; Ito, Ryota; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2016-04-21

    The electrochemical oxidation of 2-propanol over Pt and Pd electrodes was evaluated in alkaline media. Linear sweep voltammograms (LSVs), chronoamperograms (CAs), and simultaneous time-resolved attenuated total reflection infrared (ATR-IR) spectra of both electrodes were obtained in a 0.25 M KOH solution containing 1 M 2-propanol. The onset potential of 2-propanol oxidation for Pt was lower than that for Pd in LSVs while the degree of performance degradation observed for Pd was significantly smaller than that observed for Pt in CAs. The main product of 2-propanol oxidation was acetone over both electrodes and, over Pt only, acetone produced was catalytically oxidized to the enolate ion, which was accumulated on the Pt surface, leading to significant performance degradation. Carbon dioxide and carbonate species (CO3(2-), HCO3(-)) were not observed during 2-propanol oxidation over both electrodes, indicating that the complete oxidation of 2-propanol to CO2 will be a minor reaction. PMID:27009749

  16. Adsorption and dehydrogenation of 2-propanol on the surface of γ-Al2O3-supported gold

    Martinez-Ramirez, Z.; Gonzalez-Calderon, J. A.; Almendarez-Camarillo, A.; Fierro-Gonzalez, J. C.

    2012-08-01

    The adsorption and reactions of 2-propanol on γ-Al2O3 and γ-Al2O3-supported gold samples were investigated by infrared (IR) spectroscopy, modulated differential scanning calorimetry (MDSC) and mass spectrometry. Adsorption of the alcohol on the samples at room temperature led to formation of molecularly adsorbed 2-propanol and 2-propoxide species bonded to Al3+ sites. Treatment of γ-Al2O3 after alcohol adsorption in flowing He from 25 to 300 °C led to 2-propanol desorption, without evidence of surface reactions. In contrast, when supported gold samples were exposed to the same thermal treatment, formation of acetone and H2 was observed by mass spectra of the effluent gases from the flow reactor. Concomitantly, IR spectra of the samples showed the appearance of a band at 1698 cm- 1, assigned to νCO vibrations of adsorbed acetone. The formation of acetone occurred by the dehydrogenation of 2-propoxide species bonded to Al3+ sites, as evidenced by (a) the decrease in the intensities of their IR bands and (b) the presence of a MDSC peak at approximately the same temperature as that at which acetone was formed and the 2-propoxide species were consumed. It is proposed that gold particles on the γ-Al2O3 surface facilitate breaking of the β-Csbnd H bond of neighboring surface 2-propoxide species to give acetone. Our results emphasize the bifunctional character of supported gold catalysts for the dehydrogenation of alcohols.

  17. Molecular interactions in binary mixtures of 1-butoxy-2-propanol with alcohols at different temperatures: A thermophysical and spectroscopic approach

    Highlights: • Binary mixtures of 1-butoxy-2-propanol with alcohols have been studied at different temperatures. • Strong H-bonding interactions between the components are confirmed that decreases with increasing chain length of alcohols. • Thermophysical and FT-IR spectroscopic studies strongly corroborate the experimental and computational analysis results. - Abstract: This paper reports densities (ρ) and speeds of sound (u) of 1-butoxy-2-propanol CH3(CH2)3OC3H6OH, 1-propanol CH3(CH2)2OH, 2-propanol (CH3)2CHOH, 1-butanol CH3(CH2)3OH and 2-butanol CH3CH2CH(OH)CH3 and their binary mixtures with 1-butoxy-2-propanol as a common component, measured at T = (293.15, 298.15, 303.15, 308.15 and 313.15) K over the entire composition range. These experimental values of density and speed of sound were used to calculate the values of excess molar volumes, VmE, deviations in molar isentropic compressibility Δκs and deviations in speed of sound uD. Further, experimental densities were used to estimate apparent molar volumes Vϕ,i, partial molar volumes V‾m,1, excess partial molar volumes V‾m,1E and their limiting values at infinite dilution Vϕ,i∞, V‾m,i∞ and V‾m,iE,∞ respectively. The variations observed in these properties, with composition and temperature, are discussed in terms of molecular interactions due to physical and chemical effects between the unlike molecules of the binary mixtures. These properties, especially excess functions, are found to be quite sensitive towards the intermolecular interactions in liquid mixtures. These excess functions and deviations have also been correlated using Redlich–Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors. FT-IR studies of these mixtures are also reported

  18. Volumetric Properties of Dilute Aqueous Solutions of 1- and 2-propanol to 50 MPa and 373.15 K

    Seitz, J.; Bahramian, J.; Blackwell, R.; Inaki, T.; York, D.; Schulte, M. D.

    2014-12-01

    The need to accurately model and understand reactions among organic compounds and biomolecules in solution is necessary to develop realistic chemical models for the reactions leading to the emergence of life and metabolic processes of extremophiles under elevated temperature and pressure conditions. Unfortunately, the scarcity of experimentally determined volumetric (and other) properties for important compounds at high temperatures and pressures leads to uncertainty in the calculation of reaction properties. Experimentally determined volumetric properties of aqueous solutions at non-standard conditions provide direct tests of current estimation methods and aid in the refinement of these methods. The goal of our research is to provide a database of experimentally determined volumetric properties. In previous studies, we have examined important organic molecules and biomolecules such as adenosine, coenzyme M and D-ribose. In this study, we investigate the volumetric properties of the structural isomers 1- and 2-propanol. 1-propanol (n-propanol) is a primary alcohol (CH3CH2CH2OH) and 2-propanol (isopropanol) is the simplest example of a secondary alcohol (CH3CHOHCH3). These compounds differ slightly in structure depending on to which carbon atom the hydroxyl group is bonded and will provide a sensitive test of current estimation methods and lead to more accurate predictions of the properties of complex aqueous systems at elevated temperatures and pressures. We obtained the densities of aqueous solutions of the alchohols using an Anton Paar DMA HP vibrating tube densimeter. Pressure was measured (pressure transducer) to an accuracy of ±0.01% and temperature was measured (integrated platinum thermometer) with an accuracy of ±0.05 K. Experimental uncertainty of density measurements is less than ±0.0001 g·cm-3. The partial molar volumes at infinite dilution (V∞) for 1- and 2-propanol were calculated from the measured densities and are shown in the figure at 0

  19. Catalytic properties of pure and K+-doped Cu O/Mg O system towards 2-propanol conversion

    Cu O/Mg O system having different compositions was prepared by impregnation method followed by calcination at 400-900 C. The effect of Cu O content, calcination temperature and doping with small amounts of K+ species (1-3 mol %) on physicochemical, surface and catalytic properties of the system were investigated using X-ray diffraction, adsorption of N2 at - 196 C, and conversion of isopropyl alcohol at 150-400 C using a flow technique. The results revealed that the solids having the formulae 0.2 and 0.3 Cu O/Mg O calcined at 400 C consisted of nano sized Mg O and Cu O as major phases together with Cu2O as minor phase. The Bet-surface areas of different absorbents are decreased by increasing Cu O content, calcination temperature and K+-doping. Mg O-support material showed very small catalytic activity in 2-propanol conversion. The investigated system behaved as selective catalyst for dehydrogenation of 2-propanol with selectivity >80%. The catalytic activity increased by increasing Cu O content and decreased by increasing the calcination temperature within 400-900 C. K+-doping increased the catalytic activity and catalytic durability. (Author)

  20. Isotopic labeling as a tool to establish intramolecular vibrational coupling: The reaction of 2-propanol on Mo(110)

    The reactions of 2-propanol on Mo(110) were investigated using temperature programmed reaction, high resolution electron energy loss, and x-ray photoelectron spectroscopies. 2-Propanol forms 2-propoxide upon adsorption at 120 K on Mo(110). The 2-propoxide intermediate deoxygenates via selective γ C--H bond scission to eliminate propene as well as C--O bond hydrogenolysis to form trace amounts of propane. The C--O bond of 2-propoxide is estimated to be nearly perpendicular to the surface. Selective isotopic labeling was used to establish the coupling between the C--O stretch and modes associated with the hydrocarbon framework. The degree of coupling was strongly affected by bonding to the surface, primarily due to weakening of the C--O bond when 2-propoxide is bound to Mo(110). Selective isotopic labeling was, therefore, essential in making vibrational assignments and in identifying key reaction steps. Only a small kinetic isotope effect was observed during reaction of (CD3)(CH3)CHOH, consistent with a substantial component of C--O bond breaking in the transition state for propene elimination. Coupling of the C--O stretch to motion of the methyl group is also suggested to be important in the transition state for propene elimination

  1. Pulse radiolysis of porphyrin and ferriporphyrin solutions in 2-propanol-carbon tetrachloride systems. Protonation and ligand exchange kinetics

    Pulse radiolysis of aqueous and nonaqueous 2-propanol-acetone-carbon tetrachloride mixtures has been investigated by means of conductivity measurements and spectrophotometry. In these solvent mixtures, a pulse of hydrochloric acid originating from either primary events of solvent radiolysis or from further reactions of carbon tetrachloride with radicals derived from 2-propanol and acetone, is produced within ca 100 nanoseconds. Further production of hydrochloric acid occurs as a result of chain reactions involving hydrogen abstraction by CCl3 or CCl3O2 radicals. These latter radicals appear to be much more reactive and are likely to be involved in the reaction unless the solutions have been thoroughly deoxygenated. Protonation Reactions of porphyrins and ferriporphyrins, which do not react rapidly with the above radicals, were followed by means of spectrophotometric measurements. In turn, these reactions may be used to monitor hydrochloric acid formation. Spectrophotometric measurements on porphyrins corroborate conductivity results, although a quantitative comparison is not feasible because of differences in solvent properties. 6 figures

  2. Isotopic labeling as a tool to establish intramolecular vibrational coupling: The reaction of 2-propanol on Mo(110)

    Uvdal, P.; Wiegand, B.C.; Serafin, J.G.; Friend, C.M. (Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138 (United States))

    1992-12-01

    The reactions of 2-propanol on Mo(110) were investigated using temperature programmed reaction, high resolution electron energy loss, and x-ray photoelectron spectroscopies. 2-Propanol forms 2-propoxide upon adsorption at 120 K on Mo(110). The 2-propoxide intermediate deoxygenates via selective {gamma} C--H bond scission to eliminate propene as well as C--O bond hydrogenolysis to form trace amounts of propane. The C--O bond of 2-propoxide is estimated to be nearly perpendicular to the surface. Selective isotopic labeling was used to establish the coupling between the C--O stretch and modes associated with the hydrocarbon framework. The degree of coupling was strongly affected by bonding to the surface, primarily due to weakening of the C--O bond when 2-propoxide is bound to Mo(110). Selective isotopic labeling was, therefore, essential in making vibrational assignments and in identifying key reaction steps. Only a small kinetic isotope effect was observed during reaction of (CD{sub 3})(CH{sub 3})CHOH, consistent with a substantial component of C--O bond breaking in the transition state for propene elimination. Coupling of the C--O stretch to motion of the methyl group is also suggested to be important in the transition state for propene elimination.

  3. Catalytic properties of pure and K{sup +}-doped Cu O/Mg O system towards 2-propanol conversion

    El-Molla, S. A.; Amin, N. H.; Hammed, M. N.; Sultan, S. N. [Ain Shams University, Faculty of Education, Chemistry Department, Roxy, Heliopolis, Cairo 11757 (Egypt); El-Shobaky, G. A., E-mail: saharelmolla@yahoo.com [National Research Center, Dokki, Cairo (Egypt)

    2013-08-01

    Cu O/Mg O system having different compositions was prepared by impregnation method followed by calcination at 400-900 C. The effect of Cu O content, calcination temperature and doping with small amounts of K{sup +} species (1-3 mol %) on physicochemical, surface and catalytic properties of the system were investigated using X-ray diffraction, adsorption of N{sub 2} at - 196 C, and conversion of isopropyl alcohol at 150-400 C using a flow technique. The results revealed that the solids having the formulae 0.2 and 0.3 Cu O/Mg O calcined at 400 C consisted of nano sized Mg O and Cu O as major phases together with Cu{sub 2}O as minor phase. The Bet-surface areas of different absorbents are decreased by increasing Cu O content, calcination temperature and K{sup +}-doping. Mg O-support material showed very small catalytic activity in 2-propanol conversion. The investigated system behaved as selective catalyst for dehydrogenation of 2-propanol with selectivity >80%. The catalytic activity increased by increasing Cu O content and decreased by increasing the calcination temperature within 400-900 C. K{sup +}-doping increased the catalytic activity and catalytic durability. (Author)

  4. Volumetric properties of ternary (IL + 2-propanol or 1-butanol or 2-butanol + ethyl acetate) systems and binary (IL + 2-propanol or 1-butanol or 2-butanol) and (1-butanol or 2-butanol + ethyl acetate) systems

    Highlights: ► Experimental densities were determined at T = (298.15, 303.15, and 313.15) K. ► IL: methyl trioctylammonium bis(trifluoromethylsulfonyl)imide was used. ► Virial Based Mixing Rule correlation of the binary excess molar volume data. ► Binary excess molar volume was both negative and positive. ► Ternary excess molar volume data was correlated with the Cibulka equation. - Abstract: The experimental densities for the binary or ternary systems were determined at T = (298.15, 303.15, and 313.15) K. The ionic liquid methyl trioctylammonium bis(trifluoromethylsulfonyl)imide ([MOA]+[Tf2N]−) was used for three of the five binary systems studied. The binary systems were ([MOA]+[Tf2N]− + 2-propanol or 1-butanol or 2-butanol) and (1-butanol or 2-butanol + ethyl acetate). The ternary systems were {methyl trioctylammonium bis(trifluoromethylsulfonyl)imide + 2-propanol or 1-butanol or 2-butanol + ethyl acetate}. The binary and ternary excess molar volumes for the above systems were calculated from the experimental density values for each temperature. The Redlich–Kister smoothing polynomial was fitted to the binary excess molar volume data. Virial-Based Mixing Rules were used to correlate the binary excess molar volume data. The binary excess molar volume results showed both negative and positive values over the entire composition range for all the temperatures. The ternary excess molar volume data were successfully correlated with the Cibulka equation using the Redlich–Kister binary parameters.

  5. Equilibrium solubility of CO2 in aqueous solutions of 1-amino-2-propanol as function of concentration, temperature, and pressure

    Research highlights: → Gas solubility of CO2 in aqueous solutions of 1-amino-2-propanol was measured. → Solubility increases as pressure and concentration of 1-amino-2-propanol increase. → The Kent-Eisenberg model was used to correlate all the experimental results. → Aqueous solutions of MIPA are an excellent alternative to use in gas purification. - Abstract: Using a dynamic method with recirculation of the vapour phase, experimental values for the gas solubility of carbon dioxide in aqueous solutions of 1-amino-2-propanol (MIPA) were measured at T = (313.15 and 393.15) K, over the pressure range of (0.2 to 2436.4) kPa. The concentrations of the studied aqueous MIPA solutions were (0.20, 0.30, 0.40, and 0.50) mass fraction. The results of gas solubility are given as the partial pressure of CO2, pCO2, against its mole ratio, αCO2 (mol CO2 · mol-1 MIPA), and its mole fraction, xCO2. It is observed that the solubility of CO2 increases as the concentration of MIPA in solution increases, at a given temperature throughout the pressure range considered; also the solubility values increase, under constant temperature, as the pressure increases in the studied concentration range of MIPA. The physicochemical model of Kent and Eisenberg was used to correlate simultaneously all the experimental results of the solubility of CO2 in the studied aqueous solutions of MIPA. The model correlates satisfactorily the experimental results. The deviation for pressure was 96.9 kPa using 62 experimental solubility points. The solubility results of carbon dioxide presented in this work are compared with those reported in the literature for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and N-methyldiethanolamine (MDEA) and it is possible to conclude that the aqueous solutions of MIPA are an excellent alternative to use in gas purification processes, since the magnitude of the solubility results of MIPA solutions was found to be

  6. (Liquid + liquid) equilibrium of (water + 2-propanol + 1-butanol + salt) systems at T = 313.15 K and T = 353.15 K: Experimental data and correlation

    Pereira, Milton A.P. [School of Chemical Engineering, State University of Campinas, P.O. Box 6066, 13081-970 Campinas-SP (Brazil); Aznar, Martin [School of Chemical Engineering, State University of Campinas, P.O. Box 6066, 13081-970 Campinas-SP (Brazil)]. E-mail: maznar@feq.unicamp.br

    2006-06-15

    (Liquid + liquid) equilibrium data for the quaternary systems (water + 2-propanol + 1-butanol + potassium bromide) and (water + 2-propanol + 1-butanol + magnesium chloride) were measured at T = 313.15 K and T = 353.15 K. The overall salt concentrations were 5 and 10 mass percent. Ternary (liquid + liquid) equilibrium data for the salt-free system (water + 2-propanol + 1-butanol) were also determined and found to be in good agreement with data from the literature. The NRTL model for the activity coefficient was used to correlate the data. New interaction parameters were estimated, using the Simplex minimization method and a concentration-based objective function. The results are very satisfactory, with root mean square deviations between experimental and calculated compositions of both phases being less than 0.5%.

  7. The electro-oxidation of the mixture of formaldehyde and 2-propanol on gold (100 and (111 single crystal planes in alkaline medium

    BRANISLAV Z. NIKOLIC

    2000-12-01

    Full Text Available The effect of formaldehyde on the oxidation of 2-propanol and vice versa on gold single crystal planes (100 and 111 was studied. An activating effect in the reaction of the simultaneous oxidation of 2-propanol and formaldehyde was obtained on a gold (100 plane. In the case of a gold (111 electrode, the activation effect was not obtained. It was concluded that the adsorption of formaldehyde on the electrode surface prevents the adsorption of poisoning species formed during the electro-oxidation of 2-propanol on the Au(100 plane, while this is not the case on the Au(111 plane. The different behaviour is caused by the difference in the symmetry of the surface atoms of these two Au single-crystal planes.

  8. Experimental and modeling investigations of solubility and saturated liquid densities and viscosities for binary systems (methane +, ethane +, and carbon dioxide + 2-propanol)

    Highlights: • Solubilities of CH4, C2H6, and CO2 in 2-propanol and saturated density and viscosity. • Solubility of C2H6 in 2-propanol is higher than CH4 and CO2. • Dissolution of CO2 increases liquid density and reduces liquid viscosity. • Liquid density and viscosity reduces with dissolution of CH4 and C2H6. • Solubilities and saturated liquid densities were predicted with SRK and PR EOS. -- Abstract: Solubilities of methane, ethane, and carbon dioxide in 2-propanol have been measured at the temperatures (303 and 323) K and at the pressures up to 6 MPa using an in-house designed PVT apparatus. The saturated liquid properties, density and viscosity, were also measured in each experiment. Prior to the phase equilibrium measurements, the density and viscosity of pure 2-propanol were measured at the temperatures (303 and 323) K over the pressure range (0.1 to 10) MPa. The dissolution of carbon dioxide in 2-propanol caused a decline in the viscosity of saturated liquid phase while an increase in the density of gas-expanded liquid was observed. The viscosity-pressure trends for methane- and ethane-saturated liquid viscosities were similar to carbon dioxide, but the saturated liquid densities decreased with the dissolution of methane and ethane in 2-propanol. Solubility increased with pressure and decreased with temperature for all compressed gases (methane, ethane and carbon dioxide). The experimental data were well correlated using Soave–Redlich–Kwong and Peng–Robinson equations of state. The solubilities and saturated liquid densities were well represented with both equations of state, and there is no superior equation of state for the modeling of the phase compositions and saturated liquid densities

  9. Removal of 2-propanol from water by pervaporation using poly(vinylidene fluoride) membrane filled with carbon black

    Sardarabadi, Hamideh; Mousavi, Seyed Mahmoud; Saljoughi, Ehsan

    2016-04-01

    In the present study, several filled poly(vinylidene fluoride) (PVDF) membranes by the addition of various weight fractions from carbon black (CB) to the casting solution were prepared for the removal of 2-propanol from aqueous solution in pervaporation process. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), contact angle and swelling degree measurements were used to study morphology and properties of the prepared membranes. Separation experiments were carried out at a feed temperature of 45 °C and a permeate pressure of 18 mmHg. The results demonstrated that the addition of carbon black filler resulted in formation of the membranes with denser structure; lower permeation flux and degree of swelling; and higher crystallinity, separation factor, contact angle, and pervaporation separation index.

  10. Effect of temperature and 2-propanol-acetone composition on enthalpy and entropy of solvation of ions Σ(Na+, I-)

    Summary enthalpy and entropy of ion solvation Σ(Na+, I-) in the 2-propanol - acetone system in the whole interval of mixed solvent compositions at 278.15 up to 318.15 K are determined on the basis of EMF measurements of chains without transfer

  11. Supplementary vapor pressure data of the glycol ethers, 1-methoxy-2-propanol, and 2-methoxyethanol at a pressure range of (15 to 177) kPa

    Highlights: ► Vapor pressure of 2-methoxyethanol and 1-methoxy-2-propanol were measured. ► Complementary data are reported at ranges of (342 to 417) K and (15 to 177) kPa. ► Three commonly used vapor pressure equations were fitted to experimental data. ► The parameters of Antoine and Wagner type equations were estimated. ► The relative deviations (rmsd) from the three vapor pressure equations were <0.4%. - Abstract: The vapor pressure of pure 1-methoxy-2-propanol and 2-methoxyethanol, commonly used as co-solvents in inks, paints, coatings, organic/water solutions among many other applications, were measured with a dynamic recirculation apparatus at a pressure range of (15 to 177) kPa. The measurements were performed at temperature ranges of (342 to 412) K for 1-methoxy-2-propanol and (346 to 417) K for 2-methoxyethanol. The maximum likelihood method was used to estimate the parameters of the Antoine equation, the parameters of an extended Antoine equation and the Wagner equation were determined by non linear least squares method. The three models showed root mean square deviations (rmsd) of 0.39%, 0.38%, and 0.29%, and 0.37%, 0.33%, and 0.32%, for 1-methoxy-2-propanol and 2-methoxyethanol, respectively. Additionally, the experimental data and correlation were compared with those available in the literature.

  12. Effect of temperature and the composition of the water-2-propanol solvent on thermodynamic characteristics of solvation of ion Σ (Na+, I-)

    Measurements of electromotive force of chains without transport were used to determine the summary standard Gibbs energies, enthalpies and entropies of ion (Na+, I-) solvation in water-2-propanol system in all range of mixed solvent compositions at temperatures from 278.15 up to 318.15 K

  13. Photocatalytic Oxidation of Low-Level Airborne 2-Propanol and Trichloroethylene over Titania Irradiated with Bulb-Type Light-Emitting Diodes

    Wan-Kuen Jo

    2013-01-01

    Full Text Available This study examined the photocatalytic oxidation of gas-phase trichloroethylene (TCE and 2-propanol, at indoor levels, over titanium dioxide (TiO2 irradiated with light-emitting diodes (LED under different operational conditions. TiO2 powder baked at 450 °C exhibited the highest photocatalytic decomposition efficiency (PDE for TCE, while all photocatalysts baked at different temperatures showed similar PDEs for 2-propanol. The average PDEs of TCE over a three hour period were four, four, five, and 51% for TiO2 powders baked at 150, 250, 350, and 450 °C, respectively. The average PDEs of 2-propanol were 95, 97, 98, and 96% for TiO2 powders baked at 150, 250, 350, and 450 °C, respectively. The ratio of anatase at 2θ = 25.2° to rutile at 2θ = 27.4° was lowest for the TiO2 powder baked at 450 °C. Although the LED-irradiated TiO2 system revealed lower PDEs of TCE and 2-propanol when compared to those of the eight watt, black-light lamp-irradiated TiO2 system, the results for the PDEs normalized to the energy consumption were reversed. Other operational parameters, such as relative humidity, input concentrations, flow rate, and feeding type were also found to influence the photocatalytic performance of the UV LED-irradiated TiO2 system when applied to the cleaning of TCE and 2-propanol at indoor air levels.

  14. A Fundamental Equation of State for 2-propanol (C3H8O) in the Extended Equation of State Format

    An innovative method for the regression of a fundamental equation of state of a pure fluid was recently proposed. This technique, called an extended equation of state, adopts a framework similar to the extended corresponding states method but uses a cubic equation for the target fluid instead of the equation of state for the reference fluid, and shape functions are expressed through a multilayer feedforward neural network. The use of a neural network assures very high flexibility of the functional forms to be regressed, allowing the resulting model to represent the thermodynamic properties of a pure fluid with an accuracy comparable to that attained by state-of-the-art multiparameter equations of state. The technique is applied here to 2-propanol to derive a dedicated equation of state in a heuristic mode directly from the available experimental data. The majority of the data cover the range of temperatures from 280 to 600 K and pressures up to 50 MPa; this is also the validity range of the developed equation. For the present case, primarily due to the unfavorable situation of the data, all of the available thermodynamic properties have been used for the regression procedure in order to get the expected accuracy. The model has been validated with data for coexistence states, density, isobaric and isochoric heat capacities, and speed of sound. The obtained results are satisfactory because the proposed equation of state represents the available data within their mean experimental uncertainties.

  15. Excess isentropic compressibility and speed of sound of the ternary mixture 2-propanol + diethyl ether + n-hexane and the constituent binary mixtures at 298.15 K

    Gokhan Sovaroglu; Ertunc Aral

    2006-02-01

    Speed of sound and densities of the ternary mixture 2-propanol + diethyl ether + n-hexane and also the binary mixtures 2-propanol + diethyl ether and 2-propanol + n-hexane have been measured at the entire composition range at 298.15 K. The excess isentropic compressibilities and the excess speed of the sound have been calculated from experimental densities and speed of sound. These excess properties of the binary mixtures were fitted to Redlich-Kister equation, while the Cibulka's equation was used to fit the values related to the values to the ternary system. These excess properties have been used to discuss the presence of significant interactions between the component molecules in the binary mixtures and also the ternary mixtures. Speed of sound of the binary mixtures and the ternary mixture have been compared with calculated values from free length theory (FLT), collision factor theory (CFT), Nomoto's relation (NR), Van Deal's ideal mixing relation (IMR) and Junjie's relation (JR). The results are used to compare the relative merits of these theories and relations in terms of the root mean square deviation relative (RMSDr).

  16. Calorimetric investigations of hydrogen bonding in binary mixtures containing pyridine and its methyl-substituted derivatives. II. The dilute solutions of methanol and 2-methyl-2-propanol

    Enthalpies of solution of methanol and 2-methyl-2-propanol (tert-butanol) in pyridine and its methyl derivatives were investigated in the range of mole fractions of alcohol x≤0.02 at temperature 298.15 K by a titration calorimeter. Dissolution of methanol is an exothermic process, with heat effects very close to those for water reported in part I of this study. The negative enthalpy of solution increases in the following order: pyridine < 3-methylpyridine < 4-methylpyridine < 2-methylpyridine < 2,6-dimethylpyridine < 2,4,6-trimethylpyridine. Positive enthalpies of solution of 2-methyl-2-propanol increase as follows: 2-methylpyridine < 2,4,6-trimethylpyridine < 4-methylpyridine < 2,6-dimethylpyridine < 3-methylpyridine < pyridine. The propensity of pyridine derivatives to hydrogen bonding is enhanced by the ortho effect. Methyl groups are probably too small to prevent the nitrogen atom in the pyridine ring from hydrogen bonding. However, spacious hydrocarbon group in 2-methyl-2-propanol molecule makes the bonding difficult for 2,6-dimethylpyridine and 2,4,6-trimethylpyridine, thus the number of O-H···N bonds is smaller than that in the solutions of methanol or water. The two latter seem to be very close to each other

  17. Densities, viscosities, refractive indices, and surface tensions for binary and ternary mixtures of 2-propanol, tetrahydropyran, and 2,2,4-trimethylpentane

    Densities, viscosities, refractive indices, and surface tensions of the ternary system (2-propanol + tetrahydropyran + 2,2,4-trimethylpentane) at T = 303.15 K and its constituent binary systems (2-propanol + tetrahydropyran, 2-propanol + 2,2,4-trimethylpentane, and tetrahydropyran + 2,2,4-trimethylpentane) at T = (293.15, 303.15, 313.15, and 323.15) K were measured at atmospheric pressure. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic microviscometer based on the rolling-ball principle. Refractive indexes were measured using a digital Abbe-type refractometer. Surface tensions were determined by the Wilhelmy-plate method. From these data, excess molar volumes, deviations in viscosity, deviations in refractive index, and deviations in surface tension were calculated. The results for the binary and ternary systems were fitted to the Redlich-Kister equation and the variable-degree polynomials in terms of compositions, respectively. The experimental and calculated quantities are used to study the nature of mixing behaviour between mixture components.

  18. LIQUID-LIQUID EQUILIBRIA FOR MIXTURES OF WATER,DECANE and 1-ETHOXY-2-PROPANOL%1-乙氧基-2-丙醇/水/癸烷的液液平衡

    陈瑶; 李任强; 田村和弘

    2003-01-01

    Experimental data of ternary liquid-liquid equilibria for mixtures of 1-ethoxy-2-propanol, water and decane were measured at 298.15K.Extended UNIQUAC model was empolyed to correlate those data. The extended UNIQUAC model successfully represented the thermodynamic properties for the ternary system of 1-ethoxy-2-propanol, water and decane. These experimental results are useful for designing the separation and extraction process.

  19. Studies of mixing properties of binary systems of 2-propanol with hexadecane and squalane at T = (298.15, 303.15, and 308.15) K

    The present paper reports the experimental data for density, ρ, viscosity, η, and speeds of sound, u for the binary mixtures of 2-propanol, (CH3)2CHOH with hexadecane, C16H34 over the miscibility region (0 1 30H62 over the miscibility region (0 1 mE, viscosity deviations, Δη, excess molar isentropic compressibility, KS,mE, and deviations in speed of sound, uD, from their ideal values uid. These excess parameters and deviations are used to interpret the molecular interactions in these binary mixtures

  20. Liquid density of oxygenated additive 2-propanol at pressures up to 140 MPa and from 293.15 K to 403.15 K

    Highlights: ► New density data for 2-propanol are reported. ► The pressure and temperature intervals are 0.1–140 MPa and 293.15–403.15 K. ► 175 measured data points were fitted to a Tait-like equation. ► Experimental data points have been compared to Cibulka’s correlation. ► The isobaric expansivity and the isothermal compressibility have been derived. - Abstract: This work reports new density data (175 points) of 2-propanol at 12 temperatures between 293.15 and 403.15 K (every 10 K), and 15 pressures from 0.1 to 140 MPa (every 10 MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5 kg·m−3 was used to perform these measurements. The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

  1. Ternary liquid-liquid equilibria of dimethyl carbonate + 2-propanol + water system at 303.15 and 313.15 K

    Ginting, Rizqy Romadhona; Mustain, Asalil; Tetrisyanda, Rizki; Gunardi, Ignatius; Wibawa, Gede

    2015-12-01

    In this work, liquid-liquid equilibria data of dimethyl carbonate (DMC) + 2-propanol + water system were accurately determined at 303.15 and 313.15 K using stirred and jacketed equilibrium cell under atmospheric pressure. The reliabilities of the experimental data were confirmed using Bachman-Brown correlation giving r-squared value of 0.9993 and 0.9983 at 303.15 and 313.15 K, respectively. Experimental data obtained in this work exhibit Treybal's Type I ternary phase behavior. The selectivity and distribution coefficient of DMC increases with addition of DMC concentration in the organic phase. On the other hand, the effect of temperature to phase boundary was found to be not significant. The data were correlated well using the Non-Random Two Liquid (NRTL) and Universal Quasi-Chemical (UNIQUAC) activity coefficient models with root-mean-square deviation of 1.5% and 1.3%, respectively.

  2. Metal-template Condensation of 1,3-Diamino-2-propanol and Formaldehyde: Synthesis, Crystal Structure, and Magnetic Properties of a New Dinuclear Copper(II) Complex

    Polynuclear transition metal complexes with relatively strong intramolecular metal-metal interactions have received considerable attention because of their interesting chemical properties and/or potential applications in various fields, such as supramolecular chemistry, catalysts for organic reactions, and materials chemistry.1-11 Especially, dinuclear copper(II) complexes are known to be useful systems for the study of long-distance metal-metal interactions, since the metal ion has only one unpaired electron. 3-11 This work shows that a new μ-alkoxo-μ-acetato-bridged dinuclear copper(II) complex, 1, can be prepared by the one-pot reaction of 1,3-diamino-2-propanol and formaldehyde in the presence of Cu(OAc)2·H2O. Each mononuclear unit has N2O3-donor donor set and exhibits distorted square-pyramidal coordination geometry with an apical hydroxo group. Interestingly, the complex shows relatively strong ferromagnetic coupling.

  3. Enhanced photocatalytic degradation of 2-propanol over macroporous GaN/ZnO solid solution prepared by a novel sol-gel method

    Macroporous GaN/ZnO solid solution photocatalyst is synthesized through a novel sol-gel method under mild conditions. The performance of as-synthesized solid solution photocatalyst is evaluated for decomposition of gaseous 2-propanol (IPA). It is found that due to enhancement in both the adsorption to gaseous IPA and the absorbance to visible light, the porous GaN/ZnO solid solution exhibits a good photocatalytic performance for IPA decomposition. Moreover, the mechanism for photocatalytic degradation IPA over porous GaN/ZnO solid solution is also investigated in comparison with those for the two end materials ZnO and GaN. The trapping effects with different scavengers prove that both the photoexcited electrons and holes affect the IPA photodegradation process, simultaneously

  4. Isothermal (vapour + liquid) equilibrium for binary mixtures of polyethylene glycol mono-4-nonylphenyl ether (PEGNPE) with methanol, ethanol, or 2-propanol

    Highlights: → An autoclave apparatus was used for binary (vapour + liquid) equilibrium data measurement. → The studied systems are polyethylene glycol mono-4-nonylphenyl ether with alcohols. → The saturated pressure data were fitted accurately to the Antoine equation. → The NRTL model correlated well the phase equilibrium data. → The solvent activities have been calculated. - Abstract: Saturated pressures of three binary systems of oligomeric polyethylene glycol mono-4-nonylphenyl ether (PEGNPE) with methanol, ethanol, and 2-propanol have been measured by using an autoclave (vapour + liquid) equilibrium (VLE) apparatus at temperatures ranging from (340 to 455) K and the oligomer content ranging from 0.100 to 0.400 in mole fraction. With a given feed composition, equilibrium pressures were measured at various temperatures to obtain VLE data. The experimental data were fitted to the Antoine equation and also correlated with activity coefficient models, the NRTL and the UNIQUAC. The correlation results showed good agreement between the calculated values and the experimental data. In general, the NRTL model yielded better results. Additionally, the solvent activities were evaluated from the experimental results and were compared with those from the NRTL and the UNIQUAC models.

  5. Solvent structure effects on solvated electron reactions in mixed solvents: negative ions in 1-propanol-water and 2-propanol-water

    In models of the kinetics of chemical reactions in solution the solvent is commonly assumed to be a uniform continuum. An example is the Smoluchowski-Debye-Stokes-Einstein equation for the rate constant k2 of a bimolecular reaction between charged or polar species: k2 κRTfrr/1.5ηrd where κ = probability that a reactant encounter pair will react, R = gas constant, T = temperature, f = Coulombic interaction factor, rr = effective radius for reaction, η = solvent viscosity, and rd = effective radius for mutual diffusion. The equation is useful in evaluating effects of bulk-fluid properties on reaction rates. Residual effects are attributed to more specific solvent behaviour. Rate constants and activation energies E2 of reactions of solvated electrons es- with NO3- and CrOr2- ions vary with the composition of 1-propanol-water and 2-propanol-water mixed solvents. Plots of k2η/fT against solvent composition are nonlinear and change with solvent pair and with reactant pair. Measured molar conductivities Λ0(Li+, NO3-) and Λ0(2Li+, CrO42-) indicate the solvent dependence of rd for the mutual diffusion of Li+ and NO3- or CrO42-. The liquid structure influences both the rate of diffusion of the reactants and the probability of reaction of a reactant encounter pair. (author)

  6. Measurement and modeling of densities and sound velocities of the systems [poly(propylene glycol)+methanol, +ethanol, +1-propanol, +2-propanol and +1-butanol] at T=298.15K

    Experiments have been performed at T=298.15K to measure the density and sound velocity of the systems [poly(propylene glycol)+methanol, +ethanol, +1-propanol, 2-propanol and +1-butanol] over the whole range of composition. From these measurements, values of the excess molar volume (Vmex) and excess molar isentropic compression, Ks,mex, equal to -(-bar Vmex/-bar p)s were calculated. The excess molar volume for all of these systems were found to be negative and decreases in magnitude as size of alcohol increases, except for 2-propanol solutions for which the magnitude of the excess volume is higher than that of 1-butanol solutions. Expressions for VmexandKs,mex of polymer solutions were obtained for the model of Flory-Huggins and the polymer non-random two liquid (NRTL) model. These expressions were used to fit the experimental VmexandKs,mex data of the investigated systems

  7. Preparation of promoted platinum catalysts of designed geometry and the role of promoters in the liquid-phase oxidation of 1-methoxy-2-propanol

    Mallat, T.; Bodnar, Z.; Baiker, A. (Swiss Federal Institute of Technology, Zuerich (Switzerland)); Greis, O.; Struebig, H. (Technical Univ., Hamburg (Germany)); Reller, A. (Univ. of Hamburg (Germany))

    1993-07-01

    Alumina-supported or unsupported M/Pt-type catalysts were prepared by consecutive reduction of Bi, Pb, Sn, Ru, Au, or Ag modifiers (M) onto Pt particles. Structural and chemical properties of the bimetallics were studied by electron microscopy combined with energy dispersive X-ray analysis and an electrochemical (cyclic voltammetric) polarization method. Preferential deposition of promoter metal submonolayers on Pt was observed at moderate surface coverages ([theta][sub M]<0.5-0.8). Some bulk metal crystallite formation as [open quotes]bridges[close quotes] between small Pt particles covered partially with promoter was also observed on alumina-supported Bi/Pt and Pb/Pt catalysts. Measurement of the electrochemical potential of the catalyst slurry during the oxidation of 1-methoxy-2-propanol to methoxyacetone and the cyclic voltammetric polarization of the bimetallic catalysts revealed that the catalysts are in an oxidized state during reaction. The following order of promoting influence was observed: Bi > Pb [approximately] Sn > Au [approximately] Ru. Two major effects of promoters are suggested: (i) they suppress the initial irreversible adsorption of the reactant alcohol on Pt which results in self-poisoning, and (ii) they form new active centers that adsorb the oxidizing species (OH) better than Pt. A formal rate equation is suggested (r = f [center dot] [theta][sub org] [center dot] [theta][sub OH]) which explains the optimum in promoter/platinum ratio. The different influences of the promoters are explained by their hydrogen and oxygen sorption characteristics and by the surface geometry of the bimetallic catalysts. 51 refs., 12 figs., 1 tab.

  8. Thermal studies on oxidation-reduction of LnCu2 intermetallic compounds and their catalytic behavior for 2-propanol decomposition

    High temperature oxidation-reduction studies were undertaken on binary intermetallic compounds LnCu2 (Ln = La, Ce, Pr, Nd, Eu, Gd, Dy, Tm, Yb). A two steps cycle was optimized by O2-TG and H2-TG or H2-TPR studies along the lanthanide series. The oxidation mass uptake occurs over a wide range of temperature (200-900 deg. C), leading to two bimetallic copper-lanthanide oxides families according to the lanthanide: 3CuO.Ln2CuO4 (Ln = La, Pr, Nd, Eu, Gd) and 2CuO.Ln2Cu2O5 (Ln = Dy, Tm, Yb), except for CeCu2 that gives 2CuO.CeO2. Under hydrogen, all systems exhibit two reduction steps accompanied by mass losses in the 150-600 deg. C temperature range. The first mass loss is linked to the reduction of CuO, whereas the second mass loss corresponds to copper reduction in the Ln2CuO4 or Ln2Cu2O5 phase with concomitant formation of Ln2O3. The reduction products were characterized by XRD and different stoichiometries were obtained according to the lanthanide: 2Cu/CeO2, 3Cu/Ln2CuO4 or 2Cu/Ln2Cu2O5, after the first reduction step, and 4Cu/Ln2O3 after the second reduction one. Therefore, the binary intermetallic compounds LnCu2 decompose into a copper-rare earth oxide phase that after reduction leaves their surface highly enriched on the copper. The structure of the oxidized and reduced intermetallics can best be described as copper embedded in lanthanide oxides (Ln2O3) or 'type supported catalysts' and exhibited activity for the 2-propanol oxidative dehydrogenation-dehydration reaction, which was also used to characterize their acid-base properties.

  9. Partial molar volumes of organic solutes in water. XII. Methanol(aq), ethanol(aq), 1-propanol(aq), and 2-propanol(aq) at T = (298 to 573) K and at pressures up to 30 MPa

    Density data for dilute aqueous solutions of methanol, ethanol, 1-propanol, and 2-propanol are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at from T = (298.15 up to 573.15) K and at pressure close to the saturated vapor pressure of water, at p = 30 MPa and at pressure between these limits. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter

  10. Excess molar enthalpies of ethylformate and (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) at T=(298.15 and 308.15)K and p=(5 and 10)MPa

    A high-pressure flow-mixing isothermal microcalorimeter is used to determine the excess molar enthalpies of five binary systems for ethylformate and (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) at T=(298.15 and 308.15) K and p=(5 and 10)MPa. The smooth values calculated by Redlich-Kister equation of HmE are also compared with the experimental results

  11. Densities and speeds of sound for binary mixtures of (1,3-dioxolane or 1,4-dioxane) with (2-methyl-1-propanol or 2-methyl-2-propanol) at the temperatures (298.15 and 313.15) K

    This paper reports densities and speeds of sound for the binary mixtures of (1,3-dioxolane or 1,4-dioxane) with (2-methyl-1-propanol or 2-methyl-2-propanol) at the temperatures (298.15 and 313.15) K. Excess volumes and excess isentropic compressibility coefficients have been calculated from experimental data and fitted by means of a Redlich-Kister type equation. The ERAS model has been used to calculate the excess volumes of the four systems at both temperatures

  12. Determination and modelling of osmotic coefficients and vapour pressures of binary systems 1- and 2-propanol with CnMimNTf2 ionic liquids (n = 2, 3, and 4) at T = 323.15 K

    Highlights: → Osmotic coefficients of 1- and 2-propanol with CnMimNTf2 (n = 2, 3, and 4) are determined. → Experimental data were correlated with extended Pitzer model of Archer and MNRTL. → Mean molal activity coefficients and excess Gibbs free energies were calculated. → Effect of the anion is studied comparing these results with literature. - Abstract: The osmotic and activity coefficients and vapour pressures of binary mixtures containing 1-propanol, or 2-propanol and imidazolium-based ionic liquids with bis(trifluoromethylsulfonyl)imide as anion (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C2MimNTf2, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, C3MimNTf2, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C4MimNTf2) were determined at T = 323.15 K using the vapour pressure osmometry technique. The experimental osmotic coefficients were correlated using the extended Pitzer model modified by Archer and the MNRTL model, obtaining standard deviations lower than 0.033 and 0.064, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the mixtures studied were calculated from the parameters of the extended Pitzer model modified by Archer. Besides the effect of the alkyl-chain of the cation, the effect of the anion can be assessed comparing the experimental results with those previously obtained for imidazolium ionic liquids with sulphate anions.

  13. Determination of Acetophenone and 2-Phenyl-2-propanol Release in EVA Material%EVA材料中苯乙酮和2-苯基-2-丙醇释放量的测定

    陈皖芳; 穆江华; 钱明伟

    2011-01-01

    本方法采用顶空GC-MS测定EVA材料中的苯乙酮和2-苯基-2-丙醇的释放量。方法检测限为5 mg/kg,EVA材料中的平均加标回收率为90.0%~105%。方法简捷、快速、准确,适用于EVA材料中苯乙酮和2-苯基-2-丙醇释放量的测定。%An analytical method based on using headspace extraction EVA material,the capillary vessel column gas phase mass spectrography carried on qualitative and quota to acetophenone and 2-Phenyl-2-propanol release.The method examination limit was 5 mg/kg,the mean recoveries for packaging material samples were 90.0 %~105 %.The method was accurate,simple,rapid and feasible for the inspection of acetophenone and 2-Phenyl-2-propanol release in EVA materials.

  14. Densities and volumetric properties of (N-(2-hydroxyethyl)morpholine + ethanol, + 1-propanol, + 2-propanol, + 1-butanol, and + 2-butanol) at (293.15, 298.15, 303.15, 313.15, and 323.15) K

    Densities of binary mixtures of N-(2-hydroxyethyl)morpholine with ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol were measured over the entire composition range at temperatures from (293.15 to 323.15) K and atmospheric pressure using a vibrating-tube densimeter. The excess molar volumes, VE were calculated from density data and fitted to the Redlich-Kister polynomial equation. Apparent molar volumes, partial molar volume at infinite dilution and the thermal expansion coefficient of the mixtures were also calculated. The VE values were found to be negative over the entire composition range and at all temperatures studied and become less negative with increasing carbon chain length of the alkanols

  15. Application of the margin of exposure (MoE) approach to substances in food that are genotoxic and carcinogenic: example: (CAS No. 96-23-1) 1,3-dichloro-2-propanol (DCP).

    Williams, Gary; Leblanc, Jean-Charles; Setzer, R Woodrow

    2010-01-01

    1,3-Dichloro-2-propanol (DCP) is formed in foods under a variety of conditions. It was positive in a variety of in vitro genotoxicity tests, but was negative in two in vivo studies. DCP produced neoplasms at several sites in rats. Kidney tumours in male rats were selected as the critical tumour type. Dose-response modelling of the data for DCP gave a BMDL(10) for combined kidney carcinomas and adenomas in male rats of 9.62 mg/kg-body weight (bw)/day. The exposure of humans was estimated at an average of 0.00009 mg/kg-bw/day and a high exposure of 0.000136 mg/kg-bw/day. The MOEs for these exposures were 100,000 and 70,000, respectively. PMID:20113855

  16. Excess molar enthalpies of {diethyl oxalate + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa

    Highlights: • The excess molar enthalpies for four binary systems of diethyl oxalate + alcohols were determined. • The densities of the diethyl oxalate at different temperature were measured. • The excess molar enthalpies increase with temperature and the molecular size of the alcohols. • The experimental data were correlated by two local-composition models (NRTL and UNIQUAC). -- Abstract: A flow-mixing isothermal microcalorimeter was used to measure excess molar enthalpies for four binary systems of {diethyl oxalate + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa. The densities of the diethyl oxalate at different temperature were measured by using a vibrating-tube densimeter. All systems exhibit endothermic behaviour over the whole composition range, which means that the rupture of interactions is energetically the main effect. The excess molar enthalpies increase with temperature and the molecular size of the alcohols. The experimental results were correlated by using the Redlich–Kister equation and two local-composition models (NRTL and UNIQUAC)

  17. Apparent molar volumes and apparent molar heat capacities of dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

    Apparent molar volumes Vphi and apparent molar heat capacities Cp,phi have been determined for dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa. The molalities investigated ranged from 0.05 mol·kg-1 to 1.0 mol·kg-1. We used a vibrating tube densimeter (DMA 512P, Anton PAAR, Austria) to determine the densities and volumetric properties. Heat capacities were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter (NanoDSC 6100, Calorimetry Sciences Corporation, American Fork, UT, USA). The results were fit by regression to equations that describe the surfaces (Vphi,T,m) and (Cp,phi,T,m). Infinite dilution partial molar volumes V20 and heat capacities C0p,2 were obtained over the range of temperatures by extrapolation of these surfaces to m=0 mol·kg-1

  18. Noninvasive assessment of hypoxia with 3-[18F]-fluoro-1-(2-nitro-1-imidazolyl)-2-propanol ([18F]-FMISO): a PET study in two experimental models of human glioma

    Despite multiple advances in cancer therapies, patients with glioblastoma (GBM) still have a poor prognosis. Numerous glioma models are used not only for the development of innovative therapies but also to optimize conventional ones. Given the significance of hypoxia in drug and radiation resistance and that hypoxia is widely observed among GBM, the establishment of a reliable method to map hypoxia in preclinical human models may contribute to the discovery and translation of future and more targeted therapies. The aim of this study was to compare the hypoxic status of two commonly used human ortho-topic glioma models (U87 and U251) developed in rats and studied by noninvasive hypoxia imaging with 3-[18F] fluoro-1-(2-nitro-1-imidazolyl)-2-propanol-micro-positron emission tomography ([18F]-FMISO-μPET). In parallel, because of the relationships between angiogenesis and hypoxia, we used magnetic resonance imaging (MRI), histology, and immunohistochemistry to characterize the tumoral vasculature. Although all tumors were detectable in T2-weighted MRI and 2-deoxy-2-[18F]fluoro-D-glucose-mu PET, only the U251 model exhibited [18]-FMISO uptake. Additionally, the U251 tumors were less densely vascularized than U87 tumors. Our study demonstrates the benefits of noninvasive imaging of hypoxia in preclinical models to define the most reliable one for translation of future therapies to clinic based on the importance of intratumoral oxygen tension for the efficacy of chemotherapy and radiotherapy. (authors)

  19. Excess molar enthalpies and excess molar volumes of formamide + 1-propanol or 2-propanol and thermodynamic modeling by Prigogine–Flory–Patterson theory and Treszczanowicz–Benson association model

    Highlights: ► Measured HmE and VmE data of formamide + propanol were interpreted in terms of PFP theory. ► Treszczanowicz–Benson association model was also applied to these binary systems. ► The calculated HmE and VmE values compared well with corresponding experimental data. ► Extent of H-bonding in formamide and propanol in their mixture was reflected in ΔhH0 and KH. - Abstract: Excess molar enthalpies (HmE) at 298.15 K and 308.15 K and excess molar volumes (VmE) at 308.15 K for formamide (1) + 1-propanol or 2-propanol (2) mixtures have been measured over the entire composition range. The excess enthalpies and excess volumes data have been utilized to study the thermodynamics of molecular interactions in terms of Prigogine–Flory–Patterson theory and Treszczanowicz–Benson association model with a Flory contribution term. In this paper, this Treszczanowicz–Benson association model was applied, for the first time, to binary mixtures containing both components associated (propanol and formamide) through hydrogen bonding. In both the cases, when either of formamide or propanol was assumed to be associated, the calculated HmE and VmE values compared well with corresponding experimental data. Extent of inter-molecular H-bonding in formamide and propanol in their binary mixtures was also reflected in their molar enthalpy of association of H-bonding ΔhH0 and association constant KH

  20. Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol

    Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250 K to 330 K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Poynting correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality

  1. Support vector classification for structure-activity-relationship of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols%支持向量分类算法用于1-(1H-1,2,4-三唑-1-基)-2-(2,4-二氟苯基)-3-取代-2-丙醇化合物的构效关系研究

    纪晓波; 陆文聪; 蔡煜东; 陈念贻

    2007-01-01

    The support vector classification (SVC) was employed to make a model for classification of antifungal activities of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols triazole derivatives. The compounds with high antifungal activities and those with low antifungal activities were compared on the basis of the following molecular descriptors: net atomic charge on the atom N connecting with R, dipole moment and heat of formation. By using the SVC, a mathematical model was constructed, which can predict the antifungal activities of the triazole derivatives, with an accuracy of 91% on the basis of the leave-one-out cross-validation (LOOCV) test. The results indicate that the performance of the SVC model can exceed that of the principal component analysis (PCA) and K-Nearest Neighbor (KNN) models for this real world data set.

  2. Interface between platinum(111) and liquid isopropanol (2-propanol): A model for molecular dynamics studies

    Tarmyshov, Konstantin B.; Müller-Plathe, Florian

    2007-02-01

    A molecular dynamics model and its parametrization procedure are devised and used to study adsorption of isopropanol on platinum(111) (Pt(111)) surface in unsaturated and oversaturated coverages regimes. Static and dynamic properties of the interface between Pt(111) and liquid isopropanol are also investigated. The magnitude of the adsorption energy at unsaturated level increases at higher coverages. At the oversaturated coverage (multilayer adsorption) the adsorption energy reduces, which coincides with findings by Panja et al. in their temperature-programed desorption experiment [Surf. Sci. 395, 248 (1998)]. The density analysis showed a strong packing of molecules at the interface followed by a depletion layer and then by an oscillating density profile up to 3nm. The distribution of individual atom types showed that the first adsorbed layer forms a hydrophobic methyl "brush." This brush then determines the distributions further from the surface. In the second layer methyl and methine groups are closer to the surface and followed by the hydroxyl groups; the third layer has exactly the inverted distribution. The alternating pattern extends up to about 2nm from the surface. The orientational structure of molecules as a function of distance of molecules is determined by the atom distribution and surprisingly does not depend on the electrostatic or chemical interactions of isopropanol with the metal surface. However, possible formation of hydrogen bonds in the first layer is notably influenced by these interactions. The surface-adsorbate interactions influence the mobility of isopropanol molecules only in the first layer. Mobility in the higher layers is independent of these interactions.

  3. Catalytic Hydrotreatment of Humins in Mixtures of Formic Acid/2-Propanol with Supported Ruthenium Catalysts.

    Wang, Yuehu; Agarwal, Shilpa; Kloekhorst, Arjan; Heeres, Hero Jan

    2016-05-10

    The catalytic hydrotreatment of humins, which are the solid byproducts from the conversion of C6 sugars (glucose, fructose) into 5-hydroxymethylfurfural (HMF) and levulinic acid (LA), by using supported ruthenium catalysts has been investigated. Reactions were carried out in a batch setup at elevated temperatures (400 °C) by using a hydrogen donor (formic acid (FA) in isopropanol (IPA) or hydrogen gas), with humins obtained from d-glucose. Humin conversions of up to 69 % were achieved with Ru/C and FA, whereas the performance for Ru on alumina was slightly poorer (59 % humin conversion). Humin oils were characterized by using a range of analytical techniques (GC, GC-MS, GCxGC, gel permeation chromatography) and were shown to consist of monomers, mainly alkyl phenolics (>45 % based on compounds detectable by GC) and higher oligomers. A reaction network for the reaction is proposed based on structural proposals for humins and the main reaction products. PMID:26836970

  4. Calibration of a low temperature calorimeter and application in the determination of isobaric heat capacity of 2-propanol

    Casas, L.M., E-mail: lmcasas@uvigo.es [Departamento de Fisica Aplicada, Facultade de Ciencias Experimentais, Universidade de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Plantier, F. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes - UMR 5150, Universite de Pau et des Pays de l' Adour, BP 1155, 64013 Pau (France); Pineiro, M.M.; Legido, J.L. [Departamento de Fisica Aplicada, Facultade de Ciencias Experimentais, Universidade de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Bessieres, D. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes - UMR 5150, Universite de Pau et des Pays de l' Adour, BP 1155, 64013 Pau (France)

    2010-08-10

    Nowadays, the experimental thermodynamic characterization of solvents in an extended range of temperatures and pressures is essential for the development of a wide variety of industrial applications (refrigeration, reactors, pumping, etc.). Moreover, accurate experimental data are also the key for the successful development and subsequent benchmarking of thermodynamic theoretical models. In the particular case of isobaric heat capacities, there are quite a lot of reported experimental high temperature data but, on the other hand, low temperature data are practically inexistent for most compounds. Bearing this limitation in mind, the present work is focused on the development of a new calibration methodology for calorimetric determination of isobaric heat capacities in liquid state at low temperatures. For this purpose, a Calvet calorimeter, SETARAM BT 2.15 has been used. By means of the calibration procedure explained below, this calorimeter allows to determine phase transitions and thermodynamic properties in a wide range of temperature (233.15-473.15 K) and pressure (0.1-100 MPa).

  5. Influence of anionic stabilization of alumina particles in 2-propanol medium on the electrophoretic deposition and mechanical properties of deposits

    Drdlík, D.; Bartoníčková, E.; Hadraba, Hynek; Cihlář, J.

    2014-01-01

    Roč. 34, č. 14 (2014), s. 3365-3371. ISSN 0955-2219 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Anionic stabilization * Electric conductivity * Alumina * Electrophoretic deposition Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.947, year: 2014

  6. Calibration of a low temperature calorimeter and application in the determination of isobaric heat capacity of 2-propanol

    Nowadays, the experimental thermodynamic characterization of solvents in an extended range of temperatures and pressures is essential for the development of a wide variety of industrial applications (refrigeration, reactors, pumping, etc.). Moreover, accurate experimental data are also the key for the successful development and subsequent benchmarking of thermodynamic theoretical models. In the particular case of isobaric heat capacities, there are quite a lot of reported experimental high temperature data but, on the other hand, low temperature data are practically inexistent for most compounds. Bearing this limitation in mind, the present work is focused on the development of a new calibration methodology for calorimetric determination of isobaric heat capacities in liquid state at low temperatures. For this purpose, a Calvet calorimeter, SETARAM BT 2.15 has been used. By means of the calibration procedure explained below, this calorimeter allows to determine phase transitions and thermodynamic properties in a wide range of temperature (233.15-473.15 K) and pressure (0.1-100 MPa).

  7. Excess molar enthalpies of ternary mixtures of (methanol, ethanol + 2-propanol + 1,4-dioxane) at T=298.15 K

    Ternary excess molar enthalpies for the {x1CH3OH + x2i-C3H7OH + (1-x1-x2)c-C4H8O2} and {x1C2H5OH + x2i-C3H7OH + (1-x1-x2)c-C4H8O2} mixtures have been measured by a flow microcalorimeter at T=298.15 K and ambient pressure. The experimental results are correlated with a polynomial equation and used to construct constant excess enthalpy contours. Furthermore, the results have been compared with those calculated from a UNIQUAC associated-solution model. This model considers the self-association of like alcohols, multicross-association of unlike alcohols, and solvation between alcohols and 1,4-dioxane. The model with the association constants, solvation constants, and binary information alone predict the ternary excess molar enthalpies satisfactorily

  8. Isothermal (Vapour + Liquid) Equilibria in the Binary and Ternary Systems Composed of 2-Propanol, 2,2,4-Trimethylpentane and 2,4-Dimethyl-3-Pentanone

    Pavlíček, Jan; Wichterle, Ivan

    2012-01-01

    Roč. 45, č. 1 (2012), s. 83-89. ISSN 0021-9614 R&D Projects: GA ČR GA104/07/0444 Institutional research plan: CEZ:AV0Z40720504 Keywords : alcohol * ketone * hydrocarbon Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.297, year: 2012

  9. Hydrogen transfer reaction of cyclohexanone with 2-propanol catalysed by CeO2-ZnO materials: Promoting effect of ceria

    Braja Gopal Mishra; G Ranga Rao; B Poongodi

    2003-10-01

    Ce-Zn-O mixed oxides were prepared by amorphous citrate process and decomposition of the corresponding acetate precursors. The resulting materials were characterised by TGA, XRD, UV-Vis-DRS, EPR, SEM and surface area measurements. XRD and DRS results indicated fine dispersion of the ceria component in the ZnO matrix. EPR results clearly indicate the presence of oxygen vacancy and defect centres in the composite oxide. Addition of CeO2 to ZnO produced mixed oxides of high surface area compared to the pure ZnO. Hydrogen transfer reaction was carried out on these catalytic materials to investigate the effect of rare earth oxide on the activity of ZnO. Addition of ceria into zinc oxide was found to increase the catalytic activity for hydrogen transfer reaction. The catalytic activity also depended on the method of preparation. Citrate process results in uniformly dispersed mixed oxide with higher catalytic activity.

  10. Experimental excess molar properties of binary mixtures of (3-amino-1-propanol + isobutanol, 2-propanol) at T = (293.15 to 333.15) K and modelling the excess molar volume by Prigogine–Flory–Patterson theory

    Highlights: ► Density and viscosity of binary mixtures of propanol derivatives were measured at T = (293.15 to 333.15) K. ► The excess molar properties were calculated from these experimental data and correlated by Redlich–Kister equation. ► The PFP model was applied for correlating the excess molar volumes. - Abstract: Density and viscosity of binary mixtures of (x13-amino-1-propanol + x2isobutanol) and (x13-amino-1-propanol + x22-propanol) were measured over the entire composition range and from temperatures (293.15 to 333.15) K at ambient pressure. The excess molar volumes and viscosity deviations were calculated and correlated by the Redlich–Kister (RK) equation. The thermal expansion coefficient and its excess value, isothermal coefficient of excess molar enthalpy, and excess partial molar volumes were determined by using the experimental values of density and are described as a function of composition and temperature. The excess molar volumes are negative over the entire mole fraction range for both mixtures and increase with increasing temperature. The excess molar volumes obtained were correlated by the Prigogine–Flory–Patterson (PFP) model. The viscosity deviations of the binary mixtures are negative over the entire composition range and decrease with increasing temperature.

  11. Synthesis and antifungal activity of 1- ( 1 H-1, 2,4-triazol-1-yl) -2- (2,4-difluorophenyl)-3-(4-substituted acyl piperazin-1-yl)-2-propanols

    LIANG Shuang; LIU Chao-mei; ZHU Jie; HE Qiu-qin; JIANG Yuan-ying; CAO Yong-bin

    2004-01-01

    Objective: To study the effect of fluconzole derivatives from a side chain containing 4-substituted acyl piperazin-1-yl on antifungal activity. Methods: Fourteen title compounds were synthesized and confirmed by the elementary analysis, 1HNMR and IR spectra. Five deep fungal strains and 3 shallow fungal strains were chosen as the experimental strains. Minimum inhibitory concentrations(MICs) of all title compounds were determined by the method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) using RPMI 1640 test medium. Results: Among the 14title compounds, 12 were first reported. The results of preliminary antifungal test showed that all the title compounds exhibited potent antifungal activities to a certain extent. The activity of 4 compounds were more than 4 times as high as that of fluconazole and equal to that of ketoconazole against Candida albicans in vitro(MIC80 value≤0. 125 μg/ml). Conclusion:Introduction of a side chain containing 4-substituted acyl piperazin-l-yl into the main part of fluconazole has important influence on antifungal activities of title compounds.

  12. Excess Molar Volumes and Viscosities for Binary Mixtures of 1-Alkoxypropan-2-ols with 1-Butanol,and 2-Butanol at 298.15 K and Atmospheric Pressure

    PAL Amalendu; GABA Rekha

    2007-01-01

    Excess molar volumes VEm and kinematic viscosities v have been measured as a function of composition for binary mixtures of propylene glycol monomethyl ether (1-methoxy-2-propanol),MeOCH2CH(OH)Me,propylene glycol monoethyl ether (1-ethoxy-2-propanol), EtOCH2CH(OH)Me,propylene glycol monopropyl ether (1-propoxy-2-propanol), PrOCH2CH(OH)Me, propylene glycol monobutyl ether (1-butoxy-2-propanol),BuOCH2CH(OH)Me,and propylene glycol tert-butyl ether (1-tert-butoxy-2-propanol),t-BuOCH2CH(OH)Me with 1-butanol,and 2-butanol,at 298.15 K and atmospheric pressure.The excess molar volumes are negative across the entire range of composition for all the systems with 1-butanol,and positive for the systems 2-butanol+1-methoxy-2-propanol,and +1-propoxy-2-propanol,negative for the systems 2-butanol+1-butoxy-2-propanol,and change sign for the systems 2-butanol+1-ethoxy-2-propanol,and +1-tert-butoxy-2-propanol.From the experimental data,the deviation in dynamic viscosity η from Σxiηi has been calculated.Both excess molar volumes and viscosity deviations have been correlated using a Redlich-Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors.

  13. Derivatives of 1,3-oxazolidines on the base of diamino-alcohols

    In this article authors investigated the reaction of 1-cyclohexyl amino-3-diethyl amino-2-propanol, 1-butylamine-3-diethyl amino-2-propanol. By authors was determined that reaction of initial diamino-alcohols with furfural passing at molar correlation of reagents 1:1 at temperature 20-22digC at presence dehydrating medium-potash during 36 hours

  14. The methods of synthesis of glycerin derivatives

    In this chapter of book authors present some methods of synthesis of glycerin derivatives, in particular, synthesis of 3-met oxi-1.2-propandiol, 1.3-di-benzil-oxi-2-propanol, 1-ge xi-lox-3-chlorine-2-propanol and other

  15. Preparation of Pt Ru/C electrocatalysts using gamma radiation for application as anode in direct methanol fuel cell

    PtRu nanoparticles supported on carbon (PtRu/C electrocatalysts) were prepared submitting a water/2-propanol mixture containing the metal ions and the carbon support to gamma radiation. The water/2-propanol (v/v) and the total dose (kGy) were studied. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry. The methanol electro-oxidation was studied by cyclic voltammetry using the thin porous coating. In the studied conditions, the electrocatalytic activity of the prepared electrocatalysts depend on the water/2-propanol ratio used in the reaction medium. (author)

  16. Research of component adsorption from the binary mixture of organic solvents

    Карван, Світлана Анатоліївна; Сарібєков, Георгій Савич

    2010-01-01

    Results of superficial tension determinaition of solutions of mixed solvents on the basis of perchloroethylene and 2-propanol are resulted, characteristics of absorption monolayer of their molecules are calculated. Regularities of solvents adsorption by textile materials are investigated.

  17. Amlodipine Benzenesulfonate: A Mechanistic Investigation of Its Industrial Preparation via Detritylation of N-tritylamlodipine and Related NMR Studies

    Furlan, Borut; Grdadolnik, Simona Golič; Hočevar, Stanko; Kocjan, Darko; Levec, Janez; Maskill, Howard; Navrátilová, Hana; Pospíšil, Jiří; Potáček, Milan; Urleb, Uroš; Žmitek, Janko

    2009-01-01

    Kinetics and product analysis of detritylation of N-tritylamlodipine by benzenesulfonic acid in methanol, methanol-chloroform (volume ratio 9:1), ethanol, 2-propanol, and methanol/2-propanol (mole ratio 1:1) have been investigated by HPLC; amongst these reaction conditions are ones closely similar to those of one method of manufacturing amlodipine benzenesulfonate. Kinetics of detritylation of Ntritylamlodipine have also been investigated in methanol-d4 by 1H NMR spectroscopy and the agreemen...

  18. Reconstitution baking tests with defatted wheat flour are suitable for determining the functional effects of lipase-treated wheat lipids.

    Schaffarczyk, Monika; Østdal, Henrik; Matheis, Olivia; Jekle, Mario; Koehler, Peter

    2016-06-01

    A microscale reconstitution baking test, using wheat flour defatted with 2-propanol at 20 °C, was established to determine the functional effects of lipids isolated from lipase-treated wheat dough. Proper selection of solvent and extraction temperature was of major importance to maintain the functionality of defatted flour. Dough and gluten from flour defatted with water-saturated 1-butanol (WSB; extracted at 20 °C) and 2-propanol (extracted at 75 °C) had inferior extensibility and loaf volume compared to control flour extracted with 2-propanol at 20 °C. Quantitation of gluten proteins showed that defatting with WSB (20 °C) or 2-propanol (75 °C) decreased the gliadin and increased the glutenin content. Possible reasons were thiol-disulfide interchange reactions, caused either by heat (2-propanol, 75 °C) or by the solvent WSB, which affected gluten proteins. Confocal laser scanning microscopy showed that regular, interconnected gluten structures were only present in dough from flour defatted with 2-propanol at 20 °C. PMID:26830576

  19. Catalytic activity of poly[(methacrylato)aluminum(III)] obtained at different gamma-radiation doses

    Vilchis-Nestor, A.R. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Paseo Tollocan and Paseo Colon, A.P. A-20, Toluca, C.P. 50120 (Mexico); Urena-Nunez, F., E-mail: fernando.urena@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, km 36.5, Carretera Mexico-Toluca, Ocoyoacac, Estado de Mexico, C.P. 52750 (Mexico); Sanchez-Mendieta, V. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Paseo Tollocan and Paseo Colon, A.P. A-20, Toluca, C.P. 50120 (Mexico); Perez-Hernandez, R. [Instituto Nacional de Investigaciones Nucleares, km 36.5, Carretera Mexico-Toluca, Ocoyoacac, Estado de Mexico, C.P. 52750 (Mexico)

    2011-11-15

    A novel coordination polymer was obtained throughout the polymerization of aluminum(III) methacrylate at different doses (10, 20, 30, 40, 50 and 80 kGy) using gamma-radiation as initiator. The materials were characterized by electronic paramagnetic resonance (EPR), thermogravimetric analyses (TGA) and scanning electron microscopy/electron dispersive X-ray analyses (SEM/EDAX) techniques; particle size distribution and surface areas were also determined. The samples of poly[(methacrylato)aluminum(III)] obtained at different {gamma}-doses were found to catalyze 2-propanol dehydrogenation and dehydration to acetone and propene. A noticeable activity was observed with Poly[(methacrylato)aluminum(III)] obtained at 50 kGy, which has higher conversion of 2-propanol and the highest selectivity to acetone ({approx}90%). Results suggest that the decomposition of 2-propanol is correlated with the effect of gamma-radiation on the structure and surface area of the catalysts. - Highlights: > We report the synthesis of micro-crystalline novel poly[(methacrylato)aluminum(III)]. > Polymer was obtained throughout the polymerization of Al(III) methacrylate at different doses. > PMALs were found to catalyze 2-propanol dehydrogenation and dehydration to acetone and propene. > PMAL obtained at 50 kGy has the higher conversion of 2-propanol and selectivity to acetone ({approx}90%).

  20. Infrared laser induced organic reactions. 2. Laser vs. thermal inducment of unimolecular and hydrogen bromide catalyzed bimolecular dehydration of alcohols

    It has been demonstrated that a mixture of reactant molecules can be induced by pulsed infrared laser radiation to react via a route which is totally different from the pathway resulting from heating the mixture at 3000C. The high-energy unimolecular elimination of H2O from ethanol in the presence of 2-propanol and HBr can be selectively induced with a pulsed CO2 laser in preference to either a lower energy bimolecular HBr-catalyzed dehydration or the more facile dehydration of 2-propanol. Heating the mixture resulted in the almost exclusive reaction of 2-propanol to produce propylene. It was demonstrated that the bimolecular ethanol + HBr reaction cannot be effectively induced by the infrared laser radiation as evidenced by the detrimental effect on the yield of ethylene as the HBr pressure was increased. The selective, nonthermal inducement of H2O elimination from vibrationally excited ethanol in the presence of 2-propanol required relatively low reactant pressures. At higher pressures intermolecular V--V energy transfer allowed the thermally more facile dehydration from 2-propanol to become the predominant reaction channel

  1. Preconcentration in gas or liquid phases using adsorbent thin films

    Antonio Pereira Nascimento Filho

    2006-03-01

    Full Text Available The possibility of preconcentration on microchannels for organic compounds in gas or liquid phases was evaluated. Microstructures with different geometries were mechanically machined using poly(methyl methacrylate - PMMA as substrates and some cavities were covered with cellulose. The surfaces of the microchannels were modified by plasma deposition of hydrophilic or hydrophobic films using 2-propanol and hexamethyldisilazane (HMDS, respectively. Double layers of HMDS + 2-propanol were also used. Adsorption characterization was made by Quartz Crystal Measurements (QCM technique using reactants in a large polarity range that showed the adsorption ability of the structures depends more on the films used than on the capillary phenomena. Cellulose modified by double layer film showed a high retention capacity for all gaseous compounds tested. However, structures without plasma deposition showed low retention capacity. Microchannels modified with double layers or 2-propanol plasma films showed higher retention than non-modified ones on gas or liquid phase.

  2. Radiolytic reduction reaction of colloidal silver bromide solution

    The reduction reaction of colloidal silver bromide (AgBr3)2- in nitrous oxide gas saturated solution of some alcohols: methanol, ethanol, 2-propanol and 2-methyl-2-propanol by γ-irradiation was studied spectrophotometrically in order to elucidate the mechanism of the formation of colloidal silver bromide (AgBr3)3- at ambient temperature. The amount of colloidal silver bromide formed increases in the order: i-PrOH, EtOH, MeOH. In t-BuOH, colloidal silver bromide did not form. The relative reactivities of alcohols for colloidal silver bromide was also studied kinetically. (author)

  3. Contribution to the study of gamma radiolysis of 2-furyl butyl or substituted phenyl ketones in isopropanol

    The following ketones: 2-furyl butyl ketone (I), 2 furyl phenyl ketone (II), 2-furyl p-methylphenyl ketone (III) and 2-furyl p-methoxyphenyl ketone (IV) were synthesised and characterised. The yields of hydrogen and methane obtained during radiolysis of the mixtures ketones (I to IV)-2-propanol were determined. These yields are always lower than with pure 2-propanol. Radiolysis products for ketones (I) and (II) are studied. Analysis of radiolitical products were conducted by gas chromatography. Effect of radiation dose and ketone concentration is determined. Reaction mechanisms are studied

  4. Pulse radiolysis of sulfonato-propyl-viologen (SPV) in aqueous solution containing colloidal platinum

    The pulse radiolysis of the zwitterion sulfonato-propyl-viologen (SPV) was studied in aqueous solutions containing 2-propanol. SPV reacts with the hydrated electron and the 2-propanol radical yielding the anion radical, SPV-. The absorbance changes due to the formation of SPV- were followed at 578 nm (epsilon578 = 1.0 x 104M-1 cm-1). In the absence of colloidal platinum (Ptc) or air, SPV- is stable for at least several hours. In the presence of Ptc a single decay process was observed. The results are compared with the nitrobenzene-Ptc and methylviologen-Ptc systems. (author)

  5. Bepaling van theofylline (1,3-dimethylxanthine) in hondeplasma met behulp van reversed-phase vloeistofchromatografie

    Olling; M; Besamusca; P.; Rauws; A.G.

    1985-01-01

    In dit rapport wordt een snelle en nauwkeurige methode beschreven voor de bepaling van theofylline in plasma. Theofylline wordt uit plasma geextraheerd met chloroform/2-propanol en met behulp van reversed-phase hogedruk vloeistofchromatografie gescheiden en met spectrofotometrische detectie bepa

  6. AROMATIC AMINES IN AND NEAR THE BUFFALO RIVER

    Three sediment samples taken from the Buffalo River and two soil samples taken near its bank have been analyzed for 2-propanol-extractable, basic organic compounds by using GC/MS. Eleven aromatic amines related to the commercial production of malachite green and crystal violet we...

  7. REMEDIATING PESTICIDE CONTAMINATED SOILS USING SOLVENT EXTRACTION

    Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p'-DDT, p,p'-DDD,, p,p'-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as sol...

  8. Enrichment and identification of integral membrane proteins from barley aleurone layers by reversed-phase chromatography, SDS-PAGE and LC-MS/MS

    Hynek, Radovan; Svensson, Birte; Nørregaard Jensen, Ole; Barkholt, Vibeke; Finnie, Christine

    2006-01-01

    developed, comprising batch reversed-phase chromatography with stepwise elution of hydrophobic proteins by 2-propanol. Proteins in the most hydrophobic fraction were separated by SDS-PAGE and identified by LC-MS/MS and barley EST sequence database search. The method was efficient for enrichment of integral...

  9. Enrichment and identification of integral membrane proteins from barley aleurone layers by reversed-phase chromatography, SDS-PAGE, and LC-MS/MS

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.; Barkholt, Vibeke; Finnie, Christine

    2006-01-01

    was developed, comprising batch reversed-phase chromatography with stepwise elution of hydrophobic proteins by 2-propanol. Proteins in the most hydrophobic fraction were separated by SDS-PAGE and identified by LC-MS/MS and barley EST sequence database search. The method was efficient for enrichment of...

  10. The nitrogen-containing compounds on the glycerin base

    In present time in all over the world there are leading an intensive investigations on synthesis and studying positive properties of amine-derivatives on the glycerine base. To them related amine and ether-amines of propanediol-1,2; 1,3-diamines-2-propanole and different their derivatives, which present interest as a potential biological active substances

  11. Properties of electrospun pollock gelatin/poly(vinyl alcohol) and pollock gelatin/poly(lactic acid) fibers

    Pollock gelatin/poly(vinyl alcohol) (PVA) fibers were electrospun using deionized water as the solvent and pollock gelatin/poly(lactic acid) (PLA) fibers were electrospun using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. The chemical, thermal, and thermal stability properties were exami...

  12. Solid–liquid equilibria for binary and ternary systems with the Cubic-Plus-Association (CPA) equation of state

    Fettouhi, André; Thomsen, Kaj

    2010-01-01

    A systematic investigation of the CPA model's performance within solid-liquid equilibria (SLE) in binary mixtures (methane + ethane, methane + heptane, methane + benzene, methane + CO2, ethane + heptane, ethane + CO2, 1-propanol + 1,4-dioxane, ethanol + water, 2-propanol + water) is presented. Th...

  13. Design,Synthesis and Antifungal Activity of Novel Triazole Derivatives

    Chun Quan SHENG; Wan Nian ZHANG; Hai Tao JI; Yun Long SONG; Min ZHANG; You Jun ZHOU; Jia Guo LU; Jü ZHU

    2004-01-01

    Twenty-one 1-(1H-1,2,4-triazolyl)-2-(2,4-diflurophenyl)-3-(4-substituted-1- piperazinyl)-2-propanol derivatives were designed and synthesized,on the basis of the active site of lanosterol 14(-demethylase.In vitro antifungal activities showed that some of the target compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.

  14. The Optical Resolution of Chiral Tetrahedrone-type Clusters Contai- ning SCoFeM (M=Mo or W) Using High Performance Liquid Chromatography Chiral Stationary Phase

    2002-01-01

    Amylose tris (phenylcarbamate) chiral stationary phase (ATPC-CSP) was prepared and used for optical resolution of clusters 1 and 2. n-Hexane/2-propanol ( 99/1; v/v) were found to be the most suitable mobile phase on ATPC-CSP.

  15. Stereo block copolymers of L- and D-lactides

    Yui, Nobuhiko; Dijkstra, Pieter J.; Feijen, Jan

    1990-01-01

    Sequential diblock copolymers composed of L- and D-lactic acid residues were synthesized through a living ring-opening polymerization of L- and D-lactide initiated by aluminium tris(2-propanolate). The composition of the block copolymers was varied by changing the reaction conditions and monomer ove

  16. Preparation of PtRu/C anode electrocatalysts using gamma radiation for methanol electro-oxidation; Preparacao de eletrocatalisadores PtRu/C utilizando radiacao gama para aplicacao como anodo na oxidacao direta de metanol

    Silva, Dionisio Fortunato da

    2006-07-01

    Pt Ru/C (carbon-supported Pt Ru nanoparticles) anode electrocatalysts were prepared using radiolytic process (gamma radiation) and tested for methanol electro-oxidation. In this process, water/2-propanol and water/ethylene glycol solutions containing the metallic ions and the carbon support were submitted to gamma radiation under stirring. The water/alcohol ratio (v/v) and the total dose (kGy) were studied. A nominal Pt Ru atomic ratio of 50:50 were used in all experiments. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry (CV). The electro-oxidation of methanol was studied by cyclic voltammetry using the thin porous coating technique. The electrocatalysts prepared in water/2-propanol showed crystallite size in the range of 3-5 nm and Pt Ru atomic ratio of 50:50. The electrocatalysts prepared in water/ethylene glycol showed crystallite size (2-3 nm) smaller than the ones obtained in water/2-propanol, however, the Pt Ru atomic ratios obtained were approximately 80:20, showing that only part of ruthenium ions were reduced. For methanol oxidation the electrocatalytic activity depends on the water/2-propanol and water/ethylene glycol ratio used in the reaction medium. The electrocatalysts prepared in water/2-propanol showed inferior performance to the ones prepared in water/ethylene glycol, which showed similar or superior performances (amperes per gram of platinum) to the commercial electrocatalyst from E-TEK. (author)

  17. Preparation of PtRu/C anode electrocatalysts using gamma radiation for methanol electro-oxidation

    Pt Ru/C (carbon-supported Pt Ru nanoparticles) anode electrocatalysts were prepared using radiolytic process (gamma radiation) and tested for methanol electro-oxidation. In this process, water/2-propanol and water/ethylene glycol solutions containing the metallic ions and the carbon support were submitted to gamma radiation under stirring. The water/alcohol ratio (v/v) and the total dose (kGy) were studied. A nominal Pt Ru atomic ratio of 50:50 were used in all experiments. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry (CV). The electro-oxidation of methanol was studied by cyclic voltammetry using the thin porous coating technique. The electrocatalysts prepared in water/2-propanol showed crystallite size in the range of 3-5 nm and Pt Ru atomic ratio of 50:50. The electrocatalysts prepared in water/ethylene glycol showed crystallite size (2-3 nm) smaller than the ones obtained in water/2-propanol, however, the Pt Ru atomic ratios obtained were approximately 80:20, showing that only part of ruthenium ions were reduced. For methanol oxidation the electrocatalytic activity depends on the water/2-propanol and water/ethylene glycol ratio used in the reaction medium. The electrocatalysts prepared in water/2-propanol showed inferior performance to the ones prepared in water/ethylene glycol, which showed similar or superior performances (amperes per gram of platinum) to the commercial electrocatalyst from E-TEK. (author)

  18. Pulse radiolysis of malachite green leucocyanide in alcoholic solvents, the influence of oxygen

    The solutions of malachite green leucocyanide (MGCN) in methanol, n-propanol and 2-propanol were investigated using pulse radiolysis. In the presence of oxygen, MG+-carbonium ions were radiolytically formed in two different time steps. The yield of MG+ in the slower process was dependent on oxygen concentration and was proportional to the yield of intermediate MG radicals. The yield of MG was about ten times higher in 2-propanol than in methanol and n-propanol solutions. The reactants responsible for MG oxidation to MG+ were RO2, hydroxyalkylperoxyl radicals derived from alcohols. The rate constant for MG reaction with RO2 were estimated as (6.5±1) x 108M-1s-1. The molar extinction coefficient of MG was calculated. (author)

  19. Effect of combinations of nitroaromatic and nitroxyl radiosensitizers on the radiation survival response of Chinese hamster cells, V.79-753B, in vitro

    The effect of various combinations of nitroaromatic (electron-affinic) and nitroxyl (free-radical) radiosensitizers on the radiation survival response of hypoxic Chinese hamster cells, V.79-753B, was studied. A bifunctional sensitizer posessing both a free-radical and an electron-affinic nitroarene, 1-[1-oxyl-2,2,6,6-tetramethyl-4-piperidy]amino-3-[2-nitro-1-imidazolyl]-2-propanol (Ro-03-9454), was also used. In all combinations tested there was evidence that there is competition between the two types of sensitizer. This competition accounts for the mixed functional compound Ro-03-9454 being less effective than the monofunctional compound RSU-4013 (1-[1-[2-cyano-2-propyl]oxy-2,2,6,6- tetramethyl-4-piperidyl]amino-3-[2-nitro-1-imidazolyl]-2-propanol), which does not have a nitroxyl group. In combinations of nitroaromatic sensitizers the situation is more complex

  20. Correlation of crystal structures, electronic structures and photocatalytic properties in W-based oxides

    We reported a novel W-based oxide NaBi(WO4)2 with WO4 tetrahedral crystal structure as a photocatalyst for decomposition of 2-propanol. The physical characteristics of the sample were examined by XRD, BET measurement and SEM, respectively. The band gap of NaBi(WO4)2 was determined to be 3.6 eV according to the diffuse reflectance spectra of the sample. The photocatalytic activity of NaBi(WO4)2 was confirmed by decomposing 2-propanol into acetone and CO2. It showed a higher acetone generation rate (211 ppm h-1) in contrast to that of WO3 (120 ppm h-1), which consisted of WO6 octahedra. Their electronic structures were further investigated by the plane-wave based density function theory. The results suggested that the crystal field (WO6 and WO4) significantly influenced the electronic structures and hence affected the photocatalytic activity.

  1. Nitro group photoreduction of 4-(2-nitrophenyl)- and 4-(3-nitrophenyl)-1,4-dihydropyridines

    Graphical abstract: The intramolecular photoreduction of nifedipine occurs within a few ns, Φred = 0.3. The photoreduction of nimodipine and nitrendipine is enhanced in the presence of triethylamine, Φred red = 0.3 and does not depend significantly on the oxygen concentration and solvent properties. Formation of the fully reduced 4-(2-aminophenyl)-1,4-dihydropyridine as minor product is indicated by fluorescence spectroscopy. The photoreduction of nimodipine and nitrendipine is inefficient, Φred = 0.002 in acetonitrile, but markedly enhanced in the presence of donors such as triethylamine (TEA) and 2-propanol, e.g. for TEA Φred is up to 0.03. The triplet states of nimodipine and nitrendipine were characterized. They react intermolecularly with TEA and 2-propanol, forming radicals as intermediates and eventually several reduction products.

  2. Adsorption of Organic Molecules on Kaolinite from the Exchange-Hole Dipole Moment Dispersion Model.

    Johnson, Erin R; Otero-de-la-Roza, Alberto

    2012-12-11

    Intermolecular interactions between organic molecules and clay minerals are important in a wide range of chemical applications, ranging from oil-sands petroleum extraction to environmental chemistry and catalysis. The binding energies between each of benzene, n-hexane, pyridine, 2-propanol, and water and the kaolinite surface are calculated using density functional theory with the exchange-hole dipole moment dispersion model. The dominant noncovalent interactions are found to be hydrogen bonding for pyridine, 2-propanol, and water, OH-π interactions for benzene, and CH-O interactions for n-hexane. All molecules considered are more strongly bound to the hydrophilic alumina face, rather than the hydrophobic siloxane face, of kaolinte. PMID:26593201

  3. Visible-Light-Driven Selective Photocatalytic Hydrogenation of Cinnamaldehyde over Au/SiC Catalysts.

    Hao, Cai-Hong; Guo, Xiao-Ning; Pan, Yung-Tin; Chen, Shuai; Jiao, Zhi-Feng; Yang, Hong; Guo, Xiang-Yun

    2016-08-01

    Highly selective hydrogenation of cinnamaldehyde to cinnamyl alcohol with 2-propanol was achieved using SiC-supported Au nanoparticles as photocatalyst. The hydrogenation reached a turnover frequency as high as 487 h(-1) with 100% selectivity for the production of alcohol under visible light irradiation at 20 °C. This high performance is attributed to a synergistic effect of localized surface plasmon resonance of Au NPs and charge transfer across the SiC/Au interface. The charged metal surface facilitates the oxidation of 2-propanol to form acetone, while the electron and steric effects at the interface favor the preferred end-adsorption of α,β-unsaturated aldehydes for their selective conversion to unsaturated alcohols. We show that this Au/SiC photocatalyst is capable of hydrogenating a large variety of α,β-unsaturated aldehydes to their corresponding unsaturated alcohols with high conversion and selectivity. PMID:27403658

  4. Deuterium labeling studies in the transfer hydrogenation of ketones and in the disproportionation of diphenylcarbinol over alumina

    Paper describes deuterium labeling studies which confirm the direct hydrogen transfer mechanism for the transfer hydrogenation of ketones as well as for the disproportionation and the transfer hydrogenolysis of diphenylcarbinol. Methods for the preparation of diphenylcarbinol-d and 2-propanol-2-d are described. Diphenylmethane-d and diphenylmethane-d2 were prepared as standards for product identification purposes. 2-Propanol-2-d of 92% isotopic purity was used to reduce 4-methyl-2-pentanone and cyclohexanone over 2.2% Na+/Al2O3 at 3000C. Reaction products were 4-methyl-2-pentanol and cyclohexanol. Disproportionation of diphenylcarbinol produced diphenylamine, benzophenone, and water, over pure alumina at 3000C. Reaction products were analyzed by gas chromatography, and pure samples were isolated by preparative gas chromatography. Isotopic purities were estimated by ir, NMR, and mass spectrometry. A somewhat speculative representation of the direct hybrid transfer mechanism is considered

  5. Direct effect of tetrahedral alcohol species on the SPB of gold colloids: a deconvolution study

    Aqueous gold colloids with a mean diameter of 15.4 ± 1.5 nm have been transferred into a range of water–alcohol mixtures. The influence of these mixtures (methanol, ethanol, 2-propanol, and tert-butanol), which present different hydrophobic properties, on the surface plasmon band of gold nanoparticles has been studied. Shifts of gold nanoparticles’ surface plasmon band (SPB) depend on the number of methyl groups and hydrophobic character of the alcohol molecule. Results from deconvolution analysis are explained considering variations on the grade of alcohol adsorption on the nanoparticle surface. TEM images indicate aggregation of the nanoclusters in mixtures of 2-propanol and tert-butanol. ζ potential measurements support the exchange of citrate ions by alcohol molecules, which in turn reflects the existence of an additional electrostatic component

  6. Densities and viscosities of binary mixtures of {dimethylsulfoxide+aliphatic lower alkanols (C1-C3)} at temperatures from T=303.15K to T=323.15K

    Densities and viscosities for dimethylsulfoxide (DMSO) with methanol, ethanol, 1-propanol, and 2-propanol have been measured as a function of mole fraction at T=(303.15, 308.15, 313.15, 318.15, and 323.15)K and atmospheric pressure. From the measurements, excess molar volumes (VmE), excess viscosities (ηE), and Grunberg and Nissan interaction parameters (ε) have been calculated. The excess parameters are fitted to a Redlich-Kister equation. Excess molar volumes (VmE) are negative for (DMSO+methanol, +ethanol) systems throughout the whole range of composition. The (DMSO+1-propanol) system shows both positive and negative excess molar volumes and (DMSO+2-propanol) shows positive excess molar volume, hardly any negative value is observed in alcohol rich-region. The excess viscosities and interaction parameters of all the mixtures are negative except for the (DMSO+methanol) system which is positive

  7. Chemical isomeric effects on propanol glassy structures

    Cuello, G J; Bermejo, F J; Cabrillo, C

    2002-01-01

    We have studied the structure of both propanol isomers in their glassy and crystalline states by neutron diffraction. The glass-transition temperatures of 1- and 2-propanol are about 98 and 115 K, respectively and, surprisingly, even larger differences are observed for the melting temperatures of the stable crystals, which are 148 and 185 K, respectively. Their supercooled liquid phases show rather different relaxation spectra, 1-propanol manifesting strong deviations from Debye behavior, whereas 2-propanol shows a far weaker effect. We discuss the spectra obtained for the static structure factor and the static pair correlation function D(r). There is a noticeable difference in the position of the first sharp diffraction peak, which clearly indicates a density change, well correlated with the period of the intermolecular oscillations shown by D(r). (orig.)

  8. A 2D [Fe-II-bistetrazole] coordination polymer exhibiting spin-crossover properties

    Quesada, Manuel; Prins, Ferry; Roubeau, Olivier; Gamez, Patrick; Teat, Simon J.; van Koningsbruggen, Petra J.; Haasnoot, Jaap G.; Reedijk, Jan

    2007-01-01

    The reaction of 1,3-bis(tetrazol-1-yl)-2-propanol (btzpol) with Fe(BF4)(2) center dot 6H(2)O in acetonitrile yields the remarkable 2D coordination polymer [Fe-II(btzpol)(1.8)(btzpol-OBF3)(1.2)](BF4)(0.8) center dot (H2O)(0.8)(CH3CN) (1). This compound has been structurally characterized using an X-r

  9. Catalysis in the alkylation reaction of 1-naphthol with epichlorohydrin

    SLOBODANKA JOVANOVIC

    2006-09-01

    Full Text Available Two new and improved procedures were developed for the synthesis of 1-(1-naphthyloxy-2,3-epoxypropane as an important intermediate in the production of the beta-blocker and antioxidant, 1-[(1-methylethylamino]-3-(1-naphthyloxy-2-propanol (propranolol. Both base homogeneous and heterogeneous PTC catalysis were employed. High yields and remarkable selectivity were achieved. The improved purity is particularly important, in view of the quality requirements for propranolol hydrochloride as an active pharmaceutical ingredient.

  10. Green solvents from glycerol. Synthesis and physico-chemical properties of alkyl glycerol ethers

    García, José I.; García-Marín, Héctor; Mayoral, José A.; Pérez, Pascual

    2010-01-01

    A family of glycerol derivatives, consisting of over sixty 1,3-dialkoxy-2-propanols and 1,2,3-trialkoxypropanes, both symmetrically and unsymmetrically substituted at terminal positions, have been synthesized and the possible role of these glycerol derivatives as substitutive solvents has been evaluated through measurements of their physico-chemical properties. The molecular diversity of the derivatives prepared results in significant variations of polarity properties, facilitating the identi...

  11. Sonochemiluminescence of lucigenin: Evidence of superoxide radical anion formation by ultrasonic irradiation

    Matsuoka, Masanori; Takahashi, Fumiki; Asakura, Yoshiyuki; Jin, Jiye

    2016-07-01

    The sonochemiluminescence (SCL) behavior of lucigenin (Luc2+) has been studied in aqueous solutions irradiated with 500 kHz ultrasound. Compared with the SCL of a luminol system, a tremendously increased SCL intensity is observed from 50 µM Luc2+ aqueous solution (pH =11) when small amounts of coreactants such as 2-propanol coexist. It is shown that SCL intensity strongly depends on the presence of dissolved gases such as air, O2, N2, and Ar. The highest SCL intensity is obtained in an O2-saturated solution, indicating that molecular oxygen is required to generate SCL. Since SCL intensity is quenched completely in the presence of superoxide dismutase (SOD), an enzyme that can catalyze the disproportionation of O2 •‑, the generation of O2 •‑ in the ultrasonic reaction field is important in the SCL of Luc2+. In this work, the evidence of O2 •‑ production is examined by a spectrofluorometric method using 2-(2-pyridyl)benzothiazoline as the fluorescent probe. The results indicate that the yield of O2 •‑ is markedly increased in the O2-saturated solutions when a small amount of 2-propanol coexists, which is consistent with the results of SCL measurements. 2-Propanol in the interfacial region of a cavitation bubble reacts with a hydroxyl radical (•OH) to form a 2-propanol radical, CH3C•(OH)CH3, which can subsequently react with dissolved oxygen to generate O2 •‑. The most likely pathways for SCL as well as the spatial distribution of SCL in a microreactor are discussed in this study.

  12. 1-(Piperidin-1-yl)-3-(2,4,6-trimethyl-phen-yl)propan-2-ol.

    Maharramov, Abel M; Khalilov, Ali N; Gurbanov, Atash V; Allahverdiyev, Mirze A; Ng, Seik Weng

    2011-01-01

    The title compound, C(17)H(27)NO, features a bufferfly-shaped substituted 2-propanol having an aromatic ring on the 1-carbon and a piperidine ring on the 3-carbon. The piperidine ring adopts a chair conformation and its N atom shows a trigonal coordination. In the crystal, the hy-droxy group inter-acts with the N atom of an inversion-related mol-ecule, generating an O-H⋯N hydrogen-bonded dimer. PMID:21522478

  13. 1-(Piperidin-1-yl)-3-(2,4,6-trimethyl­phen­yl)propan-2-ol

    Maharramov, Abel M.; Ali N. Khalilov; Atash V. Gurbanov; Allahverdiyev, Mirze A.; Ng, Seik Weng

    2011-01-01

    The title compound, C17H27NO, features a bufferfly-shaped substituted 2-propanol having an aromatic ring on the 1-carbon and a piperidine ring on the 3-carbon. The piperidine ring adopts a chair conformation and its N atom shows a trigonal coordination. In the crystal, the hy­droxy group inter­acts with the N atom of an inversion-related mol­ecule, generating an O—H⋯N hydrogen-bonded dimer.

  14. Study of radiation chemistry of onium salt acid generators for microlithographic application

    In this study, we investigated methods to improve chemically amplified resists for microlithographic application. For the solutions of onium salts in various solvents, the amounts of generated acid after γ-ray irradiation were measured using a pH meter. A solution of iodonium salt in 2-propanol had the highest efficiency in acid generation. The results could be evaluated by Gibbs free energy of the reactions. (author)

  15. Thermal Decomposition Reaction of Acetophenone Cyclic Diperoxide in Solvents of Different Physicochemical Properties

    C. M. Mateo

    2000-03-01

    Full Text Available The thermal decomposition reaction of acetophenone cyclic diperoxide (trans-3,6-dimethyl-3,6-diphenyl-1,2,4,5-tetroxane; APDP at the initial concentration of c.a. 0.01 mol kg-1 and temperature ranges of 135.5 to 185.0° C has been investigated in dioxane and acetonitrile solutions, and in an 2-propanol/benzene mixture.

  16. Enhanced bioactivity of ZnO nanoparticles—an antimicrobial study

    Nagarajan Padmavathy and Rajagopalan Vijayaraghavan

    2008-01-01

    In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO3)2 and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed...

  17. Preparation of PtRu/C and PtSn/C electrocatalysts using electron beam irradiation for direct and ethanol fuel cell

    PtRu/C and PtSn/C electrocatalysts were prepared using electron beam irradiation. The metal ions were dissolved in water/2-propanol and water/ethylene glycol solutions and the carbon support was added. The resulting mixtures were irradiated under stirring. The effect of water/ethylene glycol and water/2-propanol (v/v) ratio, Pt:Ru and Pt:Sn atomic ratios, the irradiation time and dose rate were studied. The obtained materials were characterized by Energy dispersive analysis of X-rays (EDX), X-ray diffraction (XRD), cyclic voltammetry (CV) and Moessbauer spectroscopy. The electro-oxidation of methanol and ethanol were studied by cyclic voltammetry and chronoamperometry using the thin porous coating technique. The electrocatalysts were also tested on the Direct Methanol and Ethanol Fuel Cells. PtRu/C electrocatalysts prepared in water/ethylene glycol showed Pt:Ru atomic ratios different from the nominal ones. The results suggested that part of the Ru(III) ions were not reduced. The obtained materials showed the face-centered cubic (fcc) structure of Pt and Pt alloys with crystallite sizes of 2-3 nm. PtRu/C electrocatalysts prepared in water/2-propanol showed Pt:Ru atomic ratios similar to the nominal ones. The obtained materials also showed the fcc structure of platinum and platinum alloys with crystallite sizes of 3-4 nm. PtSn/C electrocatalysts prepared in water/ethylene glycol and water/2-propanol showed Pt:Sn atomic ratios similar to the nominal ones. The obtained materials showed the platinum (fcc) phase with crystallite sizes in the range of 2 - 4 nm and a SnO2 (cassiterite) phase. The obtained PtRu/C and PtSn/C electrocatalysts showed similar or superior performance for methanol and ethanol electro-oxidation compared to commercial PtRu/C (E-TEK) and PtSn/C (BASF) electrocatalysts. (author)

  18. PREPARED POTASSIUM SALT OF CARBOXYMETHYL PINE WOOD IN A MICROWAVE

    Вадим Иванович Маркин; Марина Юрьевна Чепрасова; Наталья Григорьевна Базарнова; Евгения Олеговна Фролова

    2013-01-01

    Microwave radiation to intensify the process of carboxymethylation of pine wood without prior separation of the individual components is proposed to use . Carboxymethylated pine wood in the form of the potassium salt obtained by treating the pine potassium hydroxide and monochloroacetic acid in 2-propanol . Composition and properties of the products were investigated . Carboxymethylcellulose isolated from carboxymethylated pine wood. Increasing the power of microwave radiation (210 to 700 W) ...

  19. Effect of acids and bases on electrophoretic deposition of

    Cihlář, J.; Drdlík, D.; Cihlářová, Z.; Hadraba, Hynek

    2013-01-01

    Roč. 33, č. 10 (2013), s. 1885-1892. ISSN 0955-2219 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA ČR GD106/09/H035 Institutional support: RVO:68081723 Keywords : Electrophoretic deposition * Zirconia * Alumina * 2-Propanol * Electrosteric stabilization Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.307, year: 2013

  20. Hydroxymethylation beyond Carbonylation: Enantioselective Iridium-Catalyzed Reductive Coupling of Formaldehyde with Allylic Acetates via Enantiotopic π-Facial Discrimination.

    Garza, Victoria J; Krische, Michael J

    2016-03-23

    Chiral iridium complexes modified by SEGPHOS catalyze the 2-propanol-mediated reductive coupling of branched allylic acetates 1a-1o with formaldehyde to form primary homoallylic alcohols 2a-2o with excellent control of regio- and enantioselectivity. These processes, which rely on enantiotopic π-facial discrimination of σ-allyliridium intermediates, represent the first examples of enantioselective formaldehyde C-C coupling beyond aldol addition. PMID:26958737

  1. Gas-chromatographic analysis of some volatile congeners in different types of strong alcoholic fruit spirits

    Kostik, Vesna; Memeti, Shaban; Bauer, Biljana

    2013-01-01

    Beside ethyl alcohol, the major active component of alcoholic beverages, almost all alcoholic drinks contain volatile and non-volatile substances called congeners. They are present in different concentrations depending on beverage type and manufacturing methods. In the current study, the major volatile compounds besides ethanol as: methanol, ethyl acetate, 1-propanol (n-propanol), 2-propanol (i-propanol), 1-butanol(n-butanol), i-butanol (2-methylpropan-1-ol), n-amyl alcohol (n-pentanol), i-am...

  2. Liquid-liquid extraction and adsorption on solid surfaces applied to used lubricant oils recovery

    J. L. Assunção Filho; L. G. M. Moura; A.C.S. RAMOS

    2010-01-01

    In this work, the recovery of base oils from waste lubricants following the steps of solvent extraction, adsorption on solids and solvent removal by evaporation was evaluated. In the step of solvent extraction, the most efficient was 1-butanol, followed by tert-butanol, 2-propanol and ethanol; for the step of adsorption, activated carbon was the most effective solid for PAH removal, confirming the similarity of these compounds with petroleum aromatic fractions. Thus, the optimum solvent-adsor...

  3. Novel pot-shaped carbon nanomaterial synthesized in a submarine-style substrate heating CVD method

    Yokoi, Hiroyuki; Hatakeyama, Kazuto; Taniguchi, Takaaki; Koinuma, Michio; Hara, Masahiro; Matsumoto, Yasumichi; ヨコイ, ヒロユキ; ハタケヤマ, カズト; タニグチ, タカアキ; コイヌマ, ミチオ; ハラ, マサヒロ; マツモト, ヤスミチ; 横井, 裕之; 畠山, 一翔; 谷口, 貴章

    2016-01-01

    We have developed a new synthesis method that includes a chemical vapor deposition process in a chamber settled in organic liquid, and applied its nonequilibrium reaction field to the development of novel carbon nanomaterials. In the synthesis at 1110-1120 K, using graphene oxide as a catalyst support, iron acetate and cobalt acetate as catalyst precursors, and 2-propanol as a carbon source as well as the organic liquid, we succeeded to create carbon nanofiber composed of novel pot-shaped uni...

  4. Penggunaan Karboksimetil Kitosan Dari Cangkang Belangkas (Tachypleus Gigas) Sebagai Adsorben Untuk Menurunkan Konsentrasi Logam Pb

    Ananda, Fatya

    2015-01-01

    Reaserch has been done on the using of carboxymethyl chitosan from horseshoe crab’s shells (Tachypleus gigas) as adsorbent to reduce concentration of Pb metal. Carboxymethyl chitosan was made by reacting chitosan sample with NaOH 40 % and monochloroacetic acid which dispersed in 2-propanol for 10 hours at room temperature that results in carboxymethyl chitosan shown by functional groups using FTIR. On the adsorption process using standard solution of Pb with concentration of 5 mg/L and variat...

  5. Washcoated Pd/Al2O3 monoliths for the liquid phase hydrodechlorination of dioxins

    Cobo, Martha; Orrego, Andrés; Conesa Ferrer, Juan Antonio

    2012-01-01

    The catalytic activity and durability of 2 wt.% Pd/Al2O3 in powder and washcoated on cordierite monoliths were examined for the liquid phase hydrodechlorination (LPHDC) of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs), also known as dioxins. NaOH was employed as a neutralizing agent, and 2-propanol was used as a hydrogen donor and a solvent. Fresh and spent powder and monolith samples were characterized by elemental analysis, surface area, hydrogen chemisorption, s...

  6. Magnetic susceptibilities of bynary non-electrolyte mixtures

    Molar magnetic susceptibilities are determined by the Goy method for the following two systems: 1-propanol + methyl acetate and 2-propanol + methyl acetate at 298 K where the three molecules are polar and the alcohol molecules are associated in their pure state. Excess diamagnetic susceptibilties are calculated to obtain information about possible interactions. Diamagnetic suscetibilities were related with molecular polarizabilities by Boyer-Donzelot's equation and compared with experimental results. (author)

  7. Systematic study of the thermal diffusion in associated mixtures

    Polyakov, P.; Wiegand, S.

    2008-01-01

    We performed systematic temperature and concentration dependent measurements of the Soret coefficient in different associated binary mixtures of water, deuterated water, dimethyl sulfoxide (DMSO), methanol, ethanol, acetone, methanol, 1-propanol, 2-propanol, and propionaldehyde using the so-called thermal diffusion forced Rayleigh scattering method. For some of the associating binary mixtures such as ethanol/water, acetone/water, and DMSO/water, the concentration xw+/- at which the Soret coef...

  8. (Vapor + liquid) equilibria of the binary mixtures of m-cresol with C1-C4 aliphatic alcohols at 95.5 kPa

    Bubble point temperatures at 95.5 kPa, over the entire composition range, are measured for the binary mixtures formed by m-cresol with: methanol, ethanol, 1-propanol, 2-propanol, and n-, iso-, sec-, and tert-butanols - using a Swietoslawski-type ebulliometer. The liquid phase composition - bubble point temperature measurements are well represented by the Wilson model. (Vapor + liquid) equilibria predicted from the model are presented

  9. Shot-noise limited detection sensitivity in multiplex CARS microscopy

    Müller, M; Schins, J.M.; Wurpel, G.W.H.

    2004-01-01

    In multiplex CARS microscopy the generated anti-Stokes signal is generated and detected simultaneously over a significant part of the vibrational spectrum. The signal-to-noise ratio of the thus detected spectra is limited only by shot-noise. This principle is demonstrated using a dilution series of 2-propanol in water. It is derived theoretically and shown experimentally that for low solute concentrations - in contrast to methods that suppress the non-resonant background - the CARS signal str...

  10. Determination of some volatile compounds in fruit spirits produced from grapes (Vitis Vinifera L.) and plums (Prunus domestica L.) cultivars

    Kostik, Vesna; Gjorgjeska, Biljana; Angelovska, Bistra; Kovacevska, Ivona

    2014-01-01

    Fruit spirits contain a large array of volatile compounds among which the important role from toxicological aspect besides ethanol has methanol, aliphatic esters and fusel alcohols. This study evaluates the content of ethanol, ethyl acetate, methanol, isopropyl alcohol (2-propanol), n-propyl alcohol (propan-l-ol), isobutyl alcohol (2-methylpropan-1-ol), n-butyl alcohol (1-butanol), isoamyl alcohol (3-methyl-1-butanol) and n-amyl alcohol (pentan-1-ol) in different grapes and plum brandies i...

  11. Reaction Mechanism and Kinetics of Aqueous Solutions of Primary and Secondary Alkanolamines and Carbon Dioxide

    BAVBEK, Olgac; ALPER, Erdoğan

    1999-01-01

    The mechanism and kinetics of the reaction between aqueous solutions of CO2 and the alkanolamines 1-amino-2-propanol, 3-amino-1-propanol,2-methyl aminoethanol and 2-ethyl aminoethanol were investigated using a stopped flow technique. It was found that the reaction orders according to power law kinetics were between 1.1 and 2.0, depending on the alkanolamine and the concentration ranges investigated. This fractional order was therefore considered to be further evidence that carbamate ...

  12. Alcohol and water adsorption in zeolitic imidazolate frameworks

    Zhang, Ke

    2013-01-01

    Alcohol (methanol, ethanol, 1-propanol, 2-propanol and 1-butanol) and water vapor adsorption in zeolitic imidazolate frameworks (ZIF-8, ZIF-71 and ZIF-90) with similar crystal sizes was systematically studied. The feasibility of applying these ZIF materials to the recovery of bio-alcohols is evaluated by estimating the vapor-phase alcohol-water sorption selectivity. © 2013 The Royal Society of Chemistry.

  13. Design, synthesis and antifungal activity of novel triazole derivatives

    Qing lie Zhao; Yan Song; Hong Gang Hu; Shi Chong Yu; Qiu Ye Wu

    2007-01-01

    Twenty-three 1 -(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-(N-cycloproyl-N-substituted-amino)-2-propanols were designed and synthesized on the basis of the active site of lanosterol 14α-demethylase.In vitro antifungal activities showed that some of the title compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.

  14. Re-Refining of Waste Lubricating Oil by Solvent Extraction

    Hassan Ali Durrani; Muhammed Ibrahim Panhwar; Rafique Akthar Kazi

    2011-01-01

    Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. ...

  15. Determining an Efficient Solvent Extraction Parameters for Re-Refining of Waste Lubricating Oils

    Hassan Ali Durrani; Muhammed Ibrahim Panhwar; Rafique Akthar Kazi

    2012-01-01

    Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK (Methyl-Ethyl-Ketone), 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, w...

  16. CHEMICAL REACTIONS AT NANOMETAL PARTICLES

    GALO CÁRDENAS-TRIVIÑO

    2005-01-01

    The concept of nanochemistry and the reactions involved are discussed. The work is focused on nanoparticles obtained from colloidal dispersions. The colloidal particles by transmission electron microscopy of low and high resolution were analyzed. The high resolution electron miscroscopy (HRTEM) allow us to classify the nanostructure of the metal particles in some polyhedral models: cubooctahedron, truncated octahedron, tetracai decahedron and icosahedron. Some HRTEM of Pd-2 propanol and Ge-2-...

  17. Rapid Estimation of Tocopherol Content in Linseed and Sunflower Oils-Reactivity and Assay

    Tjaša Prevc

    2015-08-01

    Full Text Available The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than that of γ-tocopherol in both protic and aprotic solvents. In ethyl acetate, routinely applied for the analysis of antioxidant potential (AOP of plant oils, reactions of tocopherols with DPPH are slower and concentration of tocopherols in the assay has a large influence on their molar reactivity. In 2-propanol, however, two electrons are exchanged for both α- and γ-tocopherols, independent of their concentration. 2-propanol is not toxic and is fully compatible with polypropylene labware. The chromatographically determined content of tocopherols and their molar reactivity in the DPPH assay reveal that only tocopherols contribute to the AOP of sunflower oil, whereas the contribution of tocopherols to the AOP of linseed oil is 75%. The DPPH assay in 2-propanol can be applied for rapid and cheap estimation of vitamin E content in plant oils where tocopherols are major antioxidants.

  18. Influence of solvent on the structural and morphological properties of AgI particles prepared using ultrasonic spray pyrolysis

    Silver iodide particles were synthesized in the process of ultrasonic spray pyrolysis using aqueous solutions of thermodynamically stable silver iodide clusters as precursor. The AgI particles were collected in solvents of different polarities such as water, 2-propanol and toluene. In order to study influence of solvent and aging time on the morphological and structural properties of the AgI particles ultra-filtration was employed to isolate solid material from solution. The scanning electron microscopy showed that morphology of the AgI particles is different for different solvents. The AgI particles with hexagonal/triangular shape were obtained in water and toluene, while in 2-propanol hollow spheres were formed. The X-ray diffraction analysis, besides wurtzite hexagonal and zinc blende cubic phases, revealed appearance of tetragonal high-pressure AgI modification for sample collected in toluene and for sample aged in 2-propanol. The aging in toluene induced transformation of all three modifications into single phase with one preferred orientation

  19. Effect of liquid additives in supercritical fluid deposition of copper for enhancing deposition chemistry

    Four liquid chemical reagents (ethanol, 2-propanol, hydrogen peroxide, and formic acid) were evaluated as reducing agents for supercritical fluid deposition of Cu (Cu-SCFD) using bis(2,2,6,6-tetramethyl-3,5-heptanedionato)copper as a precursor onto a Ru-coated Si substrate for ultra large scale integration metallization. Deposition was carried out using a batch-type reactor and heating the substrate from 40 deg. C to 250 deg. C at a rate of 4.5 deg. C /min. 2-propanol and hydrogen peroxide yielded Cu grains, but not a continuous Cu film. Only formic acid yielded a high-purity continuous film. Solvent effect of two chemical reagents (ethanol and 2-propanol) on Cu-SCFD with H2 as a reducing agent was also investigated by using in situ method, in which optical reflectivity of growing surface at wavelength of 770 nm was used. Ethanol addition enhanced the deposition reaction without degrading both the surface morphology and high purity of the deposited Cu film

  20. Ammonium hydroxide (NH{sub 4}OH) as etch-stop chemical for highly boron-doped silicon {delta}-layers

    Hammer, Oliver; Palitschka, Florian; Lochner, Helmut; Kubot, Tina; Kulaga-Egger, Dorota; Beckmeier, Daniel; Axt, Carolin; Biba, Josef; Schindler, Ronny; Dressler, Marc; Sulima, Torsten; Hansch, Walter [Universitaet der Bundeswehr Muenchen, Institut fuer Physik, Neubiberg (Germany)

    2010-07-01

    The downscaling process in current microelectronics results in smaller devices and thinner layers. A proper etch-stop for such thin layers, e.g. boron-doped {delta}-layer (<10nm) in a vertical device, becomes more and more challenging. Therefore an etchant with an exceedingly high selectivity to boron-doped silicon is needed. Only two wet-chemical silicon etchants, TMAH and the not common NH{sub 4}OH, are capable for CMOS technology and are not too highly toxic. The major advantage of NH{sub 4}OH in comparison to TMAH is its high selectivity of 1:8000 for intrinsic silicon with respect to boron-doped silicon. The disadvantages are formation of hillocks and more pronounced surface roughness compared to TMAH. We optimize etching parameters by variation of the etch temperature, the concentration of NH{sub 4}OH in water and the ratio of 2-propanol in the solution to achieve an etch-stop at a {delta}-layer without breaking it. Recent experiments show that a solution of TMAH and 2-propanol decreases the surface roughness and the formation of hillocks. Due to this we also perform tests with 2-propanol in a NH{sub 4}OH solution. Finally we etch a bulk unipolar device (BUD) to determine the electrical characteristics of the exposed {delta}-layer.

  1. Photo-oxidation of organic compounds in liquid low-level mixed wastes at the INEL

    A bench-scale oxidation apparatus is implemented to study the effectiveness of using an artificial ultraviolet source, a 175-watt medium pressure mercury vapor lamp, to enhance the destruction of organic contaminants in water with chemical oxidants. The waste streams used in this study are samples or surrogates of mixed wastes at the Idaho National Engineering Laboratory. The contaminants that are investigated include methylene chloride, 1,1,1-trichlorethane, 1, 1-dichlororethane, acetone, 2-propanol, and ethylenediamine tetraacetic acid. We focus on H2O2-based oxidizers for our treatment scheme, which include the UV/H2O2 system, the dark Fenton system (H2O2/Fe2+), and the photo- assisted Fenton system (UV/H2O2/Fe3+) is used in particular. Variables include concentration of the chemical oxidizer, concentration of the organic contaminant, and the elapsed reaction time. Results indicate that the photo-assisted Fenton system provides the best overall performance of the oxidizing systems listed above, where decreases in concentrations of methylene chloride, 1,1,1- trichloroethane, 1,1-dichlororethane, 2-propanol, and ethylenediamine tetraacetic acid were seen. However, UV-oxidation treatment provided no measurable benefit for a mixed waste containing acetone in the presence of 2-propanol

  2. Alcohol--Induced Polyelectrolyte-Surfactant Complex Coacervate Systems: Characterization and Applications in Enzyme and Protein Extraction

    Nejati Moshtaghin, Mahboubeh

    of FA, oppositely charged amphiphiles (surfactant-polyelectrolyte), and the charge ratio of the surfactant-polyelectrolyte on the extent of coacervation have been investigated. Furthermore, the chemical composition of each phase formed in the coacervate system was determined as a function of HFIP percentage. Phase diagrams of HFIP-PMA-CTAB and 2-propanol-PMA-CTAB were studied. The phase separation occurs over a wide range of polyelectrolyte, surfactant and alcohol concentration. In addition, a study of the dependence of coacervate volume on phase composition in different system (as defined by concentrations and mole charge ratio of amphihiles and alcohols) provided useful insight about possible underlying interactions and mechanisms. It has been concluded that neutralization favors coacervation in both systems. However, according to the compositional analysis of both HFIP and 2-propanol SPCC system, it seems that coacervation mechanisms are different. In Chapter III the properties of 2-propanol--SPCC, with analogous surfactant (CTAB) and polyelectrolyte (PMA) used in Chapter II, will be investigated. In particular, we are interested in examining the difference between the phase separation characteristics of the coacervates induced by 2-propanol and HFIP as coacervator. For this purpose, the phase behavior and the chemical composition of the phases will be analyzed as a function of 2-propanol and constituents concentrations. Chapter IV contains results of our investigations on the activity of a model enzyme (Trypsin) in 2-propanol- and FA-induced SPCC system. These investigations will facilitate understanding whether the aliphatic alcohol, AA- and FA-induced SPCC system denature the model enzymes. Such investigations also help in evaluation of the applicability of the coacervate systems developed in this work in proteomics where the proteolytic activity of enzymes is used for protein digestion. Finally, in Chapter V, the efficiency of the coacervate system (2-propanol

  3. Chemical strategies for modifications of the solar cell process, from wafering to emitter diffusion; Chemische Ansaetze zur Neuordnung des Solarzellenprozesses ausgehend vom Wafering bis hin zur Emitterdiffusion

    Mayer, Kuno

    2009-11-06

    The paper describes the classic standard industrial solar cell based on monocrystalline silicon and describes new methods of fabrication. The first is an alternative wafering concept using laser microjet cutting instead of multiwire cutting. This method originally uses pure, deionized water; it was modified so that the liquid jet will not only be a liquid light conductor but also a transport medium for etching fluids supporting thermal abrasion of silicon by the laser jet. Two etching fluids were tested experimentally; it was found that water-free fluids based on perfluorinated solvents with very slight additions of gaseous chlorine are superior to all other options. In the second section, the wet chemical process steps between wafering and emitter diffusion (i.e. the first high-temperature step) was to be modified. Alternatives to 2-propanol were to be found in the experimental part. Purification after texturing was to be rationalized in order to reduce the process cost, either by using less chemical substances or by achieving shorter process times. 1-pentanol and p-toluolsulfonic acid were identified as two potential alternatives to 2-propanol as texture additives. Finally, it could be shown that wire-cut substrates processed with the new texturing agents have higher mechanical stabilities than substrates used with the classic texturing agent 2-propanol. [German] Im ersten Kapitel wird die klassische Standard-Industrie-Solarzelle auf der Basis monokristallinen Siliziums vorgestellt. Der bisherige Herstellungsprozess der Standard-Industrie-Solarzelle, der in wesentlichen Teilen darauf abzielt, diese Verluste zu minimieren, dient als Referenz fuer die Entwicklung neuer Fertigungsverfahren, wie sie in dieser Arbeit vorgestellt werden. Den ersten thematischen Schwerpunkt bildet die Entwicklung eines alternativen Wafering-Konzeptes zum Multi-Drahtsaegen. Die Basis des neuen, hier vorgestellten Wafering-Prozesses bildet das Laser-Micro-Jet-Verfahren. Dieses System

  4. Electron solvation in liquid alcohols. Effect of microscopic liquid structure

    Complete text of publication follows. Numerous theoretical works show that excess electrons in polar liquids can localize in cavities in which the surrounding solvent molecules create an attractive potential well. These cavities are called the pre-existing traps. Existence of the preformed traps in liquids is also suggested by results of the femtosecond time-resolved studies on the solvated electron. Thus, theoretical description of the pre-existing traps in various liquids is important for understanding the process of primary electron localization in these media. In the present work the structure of liquid alcohols, obtained by computer simulation, has been analyzed in order to identify the regions that can serve as pre-existing sites for primary localization of an excess electron. The calculations were performed for two alcohols: 1-propanol and 2-propanol, at 298 K. Configurations of molecules for each liquid sample were generated in a classical Molecular Dynamics Simulations. The static and dynamical properties of the traps have been investigated and described in terms of the statistical distributions of their geometrical parameters and their lifetimes, respectively. Moreover, we have connected these properties with the local structure of the medium around the traps. Our general conclusions are as follows: (1) electron traps in 1-propanol (generally in primary alcohols) are deeper in comparison with traps in 2-propanol (secondary alcohols), (2) electron solvation process in 1-propanol, in contrast to 2-propanol, does not involve breaking of hydrogen bonding net, (3) and they are consistent with the experimental results of Zhang et al. (Radiat. Phys. Chem., 1999, 54, 433) for electrons localized in those matrices

  5. Enantioselektive Transferhydrierung mit Ruthenium(II)-Komplexen

    Henning, Frauke

    2003-01-01

    Eine Vielzahl chiraler Liganden und Komplexe wurden als Katalysatoren in der enantioselektiven Transferhydrierung von Acetophenon mit den Wasserstoffdonoren 2-Propanol und Ameisensäure getestet. Vier dreizähnige axial chirale Binaphthyle erzielen in situ mit Tris-(triphenylphosphanyl)ruthenium(II)-chlorid hohe Enantiomerenüberschüsse von bis zu 98% und Ausbeuten über 90% unter optimierten Reaktionsbedingungen. Es wird ein deutlicher OH-Effekt beobachtet, während ein NH-Effekt nicht bestätigt ...

  6. Vapour pressures and osmotic coefficients of binary mixtures of 1-ethyl-3-methylimidazolium ethylsulfate and 1-ethyl-3-methylpyridinium ethylsulfate with alcohols at T = 323.15 K

    Osmotic coefficients of binary mixtures containing alcohols (ethanol, 1-propanol, and 2-propanol) and the ionic liquids 1-ethyl-3-methylimidazolium ethylsulfate and 1-ethyl-3-methylpyridinium ethylsulfate were determined at T = 323.15 K. Vapour pressure and activity coefficients of the studied systems were calculated from experimental data. The extended Pitzer model modified by Archer, and the modified NRTL model (MNRTL) were used to correlate the experimental data, obtaining standard deviations lower than 0.012 and 0.031, respectively. The mean molal activity coefficients and the excess Gibbs free energy of the studied binary mixtures were calculated from the parameters obtained with the extended Pitzer model of Archer.

  7. Growth of gadolinium oxide this films by liquid injection MOCVD using a new gadolinium alkoxide precursor

    Thin films of neodymium oxide (Nd2O3) have been deposited on Si(100) and GaAs(100) substrates by liquid injection MOCVD using the new neodymium alkoxide, [Nd(mmp)3] (mmp = 1-methoxy-2-methyl-2-propanolate, OCMe2CH2OMe). The films were grown over a wide range of substrate temperatures (250-550 C) and were found to be of high purity, with no detectable carbon. The films exhibited the cubic C-type Nd2O3 phase or were amorphous depending on substrate temperature. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  8. Growth of praseodymium oxide and praseodymium silicate thin films by liquid injection MOCVD

    Thin films of praseodymium oxide have been deposited by liquid injection MOCVD using the volatile praseodymium alkoxide, [Pr(mmp)3] (mmp=1-methoxy-2-methyl-2-propanolate, OCMe2CH2OMe). The films were grown over a wide range of substrate temperatures (250-600 C) and were found to consist predominantly of the Pr6O11 phase. Praseodymium silicate films containing ∝ 16-22 at.-% Si were deposited over the temperature range 350-550 C using [Pr{N(SiMe3)2}3] in the absence of any additional Si source. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  9. 1-(Piperidin-1-yl)-3-(2,4,6-trimethyl­phen­yl)propan-2-ol

    Maharramov, Abel M.; Khalilov, Ali N.; Gurbanov, Atash V.; Allahverdiyev, Mirze A.; Ng, Seik Weng

    2011-01-01

    The title compound, C17H27NO, features a bufferfly-shaped substituted 2-propanol having an aromatic ring on the 1-carbon and a piperidine ring on the 3-carbon. The piperidine ring adopts a chair conformation and its N atom shows a trigonal coordination. In the crystal, the hy­droxy group inter­acts with the N atom of an inversion-related mol­ecule, generating an O—H⋯N hydrogen-bonded dimer. PMID:21522478

  10. Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

    Min Sup Kim; Sang Jun Park; Bon Kang Gu; Chun-Ho Kim

    2012-01-01

    We describe here the preparation of poly(caprolactone) (PCL)-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angle...

  11. Cyclic Tetranuclear and Hexanuclear Palladium(II) Complexes and Their Host-Guest Chemistry

    Judith A. Walmsley; Zhu, Shourong; Matilla, Antonio; Donowick, Tiffanee G.; Cramp, Jessica E.; Tercero, Jose Manuel; Dalrymple, Tatyana

    2007-01-01

    Cyclic tetrameric complexes have been prepared by the reaction of Pd(en)Cl2 or Pd(dapol)Cl2, or their nitrato analogs, with Na2(5′GMP) in aqueous solution, where en = 1,2-diaminoethane, dapol = 1,3-diamino-2-propanol, 5′-GMP = guanosine 5′-monophosphate. Addition of certain small molecules containing hydrophobic groups resulted in the expansion of the tetramer to a cyclic hexamer with strong bonding of one guest per hexameric host. At pH 5-6, the guest molecule can be a cation, anion, or neut...

  12. Characterization of the Initial Reactions during the Cometabolic Oxidation of Methyl tert-Butyl Ether by Propane-Grown Mycobacterium vaccae JOB5

    Smith, Christy A.; O'Reilly, Kirk T.; Hyman, Michael R.

    2003-01-01

    The initial reactions in the cometabolic oxidation of the gasoline oxygenate, methyl tert-butyl ether (MTBE), by Mycobacterium vaccae JOB5 have been characterized. Two products, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), rapidly accumulated extracellularly when propane-grown cells were incubated with MTBE. Lower rates of TBF and TBA production from MTBE were also observed with cells grown on 1- or 2-propanol, while neither product was generated from MTBE by cells grown on casein-y...

  13. Determination of water in organic solvents by flow-injection analysis with Karl Fischer reagent and a biamperometric detection system

    Liang, Chen; Vácha, Pavel; Linden, DE

    1988-01-01

    A flow-injection system with a biamperometric flow-through detector provided with two platinum plate electrodes was tested for the determination of water with a two-component pyridine-free Karl Fischer reagent. The response was shown to be linear in the concentration range 0.03–0.11% water in methanol, ethanol or 2-propanol, with methanol as the carrier solvent. The maximum sampling frequency was about 150 samples per hr. It appeared to be possible to introduce a membrane separation step, thu...

  14. Studies on reactions of α-hydroxyalkyl radicals derived from n-propanol and n-butanol with nicotinic acid: estimation of their reduction potential

    Reactions of α-hydroxyalkyl radicals derived from n-propanol and n-butanol with nicotinic acid were studied by pulse radiolysis techniques. In these reactions adducts of α-hydroxyalkyl radicals and nicotinic acid are formed. Rate constant for these reactions were determined. These adducts were found to decay by uni-molecular pathway giving the pyridinyl radicals. From the earlier obtained linear plot of rate constants for adduct formation versus the reduction potentials of α-hydroxyalkyl radicals of 2-propanol, ethanol and methanol, reduction potentials of α-hydroxyalkyl radicals of n-propanol and n-butanol were estimated. (author)

  15. Stereo block copolymers of L- and D-lactides

    Yui, Nobuhiko; Pieter J. Dijkstra; Feijen, Jan

    1990-01-01

    Sequential diblock copolymers composed of L- and D-lactic acid residues were synthesized through a living ring-opening polymerization of L- and D-lactide initiated by aluminium tris(2-propanolate). The composition of the block copolymers was varied by changing the reaction conditions and monomer over initiator ratio and confirmed by 1H NMR analysis, molecular weight determination and optical rotation measurements. Molecular weights ranged from 1,3 to 2,0 · 104 with 1,2 < Mw/Mn < 1,4. Stereoco...

  16. Radiolytic dechlorination of polychlorinated biphenyls in transformer oil and in marine sediment

    Radiolytic dechlorination of polychlorinated biphenyls (PCBs) in transformer oil and in marine sediments has been studied. At low PCB concentrations, complete degradation of the PCBs in transformer oil was achieved without degradation of the oil. Addition of an organic base, triethylamine, enhances the radiolytic dechlorination yield. The mechanism of dechlorination has been shown to involve electron transfer to PCBs from various aromatic radical anions formed in the irradiated oil. At high PCB concentrations, large amounts of triethylamine were necessary to achieve complete radiolytic dechlorination. Preliminary results on PCB-contaminated marine sediments demonstrate that addition of 2-propanol to the sediment/water slurry increases the effectiveness of the electron beam treatment

  17. Polymerization of cardanol using soybean peroxidase and its potential application as anti-biofilm coating material.

    Kim, Yong Hwan; An, Eun Suk; Song, Bong Keun; Kim, Dong Shik; Chelikani, Rahul

    2003-09-01

    Soybean peroxidase (20 mg) catalyzed the oxidative polymerization of cardanol in 2-propanol/phospate buffer solution (25 ml, 1:1 v/v) and yielded 62% polycardanol over 6 h. Cobalt naphthenate (0.5% w/w) catalyzed the crosslinking of polycardanol and the final hardness of crosslinked polycardanol film exceeded 9 H scale as pencil scratch hardness, which shows a high potential as a commercial coating material. In addition, it showed an excellent anti-biofouling activity to Pseudomonas fluorescens compared to other polymeric materials such as polypropylene. PMID:14571976

  18. Mixing properties of binary mixtures presenting azeotropes at several temperatures

    Experimental densities, speeds of sound, and refractive indices of the binary mixtures presenting azeotropes of (ethanol with hexane or heptane or 2-butanone) and (2-propanol with 2-butanone or ethylacetate or cyclohexane) were determined from T = (293.15 to 303.15) K. Excess molar volumes, changes of refractive index on mixing and deviations in isentropic compressibility for the above systems were calculated. A function of the mole fraction and temperature polynomial equation was used to fit these quantities. The standard deviations between experimental and calculated values are shown

  19. Solubility of pyrene in binary alcohol + cyclohexanol and alcohol + 1-pentanol solvent mixtures at 299.2 K

    McHale, M.E.R.; Horton, A.S.M.; Padilla, S.A.; Trufant, A.L.; De La Sancha, N.U.; Vela, E.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-11-01

    Experimental solubilities are reported for pyrene dissolved in five binary alcohol + cyclohexanol and seven binary alcohol + 1-pentanol solvent mixtures at 26 C. Alcohol cosolvents include 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and 2-pentanol. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the 12 systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  20. Solubility of anthracene in binary alcohol + 2-methoxyethanol solvent mixtures

    McHale, M.E.R.; Powell, J.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-01-01

    Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-methoxyethanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  1. Characterization of catalytic supports based in mixed oxides for control reactions of NO and N2O

    The catalytic supports Al2O3, La2O3 and Al2O3-La2O3 were prepared by the Precipitation and Coprecipitation techniques. The catalytic supports Al2O3, La2O3 and Al2O3-La2O3 were characterized by several techniques to determine: texture (Bet), crystallinity (XRD), chemical composition (Sem)(Ftir) and it was evaluated their total acidity by reaction with 2-propanol. The investigation will be continued with the cobalt addition and this will be evaluated for its catalytic activity in control reactions of N O and N2O. (Author)

  2. Separation of the four pairs of enantiomers of vincamine alkaloids by enantioselective high-performance liquid chromatography.

    Caccamese, S; Principato, G

    2000-09-29

    The four enantiomeric pairs of vincamine group alkaloids were separated by HPLC using Chiralpak AD as chiral stationary phase (CSP) and various n-hexane-2-propanol and n-hexane-ethanol mobile phases. (+)-cis-Vincamine, which is used in pharmaceutical preparations, is eluted much faster than its optical isomer, with separation factors of 2.4 and 3.5, respectively in these mobile phases. Other CSPs gave negative results. A chiral recognition mechanism is proposed and circular dichroism spectra of the individual enantiomers are presented. PMID:11043586

  3. Extended UNIQUAC Model for Correlation and Prediction of Vapor-Liquid-Liquid-Solid Equilibria in Aqueous Salt Systems Containing Non-Electrolytes. Part B. Alcohol (Ethanol, Propanols, Butanols) - Water-salt systems

    Thomsen, Kaj; Iliuta, Maria Cornelia; Rasmussen, Peter

    2004-01-01

    The Extended UNIQUAC model for electrolyte solutions is an excess Gibbs energy function consisting of a Debye-Huckel term and a term corresponding to the UNIQUAC equation. For vapor-liquid equilibrium calculations, the fugacities of gas-phase components are calculated with the Soave-Redlich-Kwong......-propanol, 2-methyl 2-propanol) and various ions (Na+, K+, NH4+, Cl-, NO3, SO42-, SO32-, HSO3-, CO32-, and HCO3-) shows the capability of the model to accurately represent the phase behavior of these kinds of systems. (C) 2004 Elsevier Ltd. All rights reserved....

  4. New Chiral Metal Cluster Systems for Catalytic Asymmetric Syntheses of Chiral Alcohols

    LI Yan-yun; CHEN Jian-shan; YANG Chuan-bo; DONG Zhen-rong; LI Bao-zhu; ZHANG Hui; GAO Jing-xing; TAKAO Ikariya

    2004-01-01

    The efficient chiral Ru3(CO)12 systems were prepared in situ from Ru3(CO)12 and various chiral diiminoor diamino-diphosphine tetradentate ligands. The systems have been used for the asymmetric transfer hydrogenation of propiophenone in 2-propanol, leading to 1-phenyl-1-propanol in a 98% yield and 96% e.e. The IR study suggests that the carbonyl hydride anion [HRu3(CO)11]- most probably exists as a principal species under the reaction conditions. The high chiral efficiency may be due to the synergetic effect produced by the neighboring ruthenium atoms and a special chiral micro-environment involving the polydentate ligand and the Ru3 framework.

  5. Analysis of 3-MCPD and 1,3-DCP in Various Foodstuffs Using GC-MS

    Kim, Wooseok; Jeong, Yun A; On, Jiwon; Choi, Ari; Lee, Jee-yeon; Lee, Joon Goo; Lee, Kwang-Geun; Pyo, Heesoo

    2015-01-01

    3-Monochloro-1,2-propanediol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) are not only produced in the manufacturing process of foodstuffs such as hydrolyzed vegetable proteins and soy sauce but are also formed by heat processing in the presence of fat and low water activity. 3-MCPD exists both in free and ester forms, and the ester form has been also detected in various foods. Free 3-MCPD and 1,3-DCP are classified as Group 2B by the International Agency for Research on Cancer. Although th...

  6. Response surface methodology for the optimization of dispersive liquid-liquid microextraction of chloropropanols in human plasma.

    Gonzalez-Siso, Paula; Lorenzo, Rosa A; Regenjo, María; Fernández, Purificación; Carro, Antonia M

    2015-10-01

    Chloropropanols are processing toxicants with a potential risk to human health due to the increased intake of processed foods. A rapid and efficient method for the determination of three chloropropanols in human plasma was developed using ultrasound-assisted dispersive liquid-liquid microextraction. The method involved derivatization and extraction in one step followed by gas chromatography with tandem mass spectrometry analysis. Parameters affecting extraction, such as sample pH, ionic strength, type and volume of dispersive and extraction solvents were optimized by response surface methodology using a pentagonal design. The linear range of the method was 5-200 ng/mL for 1,3-dichloro-2-propanol, 10-200 ng/mL for 2,3-dichloro-2-propanol and 10-400 ng/mL for 3-chloropropane-1,2-diol with the determination coefficients between 0.9989 and 0.9997. The limits of detection were in the range of 0.3-3.2 ng/mL. The precision varied from 1.9 to 10% relative standard deviation (n = 9). The recovery of the method was between 91 and 101%. Advantages such as low consumption of organic solvents and short time of analysis make the method suitable for the biomonitoring of chloropropanols. PMID:26205350

  7. Effect of reduction enhancer on a radiolytic synthesis of carbon-supported Pt–Cu nanoparticles and their structural and electrochemical properties

    Kugai, Junichiro, E-mail: jkugai@kobe-kosen.ac.jp [Kobe City College of Technology, Department of Applied Chemistry (Japan); Kubota, Chihiro; Okazaki, Tomohisa; Seino, Satoshi; Nakagawa, Takashi [Osaka University, Graduate School of Engineering (Japan); Nitani, Hiroaki [High Energy Accelerator Research Organization, Institute of Materials Structure Science (IMSS) (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

    2015-06-15

    In order to clarify the effect of reduction enhancer on the nanoparticle formation process and their structural and catalytic properties, carbon-supported Pt–Cu nanoparticles were synthesized by electron beam irradiation on an aqueous precursor solution in the presence/absence of reduction enhancer. In the absence of reduction enhancer, tetravalent platinum oxide particles of approximately 1 nm in diameter were formed on carbon support with copper barely precipitated, while in the presence of 2-propanol or ethylene glycol or glucose both platinum and copper precipitated as few-nanometer-sized alloy particles together with copper oxides. It was suggested that the metal nuclei produced upon electron beam irradiation do not have enough lifetime without reduction enhancer due to fast oxidation of the nuclei by oxidizing radicals, while the reduction enhancer scavenges these oxidizing radicals preventing oxidation of metallic clusters and prolonging their lifetime. Ethylene glycol gave smaller and better alloyed particles with less copper oxides compared to 2-propanol since the carbonyl compounds derived from oxidation of ethylene glycol protect metallic clusters from oxidation further prolonging their lifetime. In the electrochemical measurements, the methanol oxidation activities of Pt–Cu/C catalysts were well explained by their structural characteristics.

  8. Microstructural and auger microanalytical characterization of Cu-Hf and Cu-Ti catalysts.

    Pisarek, M; Janik-Czachor, M

    2006-06-01

    Degradation processes occurring at the surface and in the bulk of Cu-based amorphous alloys during cathodic hydrogen charging were used for promoting the catalytic activity of such alloys. These processes modifying the structure, composition, and morphology of the substrate proved to be useful methods for transforming Cu-Hf and inactive Cu-Ti amorphous alloy precursors into active and durable catalysts. Indeed, their catalytic activity for dehydrogenation of 2-propanol increased up to a conversion level of approximately 60% at selectivities to acetone of about 99% for Cu-Ti and to conversion of approximately 90% at selectivities of approximately 95% for Cu-Hf. Previous attempts carried out by aging in air or hydrogen charging from the gas phase resulted in a maximum conversion level up to 15% for Cu-Hf and up to 3% for Cu-Ti. High resolution Auger spectroscopy allowed changes occurring during the activation process to be identified, namely, the formation of small Cu particles on the HfO2 surface and the formation of highly porous particles containing mostly Cu and some Ti and O (Cu-Ti-O) on a Cu-Ti substrate. Differences in the chemistry and structure of both catalysts are discussed, and the implications for catalytic function are considered. A probable configuration of active sites on the Cu-Ti-O/Ti-O-Cu catalyst for dehydrogenation of 2-propanol is proposed. PMID:17481359

  9. Adsorption and Reaction of C1-C3 Alcohols over CeOx(111) Thin Films

    D Mullins; S Senanayake; T Chen

    2011-12-31

    This study reports the interaction of methanol, ethanol, 1-propanol, and 2-propanol with well-ordered CeO{sub 2}(111) thin film surfaces. All of the alcohols adsorb at low temperature by forming alkoxy and hydroxyl species on the surface. On fully oxidized CeO{sub 2}(111), recombination occurs between some of the alkoxys and hydroxyls, resulting in alcohol desorption near 220 K. At the same temperature, some of the surface hydroxyls disproportionate to produce water and the loss of lattice O. The remaining alkoxys react above 550 K. The primary alcohols favor dehydrogenation products (aldehydes). There is a net loss of O from the system, resulting in a reduction of the ceria. The secondary alcohol, 2-propanol, undergoes primarily dehydration, producing propene with no net change in the cerium oxidation state. Reduced CeO{sub x}(111) competes with the gaseous products for available O. Little or no water is produced. The reaction selectivity for the C{sub 2} and C{sub 3} alcohols shifts toward favoring dehydration products. The loss of O from the alcohols leads to oxidation of the reduced ceria. Compared with the oxidized surface, the alkene desorption shifts to lower temperature, whereas the aldehyde desorption shifts to higher temperature. This indicates that, on the reduced surface, it is easier to break the C-O bond but more difficult to break the O-substrate bond.

  10. Enhancement of percutaneous absorption of finasteride by cosolvents, cosurfactant and surfactants.

    Javadzadeh, Yousef; Shokri, Javad; Hallaj-Nezhadi, Somayeh; Hamishehkar, Hamed; Nokhodchi, Ali

    2010-12-01

    The enhancing effects of routinely used co-solvents, propylene glycol and 2-propanol, anionic and cationic surfactants and a co-surfactant with different concentrations were evaluated on the skin permeation of Finasteride. In vitro permeation experiments with rat skin revealed that the solvent mixture is a very important factor in the penetration of Finasteride through the skin. Unexpectedly, cationic and anionic surfactants in various concentrations did not show any enhancement effect on drug transdermal absorption but co-surfactant Transcutol P increased skin penetration of Finastride significantly. Transcutol P with 0.25% and 1% showed the best enhancement in the initial and final sampling time, respectively. Transcutol P in a concentration of 0.25% increased skin absorption of the drug nearly 3.6 times in the first 15 min. The highest enhancement ratio (ER) was gained in the presence of 1% Transcutol P (ER = 5.98). In this study, among the different topical Finastride formulations, Transcutol P 1% in combination with water, propylene glycol and 2-propanol (30, 10, and 60) showed the highest enhancement ratio. PMID:19929166

  11. Electron beam induced synthesis of uranium dioxide nanoparticles: Effect of solvent composition

    Rath, M. C.; Keny, S. J.; Naik, D. B.

    2016-09-01

    The effect of various compositions of solvents was investigated on the electron beam induced synthesis of uranium dioxide, UO2 nanoparticles. The synthesis was carried out at different pHs from 2 to 7 in the aqueous solutions containing 10 mM uranyl nitrate and 10% 2-propanol. The formation of UO2 nanoparticles was found to occur only in the pH range from 2.5 to 3.7. Experiments were also carried out in the aqueous solutions containing various other alcohols (10% v/v) such as methanol, ethanol, 1-propanol, 1-butanol or tert-butanol as well as in solutions containing 10 mM sodium formate at pH 3.4. The formation of UO2 nanoparticles in the aqueous solutions was found to occur only in the presence of ethanol, 1-propanol, 2-propanol or 1-butanol. It is therefore confirmed that the electron beam induced synthesis of UO2 nanoparticles strongly depends on the solvent compositions as well as the pH of the medium.

  12. Thermodynamic properties of binary liquid mixtures of diethylenetriamine with alcohols at different temperatures

    Highlights: → Thermodynamic study of diethylenetriamine + 2-methyl-1-propanol, +2-propanol or +1-butanol have been made. → Excess molar volumes and isentropic compressibility were determined. → Types of interactions were discussed based on derived properties. - Abstract: Densities, ρ, viscosities, η, and speeds of sound, u, were measured for the binary liquid mixtures containing diethylenetriamine with 2-methyl-1-propanol, 2-propanol and 1-butanol at 293.15, 298.15, 303.15, 308.15 and 313.15 K. From density and speed of sound data, excess molar volumes, VmE and deviations in isentropic compressibility, Δκs, and speed of sound, Δu have been evaluated. Viscosity data were used to compute deviations in viscosity and excess Gibbs energy of activation of viscous flow ΔG*E at 298.15, 303.15 and 308.15 K. A Redlich-Kister type equation was applied to fit the excess molar volumes and deviations in isentropic compressibility, speed of sound and viscosity data. The viscosity data have been correlated with the equations of Grunberg-Nissan, Tamura-Kurata, Heric-Brewer and of Hind et al. All the binary systems of the present study have negative values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which indicates strong interactions between the components of binary mixtures.

  13. Effect of reduction enhancer on a radiolytic synthesis of carbon-supported Pt–Cu nanoparticles and their structural and electrochemical properties

    In order to clarify the effect of reduction enhancer on the nanoparticle formation process and their structural and catalytic properties, carbon-supported Pt–Cu nanoparticles were synthesized by electron beam irradiation on an aqueous precursor solution in the presence/absence of reduction enhancer. In the absence of reduction enhancer, tetravalent platinum oxide particles of approximately 1 nm in diameter were formed on carbon support with copper barely precipitated, while in the presence of 2-propanol or ethylene glycol or glucose both platinum and copper precipitated as few-nanometer-sized alloy particles together with copper oxides. It was suggested that the metal nuclei produced upon electron beam irradiation do not have enough lifetime without reduction enhancer due to fast oxidation of the nuclei by oxidizing radicals, while the reduction enhancer scavenges these oxidizing radicals preventing oxidation of metallic clusters and prolonging their lifetime. Ethylene glycol gave smaller and better alloyed particles with less copper oxides compared to 2-propanol since the carbonyl compounds derived from oxidation of ethylene glycol protect metallic clusters from oxidation further prolonging their lifetime. In the electrochemical measurements, the methanol oxidation activities of Pt–Cu/C catalysts were well explained by their structural characteristics

  14. Thermochemistry of the solution of β-alanine in (H2O + alcohol) mixtures at 298.15 K

    Highlights: • Enthalpies of β-alanine dissolution have been measured in aqueous solution of MeOH, EtOH, 1-PrOH and 2-PrOH. • Measured data were reported as functions of composition of water + alcohol mixtures. • Enthalpy coefficients of pairwise interactions have been analyzed in terms of McMillan–Mayer theory. - Abstract: The enthalpies of the solution of β-alanine in H2O + (methanol, ethanol, 1-propanol and 2-propanol) mixtures with alcohol content up to 0.4 mol fractions, have been determined calorimetrically at T = 298.15 K. The standard enthalpies of the solution and transfer of β-alanine from water to aqueous alcohol have been calculated. The effect of structure properties of a mixed solvent on specified enthalpy characteristics of β-alanine is discussed. The enthalpy coefficients of pairwise interactions between β-alanine and alcohol molecules have been computed. It has been found that these coefficients become increasingly positive in methanol, ethanol, 1-propanol, and 2-propanol sequence. A comparative analysis of thermodynamic characteristics of dissolution of β-alanine and D,L-α-alanine in the mixtures studied has been made

  15. Solubility of anthracene and pyrene in binary alcohol + alcohol solvent mixtures

    Zvaigzne, A.I.; McHale, M.E.R.; Powell, J.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1995-11-01

    Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in binary 1-octanol + 2-propanol, 2-butanol + 1-butanol, 1-octanol + 1-butanol, 3-methyl-1-butanol + 1-propanol, and 2-methyl-1-propanol + 1-butanol mixtures at 25 C, and for pyrene dissolved in binary solvent mixtures containing 2-ethyl-1-hexanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 26 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the 12 systems studied, the combined NIBS/Redlich-Kister equation was found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.4%. Slightly larger deviations were noted in the case of the modified Wilson equation.

  16. Construction of heterologous gene expression cassettes for the development of recombinant Clostridium beijerinckii.

    Oh, Young Hoon; Eom, Gyeong Tae; Kang, Kyoung Hee; Joo, Jeong Chan; Jang, Young-Ah; Choi, Jae Woo; Song, Bong Keun; Lee, Seung Hwan; Park, Si Jae

    2016-04-01

    Gene-expression cassettes for the construction of recombinant Clostridium beijerinckii were developed as potential tools for metabolic engineering of C. beijerinckii. Gene expression cassettes containing ColE1 origin and pAMB origin along with the erythromycin resistance gene were constructed, in which promoters from Escherichia coli, Lactococcus lactis, Ralstonia eutropha, C. acetobutylicum, and C. beijerinckii are examined as potential promoters in C. beijerinckii. Zymogram analysis of the cell extracts and comparison of lipase activities of the recombinant C. beijerinckii strains expressing Pseudomonas fluorescens tliA gene suggested that the tliA gene was functionally expressed by all the examined promoters with different expression level. Also, recombinant C. beijerinckii expressing C. beijerinckii secondary alcohol dehydrogenase by the constructed expression cassettes successfully produced 2-propanol from glucose. The best promoter for TliA expression was the R. eutropha phaP promoter while that for 2-propanol production was the putative C. beijerinckii pta promoter. Gene expression cassettes developed in this study may be useful tools for the construction of recombinant C. beijerinckii strains as host strains for the valuable chemicals and fuels from renewable resources. PMID:26780375

  17. Effect of morphology and solvent on two-photon absorption of nano zinc oxide

    Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novel precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide

  18. Impact of growth kinetics on morphology and pore structure of TiO2-one-pot synthesis of macroporous TiO2 microspheres.

    Zhong, Ziyi; Chen, Fengxi; Ang, Thiam-Peng; Han, Yifan; Lim, Weiqiang; Gedanken, Aharon

    2006-06-12

    Titanium dioxide was synthesized by the hydrolysis of titanium tetraisopropoxide (TTIP) in the presence of acetic acid, 2-propanol, and organic amines (octylamine, aniline, and isobutylamine). H2O was supplied by an esterification reaction between acetic acid and 2-propanol (denoted as H2Oe), and/or by intentionally adding it (denoted as H2Oa). It was found that the quantity of H2Oa plays a crucial role in the morphology and porous structure of the final TiO2 product. Without the addition of H2Oa, 1D and porous TiO2 was synthesized. With the addition of H2Oa, and when the H2Oa:TiO2 molar ratio was in the range of 1:1 to 60:1, macroporous TiO2 microspheres possessing a large surface area and high thermal stability were obtained. When the H2Oa:TiO2 molar ratio exceeded 60:1, porous TiO2 with an irregular shape was formed. The variation in the morphology and porous structure is attributed to the manipulation of the growth kinetics by the addition of water. PMID:16749824

  19. Effect of morphology and solvent on two-photon absorption of nano zinc oxide

    Kavitha, M.K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); Haripadmam, P.C.; Gopinath, Pramod; Krishnan, Bindu [Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); John, Honey, E-mail: honey@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India)

    2013-05-15

    Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novel precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.

  20. Quantitative structure-retention relationship of selected imidazoline derivatives on α1-acid glycoprotein column.

    Filipic, Slavica; Ruzic, Dusan; Vucicevic, Jelica; Nikolic, Katarina; Agbaba, Danica

    2016-08-01

    The retention behaviour of 22 selected imidazoline drugs and derivatives was investigated on α1-acid glycoprotein (AGP) column using Sørensen phosphate buffer (pH 7.0) and 2-propanol as organic modifier. Quantitative Structure-Retention Relationships (QSRR) models were built using extrapolated logkw values as well as isocratic retention factors (logk5, logk8, logk10, logk12, logk15 obtained for 5%, 8%, 10%, 12%, and 15%, of 2-propanol in mobile phase, respectively) as dependant variables and calculated physicochemical parameters as independant variables. The established QSRR models were built by stepwise multiple linear regression (MLR) and partial least squares regression (PLS). The performance of the stepwise and PLS models was tested by cross-validation and the external test set prediction. The validated QSRR models were compared and the optimal PLS-QSRR model for logkw and each isocratic retention factors (PLS-QSRR(logk5), PLS-QSRR(logk8), PLS-QSRR(logk10), MLR-QSRR(logk12), MLR-QSRR(logk15)) were selected. The QSRR results were further confirmed by Linear Solvation Energy Relationships (LSER). LSER analysis indicated on hydrogen bond basicity, McGowan volume and excess molar refraction as the most significant parameters for all AGP chromatographic retention factors and logkw values of 22 selected imidazoline drugs and derivatives. PMID:26968888

  1. Influence of the composition of aqueous-alcohol solvents on the thermodynamic characteristics of L-phenylalanine dissolution at 298.15 K

    Badelin, Valentin G. [Laboratory of Thermodynamics of Solutions of Non-electrolytes and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045, Ivanovo (Russian Federation); Smirnov, Valeriy I., E-mail: vis@isc-ras.ru [Laboratory of Thermodynamics of Solutions of Non-electrolytes and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045, Ivanovo (Russian Federation)

    2011-11-10

    Highlights: Black-Right-Pointing-Pointer Enthalpies of L-phenylalanine dissolution have been measured in aqueous methanol, ethanol, 1-propanol and 2-propanol. Black-Right-Pointing-Pointer The measured data were reported as functions of composition of water + alcohol mixtures. Black-Right-Pointing-Pointer Enthalpy coefficients of pair-wise interactions have been analyzed in terms of McMillan-Mayer theory. Black-Right-Pointing-Pointer A comparative analysis of the characteristics of dissolution of L-phenylalanine and some other L-amino acids in the similar systems has been made. - Abstract: The enthalpies of L-phenylalanine dissolution in aqueous methanol, ethanol, 1-propanol and 2-propanol have been determined by calorimetry at 298.15 K and alcohol mole fractions up to x{sub 2} {approx}0.4. The standard enthalpies of solution {Delta}{sub sol}H Degree-Sign and transfer {Delta}{sub tr}H Degree-Sign from water to the mixed solvent as well as the enthalpy coefficients of L-phenylalanine-alcohol pair-wise interactions were calculated. The interrelation of the enthalpies of dissolution and transfer for L-phenylalanine with structural features of alcohols has been determined. A comparative analysis of the thermodynamic characteristics of dissolution of L-phenylalanine and some other amino acids (glycine, L-alanine, L-threonine and L-valine) in the mixtures studied has been made.

  2. Determination and correlation of solubility of tylosin tartrate in alcohol mixtures

    Graphical abstract: Data on (solid + liquid) equilibrium of tylosin tartrate in {methanol + (ethanol, 1-propanol or 2-propanol)} solvents was measured over temperature range from (278.15 to 323.15) K under atmospheric pressure by a gravimetric method. From the experimental results, it can be seen that solubility of tylosin tartrate increases with increasing mass fraction of methanol in mixed solvents at a constant temperature, and increases with increasing temperature at the same mass fraction. The solubility of tylosin tartrate in methanol is higher than in methanol mixture solvents, and in 2-propanol is the lowest. The solubility data were correlated well with modified Apelblat equation, λh equation and van’t Hoff equation, and that modified Apelblat equation was more accurate than λh equation and van’t Hoff equation. Further, the standard enthalpy, standard entropy and standard Gibbs free energy of solution of tylosin tartrate in mixed solvents were calculated according to solubility data and model parameters with modified Apelblat equation and van’t Hoff equation. - Highlights: • The solubility of tylosin tartrate in selected solvents has been obtained in this work. • The results show that the three models agree well with the experimental data. • The modified Apelblat model were more accurate than λh model and van’t Hoff model. • The dissolution enthalpy and entropy of tylosin tartrate were calculated from the solubility data. - Abstract: Data on (solid + liquid) equilibrium of tylosin tartrate in {methanol + (ethanol, 1-propanol or 2-propanol)} solvents will provide essential support for industrial design and further theoretical studies. In this study, the solubility of tylosin tartrate in alcohol mixtures was measured over temperature range from (278.15 to 323.15) K under atmospheric pressure by a gravimetric method. From the experimental results, the solubility of tylosin tartrate in selected solvents noted above was found to increase with

  3. Scale-up of a fixed bed electrochemical reactor consisting of parallel screen electrode used for p-aminophenol production

    The behavior of a fixed bed consisting of amalgamated copper screens has been investigated for the electrolytic reduction of nitrobenzene to p-aminophenol under potentiostatic condition (controlled potential). The preparative electrolysis of nitrobenzene was carried out using supporting electrolytes consisting of 2 M H2SO4 in a solution of 50% 2-propanol/50% water (v/v). The criterion for scale-up (εn) was determined through application of one-dimensional model. The polarization curves that describe the reduction of nitrobenzene to p-aminophenol were obtained experimentally by using a pilot scale for different nitrobenzene concentrations and flow rates of catholyte. It was found that the effectiveness factor (εn) increases with increasing flow rate, and decreasing nitrobenzene concentration. An optimum thickness of bed equal to 0.6 cm was obtained, in which the effectiveness factor not less than 0.588, to ensure a well distribution of current and potential

  4. Isomerización de n-Pentano mediante óxidos de circonio dopados con ión borato

    L. A. Cortez-Lajas; J. M. Hernández-Enríquez; A. Castillo-Mares; J. L. Rivera-Armenta; G. Sandoval-Robles; L. A. García-Serrano; R. García-Alamilla

    2006-01-01

    Se sintetizaron hidróxido de circonio puro y modificado con un 15% de iones borato. Ambos se calcinaron en atmósfera dinámica de aire durante 3 h a 400, 500 y 600ºC. Los soportes se caracterizaron mediante fisisorción de nitrógeno, espectroscopía infrarroja, titulación potenciométrica con n-butilamina y deshidratación del 2-propanol. Después de la calcinación los soportes se impregnaron con 0.5% peso de platino y se probaron en isomerización de n-pentano a presión atmosférica. La acidez...

  5. Síntesis de óxidos mixtos de Al2O3-ZrO2 y el efecto de la sulfatación

    M. L. Guevara Franco; S. Robles Andrade; García Alamilla, R.; G. Sandoval Robles; J. M. Domínguez Esquivel; J. ZAMORA

    2003-01-01

    En este trabajo se sintetizaron óxidos mixtos de alúmina y circonia por el método sol-gel, y se estudió el efecto de la sulfatación en las propiedades del soporte, probando 3 métodos y dos fuentes de sulfato. Se caracterizaron por DRX, MEB, adsorción de N2, titulación potenciométrica con n-butilamina, deshidratación de 2-propanol y finalmente para probar su actividad catalítica, en isomerización de n-hexano a presión atmosférica. Los resultados mostraron que la sulfatación con ácido sulfúrico...

  6. X-Ray structure and cytotoxic activity of a picolinate ruthenium(II–arene complex

    IVANKA IVANOVIĆ

    2011-01-01

    Full Text Available A ruthenium(II–arene complex with picolinic acid, [(η6-p-cymeneRuCl(pico]∙H2O, was prepared by the reaction of [(η6-p-cymeneRuCl2]2 with picolinic acid in a 1:2 molar ratio in 2-propanol. The compound was characterized by elemental analysis, and IR and NMR spectroscopy. X-ray diffraction analysis showed that the molecule adopts a “three-leg piano-stool” geometry, which is common for this type of complexes. The cytotoxic activity of the complex was tested in two human cancer cell lines HeLa (cervix and FemX (melanoma by MTT assay. The IC50 values were at 82.0 and 36.2 µmol dm-3 for HeLa and FemX cells, respectively.

  7. Research Update: A hafnium-based metal-organic framework as a catalyst for regioselective ring-opening of epoxides with a mild hydride source

    Reaction of styrene oxide with sodium cyanoborohydride and a catalytic amount of Hf-NU-1000 yields the anti-Markovnikov product, 2-phenylethanol, with over 98% regioselectivity. On the other hand, propylene oxide is ring opened in a Markovnikov fashion to form 2-propanol with 95% regioselectivity. Both styrene oxide and propylene oxide failed to react with sodium cyanoborohydride without the addition of Hf-NU-1000 indicative of the crucial role of Hf-NU-1000 as a catalyst in this reaction. To the best of our knowledge, this is the first report of the use of a metal-organic framework material as a catalyst for ring-opening of epoxides with hydrides

  8. Effect of solvents on propylene epoxidation over TS-1 catalyst

    Yulong WU; Qingshan LIU; Xueli SU; Zhentao MI

    2008-01-01

    Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetoni-trile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization.

  9. Osmotic coefficients of binary mixtures of 1-butyl-3-methylimidazolium methylsulfate and 1,3-dimethylimidazolium methylsulfate with alcohols at T = 323.15 K

    Measurements of osmotic coefficients of BMimMSO4 (1-butyl-3-methylimidazolium methylsulfate) and MMimMSO4 (1,3-dimethylimidazolium methylsulfate) with ethanol, 1-propanol, and 2-propanol at T = 323.15 K are reported in this work. Vapour pressure and activity values for the binary systems studied are obtained from experimental results. The osmotic coefficients are correlated using the extended Pitzer model modified by Archer and the modified NRTL (MNRTL) model. The standard deviations obtained with both models are lower than 0.013 and 0.060, respectively. The parameters obtained with the extended Pitzer model of Archer are used to calculate the mean molal activity coefficients and the excess Gibbs free energy of the binary mixtures

  10. Vapour pressures, osmotic and activity coefficients for binary mixtures containing (1-ethylpyridinium ethylsulfate + several alcohols) at T = 323.15 K

    Osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1-ethylpyridinium ethylsulfate were determined at T = 323.15 K using the vapour pressure osmometry technique. From the experimental results, vapour pressure and activity coefficients can be determined. For the correlation of osmotic coefficients, the extended Pitzer model modified by Archer, and the modified NRTL (MNRTL) model were used, obtaining deviations lower than 0.017 and 0.047, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the binary mixtures studied were determined from the parameters obtained with the extended Pitzer model modified by Archer.

  11. Characterization of catalytic supports based in mixed oxides for control reactions of NO and N{sub 2}O; Caracterizacion de soportes cataliticos basados en oxidos mixtos para reacciones de control de NO y N{sub 2}O

    Garcia C, M.A.; Perez H, R.; Gomez C, A.; Diaz, G. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were prepared by the Precipitation and Coprecipitation techniques. The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were characterized by several techniques to determine: texture (Bet), crystallinity (XRD), chemical composition (Sem)(Ftir) and it was evaluated their total acidity by reaction with 2-propanol. The investigation will be continued with the cobalt addition and this will be evaluated for its catalytic activity in control reactions of N O and N{sub 2}O. (Author)

  12. Advances in the catalysts development in base of mixed oxides for control reactions of N{sub 2}O; Avances en el desarrollo de catalizadores a base de oxidos mixtos para reacciones de control de N{sub 2}O

    Garcia, M.A.; Perez, R.; Gomez, A.; Diaz, G. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were prepared by the precipitation and coprecipitation techniques. The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were characterized by several techniques for to determine texture (BET), crystallinity (XRD), chemical composition (SEM), FTIR and it was evaluated their total acidity by the reaction with 2-propanol. It was continued with the cobalt addition by Impregnation and coprecipitation and it was evaluated its catalytic activity in the N{sub 2}O decomposition reaction. Also it was realized the N{sub 2}O reduction with Co using these catalysts. (Author)

  13. Effect of temperature on the enthalpies of formation of water- o-xylene-Triton X-100 microemulsions

    Batov, D. V.; Kartsev, V. N.; Shtykov, S. N.

    2013-03-01

    Enthalpies of solution for water- o-xylene-Triton X-100 (TX-100) microemulsions and their components in 2-propanol are determined thermochemically at 288.15, 298.15, and 313.15 K. Enthalpies of formation for the microemulsions are calculated using a thermochemical cycle. It is shown that the enthalpies of formation are negative and fall in moving from water/oil microemulsions to oil/water microemulsions. The obtained data show that strong molecular interactions between components in the investigated systems favor the formation of thermodynamically stable microemulsions. It is concluded that the spontaneous formation of the microemulsions can be due to both the entropy and enthalpy contributions to the change in free energy.

  14. Direct optical observation of the formation of some aliphatic alcohol radicals. A pulse radiolysis study

    E Janata

    2002-12-01

    The kinetics of the reactions of hydroxyl radicals and hydrogen atoms with some aliphatic alcohols in aqueous solutions were studied using pulse radiolysis. Based on the increase in optical absorption in the UV region, the rate constants for the reaction of hydroxyl radicals and hydrogen atoms with methanol, ethanol, 2-propanol or -butyl alcohol were determined to be 9.0 × 108, 2.2 × 109, 2.0 × 109, 6.2 × 108 and 1.1 × 106, 1.8 × 107, 5.3 × 107, 2.3 × 105 dm3 mol-1 s-1 respectively. The bimolecular decay rate constants for the alcohol radicals produced in methanol and ethanol were evaluated to be 2 .4 × 109 and 1.5 × 109 dm3 mol-1 s-1. The values observed are in fairly good agreement with those reported earlier.

  15. The electrical characterization of a multi-electrode odor detection sensor array based on the single SnO2 nanowire

    The variation of electrical properties of individual SnO2 wedge-like nanowire along its length was characterized comparatively in a vacuum, low-pressure oxygen environment and in synthetic air mixed with various analytes. For characterization, a vapor–solid grown nanowire was indexed with multiple Pt mesoscopic contacts fabricated by e-beam induced deposition from Pt containing metalorganic precursor. The surface of the selected nanowire segments was functionalized with a catalyst via deposition of Pd nanoparticles. Detailed analysis of the electrical properties of the nanowire shows that the effective diameter of the conducting channel of the nanowire can be substantially modified along its length by the surface functionalization and nanowire width change. These variations of the electrical properties of nanowire segments are sufficient for reliable discrimination of acetone, 2-propanol, CO and hydrogen by this elemental multisensor array.

  16. Derived thermodynamic properties of alcohol + cyclohexylamine mixtures

    IVONA R. RADOVIĆ

    2010-02-01

    Full Text Available Thermal expansion coefficients, α, excess thermal expansion coefficients, αE, isothermal coefficients of pressure excess molar enthalpy, (∂HE/∂pT,x, partial molar volumes, , partial molar volumes at infinite dilution, , partial excess molar volumes, , and partial excess molar volumes at infinite dilution, , were calculated using experimental densities and excess molar volumes, , data. All calculations are performed for the binary systems of cyclohexylamine with 1-propanol or 1-butanol or 2-butanol or 2-methyl-2-propanol. The Redlich–Kister polynomial and the reduced excess molar volume approach were used in the evaluation of these properties. In addition, the aim of this investigation was to provide a set of various volumetric data in order to asses the influence of temperature, chain length and position of hydroxyl group in the alcohol molecule on the molecular interactions in the examined binary mixtures.

  17. The plasma membrane proteome of germinating barley embryos

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.;

    2009-01-01

    amphiphilicity and low abundance of membrane proteins. A fraction enriched in plasma membranes was prepared from embryos dissected from 18 h germinated barley seeds using aqueous two-phase partitioning. Reversed-phase chromatography on C-4 resin performed in micro-spin columns with stepwise elution by 2-propanol......Cereal seed germination involves a complex coordination between different seed tissues. Plasma membranes must play crucial roles in coordination and execution of germination; however, very little is known about seed plasma membrane proteomes due to limited tissue amounts combined with...... was used to reduce soluble protein contamination and enrich for hydrophobic proteins. Sixty-one proteins in 14 SDS-PAGE bands were identified by LC-MS/MS and database searches. The identifications provide new insight into the plasma membrane functions in seed germination....

  18. Ruthenium-Catalyzed Transfer Hydrogenation for C-C Bond Formation: Hydrohydroxyalkylation and Hydroaminoalkylation via Reactant Redox Pairs.

    Perez, Felix; Oda, Susumu; Geary, Laina M; Krische, Michael J

    2016-06-01

    Merging the chemistry of transfer hydrogenation and carbonyl or imine addition, a broad new family of redox-neutral or reductive hydrohydroxyalkylations and hydroaminomethylations have been developed. In these processes, hydrogen redistribution between alcohols and π-unsaturated reactants is accompanied by C-C bond formation, enabling direct conversion of lower alcohols to higher alcohols. Similarly, hydrogen redistribution between amines to π-unsaturated reactants results in direct conversion of lower amines to higher amines. Alternatively, equivalent products of hydrohydroxyalkylation and hydroaminomethylation may be generated through the reaction of carbonyl compounds or imines with π-unsaturated reactants under the conditions of 2-propanol-mediated reductive coupling. Finally, using vicinally dioxygenated reactants, that is, diol, ketols, or diones, successive transfer hydrogenative coupling occurs to generate 2 C-C bonds, resulting in products of formal [4+2] cycloaddition. PMID:27573275

  19. Growth of neodymium oxide this films by liquid injection MOCVD using a new neodymium alkoxide precursor

    Thin films of gadolinium oxide, GdOx, have been deposited by liquid injection MOCVD using the volatile gadolinium alkoxide precursor, [Gd(mmp)3] (mmp=1-methoxy-2-methyl-2-propanolate, OCMe2CH2OMe). Carbon-free GdOx films were grown over a wide range of substrate temperatures (300-600 C) on both Si(100) and GaAs(100) substrates. X-ray diffraction (XRD) data indicated that GdOx films grown on Si(100) were amorphous at low deposition temperatures, and crystalline with a C-type structure at growth temperatures of 450 C and above. GdOx films grown on GaAs at 450 C showed a strong preferred orientation, dominated by the (222) reflection. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  20. Photo catalytic degradation of organic pollutants diluted in water using TiO2 loaded on fluoride-modified hydrophobic meso porous silica

    The synthesis of the hydrophobic meso-porous silica (denoted as HMS(F)) was performed using tetraethyl orthosilicate (TEOS), tetraethylammonium fluoride (TEAF) as the source of the fluoride and dodecyl-amine (DDA) as templates. The TiO2 loaded on the hydrophobic HMS(F) (TiO2/HMS(F)) exhibited the efficient photo-catalytic performance for the degradation of alcohols (2-propanol and 2-hexanol) diluted in water. The amount of adsorption of alcohols and the photo-catalytic reactivity for the degradation increased with increasing the content of fluoride ions in these photo-catalysts. The hydrophobic meso-porous surface is suitable as photo-catalytic reaction field for the degradation of organic compounds diluted water. (authors)

  1. Pulmonary Toxicity of Perfluorinated Silane-Based Nanofilm Spray Products: Solvent Dependency

    Nørgaard, Asger Wisti; Hansen, Jitka S.; Sørli, Jorid Birkelund;

    2014-01-01

    A number of cases of pulmonary injury by use of aerosolized surface coating products have been reported worldwide. The aerosol from a commercial alcohol-based nanofilm product (NFP) for coating of nonabsorbing surfaces was found to induce severe lung damage in a recent mouse bioassay. The NFP...... POTS has been investigated. BALB/cA mice were exposed to aerosolized water-based NFPs containing POTS, and solutions of hydrolyzed POTS in methanol, ethanol, and 2-propanol, respectively. No acute respiratory effect was observed at exposure concentrations up to 110mg/m3 with an aqueous solution of POTS...... aerosolized POTS in methanol further exacerbated the tidal volume reduction, demonstrating that the concentration of vaporized solvent participated in the toxicity of POTS....

  2. Efecto de solvente sobre la descomposición térmica de trans-3,6-dimetil-3,6-difenil-1,2,4,5-tetraoxaciclohexano en solución

    Eyler Gladys N.

    2004-01-01

    Full Text Available The thermal decomposition reaction of trans-3,6-dimethyl-3,6-diphenyl-1,2,4,5-tetraoxacyclohexane (acetophenone cyclic diperoxide, DPAF, in different solvents (methanol, 1,4-dioxane, acetonitrile and 2-propanol/benzene mixtures in the initial concentration and temperature ranges of (4.2-10.5 x 10-3 M and 140.0 to 185.0 ºC, respectively, follows a pseudo first order kinetic law up to at least 70% DPAF conversion. An important solvent effect on the rate constant values, activation parameters (DH# and DS# and reaction products obtained in different solvents is detected, showing that the reaction is accelerated in alcohols.

  3. Photochemical and hot H atom reactions of acetaldehyde

    Photolysis and hot hydrogen atom reactions of acetaldehyde have been studied simultaneously not only with a cadmium but also with a zinc resonance lamp as the light source. Contrary to previous results, new products (acetone, ethanol, 2-propanol, ethyl acetoacetate, and diacetone alcohol) are identified in the photolysis of acetaldehyde. On the other hand, the principal products in decreasing order from the hot atom reaction with acetaldehyde have been established to be hydrogen, biacetyl, methane, carbon monoxide, and ethanol, whereas acetone and ethylene existed as minor products. A study of product quantum yields at 214 nm vs. various [CH3CHO]/[CH2S] ratios are reported. The formation of several unexpected products in these studies strongly suggested that the aldehyde functional group of acetaldehyde has an unsaturated character relative to the addition of both hydrogen atoms and methyl radicals. This latter new observation and accompanying mechanisms are discussed. 2 figures, 6 tables

  4. Nitrogen-doped titanium dioxide photocatalysts for visible response prepared by using organic compounds

    Yoshio Nosaka, Masami Matsushita, Junichi Nishino and Atsuko Y. Nosaka

    2005-01-01

    Full Text Available In order to utilize visible light in photocatalytic reactions, nitrogen atoms were doped in commercially available photocatalytic TiO2 powders by using an organic compound such as urea and guanidine. Analysis by X-ray photoelectron spectroscopy (XPS indicated that N atoms were incorporated into two different sites of the bulk phase of TiO2. A significant shift of the absorption edge to a lower energy and a higher absorption in the visible light region were observed. These N-doped TiO2 powders exhibited photocatalytic activity for the decomposition of 2-propanol in aqueous solution under visible light irradiation. The photocatalytic activity increased with the decrease of doped N atoms in O site, while decreased with decrease of the other sites. Degradation of photocatalytic activity based on the release of nitrogen atoms was observed for the reaction in the aqueous suspension system.

  5. Determining an efficient solvent extraction parameters for re-refining of waste lubricating oils

    Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK ((Methyl-Ethyl-Ketone), 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, when temperature of extraction increased the oil losses percent also decreased. This is due to the solvent ability that dissolves the base oil in waste lubricating oil and determines the best SOR (Solvent Oil Ratio) and extraction temperatures. (author)

  6. Effect of temperature on O anion radical reactions and equilibria: a pulse radiolysis study

    The pKa of the hydroxyl radical was measured over the 20-800C temperature range. At 200C, the pKa was 11.84 and fell to 10.81 at 800C. The dissociation constant for the ozonide anion (O2-anion radical ↔ O2 + O anion radical) was found to be 5.5 x 10-7 mol dm-3 at 200C and 46.2 x 10-7 mol dm-3 at 700C. The rate constants and activation energies for the reaction of O anion radical and OH with 2-propanol, methanol and 3-hexene-1,6-dicarboxylate ions have also been measured. (author)

  7. Effect of temperature on O⊘ reactions and equilibria: A pulse radiolysis study

    Elliot, Allen John; McCracken, David Ritchie

    The p Ka of the hydroxyl radical was measured over the 20-80°C temperature range. At 20°C, the p Ka was 11.84 and fell to 10.81 at 80°C. The dissociation constant for the ozonide anion (O⊘ 3⇌O 2+O⊘) was found to be 5.5 × 10 -7 mol dm -3 at 20°C and 46.2 × 10 -7 mol dm -3 at 70°C. The rate constants and activation energies for the reaction of O⊘ and OH with 2-propanol, methanol and 3-hexene-1,6-dicarboxylate ions have also been measured.

  8. Thermodynamic properties of binary mixtures containing dimethyl carbonate+2-alkanol: Experimental data, correlation and prediction by ERAS model and cubic EOS

    Almasi, Mohammad

    2013-03-01

    Densities and viscosities for binary mixtures of dimethyl carbonate with 2-propanol up to 2-heptanol were measured at various temperatures and ambient pressure. From experimental data, excess molar volumes, VmE. were calculated and correlated by the Redlich-Kister equation to obtain the binary coefficients and the standard deviations. Excess molar volumes, VmE, are positive for all studied mixtures over the entire range of the mole fraction. The ERAS-model has been applied for describing the binary excess molar volumes and also Peng-Robinson-Stryjek-Vera (PRSV) equation of state (EOS) has been used to predict the binary excess molar volumes and viscosities. Also several semi-empirical models were used to correlate the viscosity of binary mixtures.

  9. Degradation and miscibility of poly(DL-lactic acid)/poly(glycolic acid) composite films: Effect of poly(DL-lactic-co-glycolic acid)

    Zhigang Ma; Na Zhao; Chengdong Xiong

    2012-08-01

    The in vitro degradation behaviour of poly(glycolic acid) (PGA) and its composite films containing poly(DL-lactic acid) (PDLLA) and poly(DL-lactic-co-glycolic acid) (PDLGA) were investigated via mass loss, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). All the films were prepared by solution casting, using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. Since the degradation rate of PDLLA is lower than that of PGA, those of the PDLLA/PGA composite films decreased. As a compatibilizer, PDLGA improved the compatibility and hydrolytic stability of PDLLA/PGA composite films. Changes in the composite films indicate that this kind of PGA-based composite biomaterial may be applicable to device design for clinical application in the future.

  10. Radiosynthesis of a chloroacetanilide herbicide ([phenyl-4-3 H] acetochlor) and a dichloroacetamide safener for herbicides [2,2-dimethyl-3 H]R-29148

    2-Chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl) acetamide (the chloroacetanilide herbicide acetochlor) and 3-(dichloroacetyl)-2,2,5-trimethyl-1, 3-oxazolidine (the dichloroacetamide safener R-29148) are required at high specific activity for studies on their metabolism and mode of action. [phenyl-4-3H]Acetochlor was obtained at 22 Ci/mmol in 71% yield by reductive dehalogenation of iodoacetochlor with tritium gas in ethanol in the presence of palladium on carbon and triethylamine. [2,2-dimethyl-3H]R-29148 was prepared at 15 Ci/mmol by treating acetone and 1-amino-2-propanol in pentane with two equivalents of NaOH in tritiated water (i.e. hydroxide ion-catalyzed enolization of acetone) followed by dichloroacetyl chloride. (Author)

  11. PREPARED POTASSIUM SALT OF CARBOXYMETHYL PINE WOOD IN A MICROWAVE

    Вадим Иванович Маркин

    2013-10-01

    Full Text Available Microwave radiation to intensify the process of carboxymethylation of pine wood without prior separation of the individual components is proposed to use . Carboxymethylated pine wood in the form of the potassium salt obtained by treating the pine potassium hydroxide and monochloroacetic acid in 2-propanol . Composition and properties of the products were investigated . Carboxymethylcellulose isolated from carboxymethylated pine wood. Increasing the power of microwave radiation (210 to 700 W and the duration of the first and second stages of the process of carboxymethylation (20-30 sec increases the content of carboxymethyl groups (18,3-25,6 %. Abnormally low solubility of the potassium salts of carboxymethylated pine wood (10–18% compared to the sodium salt with a comparable content of carboxymethyl groups was detected. Study viscosity of aqueous solutions carboxymethylated pine and carboxymethylcellulose derived from it was performed. It is shown that the samples obtained at microwave power of 210 W have abnormal flow curves.

  12. Immobilization of RuS2 Nanoparticles Prepared in Reverse Micellar System onto Thiol-Modified Polystyrene Particles and their Photocatalytic Properties

    RuS2 nanoparticles, smaller than 3 nm in diameter, were prepared by H2S gas injection into the AOT/isooctane reverse micellar solution containing RuCl3 aqueous solution. The nanoparticle size was found to be independent of the Wo (water content) value of the reverse micellar system, as shown by TEM observation. The recovery and immobilization of the RuS2 nanoparticles from reverse micelles onto thiol-modified polystyrene particles (PSt-SH) were successfully carried out, by the addition of PSt-SH into the reverse micellar solution under conditions of mild stirring. The resulting composites, PSt-RuS2, showed photocatalytic activity for H2 generation form aqueous solution containing 2-propanol and Na2SO3 as sacrificial electron donors

  13. "Phase diagrams of Lecithin-based microemulsions containing Sodium Salicylate "

    "Aboofazeli R

    2000-08-01

    Full Text Available Partial phase diagrams were constructed at 25°C to investigate the phase behaviour of systems composed of soybean lecithin, water, sodium salicylate, alcohol and isopropyl myristate. The lecithins used were the commercially available soy bean lecithins, namely E200 and E170 (phosphatidyl choline purities greater than 95% and 68-72% respectively. The cosurfactants employed were n-propanol, 2-propanol and n-butanol and these were used at lecithin/alcohol weight ratios (Km of 1:1 and 1.5:1. At a given Km, the aqueous phase consisted of a 2% w/w sodium salicylate solution. Phase diagrams showed the area of existence of a stable isotropic region along the surfactant/oil axis (i.e., reverse microemulsion area. The extension of the microemulsion domain was influenced by the purity of surfactant, the lecithin/alcohol weight ratios and the kind of the alcohol.

  14. Liquid-liquid extraction and adsorption on solid surfaces applied to used lubricant oils recovery

    J. L. Assunção Filho

    2010-12-01

    Full Text Available In this work, the recovery of base oils from waste lubricants following the steps of solvent extraction, adsorption on solids and solvent removal by evaporation was evaluated. In the step of solvent extraction, the most efficient was 1-butanol, followed by tert-butanol, 2-propanol and ethanol; for the step of adsorption, activated carbon was the most effective solid for PAH removal, confirming the similarity of these compounds with petroleum aromatic fractions. Thus, the optimum solvent-adsorbent pair for the recovery of used lubricant oils through the proposed methodology was 1-butanol/activated carbon. At the end of the process, it was possible to establish a set of steps that permit the recovery of lubricant base oils with lower content of contaminants.

  15. Soporte de Nuevas Películas de TiO2 y TiO2/SiO2 sobre Gránulos de Poliéster para Aplicación en Fotocatálisis Support of New TiO2 and TiO2/SiO2 Films on Polyester Granules for Photocatalytic Applications

    Marín, Juan M.; Navío, José A.; LUIS A. RIOS; Gloria Restrepo

    2008-01-01

    Películas de TiO2 o TiO2/SiO2 fueron soportadas sobre gránulos de poliéster usando mecanismos de difusión y posterior tratamiento térmico a 100ºC. Se emplearon dos clases de geles. El primero fue preparado usando diferentes cantidades de TiO2, cloruro de metileno y silicona líquida. El segundo fue obtenido por medio del método sol-gel, empleado para producir una matriz de sílice a partir de la hidrólisis el tetraetilo ortosilicato, en un medio orgánico de 2-propanol, en el cual se dispersó el...

  16. PREPARATION OF POLYETHERSULFONE ULTRAFILTRATION MEMBRANES FOR MILK CONCENTRATION AND EFFECTS OF ADDITIVES ON THEIR MORPHOLOGY AND PERFORMANCE

    S.S. Madaeni; A. Rahimpour

    2005-01-01

    Polyethersulfone membranes were prepared from quaternary systems containing N,N-dimethylacetamide (DMAc) as solvent, polyvinylpyrrolidone (PVP) as constant additive and acetic acid, acetone and water as variable additives. Phase inversion via immersion precipitation was employed for manufacturing of membranes. The prepared films were immersed in the mixture of pure water and 2-propanol (30/70 vol%) as the non-solvent. Acetic acid caused an increment in the flux at high polymer concentration (16wt%) and a decline in the flux at low polymer concentrations (10 wt% and 13 wt%). Acetone and water as the solvent in the casting solution declined the flux at any polymer concentration tested. The morphology and performance of the prepared membranes were investigated by scanning electron microscopy and separation experiments using milk as the feed.

  17. Lipase-catalyzed biodiesel synthesis with different acyl acceptors

    Ognjanović Nevena D.

    2008-01-01

    Full Text Available Biodiesel is an alternative fuel for diesel engine that is environmentally acceptable. Conventionally, biodiesel is produced by transesterification of triglycerides and short alcohols in the presence of an acid or an alkaline catalyst. There are several problems associated with this kind of production that can be resolved by using lipase as the biocatalyst. The aim of the present work was to investigate novel acyl acceptors for biodiesel production. 2-Propanol and n-butanol have a less negative effect on lipase stability, and they also improve low temperature properties of the fuel. However, excess alcohol leads to inactivation of the enzyme, and glycerol, a major byproduct, can block the immobilized enzyme, resulting in low enzymatic activity. This problem was solved by using methyl acetate as acyl acceptor. Triacetylglycerol is produced instead of glycerol, and it has no negative effect on the activity of the lipase.

  18. Design, synthesis, and antifungal activities of novel triazole derivatives containing the benzyl group

    Xu K

    2015-03-01

    Full Text Available Kehan Xu,1,* Lei Huang,1,* Zheng Xu,2 Yanwei Wang,1,3 Guojing Bai,1 Qiuye Wu,1 Xiaoyan Wang,1 Shichong Yu,1 Yuanying Jiang1 1School of Pharmacy, Second Military Medical University, Shanghai, 2Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 3Number 422 Hospital of PLA, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Abstract: In previous studies undertaken by our group, a series of 1-(1H-1,2,4-triazole-1-yl-2-(2,4-difluorophenyl-3-substituted-2-propanols (1a–r, which were analogs of fluconazole, was designed and synthesized by click chemistry. In the study reported here, the in vitro antifungal activities of all the target compounds were evaluated against eight human pathogenic fungi. Compounds 1a, 1q, and 1r showed the more antifungal activity than the others. Keywords: triazole, synthesis, antifungal activity, CYP51

  19. Design and synthesis of novel triazole antifungal derivatives based on the active site of fungal lanosterol 14a-demethylase (CYP51)

    Zhi Gang Dan; Jun Zhang; Shi Chong Yu; Hong Gang Hu; Xiao Yun Chai; Qing Yan Sun; Qiu Ye Wu

    2009-01-01

    A series of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-(N-isoproyl-N-substituted-amino)-2-propanols have been designed and synthesized on the basis of the active site of lanosterol 14a-demethylase (CYP51). Their structures were confirmed by MS and 1H NMR. In vitro antifungal activities of these synthesized compounds were evaluated against eight human pathogenic fungi. The results showed that all title compounds exhibited activity against fungi tested to some extent. Compounds 3c, 3d, 7a, 7b and 7c exhibited more potent antifungal activities against nearly all fungi tested except Aspergillus fumigatus than fluconazole.

  20. Pharmacokinetic study of inosiplex tablets in healthy Chinese volunteers by hyphenated HPLC and tandem MS techniques

    Mo Chen; Yuan Zhang; Xiao-Ting Que; Ya Ding; Lin Yang; Ai-Dong Wen; Tai-Jun Hang

    2013-01-01

    Inosiplex is a compound formulation composed of inosine and p-acetaminobenzoic acid (PABA) salt of N,N-dimethylamino-2-propanol (DIP). This study was to investigate the clinical plasma pharmacokinetic properties of DIP and PABA after single and multiple oral doses of inosiplex tablets in healthy Chinese volunteers. The established LC/MS/MS method for plasma DIP determination had a linear range of 0.02-10 mg/mL, and the HPLC method for plasma PABA determination had a linear range of 0.05-40 mg/mL. Linear pharmacokinetic characteristics were found with single oral doses of 0.5, 1.0 and 2.0 g. No obvious accumulation effects were observed for DIP and PABA.

  1. LET and dose rate effect on radiation-induced copolymerization in physical gel

    Nakagawa, Seiko, E-mail: Nakagawa.Seiko@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku, Tokyo 135-0064 (Japan); Taguchi, Mitsumasa; Kimura, Atsushi; Nagasawa, Naotsugu; Hiroki, Akihiro [Environmental Radiation Processing Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-09-01

    Highlights: •LET and dose rate effect on polymerization in gel was almost the same as in solution. •The ratio of the dose rate effect in the gel was higher than that in solution. •The initiation and termination processes show the difference on the dose rate effect. -- Abstract: N{sub 2}-saturated 2-propanol solutions containing styrene and maleimide were gelled by the addition of hydroxypropylcellulose and irradiated by proton, He and C-ion beams. The trend in the dose rate and LET effects on the yield and molecular weight distribution of the polymer produced in the gel was almost the same in the solution. On the contrary, the dose rate effect in the gel was higher than that in the solution. This effect was accelerated for irradiations by proton as well as heavier ion with a higher LET value.

  2. Enantiomeric resolution of (±)-licarin A by high-performance liquid-chromatography using a chiral stationary phase.

    Pereira, Ana Carolina; Magalhães, Lizandra G; Januário, Ana Helena; Pauletti, Patrícia M; Cunha, Wilson Roberto; Bastos, Jairo Kenupp; Nanayakkara, Dhammika N P; Silva, Márcio Luis A e

    2011-09-28

    (±)-Licarin A (1), a neolignan obtained by the oxidative coupling reaction of isoeugenol, had in this study its enantiomers resolved. A novel, quick and efficient enantiomeric resolution of 1 was directly performed by chiral high-performance liquid chromatography (HPLC-PDA) protocol (CHIRALPACK(®) AD column; 9:1 (v/v) n-hexane:2-propanol; 1.0 mL/min). This method provided a chromatogram profile with a well-resolved peak separation. After isolation of each enantiomer with ee>99.9%, they were analysed in a polarimeter. Compound 2, which showed a retention time (t(r)) of 12.13 min, was the (+)-enantiomer and compound 3 (t(r)=18.90 min) was the (-)-enantiomer. PMID:21868019

  3. Estimation of antiradiative properties of thiols according to the deviation of the radical yield from the additivity rule

    The formation of the radicals in binary solutions of alkanes, alcohols and acids based on thiols has been investigated. It is established that in all the systems a disturbance of the additivity rule for the whole radical yield (Gsub(R)) takes place. On the example of the system 2-propanol-ethanethiol, it is shown that with an increasing of the thiol electron share (esub(T)) from 0.1 to 0.9, the whole radical yield of the alcohol, thiyl and molecular ion-radicals decreases from 3.8 to 0.5x=1/100 ev. Moreover, the yield value reaches a maximal deviation from the additivity rule at esub(T)=0.2. This is a measure of antiradiative properties of thiols concerning alcohols. (author)

  4. Effect of Pt:Sn atomic ratio on the preparation of PtSn/C electrocatalysts using electron beam irradiation

    PtSn/C electrocatalysts were prepared with Pt:Sn atomic ratios of 3:1, 1:1 and 1:3 in water/2-propanol using electron beam irradiation. The obtained materials were characterized by EDX, XRD and cyclic voltammetry. The ethanol electro-oxidation was studied by chronoamperometry. The XRD diffractograms of the PtSn/C electrocatalysts showed typical face-centered cubic (fcc) structure of platinum and the presence of a SnO2 phase (cassiterite). The mean crystallite sizes of Pt fcc phase was in the range of 3.0-3.5 nm. The PtSn/C electrocatalysts were active for ethanol electro-oxidation at room temperature and the material prepared with Pt:Sn atomic ratio of 1:1 showed the best activity. (author)

  5. Solubility of anthracene in binary alcohol + 3-methoxy-1-butanol solvent mixtures

    McHale, M.E.R.; Horton, A.S.M.; Padilla, S.A.; Trufant, A.L.; Sancha, N.U. De La; Vela, E.; Powell, J.R.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1997-01-01

    Experimental solubilities are reported for anthracene dissolved in ten binary mixtures containing 3-methoxy-1-butanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 1-octanol, and 2-ethyl-1-hexanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the ten systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being 0.4% and 0.5% for the combined NIBS/Redlich-Kister and modified Wilson equations, respectively.

  6. Solubility of anthracene in binary alcohol + 2-propoxyethanol solvent mixtures

    McHale, M.E.R.; Powell, J.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-03-01

    Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-propoxyethanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-octanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  7. Solubility of anthracene in binary alcohol + 2-pentanol and alcohol + 4-methyl-2-pentanol solvent mixtures

    Powell, J.R.; McHale, M.E.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-07-01

    Experimental solubilities are reported for anthracene dissolved in 16 binary mixtures containing either 2-pentanol or 4-methyl-2-pentanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-octanol, 2-methyl-1-propanol and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the 16 systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being 0.3% and 0.5% for the combined NIBS/Redlich-Kister and modified Wilson equations, respectively.

  8. Solubility of anthracene in binary alcohol + 2-ethyl-1-hexanol solvent mixtures

    Powell, J.R.; McHale, M.E.R.; Kauppila, A.S.M.; Otero, P.; Jayasekera, M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1995-11-01

    Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-ethyl-l-hexanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values on the order of 0.6%.

  9. Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one: Synthesis, characterization, catalytic and antibacterial studies

    AYALOOR SUBRAMANIAN RAMASUBRAMANIAN

    2011-01-01

    Full Text Available Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II, Ni(II, Co(II and Pd(II, were synthesized and characterized by physico–chemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II and Ni(II complexes were assigned octahedral geometries, while the Cu (II and Pd(II complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2-methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO as co-oxidant. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.

  10. Defectivity decrease in the photolithography process by AMC level reduction through implementation of novel filtration and monitoring solutions

    Pic, Nicolas; Martin, Christophe; Vitalis, Michel; Calarnou, Thierry; Camlay, Daniel; Grosjean, Catherine; Lanier, Arnaud; Kames, Jost; Acksel, Alexander; Galvez, Christophe

    2010-03-01

    A case study of drastic photolithography defectivity reduction on i-line and Deep-UV (DUV) tools is presented. We show how this result is linked with reduction of Airborne Molecular Contamination (AMC) in clean room by combined installation of novel type of filters on tracks and on the recirculation air treatment. The root cause was identified to be the presence of acetic acid in clean room created by a reaction with the filters (mounted on track tools to exclude ammonia contamination of the process) and the photo solvent itself (here mainly 1-methoxy-2-propanol acetate: PGMEA). Crucial for the project success was the use of a real time monitoring tool to detect the sources of Volatile Organic Compounds (VOC). Finally, a model of chemical reaction of satellite defects creation is discussed based on a Time of Flight Static SIMS (TOF SSIMS) analysis together with new AMC specification for acetic acid for the photolithography area.

  11. 利用二元体系的C-H红外光谱推算汽液平衡数据%Prediction of Vapor-Liquid Equilibrium Data from C-H Band Shift of IR Spectra in Some Binary Systems

    朱霄; 姚加; 李浩然; 韩世钧

    2007-01-01

    Prediction of vapor-liquid equilibrium (VLE) is extremely necessary to separate liquid mixture in chemical production, especially when the required experimental data are difficult to measure, or the measurement is not economical. The infinite dilution activities can be used to predict VLE. However, it needs both thc ends of the activities that are difficult to obtain for many systems. In the present study, a new model is proposed for correlating the frequency shift of C-H stretching band of IR spectra over the whole concentration. Investigated mixtures include water/2-propanol, water/N, N-dimethylformamide (DMF), water/methanol, water/ethanol, water/1, 4-dioxane,and water/dimethylsulfoxidc (DMSO) systems. Simultaneous correlations of C-H frequency shift and VLE data arc made. Furthermore, the VLE data were predicted with satisfactory results by the parameters obtained from IR spectra coupled with one of the infinite dilution activity coefficients.

  12. One-step synthesis of graphene-Pt nanocomposites by gamma-ray irradiation

    Tokai, Akihiro; Okitsu, Kenji; Hori, Fuminobu; Mizukoshi, Yoshiteru; Iwase, Akihiro

    2016-06-01

    We developed a one-step gamma-ray irradiation method to synthesize nanocomposites composed of graphene and Pt nanoparticles from aqueous solution containing graphene and Pt(IV) complex ions in the presence of 2-propanol (IPA) or sodium dodecyl sulfate (SDS). It was confirmed that gamma-ray irradiation provided carbonyl groups on graphene and Pt nanoparticles formed from the radiolytic reduction of Pt(IV) complex ions were deposited onto the carbonyl modified graphene. In the presence of IPA, small Pt nanoparticles were deposited on graphene, but large Pt nanoparticles were deposited in the presence of SDS: the size of Pt nanoparticles formed was larger in the presence of SDS than IPA. Based on the results, formation and deposition mechanisms of Pt nanoparticles were proposed.

  13. ANALYSIS OF OUT OF DATE MCU MODIFIER LOCATED IN SRNL

    Crawford, C.

    2014-10-22

    SRNL recently completed density measurements and chemical analyses on modifier samples stored in drums within SRNL. The modifier samples date back to 2008 and are in various quantities up to 40 gallons. Vendor information on the original samples indicates a shelf life of 5 years. There is interest in determining if samples that have been stored for more than the 5 year shelf life are still acceptable for use. The Modular Caustic Side Solvent Extraction Unit (MCU) Solvent component Cs-7SB [(2,2,3,3- tetraflouropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, CAS #308362-88-1] is used as a diluent modifier to increase extractant solubility and provide physical characteristics necessary for diluent trimming.

  14. Lipase-catalyzed synthesis of fatty acid amide (erucamide) using fatty acid and urea.

    Awasthi, Neeraj Praphulla; Singh, R P

    2007-01-01

    Ammonolysis of fatty acids to the corresponding fatty acid amides is efficiently catalysed by Candida antartica lipase (Novozym 435). In the present paper lipase-catalysed synthesis of erucamide by ammonolysis of erucic acid and urea in organic solvent medium was studied and optimal conditions for fatty amides synthesis were established. In this process erucic acid gave 88.74 % pure erucamide after 48 hour and 250 rpm at 60 degrees C with 1:4 molar ratio of erucic acid and urea, the organic solvent media is 50 ml tert-butyl alcohol (2-methyl-2-propanol). This process for synthesis is economical as we used urea in place of ammonia or other amidation reactant at atmospheric pressure. The amount of catalyst used is 3 %. PMID:17898456

  15. Research Update: A hafnium-based metal-organic framework as a catalyst for regioselective ring-opening of epoxides with a mild hydride source

    Casey J. Stephenson

    2014-12-01

    Full Text Available Reaction of styrene oxide with sodium cyanoborohydride and a catalytic amount of Hf-NU-1000 yields the anti-Markovnikov product, 2-phenylethanol, with over 98% regioselectivity. On the other hand, propylene oxide is ring opened in a Markovnikov fashion to form 2-propanol with 95% regioselectivity. Both styrene oxide and propylene oxide failed to react with sodium cyanoborohydride without the addition of Hf-NU-1000 indicative of the crucial role of Hf-NU-1000 as a catalyst in this reaction. To the best of our knowledge, this is the first report of the use of a metal-organic framework material as a catalyst for ring-opening of epoxides with hydrides.

  16. Determining an Efficient Solvent Extraction Parameters for Re-Refining of Waste Lubricating Oils

    Hassan Ali Durrani

    2012-04-01

    Full Text Available Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK (Methyl-Ethyl-Ketone, 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, when temperature of extraction increased the oil losses percent also decreased. This is due to the solvent ability that dissolves the base oil in waste lubricating oil and determines the best SOR (Solvent Oil Ratio and extraction temperatures.

  17. Correlation and prediction of thermodynamic properties of binary mixtures from perturbed chain statistical associating fluid theory

    Almasi, Mohammad

    2014-11-01

    Densities and viscosities for binary mixtures of Diethanolamine (DEA) + 2 alkanol (2 propanol up to 2 pentanol) were measured over the entire composition range and temperature interval of 293.15-323.15 K. From the density and viscosity data, values of various properties such as isobaric thermal expansibility, excess isobaric thermal expansibility, partial molar volumes, excess molar volumes and viscosity deviations were calculated. The observed variations of these parameters, with alkanols chain length and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. The ability of the perturbed chain statistical associating fluid theory (PC-SAFT) to correlate accurately the volumetric behavior of the binary mixtures is demonstrated.

  18. Synthesis of TiO2 Nanoparticles via a Ti(Ⅳ) Complex with Stearic Acid and the Photocatalytic Activity for Organic Oxidation

    XU,Yi-Ming(许宜铭); YU,Xiao-Han(于小涵); LIU,Hui-Jun(刘惠君)

    2002-01-01

    The nano-sized particles of TiO2 were prepared by thermal decomposition of titanium(Ⅳ) tetrabutanoxide complex with stearic acid at 450 ℃ in the air. It was observed that the amount of stearic acid, used initially for the complex synthesis in 2-propanol at 25 ℃, had great influence on the physical properties of the prepared TiO2 including crystal structure,the particle size, surface area and the adsorption capacity for organic substrate of a textile dye X3B in water, and thereafter the photocatalytic activity for the dye oxidation. Some samples displayed lower adsorption capacity for the organic substrate in water than a TiO2 of Degussa p25, but higher photocatalytic activity for the organic oxidation. Possible reason for the observed difference was discussed in the text.

  19. Stability of ZnO quantum dots tuned by controlled addition of ethylene glycol during their growth

    Zimmermann, Lizandra M.; Baldissera, Paulo V.; Bechtold, Ivan H.

    2016-07-01

    ZnO quantum dots were prepared via a sol–gel route from zinc acetate and sodium hydroxide. The influence of ethylene glycol addition during the first stages of reaction (1–5 min) as a stabilizer, as well as the influence of its concentration in 2-propanol were investigated. The optimization led to particles with enough stability and homogeneity around 3.7 nm of diameter to allow for quantum confinement effect. Spectroscopic UV–vis absorption measurements allowed to explore the underlying mechanism of nucleation and growth and to have the control of it. The emission of the ZnO nanoparticles was explored under experimental perturbations with addition of small amounts of water to investigate the interplay between surface defects and the excitonic effect. The results suggest that the water interferes directly on the defects first and later on the excitonic recombination. Their morphology was determined with transmission electron microscopy.

  20. Optimization of ultrasound-assisted extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant (Solanum melongena L.) peel.

    Dranca, Florina; Oroian, Mircea

    2016-07-01

    The present study describes the extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant peel using ultrasonic treatments and methanol and 2-propanol as extraction solvents. The extraction yields were optimized by varying the solvent concentration, ultrasonic frequency, temperature and time of ultrasonic treatment. Box-Behnken design was used to investigate the effect of process variables on the ultrasound-assisted extraction. The results showed that for TPC extraction the optimal condition were obtained with a methanol concentration of 76.6%, 33.88 kHz ultrasonic frequency, a temperature of 69.4 °C and 57.5 min extraction time. For TMA the optimal condition were the following: 54.4% methanol concentration, 37 kHz, 55.1 °C and process time of 44.85 min. PMID:26701808

  1. Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

    Zhitnev, Yu. N.; Tveritinova, E. A.; Chernyak, S. A.; Savilov, S. V.; Lunin, V. V.

    2016-06-01

    Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2-C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

  2. PDMS-coated fiber volatile organic compounds sensors.

    Ning, Xiangping; Yang, Jingyi; Zhao, Chun Liu; Chan, Chi Chiu

    2016-05-01

    The functionality of poly(dimethylsiloxane) (PDMS)-based interferometric fiber sensors for volatile organic compounds (VOCs) detection is investigated and experimentally demonstrated. Two interferometric configurations are considered in this work, namely Fabry-Perot (FP) and Sagnac interferometers (SI). Both sensors are functionalized with a thin layer of VOC-sensitive polymer: PDMS, whose degree of swelling varies as a function of VOC concentrations. This swelling effect will result in an optical path length and birefringence modulation for FP and SI sensors, respectively. In this paper, the two common VOCs, ethanol and 2-propanol, were detected by the proposed sensor and the inverse matrix method was used to differentiate the VOC in gas mixture. PMID:27140369

  3. Dynamics of water and solute transport in polymeric reverse osmosis membranes via molecular dynamics simulations

    Shen, Meng; Lueptow, Richard M

    2016-01-01

    The Angstrom-scale transport characteristics of water and six different solutes, methanol, ethanol, 2-propanol, urea, Na+, and Cl-, were studied for a polyamide reverse osmosis (RO) membrane, FT-30, using non-equilibrium molecular dynamics (NEMD) simulations. Results indicate that water transport increases with an increasing fraction of connected percolated free volume, or water-accessible open space, in the membrane polymer structure. This free volume is enhanced by the dynamic structure of the membrane at the molecular level as it swells when hydrated and vibrates due to molecular collisions allowing a continuous path connecting the opposite membrane surfaces. The tortuous paths available for transport of solutes result in Brownian motion of solute molecules and hopping from pore to pore as they pass through the polymer network structure of the membrane. The transport of alcohol solutes decreases for solutes with larger Van der Waals volume, which corresponds to less available percolated free volume, or sol...

  4. Advances in the catalysts development in base of mixed oxides for control reactions of N2O

    The catalytic supports Al2O3, La2O3 and Al2O3-La2O3 were prepared by the precipitation and coprecipitation techniques. The catalytic supports Al2O3, La2O3 and Al2O3-La2O3 were characterized by several techniques for to determine texture (BET), crystallinity (XRD), chemical composition (SEM), FTIR and it was evaluated their total acidity by the reaction with 2-propanol. It was continued with the cobalt addition by Impregnation and coprecipitation and it was evaluated its catalytic activity in the N2O decomposition reaction. Also it was realized the N2O reduction with Co using these catalysts. (Author)

  5. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  6. FULL-SCALE TESTING OF A CAUSTIC SIDE SOLVENT EXTRACTION SYSTEM TO REMOVE CESIUM FROM SAVANNAH RIVER SITE RADIOACTIVE WASTE

    Savannah River Site (SRS) personnel have completed construction and assembly of the Modular Caustic Side Solvent Extraction Unit (MCU) facility. Following assembly, they conducted testing to evaluate the ability of the process to remove non-radioactive cesium and to separate the aqueous and organic phases. They conducted tests at salt solution flow rates of 3.5, 6.0, and 8.5 gpm. During testing, the MCU Facility collected samples and submitted them to Savannah River National Laboratory (SRNL) personnel for analysis of cesium, Isopar(regsign) L, and Modifier [1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol]. SRNL personnel analyzed the aqueous samples for cesium by Inductively-Coupled Plasma Mass Spectroscopy (ICP-MS) and the solvent samples for cesium using a Parr Bomb Digestion followed by ICP-MS. They analyzed aqueous samples for Isopar(regsign) L and Modifier by gas chromatography (GC)

  7. The effect of the presence of alcohol in the dispersing phase of oxide sols on the properties of RuO2-TiO2/Ti anodes obtained by the sol–gel procedure

    R. ATANASOSKI

    2000-09-01

    Full Text Available The effect of the addition of ethanol and 2-propanol to the dispersing phase of TiO2 and RuO2 sols mixture on the morphology and, consequently, on the electrochemical properties of the sol-gel obtained activated titanium anodes was investigated. The properties of the obtained anodes were compared to those obtained by the thermal decomposition of appropriate chloride salts. The morphology of the anode coatings was examined by scanning tunneling microscopy. The electrochemical behaviour was investigated by cyclic voltammetry and by polarization measurements. An accelerated stability test was used for the examination of the stability of the anodes under simultaneous oxygen and chlorine evolution reaction. A dependence of the anode stability on the type of added alcohol is indicated.

  8. Characterization of sulfur compounds in supercritical coal extracts by gas chromatography-mass spectrometry

    Gryglewicz, Grazyna; Rutkowski, Piotr [Institute of Chemistry and Technology of Petroleum and Coal, Wroclaw University of Technology, ul. Gdanska 7/9, 50-344 Wroclaw (Poland); Yperman, Jan [Laboratory of Applied Chemistry, IMO, Limburgs Universitair Centrum, Universiteitslaan, B-3590 Diepenbeek (Belgium)

    2002-06-20

    The organosulfur compounds (OSC) in the supercritical extracts obtained from flame coal (subA) and orthocoking coal (mvb) were identified by gas chromatography-mass spectrometry. Supercritical fluid extraction was carried out with three different solvents, i.e., toluene, toluene/2-propanol and toluene/THF mixtures, at 360 C and 10 MPa in an apparatus with continuous flow of solvent. The extraction yield was in the range of 11.4-39.9 wt.% depending on the type of solvent and coal. For flame coal, diphenyl sulfide and disulfide, thiophene, benzothiophene, dibenzothiophene and benzonaphtothiophene and their C{sub 1}-C{sub 4} alkyl derivatives were detected, whereas for orthocoking coal only polycyclic aromatic sulfur heterocycles (PASH) containing two to five rings and their alkyl derivatives were found. Ligand exchange chromatography was applied to separate the PASH fraction.

  9. Application of the ERAS model to volumetric properties of binary mixtures of banana oil with primary and secondary alcohols (C1-C4) at different temperatures

    The densities of binary mixtures of {isoamyl acetate + alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol)}, including those of pure liquids, over the entire composition range were measured at temperatures (293.15 to 333.15) K and atmospheric pressure by means of a vibrating-tube densimeter. The excess molar volume, VmE, thermal expansion coefficients, α, and their excess values, αE, were calculated from density data. The VmE values are positive over the entire range of composition and temperature and become more positive with increasing temperature for all of the mixtures except for the (isoamyl acetate + methanol) mixture. The VmE values were correlated by Redlich-Kister equation and the extended real associated solution (ERAS) model was used for describing VmE values at T = 303.15 K.

  10. Thermodynamic Modeling of Several Aqueous Alkanol Solutions Containing Amino Acids with the Perturbed-Chain Statistical Associated Fluid Theory Equation of State

    Ferreira, Luisa; Breil, Martin Peter; Pinho, S. P.;

    2009-01-01

    and a fluid phase. The hypothetical melting properties of each amino acid were fitted, to accurately correlate the solubilities in pure water. Only one temperature independent binary parameter is required for each amino acid/solvent pair. The model can accurately describe the solubility of the amino......The perturbed-chain statistical associated fluid theory EoS was applied to model the solubilities of glycine, DL-alanine, L-serine, L-threonine, and L-isoleucine in pure water, pure alcohols (ethanol, I-propanol, and 2-propanol) and in mixed solvent systems. Three pure component nonassociating...... parameters for the amino acids were fitted to the densities, activity and osmotic coefficients, vapor pressures, and water activity of their aqueous solutions. The solubilities of amino acids in pure and mixed solvent systems were calculated on the basis of the phase equilibrium conditions for a pure solid...

  11. Biomineralization-Inspired Preparation of Zinc Hydroxide Carbonate/Polymer Hybrids and Their Conversion into Zinc Oxide Thin-Film Photocatalysts.

    Matsumura, Shunichi; Horiguchi, Yoshimasa; Nishimura, Tatsuya; Sakai, Hideki; Kato, Takashi

    2016-05-17

    The development of ZnO thin films has been achieved through the conversion of zinc hydroxide carbonate thin-film crystals. Crystallization of this compound is induced by a biomineralization-inspired method with polymer-stabilized amorphous precursors. The crystals grow radially on polymer matrices, leading to the formation of zinc hydroxide carbonate/polymer thin-film hybrids that fully cover the substrate. These hybrids are converted into ZnO and retain their thin-film morphologies. The resultant ZnO thin films exhibit a preferential crystallographic orientation that is attributed to the alignment of zinc hydroxide carbonate crystals before conversion. In addition, a photocatalytic function of the ZnO thin films has been demonstrated by analyzing the oxidation reaction of 2-propanol. The biomineralization-inspired approach reported herein is a promising way to develop ZnO materials with controlled morphologies and structures for photocatalytic applications. PMID:27062559

  12. Development of carborane synthons: Synthesis and chemistry of (aminoalkyl)carboranes

    A number of (aminoalkyl)-1,2-closo-dodecaboranes have been synthesized to provide carboranes with a functional group for covalent incorporation into structures of potential use in the treatment of cancer by boron neutron capture therapy (BNCT). (Phthalimidoalkyl)acetylenes reacted with decaborane to give the corresponding carboranes; removal of the phthalimido group under mild conditions using sodium borohydride in 2-propanol furnished the (aminoalkyl)carboranes which were isolated as their hydrochloride salts. An alternative approach involved the conversion of an (iodoalkyl)- or a ((tosyloxy)alkyl)carborane to the azido derivative which gave the amine on hydrogenation. An effective way of attaching a carborane moiety to thiouracil, which is selectively taken up in melanoma cells, is illustrated by the acylation of two of these amines with thiouracil-5-carboxylic acid

  13. Thermodynamic behavior of binary mixtures CnMpyNTf2 ionic liquids with primary and secondary alcohols

    Highlights: ► Osmotic coefficients of alcohols with CnMpyNTf2 (n = 2, 3, 4) are determined. ► Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. ► Mean molal activity coefficients and excess Gibbs free energies were calculated. ► The results have been interpreted in terms of interactions. - Abstract: In this paper, the osmotic and activity coefficients and vapor pressures of the binary mixtures containing the ionic liquids 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C2MpyNTf2, and 1-methyl-3-propylpyridinium bis(trifluoromethylsulfonyl)imide, C3MpyNTf2, with 1-propanol, or 2-propanol and the ionic liquid 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C4MpyNTf2, with 1-propanol or 2-propanol or 1-butanol or 2-butanol were determined at T = 323.15 K using the vapor pressure osmometry technique. The influence of the structure of the alcohol and of the ionic liquid on both coefficients and vapor pressures is discussed and a comparison with literature data on binary mixtures containing ionic liquids with different cations and anion is also performed. Besides, the results have been interpreted in terms of solute–solvent and ion–ion interactions. The experimental osmotic coefficients were correlated using the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model obtaining standard deviations lower than 0.059 and 0.102 respectively, and the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated.

  14. Influence of hydroxyl group position and temperature on thermophysical properties of tetraalkylammonium hydroxide ionic liquids with alcohols.

    Attri, Pankaj; Baik, Ku Youn; Venkatesu, Pannuru; Kim, In Tae; Choi, Eun Ha

    2014-01-01

    In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs) such as tetrapropylammonium hydroxide (TPAH) and tetrabutylammonium hydroxide (TBAH) with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol) within the temperature range 293.15-313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (V(E) ) and the deviation in isentropic compressibility (Δκs ) using the experimental values such as densities (ρ) and ultrasonic sound velocities (u) that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K) and atmospheric pressure. These excess functions were adequately correlated by using the Redlich-Kister polynomial equation. It was observed that for all studied systems, the V(E) and Δκs values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary) position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7. PMID:24489741

  15. Separation of toxic peptides (microcystins) in capillary electrophoresis, with the aid of organic mobile phase modifiers.

    Onyewuenyi, N; Hawkins, P

    1996-10-18

    A capillary electrophoretic (CE) method incorporating sodium dodecyl sulphate (SDS)-organic modifier solvents in the CE buffer was developed for the detection of toxic cyclic heptapeptide toxins (microcystins) produced by blue-green algae (cyanobacteria). The applicability of these run buffers for the analysis of microcystins was evaluated and optimum conditions for separation were determined. The migration times, elution order and selectivity of the toxic peptides were influenced by modifying the composition of the electrophoretic buffer with organic solvents [0 to 20% (v/v)]. At maximum addition, the organic solvents with the exception of acetonitrile, increased the viscosity of the buffer solution. In contrast to the migration time of the other microcystins, that of microcystin-RR was not increased by the addition of 2-propanol to the buffer solution. Rather, microcystin-RR eluted more quickly with the increase in 2-propanol, thereby effecting changes in the elution order of the microcystins. In addition, this solvent resulted in comigration of microcystin-LR and microcystin-YR. No significant relationship was found between the elution order and separation and the structure of the toxic peptides studied in micellar electrokinetic capillary chromatography with an organic modifier in the buffer solution; but there is an agreement between the effects of the organic modifiers and their dipole moments. Parameters such as linearity, sensitivity and reproducibility were also evaluated. High-efficiency separations of toxic peptide molecules having equal or nearly equal mass to charge ratios have been achieved using SDS as an additive to the running buffer. The influence of the pH has been examined. PMID:8921598

  16. (Solid + liquid) phase equilibria of tetraphenyl piperazine-1, 4-diyldiphosphonate in pure solvents

    Graphical abstract: The simulated infinite dilute solutions of TPPDP in acetic acid (a), acetone (b), 1-butanol (c), and 2-propanol (d) and their interactions (H-bond). - Highlights: • The solubilities of tetraphenyl piperazine-1, 4-diyldiphosphonate in eight organic solvents were studied. • Molecular dynamic simulation was performed to understand solubility behavior. • Solubility prediction using NRTL-SAC agreed well with experimental data. • The thermodynamic functions relative to dissolution process were predicted. - Abstract: Tetraphenyl piperazine-1, 4-diyldiphosphonate (TPPDP), a phosphorus–nitrogen containing flame retardant, was synthesized successfully, and its structure was characterized by infrared spectroscopy (IR) and nuclear magnetic resonance (1H NMR, 31P NMR). The melting temperature and fusion enthalpy of TPPDP were measured by differential scanning calorimeter (DSC). The solubility of TPPDP in dichloromethane, acetic acid, ethyl acetate, acetone, n-hexane, 1-butanol, 2-propanol and isopropyl ether have been determined at temperatures from (283.15 to 323.15) K using a static analytic method. Molecular modeling and the Scatchard–Hildebrand model were employed to discuss the results obtained and to reveal the relationship of solubility and structures of the solvents. The modified Apelblat equation, Wilson model and NRTL model were used to correlate the solubility results, in which the Wilson model provides the best fitting results. Furthermore, the non-random two liquid segment activity coefficient model (NRTL-SAC) with four types of conceptual segments was used for solubility prediction and exhibited a good agreement with experimental values except for the acetic acid system. Finally, the molar Gibbs free energy, enthalpy, and entropy of solution were predicted based on the modified Apelblat equation

  17. Efficient degassing of dissolved oxygen in aqueous media by microwave irradiation and the effect of microwaves on a reaction catalyzed by Wilkinson's catalyst

    To the extent that some reactions are oxygen-sensitive, we herein examined the degassing of dissolved oxygen in water and in 2-propanol solvent by microwave heating with regard to the effects of the microwave frequency (2.45 GHz versus 915 MHz), and with regard to when samples are subjected to electric-field-rich and magnetic-field rich 2.45-GHz microwaves. Changes in the quantity of dissolved oxygen were ascertained by monitoring its concentration in such solvents when exposed to microwave and conventional heating using a polarographic technique and by the chemical oxygen demand (COD) method. The specific microwave (non-thermal) effect played a role in the degassing process on comparing results between microwave heating and conventional heating under identical temperature conditions. The 915-MHz microwaves were more effective, at least at 60 °C, owing to their greater penetration into the solutions. No significant differences were found when degassing was carried out on exposing the water sample to 2.45-GHz microwaves with the sample located within the waveguide at positions rich in either the electric field or the magnetic field (T=80 °C). Conversion of cyclohexanone to cyclohexanol via hydrogen transfer in the presence of Wilkinson's catalyst and 2-propanol solvent (hydrogen source) was also investigated to assess the effect(s) that microwaves might have on this oxygen-sensitive reaction with respect to product yields in contrast to conventional heating by the oil-bath method. - Highlights: • Degassing dissolved oxygen in water was enhanced when using microwave heating. • Degassing was more effective with lower frequency microwaves. • Synthesis of cyclohexanol with Wilkinson's catalyst was investigated under microwave irradiation

  18. Enhancement of the electrical characteristics of MOS capacitors by reducing the organic content of H2O-diluted Spin-On-Glass based oxides

    In this work, the physical, chemical and electrical properties of Metal-Oxide-Semiconductor (MOS) capacitors with Spin-On-Glass (SOG)-based thin films as gate dielectric have been investigated. Experiments of SOG diluted with two different solvents (2-propanol and deionized water) were done in order to reduce the viscosity of the SOG solution so that thinner films (down to ∼20 nm) could be obtained and their general characteristics compared. Thin films of SOG were deposited on silicon by the sol-gel technique and they were thermally annealed using conventional oxidation furnace and Rapid Thermal Processing (RTP) systems within N2 ambient after deposition. SOG dilution using non-organic solvents like deionized water and further annealing (at relatively high temperatures ≥450 deg. C) are important processes intended to reduce the organic content of the films. Fourier-Transform Infrared (FTIR) Spectroscopy results have shown that water-diluted SOG films have a significant reduction in their organic content after increasing annealing temperature and/or dilution percentage when compared to those of undiluted SOG films. Both current-voltage (I-V) and capacitance-voltage (C-V) measurements show better electrical characteristics for SOG-films diluted in deionized water compared to those diluted in 2-propanol (which is an organic solvent). The electrical characteristics of H2O-diluted SOG thin films are very similar to those obtained from high quality thermal oxides so that their application as gate dielectrics in MOS devices is promising. Finally, it has been demonstrated that by reducing the organic content of SOG-based thin films, it is possible to obtain MOS devices with better electrical properties.

  19. Enhancement of the electrical characteristics of MOS capacitors by reducing the organic content of H{sub 2}O-diluted Spin-On-Glass based oxides

    Molina, Joel, E-mail: jmolina@inaoep.mx [National Institute of Astrophysics, Optics and Electronics, Electronics Department, Luis Enrique Erro 1, PO BOX 51 and 216, Tonantzintla, Puebla 72000 (Mexico); Munoz, Ana; Torres, Alfonso; Landa, Mauro; Alarcon, Pablo; Escobar, Manuel [National Institute of Astrophysics, Optics and Electronics, Electronics Department, Luis Enrique Erro 1, PO BOX 51 and 216, Tonantzintla, Puebla 72000 (Mexico)

    2011-10-25

    In this work, the physical, chemical and electrical properties of Metal-Oxide-Semiconductor (MOS) capacitors with Spin-On-Glass (SOG)-based thin films as gate dielectric have been investigated. Experiments of SOG diluted with two different solvents (2-propanol and deionized water) were done in order to reduce the viscosity of the SOG solution so that thinner films (down to {approx}20 nm) could be obtained and their general characteristics compared. Thin films of SOG were deposited on silicon by the sol-gel technique and they were thermally annealed using conventional oxidation furnace and Rapid Thermal Processing (RTP) systems within N{sub 2} ambient after deposition. SOG dilution using non-organic solvents like deionized water and further annealing (at relatively high temperatures {>=}450 deg. C) are important processes intended to reduce the organic content of the films. Fourier-Transform Infrared (FTIR) Spectroscopy results have shown that water-diluted SOG films have a significant reduction in their organic content after increasing annealing temperature and/or dilution percentage when compared to those of undiluted SOG films. Both current-voltage (I-V) and capacitance-voltage (C-V) measurements show better electrical characteristics for SOG-films diluted in deionized water compared to those diluted in 2-propanol (which is an organic solvent). The electrical characteristics of H{sub 2}O-diluted SOG thin films are very similar to those obtained from high quality thermal oxides so that their application as gate dielectrics in MOS devices is promising. Finally, it has been demonstrated that by reducing the organic content of SOG-based thin films, it is possible to obtain MOS devices with better electrical properties.

  20. Synthesis and physico-chemical characterization of CeO{sub 2}/ZrO{sub 2}-SO{sub 4}{sup 2-} mixed oxides

    Hernandez E, J. M.; Silva R, R.; Garcia A, R. [Instituto Tecnologico de Ciudad Madero, Div. de Estudios de Posgrado e Investigacion, Juventino Rosas y Jesus Urueta s/n, Col. Los Mangos, 89440 Ciudad Madero, Tamaulipas (Mexico); Garcia S, L. A. [IPN, Centro Interdisciplinario de Investigaciones y de Estudios sobre Medio Ambiente y Desarrollo, 30 de Junio No. 1520, Barrio La Laguna Ticoman, 07340 Mexico D. F. (Mexico); Handy, B. E.; Cardenas G, G. [Universidad Autonoma de San Luis Potosi, CIEP, Facultad de Ciencias Quimicas, Av. Dr. Manuel Nava No. 6, Zona Universitaria, 78210 SLP, San Luis Potosi (Mexico); Cueto H, A. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo No. 180, Col. Reynosa Tamaulipas, 02200 Mexico D. F. (Mexico)

    2012-07-01

    Environmentally friendly solid-acid catalysts CeO{sub 2}/ZrO{sub 2}-SO{sub 4}{sup 2-} were prepared by the sol gel method varying CeO{sub 2} content (10, 20 and 30 wt %) and using sulfation in situ, maintaining the sulfate ions amount present in the materials at 20 wt %. ZrO{sub 2} and ZrO{sub 2}-SO{sub 4}{sup 2-} were also prepared for comparison proposes using the same synthesis method. The materials were characterized by X-ray diffraction, nitrogen physisorption, potentiometric titration with n-butylamine, decomposition of 2-propanol and n-pentane isomerization. The specific surface area of ZrO{sub 2}-SO{sub 4}{sup 2-} was high (160 m{sup 2}/g) compared with the unmodified ZrO{sub 2} (80 m{sup 2}/g), however this area decreased with increasing the CeO{sub 2} content (37-100 m{sup 2}/g). There was no significant effect of CeO{sub 2} on the tetragonal structure of ZrO{sub 2}-SO{sub 4}{sup 2-}. The variation of acid sites amount runs parallel to the change of specific surface area. The acid sites amount decreased with increasing cerium oxide content. The decomposition of 2-propanol results fundamentally in the formation of dehydration products such as propylene and diisopropyl ether, both involving acid sites. In addition, a good performance during the n-pentane isomerization was observed for these materials. The selectivity towards isopentane reaches 84% when the Pt/CeO{sub 2}/ZrO{sub 2}-SO{sub 4}{sup 2-} catalyst with the highest CeO{sub 2} content was used. (Author)

  1. Preparation and characterization of Pt catalysts supported on TiO2 and ZrO2 stabilized with La2O3 for the elimination of nitric oxide

    The objective of this work is the preparation and characterization of catalytic materials with a platinum base, supported in simple and mixed oxides of titanium (TiO2) and zirconia (ZrO2) which were stabilized with 10 % in mole of lanthanum (La2O3), the preparation technique of the supports is the one of precipitation, additioning a nominal charge of 1% in weight of active phase (Pt) by means of the impregnation method by conventional wetting. All the solids were calcinated at 500 Centigrade and subsequently reduced to the same temperature in air and hydrogen flow respectively. Their characterization was applying the techniques such as: Thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC), Surface area (BET), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Decomposition of 2-propanol, Catalytic activity and selectivity. The application of these techniques allow to define and to explain the influence of the preparation method and of the thermal treatments to which were submitted the catalysts, in special the Surface area, X-ray diffraction and Scanning electron microscopy which demonstrated in evidence the morphologic structure and of crystalline phases present in the catalysts under study. The decomposition of 2-propanol, catalytic activity and selectivity show the supports and catalysts skill for the determination of acid or base sites, moreover of the selective reduction of nitric oxide respectively, the results seem to indicate that the preparation technique, precursors and the thermal treatments to what these materials were submitted have an influence on the catalyst and by consequence in the reduction reaction of nitric oxide. (Author)

  2. Determination of Odor Release in Hydrocolloid Model Systems Containing Original or Carboxylated Cellulose at Different pH Values Using Static Headspace Gas Chromatographic (SHS-GC Analysis

    Pahn-Shick Chang

    2013-02-01

    Full Text Available Static headspace gas chromatographic (SHS-GC analysis was performed to determine the release of 13 odorants in hydrocolloid model systems containing original or regio-selectively carboxylated cellulose at different pH values. The release of most odor compounds was decreased in the hydrocolloid solutions compared to control, with the amounts of 2-propanol, 3-methyl-1-butanol, and 2,3-butanedione released into the headspace being less than those of any other odor compound in the hydrocolloid model systems. However, there was no considerable difference between original cellulose-containing and carboxylated-cellulose containing systems in the release of most compounds, except for relatively long-chain esters such as ethyl caprylate and ethyl nonanoate. The release from the original and carboxylated cellulose solutions controlled to pH 10 was significantly higher than that from solutions adjusted to pH 4 and 7 in the case of some esters (ethyl acetate, methyl propionate, ethyl propionate, ethyl butyrate, butyl propionate, ethyl caproate and alcohols (2-propanol, 3-methyl-1-butanol, in particular, ethyl butyrate and 3-methyl-1-butanol. In contrast, the release of 2,3-butanedione from both the original and carboxylated cellulose solutions was increased at pH 4 and 7 compared to that at pH 10 by about 70% and 130%, respectively. Our study demonstrated that the release of some odorants could be changed significantly by addition of both original and carboxylated cellulose in hydrocolloid model systems, but only minor effect was observed in pH of the solution.

  3. Preparation and characterization of Pt catalysts supported on TiO{sub 2} and ZrO{sub 2} stabilized with La{sub 2}O{sub 3} for the elimination of nitric oxide; Preparacion y caracterizacion de catalizadores de Pt soportado en TiO{sub 2} y ZrO{sub 2} estabilizados con La{sub 2}O{sub 3} para la eliminacion de oxido nitrico

    Aguilar V, A

    2001-07-01

    The objective of this work is the preparation and characterization of catalytic materials with a platinum base, supported in simple and mixed oxides of titanium (TiO{sub 2}) and zirconia (ZrO{sub 2}) which were stabilized with 10 % in mole of lanthanum (La{sub 2}O{sub 3}), the preparation technique of the supports is the one of precipitation, additioning a nominal charge of 1% in weight of active phase (Pt) by means of the impregnation method by conventional wetting. All the solids were calcinated at 500 Centigrade and subsequently reduced to the same temperature in air and hydrogen flow respectively. Their characterization was applying the techniques such as: Thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC), Surface area (BET), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Decomposition of 2-propanol, Catalytic activity and selectivity. The application of these techniques allow to define and to explain the influence of the preparation method and of the thermal treatments to which were submitted the catalysts, in special the Surface area, X-ray diffraction and Scanning electron microscopy which demonstrated in evidence the morphologic structure and of crystalline phases present in the catalysts under study. The decomposition of 2-propanol, catalytic activity and selectivity show the supports and catalysts skill for the determination of acid or base sites, moreover of the selective reduction of nitric oxide respectively, the results seem to indicate that the preparation technique, precursors and the thermal treatments to what these materials were submitted have an influence on the catalyst and by consequence in the reduction reaction of nitric oxide. (Author)

  4. Crystallization and identification of the glycosylated moieties of two isoforms of the main allergen Hev b 2 and preliminary X-ray analysis of two polymorphs of isoform II

    Crystallization of important glycoenzymes involved in IgE-mediated latex allergy. Latex from Hevea brasiliensis contains several allergenic proteins that are involved in type I allergy. One of them is Hev b 2, which is a β-1,3-glucanase enzyme that exists in different isoforms with variable glycosylation content. Two glucanase isoforms were isolated from trees of the GV-42 clone by gel filtration, affinity and ion-exchange chromatography. Isoform I had a carbohydrate content of about 20%, with N-linked N-acetyl-glucosamine, N-acetyl-galactosamine, fucose and galactose residues as the main sugars, while isoform II showed 6% carbohydrate content constisting of N-acetyl-glucosamine, fucose, mannose and xylose. Both isoforms were crystallized by the hanging-drop vapour-diffusion method. Isoform I crystals were grown using 0.2 M trisodium citrate dihydrate, 0.1 M Na HEPES pH 7.5 and 20%(v/v) 2-propanol, but these crystals were not appropriate for data collection. Isoform II crystals were obtained under two conditions and X-ray diffraction data were collected from both. In the first condition (0.2 M trisodium citrate, 0.1 M sodium cacodylate pH 6.5, 30% 2-propanol), crystals belonging to the tetragonal space group P41 with unit-cell parameters a = b = 150.17, c = 77.41 Å were obtained. In the second condition [0.2 M ammonium acetate, 0.1 M trisodium citrate dihydrate pH 5.6, 30%(w/v) polyethylene glycol 4000] the isoform II crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 85.08, b = 89.67, c = 101.80 Å, β = 113.6°. Preliminary analysis suggests that there are four molecules of isoform II in both asymmetric units

  5. Photoinduced Electron Accumulation of Titanium Dioxide Nanoparticles Modified Electrodes

    Miyoshi, Hirokazu; Sakamoto, Kensho; Kurashina, Masaru; Kanezaki, Eiji

    Titanium dioxide (TiO2) nanoparticles (Nps) were prepared by the hydrolysis of titanium tetraisopropoxide (TTIP) in 2-propanol with different water contents (0.5 vol% to 7.2 vol%) at 45 °C. The diameter of the Nps was estimated to be 1.5±0.5 nm (L-TiO2) and 3.0±0.6 nm (S-TiO2) from the onset wavelength in the absorption spectra and by transmission electron microscopy (TEM). A modified Pt electrode with a three-layered sandwich structure was prepared; the outermost and innermost layers were composed of S-TiO2 and L-TiO2, respectively, and the middle layer contained 1, 1'-dimethyl-4,4'-bipyridyl (MV2+)/Nafion®. Irradiation by a 500 W superhigh-pressure mercury lamp produced electrons in the conduction band of TiO2. An anodic current was observed after turning off the light. The mechanism by which anodic current is generated after turning off the radiation involves the reduction of MV2+ to MV+. by photogenerated electrons on the Nps and the diffusion of MV+. in the middle layer. After turning off the irradiation, MV+. transferred an electron to the Pt electrode via holes in the innermost layer or the conduction band of S-TiO2 coincidentally localized on the Pt electrode, resulting in the generation of the anodic current. The generation of MV+. was confirmed by the absorption spectra of MV+.. As a sacrificial reagent, 2-propanol (0.1 M) was used.

  6. Enhancement and inhibition effects of water matrices during the sonochemical degradation of the antibiotic dicloxacillin.

    Villegas-Guzman, Paola; Silva-Agredo, Javier; Giraldo-Aguirre, Ana L; Flórez-Acosta, Oscar; Petrier, Christian; Torres-Palma, Ricardo A

    2015-01-01

    The sonochemical degradation of dicloxacillin (DXC) was studied in both synthetic and natural waters. Degradation routes and the effect of experimental conditions such as pH, initial DXC concentration and ultrasonic power were evaluated. Experiments were carried out with a fixed frequency (600kHz). The best performances were achieved using acidic media (pH=3) and high power (60W). The degradation process showed pseudo-first order kinetics as described by the Okitsu model. To evaluate water matrix effects, substrate degradation, in the presence of Fe(2+) and organic compounds such as glucose and 2-propanol, was studied. A significant improvement was achieved with Fe(2+) (1.0mM). Inhibition of the degradation process was observed at a relatively high concentration of 2-propanol (4.9mM), while glucose did not show any effect. Natural water showed an interesting effect: for a low concentration of DXC (6.4μM), an improvement in the degradation process was observed, while at a higher concentration of DXC (0.43mM), degradation was inhibited. Additionally, the extent of degradation of the process was evaluated through the analysis of chemical oxygen demand (COD), antimicrobial activity, total organic carbon (TOC) and biochemical oxygen demand (BOD5). A 30% removal of COD was achieved after the treatment and no change in the TOC was observed. Antimicrobial activity was eliminated after 360min of ultrasonic treatment. After 480min of treatment, a biodegradable solution was obtained. PMID:25069890

  7. Synthesis and Catalytic Hydrogen Transfer Reaction of Ruthenium(II) Complex

    Son, Jung Ik; Kim, Aram; Noh, Hui Bog; Lee, Hyun Ju; Shim, Yoon Bo; Park, Kang Hyun [Pusan National University, Busan (Korea, Republic of)

    2012-01-15

    The ruthenium(II) complex [Ru(bpy){sub 2}-(PhenTPy)] was synthesized, and used for the transfer hydrogenation of ketones and the desired products were obtained in good yield. Based on the presented results, transition-metal complexes can be used as catalysts for a wide range of organic transformations. The relationship between the electro-reduction current density and temperature are being examined in this laboratory. Attempts to improve the catalytic activity and determine the transfer hydrogenation mechanism are currently in progress. The catalytic hydrogenation of a ketone is a basic and critical process for making many types of alcohols used as the final products and precursors in the pharmaceutical, agrochemical, flavor, fragrance, materials, and fine chemicals industries. The catalytic hydrogenation process developed by Noyori is a very attractive process. Formic acid and 2-propanol have been used extensively as hydrogenation sources. The advantage of using 2-propanol as a hydrogen source is that the only side product will be acetone, which can be removed easily during the workup process. Hydrogen transfer (HT) catalysis, which generates alcohols through the reduction of ketones, is an attractive protocol that is used widely. Ruthenium(II) complexes are the most useful catalysts for the hydrogen transfer (HT) of ketones. In this method, a highly active catalytic system employs a transition metal as a catalyst to synthesize alcohols, and is a replacement for the hydrogen-using hydrogenation process. The most active system is based on Ru, Rh and Ir, which includes a nitrogen ligand that facilitates the formation of a catalytically active hydride and phosphorus.

  8. Synthesis and Catalytic Hydrogen Transfer Reaction of Ruthenium(II) Complex

    The ruthenium(II) complex [Ru(bpy)2-(PhenTPy)] was synthesized, and used for the transfer hydrogenation of ketones and the desired products were obtained in good yield. Based on the presented results, transition-metal complexes can be used as catalysts for a wide range of organic transformations. The relationship between the electro-reduction current density and temperature are being examined in this laboratory. Attempts to improve the catalytic activity and determine the transfer hydrogenation mechanism are currently in progress. The catalytic hydrogenation of a ketone is a basic and critical process for making many types of alcohols used as the final products and precursors in the pharmaceutical, agrochemical, flavor, fragrance, materials, and fine chemicals industries. The catalytic hydrogenation process developed by Noyori is a very attractive process. Formic acid and 2-propanol have been used extensively as hydrogenation sources. The advantage of using 2-propanol as a hydrogen source is that the only side product will be acetone, which can be removed easily during the workup process. Hydrogen transfer (HT) catalysis, which generates alcohols through the reduction of ketones, is an attractive protocol that is used widely. Ruthenium(II) complexes are the most useful catalysts for the hydrogen transfer (HT) of ketones. In this method, a highly active catalytic system employs a transition metal as a catalyst to synthesize alcohols, and is a replacement for the hydrogen-using hydrogenation process. The most active system is based on Ru, Rh and Ir, which includes a nitrogen ligand that facilitates the formation of a catalytically active hydride and phosphorus

  9. CNN pincer ruthenium catalysts for hydrogenation and transfer hydrogenation of ketones: experimental and computational studies.

    Baratta, Walter; Baldino, Salvatore; Calhorda, Maria José; Costa, Paulo J; Esposito, Gennaro; Herdtweck, Eberhardt; Magnolia, Santo; Mealli, Carlo; Messaoudi, Abdelatif; Mason, Sax A; Veiros, Luis F

    2014-10-13

    Reaction of [RuCl(CNN)(dppb)] (1-Cl) (HCNN=2-aminomethyl-6-(4-methylphenyl)pyridine; dppb=Ph2 P(CH2 )4 PPh2 ) with NaOCH2 CF3 leads to the amine-alkoxide [Ru(CNN)(OCH2 CF3 )(dppb)] (1-OCH2 CF3 ), whose neutron diffraction study reveals a short RuO⋅⋅⋅HN bond length. Treatment of 1-Cl with NaOEt and EtOH affords the alkoxide [Ru(CNN)(OEt)(dppb)]⋅(EtOH)n (1-OEt⋅n EtOH), which equilibrates with the hydride [RuH(CNN)(dppb)] (1-H) and acetaldehyde. Compound 1-OEt⋅n EtOH reacts reversibly with H2 leading to 1-H and EtOH through dihydrogen splitting. NMR spectroscopic studies on 1-OEt⋅n EtOH and 1-H reveal hydrogen bond interactions and exchange processes. The chloride 1-Cl catalyzes the hydrogenation (5 atm of H2 ) of ketones to alcohols (turnover frequency (TOF) up to 6.5×10(4) h(-1) , 40 °C). DFT calculations were performed on the reaction of [RuH(CNN')(dmpb)] (2-H) (HCNN'=2-aminomethyl-6-(phenyl)pyridine; dmpb=Me2 P(CH2 )4 PMe2 ) with acetone and with one molecule of 2-propanol, in alcohol, with the alkoxide complex being the most stable species. In the first step, the Ru-hydride transfers one hydrogen atom to the carbon of the ketone, whereas the second hydrogen transfer from NH2 is mediated by the alcohol and leads to the key "amide" intermediate. Regeneration of the hydride complex may occur by reaction with 2-propanol or with H2 ; both pathways have low barriers and are alcohol assisted. PMID:25195979

  10. Crystallization and identification of the glycosylated moieties of two isoforms of the main allergen Hev b 2 and preliminary X-ray analysis of two polymorphs of isoform II

    Fuentes-Silva, D. [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Mendoza-Hernández, G. [Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Stojanoff, V. [Brookhaven National Laboratory, National Synchrotron Light Source, Upton, NY (United States); Palomares, L. A. [Instituto de Biotecnología, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Zenteno, E. [Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Torres-Larios, A. [Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Rodríguez-Romero, A., E-mail: adela@servidor.unam.mx [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico)

    2007-09-01

    Crystallization of important glycoenzymes involved in IgE-mediated latex allergy. Latex from Hevea brasiliensis contains several allergenic proteins that are involved in type I allergy. One of them is Hev b 2, which is a β-1,3-glucanase enzyme that exists in different isoforms with variable glycosylation content. Two glucanase isoforms were isolated from trees of the GV-42 clone by gel filtration, affinity and ion-exchange chromatography. Isoform I had a carbohydrate content of about 20%, with N-linked N-acetyl-glucosamine, N-acetyl-galactosamine, fucose and galactose residues as the main sugars, while isoform II showed 6% carbohydrate content constisting of N-acetyl-glucosamine, fucose, mannose and xylose. Both isoforms were crystallized by the hanging-drop vapour-diffusion method. Isoform I crystals were grown using 0.2 M trisodium citrate dihydrate, 0.1 M Na HEPES pH 7.5 and 20%(v/v) 2-propanol, but these crystals were not appropriate for data collection. Isoform II crystals were obtained under two conditions and X-ray diffraction data were collected from both. In the first condition (0.2 M trisodium citrate, 0.1 M sodium cacodylate pH 6.5, 30% 2-propanol), crystals belonging to the tetragonal space group P4{sub 1} with unit-cell parameters a = b = 150.17, c = 77.41 Å were obtained. In the second condition [0.2 M ammonium acetate, 0.1 M trisodium citrate dihydrate pH 5.6, 30%(w/v) polyethylene glycol 4000] the isoform II crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 85.08, b = 89.67, c = 101.80 Å, β = 113.6°. Preliminary analysis suggests that there are four molecules of isoform II in both asymmetric units.

  11. Crystallization and Identification of the Glycosylated Moieties of Two Isoforms of the Main Allergen Hev b 2 and Preliminary X-ray Analysis of Two Polymorphs of Isoform ll

    Fuentes-Silva,D.; Mendoza-Hernandez, G.; Stojanoff, V.; Palomares, L.; Zenteno, E.; Torres-Larios, A.; Rodriguez-Romero, A.

    2007-01-01

    Latex from Hevea brasiliensis contains several allergenic proteins that are involved in type I allergy. One of them is Hev b 2, which is a {beta}-1,3-glucanase enzyme that exists in different isoforms with variable glycosylation content. Two glucanase isoforms were isolated from trees of the GV-42 clone by gel filtration, affinity and ion-exchange chromatography. Isoform I had a carbohydrate content of about 20%, with N-linked N-acetyl-glucosamine, N-acetyl-galactosamine, fucose and galactose residues as the main sugars, while isoform II showed 6% carbohydrate content consisting of N-acetyl-glucosamine, fucose, mannose and xylose. Both isoforms were crystallized by the hanging-drop vapor-diffusion method. Isoform I crystals were grown using 0.2 M trisodium citrate dihydrate, 0.1 M Na HEPES pH 7.5 and 20%(v/v) 2-propanol, but these crystals were not appropriate for data collection. Isoform II crystals were obtained under two conditions and X-ray diffraction data were collected from both. In the first condition (0.2 M trisodium citrate, 0.1 M sodium cacodylate pH 6.5, 30% 2-propanol), crystals belonging to the tetragonal space group P4{sub 1} with unit-cell parameters a = b = 150.17, c = 77.41 {angstrom} were obtained. In the second condition [0.2 M ammonium acetate, 0.1 M trisodium citrate dihydrate pH 5.6, 30%(w/v) polyethylene glycol 4000] the isoform II crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 85.08, b = 89.67, c = 101.80 {angstrom}, {beta}= 113.6{sup o}. Preliminary analysis suggests that there are four molecules of isoform II in both asymmetric units.

  12. Formation of colloidal silver nanoparticles: Capping action of citrate

    Colloidal silver sols of long-time stability are formed in the γ-irradiation of 1.0 x 10-4 M AgClO4 solutions, which also contain 0.3 M 2-propanol, 2.5 x 10-2 M N2O, and sodium citrate in various concentrations. The reduction of Ag+ in these solutions is brought about by the 1-hydroxyalkyl radical generated in the radiolysis of 2-propanol; citrate does not act as a reductant but solely as a stabilizer of the colloidal particles formed. Its concentration is varied in the range from 5.0 x 10-5 to 1.5 x 10-3 M, and the size and size distribution of the silver particles are studied by electron microscopy. At low citrate concentration, partly agglomerated large particles are formed that have many imperfections. In an intermediate range (a few 10-4 M), well-separated particles with a rather narrow size distribution and little imperfections are formed, the size slightly decreasing with increasing citrate concentration. At high citrate concentrations, large lumps of coalesced silver particles are present, due to destabilization by the high ionic strength of the solution. These findings are explained by two growth mechanisms: condensation of small silver clusters (type-1 growth), and reduction of Ag+ on silver particles via radical-to-particle electron transfer (type-2 growth). The particles formed in the intermediate range of citrate concentration were studied by high-resolution electron microscopy and computer simulations. They constitute icosahedra and cuboctahedra

  13. Influence of hydroxyl group position and temperature on thermophysical properties of tetraalkylammonium hydroxide ionic liquids with alcohols.

    Pankaj Attri

    Full Text Available In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs such as tetrapropylammonium hydroxide (TPAH and tetrabutylammonium hydroxide (TBAH with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol within the temperature range 293.15-313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (V(E and the deviation in isentropic compressibility (Δκs using the experimental values such as densities (ρ and ultrasonic sound velocities (u that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K and atmospheric pressure. These excess functions were adequately correlated by using the Redlich-Kister polynomial equation. It was observed that for all studied systems, the V(E and Δκs values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7.

  14. Effect of solvent structure on election reactivity

    The reactivity of solvated electrons (es-) with efficient (nitrobenzene, acetone) and inefficient (phenol, toluene) scavengers is affected greatly by the solvent composition in 2-propanol/water mixed solvents. 2-Propanol is the only secondary alcohol that is completely miscible with water. The variation of the nitrobenzene rate constant k2 with solvent composition displays four viscosity zones, as in primary and tertiary alcohol/water mixtures. In zone (c), where the Stokes-Smoluchowski equation applies, the nitrobenzene k2 values in the secondary alcohol/water mixtures are situated between those in the primary and tertiary alcohols, due to the relative values of the dielectric permittivity ε. The charge-dipole attraction energy varies at ε-1. The two water-rich zones (c) and (d) are characterized by a large change of viscosity η and a small change in es- solvation energy (trap depth) Er; here k2 for all the scavengers correlates with the inverse of the viscosity. In the two alcohol-rich zones (a) and (b) the change of η is small but that of Er is large; here k2 of inefficient scavengers correlates with the inverse of Er, due to the difficulty of electron transfer out of deeper traps. Activation energies E2 and entropies ΔS2(double dagger) also show composition zone behaviour. The value of ΔS2(double dagger) is more negative for less efficient scavengers; E2 varies less and does not correlate with reactivity of Er. Electron transfer from solvent to inefficient scavenger is driven by solvent rearrangement around the reaction center, reflected in ΔS2(double dagger)

  15. Simultaneous derivatization and ultrasound-assisted dispersive liquid-liquid microextraction of chloropropanols in soy milk and other aqueous matrices combined with gas-chromatography-mass spectrometry.

    Carro, A M; González, P; Lorenzo, R A

    2013-12-01

    A novel approach involving ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and derivatization combined with gas chromatography-mass spectrometry was developed for the determination of chloropropanols in water and beverages. UA-DLLME was optimized as less solvent-consuming and cost-effective extraction method for water, fruit juice, milk and soy milk samples. The effect of parameters such as the type and volume of extraction solvent, the type and volume of dispersive solvent, amount of derivatization agent, temperature, pH of sample and ionic strength was investigated and optimized for each specimen, using experimental designs. By adding acetonitrile as dispersive solvent, N-heptafluorobutyrylimizadole (HFBI) as derivatization agent and chloroform as extraction solvent, the extraction-derivatization and preconcentration were simultaneously performed. The analytical concentration range was investigated in detail for each analyte in the different samples, obtaining linearity with R(2) ranging between 0.9990 and 0.9999. The method detection limits were in the range of 0.2-1.8μgL(-1) (water), 0.5-15μgL(-1) (fruit juices) and 0.9-3.6μgkg(-1) (milk) and 0.1-1.0μgkg(-1) (soy milk). The method was applied to the analysis of a variety of specimens, with recoveries of 98-101% from water, 97-102% from juices, 99-103% from milk and 97-105% from soy beverage. The relative standard deviation (precision, n=6) varied between 1.3 and 4.9%RSD in water, 2.3 and 5.8%RSD in juices, 1.0 and 5.7%RSD in milk and 3.9 and 9.3%RSD in soy milk. The proposed method was applied to analysis of twenty-eight samples. 1,3-Dichloro-2-propanol was found in an influent water sample from urban wastewater treatment plant (WWTP) (2.1±0.04mgL(-1)) but no chloropropanols were found in the corresponding effluent water sample. This result suggests that the purification system used in the WWTP has been effective for this compound. Moreover, the results revealed the presence of 3

  16. Crystallization and preliminary X-ray diffraction analysis of the wild-type haloalkane dehalogenase DhaA and its variant DhaA13 complexed with different ligands

    Crystals of the wild-type haloalkane dehalogenase DhaA derived from R. rhodochrous NCIMB 13064 and of its catalytically inactive variant DhaA13 were grown in the presence of various ligands and diffraction data were collected to high and atomic resolution. Haloalkane dehalogenases make up an important class of hydrolytic enzymes which catalyse the cleavage of carbon–halogen bonds in halogenated aliphatic compounds. There is growing interest in these enzymes owing to their potential use in environmental and industrial applications. The haloalkane dehalogenase DhaA from Rhodococcus rhodochrous NCIMB 13064 can slowly detoxify the industrial pollutant 1,2,3-trichloropropane (TCP). Structural analysis of this enzyme complexed with target ligands was conducted in order to obtain detailed information about the structural limitations of its catalytic properties. In this study, the crystallization and preliminary X-ray analysis of complexes of wild-type DhaA with 2-propanol and with TCP and of complexes of the catalytically inactive variant DhaA13 with the dye coumarin and with TCP are described. The crystals of wild-type DhaA were plate-shaped and belonged to the triclinic space group P1, while the variant DhaA13 can form prism-shaped crystals belonging to the orthorhombic space group P212121 as well as plate-shaped crystals belonging to the triclinic space group P1. Diffraction data for crystals of wild-type DhaA grown from crystallization solutions with different concentrations of 2-propanol were collected to 1.70 and 1.26 Å resolution, respectively. A prism-shaped crystal of DhaA13 complexed with TCP and a plate-shaped crystal of the same variant complexed with the dye coumarin diffracted X-rays to 1.60 and 1.33 Å resolution, respectively. A crystal of wild-type DhaA and a plate-shaped crystal of DhaA13, both complexed with TCP, diffracted to atomic resolutions of 1.04 and 0.97 Å, respectively

  17. Sol-gel processing of metal sulfides

    Stanic, Vesha

    germanium mercaptide evolved during the sol-gel processing of GeSsb2. The titrations were performed in 2-propanol or in a 50-50 vol % mixture of 2-propanol and toluene. The ion selective Ag/Agsb2S electrode was used for equivalence point detection. Study of the Nernst equation shows that complexes were formed at the electrode surface. However, the titration equivalence point volume clearly demonstrates the formation of Agsb2S and Ge(SAg)sbn. In order to explain this discrepancy a new electrode reaction mechanism and a modified Ag/Agsb2S electrode potential equation are proposed. Effects of hydrogen sulfide and germanium ethoxide concentrations, the concentration ratio and temperature on the microstructure of the prepared GeSsb2 gels were studied. It was found that the concentrations of the reactants have the most significant influence on gel structure.

  18. Efecto del Potasio en Catalizadores CoMo/g-Al2O3-K(x sobre el Hidrotratamiento de Naftas Effect of Potassium in CoMo/g-Al2O3-K(x Catalysts on Naphtha Hydrotreating

    David J Pérez-Martínez

    2009-01-01

    Full Text Available Se prepararon catalizadores CoMo soportados en g-Al2O3 modificada con potasio (K, 1, 3 y 5% en masa y se evaluaron en reacciones simultáneas de hidrodesulfuración (HDS de 2-metiltiofeno e hidrogenación de olefinas (trimetil-1-penteno y trimetil-2-penteno. Las propiedades ácido-base de los catalizadores se determinaron utilizando desorción de amoniaco con temperatura programada (TPD y la reacción de descomposición de 2-propanol. El área superficial BET y la acidez de los catalizadores CoMo/g-Al2O3-K(x disminuyeron con el incremento en el contenido de K, mientras que la selectividad hidrodesulfuración/hidrogenación de olefinas internas (HDS/HID aumentó. Sin embargo, la actividad de los catalizadores disminuyó en todas las reacciones. La comparación con la literatura permitió establecer que las modificaciones en la estructura y dispersión de la fase activa provocadas por la introducción del potasio no son las causantes de la disminución en la actividad.CoMo catalysts supported on g-Al2O3 modified with potassium (K, 1, 3 and 5 wt% were prepared and evaluated in simultaneous hydrodesulfurization (HDS of 2-methyltiophene and hydrogenation of olefins (trimethyl-1-pentene to trimethyl-2-pentene ratio reactions. The acid-base properties of the catalysts were measured by ammonia temperature-programmed desorption (TPD and by the decomposition reaction of 2-propanol. Results showed that the BET surface area and the acidity of catalysts modified with potassium decreased when the potassium concentration increased as long as hydrodesulfurization/ hidrogenation (HDS/HYD of internal olefins increased. However, the activity of the modified catalysts decreased for all reactions. Comparison with literature information allowed establishing that modifications in the structure and dispersion of the active phase caused by the introduction of potassium are not the responsible for the activity decrease.

  19. Photosynthetic pigments and model compounds studied by pulse radiolysis

    tetrahydrofuran (THF) and 2-propanol by reaction between solvated electrons and chlorophyll a with rate constants k >= 2.1011 M-1s1 in THF and k = (1.5+-0.2).1010 M-1s-1 in 2-propanol. (author)

  20. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in rabbits

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential and is developed as refrigerant. Due to lethality observed after high concentration inhalation exposures of HFO-1234yf in a developmental toxicity study with rabbits, the biotransformation of HFO-1234yf was investigated in this species. Female New Zealand White rabbits were exposed to air containing 2000; 10,000; or 50,000 ppm (n = 3/concentration) HFO234yf. All inhalation exposures were conducted for 6 h in a dynamic exposure chamber. Animals were individually housed in metabolic cages after the end of the exposures and urines were collected at 12 h intervals for 60 h. For metabolite identification, urine samples were analyzed by 1H-coupled and 1H-decoupled 19F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by 19F-NMR chemical shifts, signal multiplicity, 1H-19F coupling constants and by comparison with synthetic reference compounds. In urine samples of rabbits exposed to 2000; 10,000; or 50,000 ppm HFO-1234yf, the predominant metabolite was N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine and accounted for app. 48% of total 19F-NMR signal intensities. S-(3,3,3-Trifluoro-2-hydroxypropanyl)mercaptolactic acid, 3,3,3-trifluoro-1,2-dihydroxypropane, 3,3,3-trifluoro-2-propanol and inorganic fluoride were also present as urinary metabolites. In incubations of rabbit liver S9 fractions containing glutathione, NADPH and HFO-1234yf, 3,3,3-trifluoro-1,2-dihydroxypropane, S-(3,3,3-trifluoro-2-hydroxypropanyl)glutathione, 3,3,3-trifluoro-2-propanol and inorganic fluoride were identified as metabolites of HFO-1234yf by 19F-NMR. The quantity of recovered metabolites in urine suggest a low extent (1/2 app. 9.5 h). The obtained results indicate that HFO-1234yf is metabolized in rabbits by a CYP450-mediated epoxidation at low rates and glutathione conjugation of the epoxide. The differences in urinary metabolite patterns between rats

  1. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in rabbits.

    Schuster, Paul; Bertermann, Rüdiger; Rusch, Georg M; Dekant, Wolfgang

    2010-05-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential and is developed as refrigerant. Due to lethality observed after high concentration inhalation exposures of HFO-1234yf in a developmental toxicity study with rabbits, the biotransformation of HFO-1234yf was investigated in this species. Female New Zealand White rabbits were exposed to air containing 2000; 10,000; or 50,000 ppm (n=3/concentration) HFO234yf. All inhalation exposures were conducted for 6 h in a dynamic exposure chamber. Animals were individually housed in metabolic cages after the end of the exposures and urines were collected at 12 h intervals for 60 h. For metabolite identification, urine samples were analyzed by (1)H-coupled and (1)H-decoupled (19)F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by (19)F-NMR chemical shifts, signal multiplicity, (1)H-(19)F coupling constants and by comparison with synthetic reference compounds. In urine samples of rabbits exposed to 2000; 10,000; or 50,000 ppm HFO-1234yf, the predominant metabolite was N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-l-cysteine and accounted for app. 48% of total (19)F-NMR signal intensities. S-(3,3,3-Trifluoro-2-hydroxypropanyl)mercaptolactic acid, 3,3,3-trifluoro-1,2-dihydroxypropane, 3,3,3-trifluoro-2-propanol and inorganic fluoride were also present as urinary metabolites. In incubations of rabbit liver S9 fractions containing glutathione, NADPH and HFO-1234yf, 3,3,3-trifluoro-1,2-dihydroxypropane, S-(3,3,3-trifluoro-2-hydroxypropanyl)glutathione, 3,3,3-trifluoro-2-propanol and inorganic fluoride were identified as metabolites of HFO-1234yf by (19)F-NMR. The quantity of recovered metabolites in urine suggest a low extent (<0.1% of dose received) of biotransformation of HFO-1234yf in rabbits, and 95% of all metabolites were excreted within 12 h after the end of the exposures (t(1/2) app. 9.5 h). The obtained results indicate that HFO-1234yf is

  2. Selective microwave sensors exploiting the interaction of analytes with trap states in TiO2 nanotube arrays

    Zarifi, M. H.; Farsinezhad, S.; Abdolrazzaghi, M.; Daneshmand, M.; Shankar, K.

    2016-03-01

    Sensing of molecular analytes by probing the effects of their interaction with microwaves is emerging as a cheap, compact, label-free and highly sensitive detection and quantification technique. Microstrip ring-type resonators are particularly favored for this purpose due to their planar sensing geometry, electromagnetic field enhancements in the coupling gap and compatibility with established printed circuit board manufacturing. However, the lack of selectivity in what is essentially a permittivity-sensing method is an impediment to wider adoption and implementation of this sensing platform. By placing a polycrystalline anatase-phase TiO2 nanotube membrane in the coupling gap of a microwave resonator, we engineer selectivity for the detection and differentiation of methanol, ethanol and 2-propanol. The scavenging of reactive trapped holes by aliphatic alcohols adsorbed on TiO2 is responsible for the alcohol-specific detection while the different short chain alcohols are distinguished on the basis of differences in their microwave response. Electrodeless microwave sensors which allow spectral and time-dependent monitoring of the resonance frequency and quality factor provide a wealth of information in comparison with electrode-based resistive sensors for the detection of volatile organic compounds. A high dynamic range (400 ppm-10 000 ppm) is demonstrated for methanol detection.Sensing of molecular analytes by probing the effects of their interaction with microwaves is emerging as a cheap, compact, label-free and highly sensitive detection and quantification technique. Microstrip ring-type resonators are particularly favored for this purpose due to their planar sensing geometry, electromagnetic field enhancements in the coupling gap and compatibility with established printed circuit board manufacturing. However, the lack of selectivity in what is essentially a permittivity-sensing method is an impediment to wider adoption and implementation of this sensing platform

  3. Assessment of lead distribution in aquatic plant Lemna minor, using sequential extraction procedure

    Complete text of publication follows. The contamination of water resources by toxic metals demands for attention since this kind of contamination, sometimes, is difficult to realize. Moreover, lead, for instance, has the capacity to be accumulated in fish and plants utilized in the food, and also in human beings, causing several disturbances. Phytoremediation is an emerging technology that employs the use of plants for the clean-up of contaminated environments. The model plant Lemna minor is a genera of Duckweed plant, and refers to a group of floating, flowering plants of the family Lemnaceae. The aquatic plant Lemna minor is relevant to many aquatic environments, including lakes, streams, effluent, rain, and sediment. The aquatic plant Lemna minor has been studied due its potential to extract lead from contaminated waters. The aim of this study was to determine the distribution of Pb in the aquatic plant Lemna minor under stress, using a modified sequential extraction with different solvents: hexane, ethyl acetate, 2-propanol, methanol, ethanol/water (1:1) and water. Non-extractable residues formed the last fraction. Elemental distributions in the plants were determined using flame atomic absorption spectroscopy (F AAS), and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). It was found that the aquatic plant L. minor has the capacity to accumulate lead: in the first day of contamination, about 79% of lead had been intake by the plant. After 7 days, the Pb content was 142 mg Kg-1. After sequential extraction, the methanol and ethanol/water fractions were dominants: 27 and 45% of total content, respectively. In these fractions we can find acids that form specific chelating agents, such as oligopeptides (phytochelatins). The hexane, ethyl acetate, and 2-propanol fractions gave the smallest isolated fraction. These fractions consisted of non-polar lipid compounds. Elemental distribution by X-ray fluorescence spectra and maps

  4. Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

    Lopes Ferreira, N.

    2005-11-15

    Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

  5. Efeito da fertilização nitrogenada em videira sobre a formação de alguns compostos volatéis no vinho Effect of vineyard nitrogen fertilization on the formation of some wine volatile coumpounds

    Lúcia Schuch Boeira

    1995-01-01

    Full Text Available Vitis vinifera cv. Gewürztraminer e Cabemet Sauvignon cultivadas em Santana do Livramento e Garibaldi foram submetidas a diferentes tratamentos nitrogenados realizados durante o período vegetativo de 1992-1993. Após a colheita e esmagamento o mosto obtido foi dividido em quatro lotes e fermentado com diferentes leveduras. As determinações dos compostos voláteis foram realizados através de cromatografia gasosa. Maiores valores de metanol foram encontrados nos vinhos de Cabemet Sauvignon (máximo 225,6mg/l. A fertilização nitrogenada provocou um aumento na concentração (mg/l de propanol-1 (min. 25 -máx. 78,2 e uma diminuição de metil-2 propanol-1 (min. 60,8 - máx. 125,9 e metil-3 + metil-2 butanol-1 (min. 85,8 - máx. 407,8 nos vinhos. Os álcoois superiores apresentaram também diferenças em relação à região, cultivar e levedura utilizada.Vitis vinifera Gewürztraminer (white variety and Cabemet Sauvignon (red growned in Santana do Livramento, RS, and Garibaldi, RS, were added with different nitrogen treatments in the vineyard during me 1992-1993 season. After harvest and crushing, the musts were divided into four lots each one added with a different yeast. The volatiles were analyzed through GC. Maximum amount of methanol was found with the red variety (225.6mg/l. Increasing nitrogen in the soil increased (mg/l propanol-1 (min. 25-max. 78.2 and decreased methyl-2 propanol-1 (min. 60.8-max. 125.9 and methyl-3+methyl-2 butanol-1 (min. 85.8-max. 407.8. The fusel alcohol fraction showed, also, differences between region,grape variety and yeast used.

  6. Synthesis of 14C-labelled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) for use in assessing the biodegradation potential of these energetic compounds

    Within the framework of an R and D project on bioremediation of soils contaminated with energetic compounds, the biodegradation of energetic products such as hexogen (RDX), trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) is under study. Microcosm assays must be performed with radioactive carbon-14 labelled products in order to follow the biodegradation process. 14C-RDX was prepared by nitration of hexamethylenetetramine (HMTA) according to the Hale process. 14C-ring and methyl labelled TNTs synthesized according to the Dorey and Carper procedure. 14C-cellulose was synthesized from 14C-glucose by Acetobacter xylinum. Nitration of the 14C-cellulose yielded 14C-nitrocellulose. 14C-glycidyl azide polymer was obtained by polymerization and azidation of 14C-epichlorohydrin (ECH) which was synthesized from 14C-glycerol. Hydrochlorination of 14C-glycerol and epoxidation of the resulting 14C-1,3-dichloro 2-propanol yielded 14C-ECH. The syntheses of these 14C-labelled explosives are described in this paper. (Author)

  7. Bimetallic nanoparticles of copper and indium by borohydride reduction

    This study investigated the preparation of copper-indium bimetallic nanoparticles through the borohydride reduction in an alcohol solution for application in ink-coating and sputtering target materials. Copper, indium metal and copper-indium intermetallic materials were synthesized by reacting CuCl2 and InCl3 with NaBH4 in 2-propanol (IPA) and tetraethylene glycol (TEG) at room temperature. The Cu-In samples contained Cu2In and CuIn phases with particle sizes of 10-100 nm and 30-200 nm in both the IPA and TEG solutions, respectively. The nanoparticulate Cu-In precursor layer was coated onto a soda-lime glass through spin-casting, where the Cu-In intermetallic phases of Cu2In and Cu11In9 were produced through heat treatment in Ar gas and a microstructured CuInSe2 layer was produced in a selenium atmosphere. Cu, In, Cu-In intermetallic nanoparticles and the films were characterized using powder X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analyses.

  8. HPLC Analysis of Egg Yolk Phosphatidylcholine by Evaporative Light Scattering Detector

    周婧; 胡仙妹; 王田心; 梁浩; 袁其朋

    2012-01-01

    Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).

  9. Can Nonpolar Polyisobutylenes be Measured by Electrospray Ionization Mass Spectrometry? Anion-Attachment Proved to be an Appropriate Method

    Nagy, Lajos; Nagy, Tibor; Deák, György; Kuki, Ákos; Purgel, Mihály; Narmandakh, Mijid; Iván, Béla; Zsuga, Miklós; Kéki, Sándor

    2016-03-01

    Polyisobutylenes (PIBs) with different end-groups including chlorine, exo-olefin, hydroxyl, and methyl prepared from aliphatic and aromatic initiators were studied by electrospray ionization mass spectrometry (ESI-MS). Independently of the end-groups, presence or absence of aromatic initiator moiety, these PIB derivatives were capable of forming adduct ions with NO3 - and Cl- ions, thus allowing the direct characterization of these compounds in the negative ion mode of ESI-MS. To obtain [PIB + NO3]- and [PIB + Cl]- adduct ions with appreciable intensities, addition of polar solvents such as acetone, 2-propanol, or ethanol to the dichloromethane solution of PIBs was necessary. Furthermore, increasing both the polarity (by increasing the acetone content) and the ion-source temperature give rise to enhanced intensities for both [PIB + NO3]- and [PIB + Cl]- ions. Energy-dependent collision induced dissociation studies (CID) revealed that increasing the collision voltages resulted in the shift of the apparent molecular masses to higher ones. CID studies also showed that dissociation of the [PIB + Cl]- ions requires higher collision energy than that of [PIB + NO3]-. In addition, Density Functional Theory calculations were performed to gain insights into the nature of the interactions between the highly non-polar PIB chains and anions NO3 - and Cl- as well as to determine the zero-point corrected electronic energies for the formation of [PIB + NO3]- and [PIB + Cl]- adduct ions.

  10. Novel Ordered Mesoporous Carbon Based Sulfonic Acid as an Efficient Catalyst in the Selective Dehydration of Fructose into 5-HMF: the Role of Solvent and Surface Chemistry.

    Karimi, Babak; Mirzaei, Hamid M; Behzadnia, Hesam; Vali, Hojatollah

    2015-09-01

    Novel ionic liquid derived ordered mesoporous carbons functionalized with sulfonic acid groups IOMC-ArSO3H and GIOMC-ArSO3H were prepared, characterized, and examined in the dehydration reaction of fructose into 5-hydroxymethylfurfural (5-HMF) both in aqueous and nonaqueous systems. To study and correlate the surface properties of these carbocatalysts and some other SBA-15 typed solid acids with 5-HMF yield, hydrophilicity index (H-index) were employed in the fructose dehydration. Our study systematically declared that almost a criterion may be expected for application of solid acids in which by increasing H-index value up to 0.8 the HMF yield enhances accordingly. More increase in H-index up to 1.3 did not change the HMF yield profoundly. Although, it has been shown that the catalyst with larger H-index (∼1.3) resulted in higher activity both in aqueous and 2-propanol systems, during the recycling process deactivation occurs because of more water uptake and the catalysts with optimum amount of H-index (∼0.8) is more robust in the dehydration of fructose. PMID:26259108

  11. Determination and correlation of the solubility of four Brønsted-acidic ionic liquids based on benzothiazolium cations in six alcohols

    Highlights: • Solubility of four acidic benzothiazolium cations-based ILs was measured. • The solubilities vary with the polarity of the solvent. • The solubility of some ILs is with “temperature-sensitive” property. • The measured solubilities were correlated by Apelblat model and λh model. • The dissolution enthalpy and entropy of ILs were calculated using the van’t Hoff equation. - Abstract: Solubilities of four acidic ionic liquids based on benzothiazolium cations in six alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) from at temperatures from (253 to 384) K were determined using a static equilibrium method under atmospheric pressure. The modified Apelblat equation and λh equation were employed to correlate the experimental data with good agreement. The solubilities of ILs increase with increasing temperature. It is interesting to find that the solubility of some ILs in alcohols are with “temperature-sensitive” properties. The solubility is related with the polarity and molecular structures of the solvent, as well as the strength of hydrogen bonding between alcohols and anionic groups of ILs. The dissolution enthalpy and entropy of ILs were calculated by the van’t Hoff equation. This study provides useful information for further research and application of the ionic liquids

  12. Multi-staging for extraction of cesium from nitric acid by a single liquid-liquid countercurrent centrifugal extractor with Taylor vortices

    Fission products that emit considerable decay heat and radioactivity, such as 137Cs, have a large impact on waste management. Small and high-performance extractor is desirable for separating such nuclei. In this study, we implemented the continuous extraction of Cs from nitric acid in a single liquid-liquid countercurrent centrifugal extractor with Taylor Vortices by calix arene-bis(t-octylbenzo-crown-6)(BOBCalixC6) as an extractant with trioctylamine(TOA) as a suppressant and with 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) as a phase modifier. Because of slow extraction kinetics of this process, extraction with multiple theoretical stages by just replacing conventional extractors into the single centrifugal extractor is difficult. Hence, we improved the dispersion of organic phase by an inner rotor made of lipophilic epoxy resin and elevating the solution temperature to lower the viscosity. Higher temperature was not appropriate from the aspect of chemical equilibrium in this process, but extraction with multiple theoretical stages was found to be possible. (author)

  13. The radiation chemistry of Hoechst 33258 and its potential radiosensitizing analogues

    Nel, P. [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemistry]|[Peter McCallum Cancer Institute, Reserach Division, East Melbourne, VIC (Australia); Cooper, R. [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemistry; Martin, R.F. [Peter McCallum Cancer Institute, East Melbourne, VIC, (Australia)

    1996-12-31

    Collaborative research between Peter MacCallum Cancer Institute and The University of Melbourne is aimed to investigate the photochemistry and radiation chemistry of the halogenated analogues m-I Hoechst and o-I Hoechst (which are being developed as potential radiosensitizers). Studies were conducted on Hoechst 33258, phenyl Hoechst, m-I Hoechst and o-I Hoechst. The chemical interaction between the Hoechst analogues and the radiolysis products of water (the hydroxy radical and the aqueous electron) were investigated by saturating aqueous solutions with nitrogen or nitrous oxide (an electron scavenger) and using 2-propanol as a hydroxy radical scavenger. Hoechst 33258 was investigated at pH 5 and pH 9. Transient absorption spectra of micromolar solutions saturated with nitrogen or nitrous oxide suggest the formation of hydroxyl radical adduct(s). The rate of formation of these transient spectra was observed to be dependent on the concentration of Hoechst 33258. Phenyl Hoechst, m- I Hoechst and o-I Hoechst were studied at pH 5. Spectra again suggest the formation of hydroxy radical adducts and that both m-I Hoechst and o-I Hoechst react with aqueous electrons.

  14. Measurement and modeling of osmotic coefficients of binary mixtures (alcohol + 1,3-dimethylpyridinium methylsulfate) at T = 323.15 K

    Research highlights: → The osmotic coefficients of binary mixtures (alcohol + ionic liquid) were determined. → The measurements were carried out with a vapor pressure osmometer at 323.15 K. → The Pitzer-Archer, and the MNRTL models were used to correlate the experimental data. → Mean molal activity coefficients and excess Gibbs free energies were calculated. - Abstract: Measurement of osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1,3-dimethylpyridinium methylsulfate were performed at T = 323.15 K using the vapor pressure osmometry technique, and from experimental data, vapor pressure, and activity coefficients were determined. The extended Pitzer model modified by Archer, and the NRTL model modified by Jaretun and Aly (MNRTL) were used to correlate the experimental osmotic coefficients, obtaining standard deviations lower than 0.017 and 0.054, respectively. From the parameters obtained with the extended Pitzer model modified by Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied binary mixtures were calculated. The effect of the cation is studied comparing the experimental results with those obtained for the ionic liquid 1,3-dimethylimidazolium methylsulfate.

  15. Leuco-crystal-violet micelle gel dosimeters: I. Influence of recipe components and potential sensitizers

    Radiochromic leuco crystal violet (LCV) micelle gel dosimeters are promising three-dimensional radiation dosimeters because of their spatial stability and suitability for optical readout. The effects of surfactant type and surfactant concentration on dose sensitivity of LCV micelle gels are tested, demonstrating that dose sensitivity and initial colour of the gel increases with increasing Triton x-100 (Tx100) concentration. Using Cetyl Trimethyl Ammonium Bromide (CTAB) in place of Tx100 produces gels that are nearly colourless prior to irradiation, but reduces the dose sensitivity. The separate effects of Tri-chloro acetic acid concentration and pH are investigated, revealing that controlling the pH near 3.6 is crucial for achieving high dose sensitivity. The sensitizing effect of chlorinated species on dose sensitivity is tested using 2,2,2-trichloroethanol (TCE), chloroform, and 1,1,1-trichloro-2-methyl-2-propanol hemihydrate. TCE gives the largest improvement in dose sensitivity and is recommended for use in micelle gel dosimeters because it is less volatile and safer to use than chloroform. Preliminary experiments on a new gel containing CTAB as the surfactant and TCE show that this new gel gives a dose sensitivity that is 24% higher than that of previous LCV micelle gels and is nearly colourless prior to irradiation. (paper)

  16. Enhanced photo-degradation of paracetamol on n-platinum-loaded TiO2: The effect of ultrasound and OH/hole scavengers.

    Ziylan-Yavaş, Asu; Ince, Nilsun H

    2016-11-01

    Elimination/mineralization of paracetamol (PCT) was investigated by catalytic oxidation under ultrasound, UV and both. The catalyst was synthesized by immobilization of nPt on TiO2 to benefit from the ability of Pt to facilitate charge transfer processes and to separate e(-)/h(+) pairs. It was found that increasing the Pt-loading enhanced the rate of sonochemical reactions, but retarded that of photolytic reactions, due to reduced UV absorption on the surface. Simultaneous application of sonolysis and photolysis was synergistic due to disaggregation of the particles and homogenization of the active species over the catalyst surface. The decay of PCT was highly dependent on the availability of OH, as the reactions were nearly terminated in the presence of a strong OH scavenger-2-propanol. However, a remarkable rate enhancement was observed in the presence of a suitable dose of I(-), which scavenges both OH and hvb(+). The result was explained by the production of excess radicals upon sonolysis of iodide solutions, and the reactivity of PCT with them. Finally, carbon mineralization was significantly hindered in the presence of both scavengers due to increased competition for OH and inefficient formation of hydroquinone arising from reduced availability of hvb(+). PMID:27518924

  17. Dual delivery of active antibactericidal agents and bone morphogenetic protein at sustainable high concentrations using biodegradable sheath-core-structured drug-eluting nanofibers.

    Hsu, Yung-Hen; Lin, Chang-Tun; Yu, Yi-Hsun; Chou, Ying-Chao; Liu, Shih-Jung; Chan, Err-Cheng

    2016-01-01

    In this study, we developed biodegradable sheath-core-structured drug-eluting nanofibers for sustainable delivery of antibiotics (vancomycin and ceftazidime) and recombinant human bone morphogenetic protein (rhBMP-2) via electrospinning. To prepare the biodegradable sheath-core nanofibers, we first prepared solutions of poly(d,l)-lactide-co-glycolide, vancomycin, and ceftazidime in 1,1,1,3,3,3-hexafluoro-2-propanol and rhBMP-2 in phosphate-buffered solution. The poly(d,l)-lactide-co-glycolide/antibiotics and rhBMP-2 solutions were then fed into two different capillary tubes controlled by two independent pumps for coaxial electrospinning. The electrospun nanofiber morphology was observed under a scanning electron microscope. We further characterized the in vitro antibiotic release from the nanofibers via high-performance liquid chromatography and that of rhBMP-2 via enzyme-linked immunosorbent assay and alkaline phosphatase activity. We showed that the biodegradable coaxially electrospun nanofibers could release high vancomycin/ceftazidime concentrations (well above the minimum inhibition concentration [MIC]90) and rhBMP-2 for >4 weeks. These experimental results demonstrate that novel biodegradable nanofibers can be constructed with various pharmaceuticals and proteins for long-term drug deliveries. PMID:27574423

  18. Synthesis, spectroscopic and catalytic properties of some new boron hybrid molecule derivatives by BF2 and BPh2 chelation

    Kilic, Ahmet; Alcay, Ferhat; Aydemir, Murat; Durgun, Mustafa; Keles, Armagan; Baysal, Akın

    2015-05-01

    A new series of Schiff base ligands (L1-L3) and their corresponding fluorine/phenyl boron hybrid complexes [LnBF2] and [LnBPh2] (n = 1, 2 or 3) have been synthesized and well characterized by both analytical and spectroscopic methods. The Schiff base ligands and their corresponding fluorine/phenyl boron hybrid complexes have been characterized by NMR (1H, 13C and 19F), FT-IR, UV-Vis, LC-MS, and fluorescence spectroscopy as well as melting point and elemental analysis. The fluorescence efficiencies of phenyl chelate complexes are greatly red-shifted compared to those of the fluorine chelate analogs based on the same ligands, presumably due to the large steric hindrance and hard π → π∗ transition of the diphenyl boron chelation, which can effectively prevent molecular aggregation. The boron hybrid complexes were applied to the transfer hydrogenation of acetophenone derivatives to 1-phenylethanol derivatives in the presence of 2-propanol as the hydrogen source. The catalytic studies showed that boron hybrid complexes are good catalytic precursors for transfer hydrogenation of aromatic ketones in 0.1 M iso-PrOH solution. Also, we have found that both steric and electronic factors have a significant impact on the catalytic properties of this class of molecules.

  19. Study of the in vitro metabolism of TJ0711 using ultra high performance liquid chromatography with quadrupole time-of-flight and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry.

    Hu, Lei; Lv, Zhenhua; Li, Gao; Xu, Xiaolong; Zhang, Chenghao; Cao, Peng; Huang, Jiangeng; Si, Luqin

    2015-06-01

    TJ0711 (1-[4-(2-methoxyethyl)phenoxy]-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanol) is a novel β-adrenoreceptor blocker with vasodilating activity. The aim of this study was to investigate the in vitro metabolic properties of TJ0711 from both qualitative and quantitative aspects using mouse, rat, dog, and human liver microsomes as well as rat hepatocytes. Two modern liquid chromatography with tandem mass spectrometry systems, ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and ultra fast liquid chromatography with quadrupole linear ion trap mass spectrometry, were utilized for the analysis. To better characterize the metabolic pathways of TJ0711, two major metabolites were incubated under the same conditions as that for TJ0711. TJ0711 was extensively metabolized in vitro, and a total of 34 metabolites, including 19 phase I and 15 phase II metabolites, were identified. Similar metabolite profiles were observed among species, and demethylation, hydroxylation, carboxylic acid formation, and glucuronidation were proposed as the major metabolic routes. Significant interspecies differences were observed in the metabolic stability studies of TJ0711. Furthermore, gender differences were significant in mice, rats, and dogs, but were negligible in humans. The valuable information provided in this work will be useful in planning and interpreting further pharmacokinetic, in vivo metabolism and toxicological studies of this novel β-blocker. PMID:25800512

  20. Understanding Solvent Effects on the Properties of Two-Dimensional Transition Metal Dichalcogenides.

    Choi, Jungwook; Zhang, Hanyu; Du, Haodong; Choi, Jong Hyun

    2016-04-13

    Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have emerged as attractive direct bandgap semiconducting materials with remarkable properties. Recently, TMDC-based electronic and optoelectronic systems have been demonstrated with various chemical doping and functionalization approaches for modulating their physical properties and enhancing device performances. However, the dependence of intrinsic properties of TMDCs on diverse solvents, which are used necessarily in fabrication processes and chemical doping, remains largely unaddressed. Here we report a charge transfer mechanism in TMDCs by commonly used solvents such as chloroform, toluene, acetone, and 2-propanol, which significantly changes the physical properties of monolayer MoS2 and WSe2. We find that the relative difference in electronegativity between solvents and TMDCs drives the transfer of electrons from or to the TMDCs, which results in photoluminescence (PL) enhancement or quenching depending on the change of carrier density in TMDCs. The analysis of exciton and trion spectral weights in MoS2 as a function of solvent electronegativity provides evidence of charge transfer. Finally, conductive atomic force microscopy (C-AFM) on TMDCs before and after immersion in the solvents further supports the charge transfer mechanism and resulting changes in carrier density. Our results highlight the importance of selection of solvents for solution-processed 2D TMDC devices and systems. PMID:27018600

  1. Effect of the propanol-water volume ratios on the properties of SnO2 nanocrystals

    Rakgalakane, B. P.; Sikhwivhilu, L. M.; Moloto, M. J.; van Wyk, J.; Moloto, N.

    2015-01-01

    Herein we report on the tuning of the morphologies of SnO2 nanocrystals (NCs) by varying the water-propanol volume ratios during the microwave synthesis. Our results show the change in morphology from spherical, when pure water is a solvent, to oriented attachment and then nanotubes, as the solvent mixture is increased from 1:1 to 2:3 to 3:2 propanol-water volume ratios. Furthermore electrical properties of solution processed thin films of the as-prepared SnO2 NCs were investigated. The 2:3 ratio sample showed the lowest resistivity of 0.95 mΩ cm. Annealing of the sample at different temperatures had an effect in electrical properties with an oscillatory trend with annealing temperature being observed. In addition there was an initial decrease in particle size upon annealing and the oriented attachment mechanism seen at room temperature was dismantled. There was subsequent increase in particle size with an increase on temperature due to Ostwald ripening.

  2. Optimal oxidative folding of the novel antimicrobial cyclotide from Hedyotis biflora requires high alcohol concentrations.

    Wong, Clarence T T; Taichi, Misako; Nishio, Hideki; Nishiuchi, Yuji; Tam, James P

    2011-08-23

    Hedyotide B1, a novel cyclotide isolated from the medicinal plant Hedyotis biflora, contains a cystine knot commonly found in toxins and plant defense peptides. The optimal oxidative folding of a cystine knot encased in the circular peptide backbone of a cyclotide poses a challenge. Here we report a systematic study of optimization of the oxidative folding of hedyotide B1, a 30-amino acid cyclic peptide with a net charge of +3. The linear precursor of hedyotide B1, synthesized as a thioester by solid phase synthesis, was cyclized quantitatively by a thia-zip cyclization to form the circular backbone and then subjected to oxidative folding in a thiol-disulfide redox system under 38 different conditions. Of the oxidative conditions examined, the nature of the organic cosolvent appeared to be critical, with the use of 70% 2-propanol affording the highest yield (48%). The disulfide connectivity of the folded hedyotide was identical to that of the native form as determined by partial acid hydrolysis. The use of such a high alcohol concentration suggests that a partial denaturation may be necessary for the oxidative folding of a cyclotide with the inverse orientation of hydrophobic side chains that are externalized to the solvent face to permit the formation of the interior cystine core in the circularized backbone. We also show that synthetic hedyotide B1 is an antimicrobial, exhibiting minimal inhibitory concentrations in the micromolar range against both Gram-positive and -negative bacteria. PMID:21776968

  3. Chromatographic analyses of fatty acid methyl esters by HPLC-UV and GC-FID

    Carvalho, Myller S.; Pinho, David M.M.; Suarez, Paulo A.Z., E-mail: psuarez@unb.br [Laboratorio de Materiais e Combustiveis, Instituto de Quimica, Universidade de Brasilia, DF (Brazil); Mendonca, Marcio A. [Faculdade de Agronomia e Medicina Veterinaria, Universidade de Brasilia, DF (Brazil); Resck, Ines S. [Laboratorio de Ressonancia Magnetica Nuclear, Universidade de Brasilia, DF (Brazil)

    2012-04-15

    An analytical method using high performance liquid chromatography with UV detection (HPLC-UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 deg C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4 (v/v) (PrHex): 100% of MeOH in 0 min, 50% of MeOH and 50% of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD < 3%), linearity (r{sup 2} > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples. (author)

  4. Crystallization and preliminary crystallographic analysis of the second GAF domain of DevS from Mycobacterium smegmatis

    The second GAF domain of the hypoxia-sensing DevS from M. smegmatis has been crystallized. The crystal belonged to space group P61 and diffracted to 2.0 Å resolution. Mycobacterium tuberculosis is known to transform into the nonreplicating persistence state under the influence of hypoxia or nitric oxide. DevS-DevR is a two-component regulatory system that mediates the genetic response for the transformation. DevS is a histidine kinase that contains two GAF domains for sensing hypoxia or nitric oxide. The second GAF from M. smegmatis DevS was crystallized using the sitting-drop vapour-diffusion method in the presence of sodium citrate and 2-propanol as precipitants. X-ray diffraction data were collected from crystals containing selenomethionine to a maximum resolution of 2.0 Å on a synchrotron beamline. The crystals belong to the hexagonal space group P61. The asymmetric unit contains one molecule, corresponding to a packing density of 2.5 Å3 Da−1. The selenium substructure was determined by the single anomalous dispersion method and structure refinement is in progress

  5. The radiation chemistry of Hoechst 33258 and its potential radiosensitizing analogues

    Collaborative research between Peter MacCallum Cancer Institute and The University of Melbourne is aimed to investigate the photochemistry and radiation chemistry of the halogenated analogues m-I Hoechst and o-I Hoechst (which are being developed as potential radiosensitizers). Studies were conducted on Hoechst 33258, phenyl Hoechst, m-I Hoechst and o-I Hoechst. The chemical interaction between the Hoechst analogues and the radiolysis products of water (the hydroxy radical and the aqueous electron) were investigated by saturating aqueous solutions with nitrogen or nitrous oxide (an electron scavenger) and using 2-propanol as a hydroxy radical scavenger. Hoechst 33258 was investigated at pH 5 and pH 9. Transient absorption spectra of micromolar solutions saturated with nitrogen or nitrous oxide suggest the formation of hydroxyl radical adduct(s). The rate of formation of these transient spectra was observed to be dependent on the concentration of Hoechst 33258. Phenyl Hoechst, m- I Hoechst and o-I Hoechst were studied at pH 5. Spectra again suggest the formation of hydroxy radical adducts and that both m-I Hoechst and o-I Hoechst react with aqueous electrons

  6. Fabrication of composite nano-particles by radiations

    Realization of composite nano-materials using radiation technology is reported to demonstrate one of the author's experimental results on noble-metallic nano-particles having the diameter less than 10 nm which are dispersed homogeneously with high density on a catalyst-supporting particle. Keeping away as such from coagulation of noble metals, thus keeping its high specific surface, functional materials, for example, magnetic materials can be used as a supporting particle. The method is to irradiate the solutions containing starting materials. Since water containing 2-propanol is decomposed by radiolysis to produce the reducing and oxidizing species, metallic ions will be reduced to metals and sometimes in the presence of polyvinyl alcohol to noble-metal colloidal solutions which has been further applied to synthesis of Au/γ-Fe2O3 composite particle. Moreover, other metals as Ag, Pt, Pd, Rh, with other supporting materials as Al2O3, TiO2, Fe3O4, ZnO, ZrO2, and CeO2 were found to be realized. Au/iron oxides magnetic composite particles were also synthesized by γ- or electron irradiation to be used magnetically separate the mixture of amino acids and DNA. (S. Ohno)

  7. Genotoxic damage induced by isopropanol in germinal and somatic cells of Drosophila melanogaster.

    Palermo, Ana María; Mudry, Marta Dolores

    2011-12-24

    Isopropanol (isopropyl alcohol, 2-propanol, IPA) is a volatile solvent widely used in domestic or industrial environments and reported as innocuous in various test systems. The aim of this work was to search for in vivo genotoxic effects of IPA in Drosophila melanogaster, studying its ability to induce nondisjunction (ND) in females, sex linked recessive lethals (SLRL) in males, and somatic mutation and/or recombination (SMART) in larvae. Treatments were acute (60min) and were administered via inhalation. IPA had low toxicity in adult flies (75% IPA mortality index, MI=12.7% (females) and 2.6% (males)) and larvae (MI=14.3%, 75% IPA). Female fertility was severely affected during the first 24h (brood I, BI) after treatment, but, afterwards, control values were recovered. IPA induced a 50-fold increase of ND (%) in 24h old females, and a six-fold rise in 4-5 d old BI offspring. Nondisjunction frequencies (%) in the offspring of broods II to V (24h in each case) were similar to control values. IPA doses of 25% and 50% (v/v), tested in 24h old females, showed a significant dose-dependent increase of ND(%)in BI only, with control values in subsequent broods. Flies gave normal offspring when kept in regular media for 24h before mating. The eye spot test (SMART) showed a significant increase at 50% IPA (pDNA directly, but perturbations of the nuclear membrane may be responsible for induction of ND. PMID:22001194

  8. Desalination of aqueous solutions by LTA and MFI zeolite membranes using pervaporation method

    A. Malekpour

    2011-12-01

    Full Text Available LTA and MFI zeolite membranes were hydrothermally grown on the surface of an α-alumina porous support. The synthesized membranes were used for removal of cationic and anionic species from aqueous solutions by the pervaporation method. The perfection of the membranes was improved by employing the multi-stage synthesis method. The membranes were characterized by XRD, SEM and IR methods. The membranes were initially evaluated by the pervaporation separation of water from aqueous 2-propanol mixtures. The separation factors obtained were 7081 and 105 for NaA and ZSM-5 membranes, respectively. The ability of membranes for desalination of some aqueous solutions containing I-, Cs+ and Sr2+ ions was examined in various conditions. These ionic species were chosen because of their importance in the nuclear sciences. Both membranes effectively removed (more than 99 wt% I-, Cs+ and Sr2+ from their singlesalt solutions (0.001mol dm-3 over a temperature range of 298-338 K. The effects of parameters such as time and temperature on the separation factors and fluxes were investigated. This work shows that, due to their excellent chemical, thermal and mechanical stability, the zeolitic membranes are useful for desalination of aqueous solutions and treating saline wastewaters by pervaporation. Therefore, this method has the ability to desalinate harsh environment solutions involving strong solvent and radioactive components.

  9. Development and characterization of coaxially electrospun gelatin coated poly (3-hydroxybutyric acid) thin films as potential scaffolds for skin regeneration

    The morphology of fibers synthesized through electrospinning has been found to mimic extracellular matrix. Coaxially electrospun fibers of gelatin (sheath) coated poly (3-hydroxybutyric acid) (PHB) (core) was developed using 2,2,2 trifluoroethanol(TFE) and 1,1,1,3,3,3 hexafluoro-2-propanol(HFIP) as solvents respectively. The coaxial structure and coating of gelatin with PHB fibers was confirmed through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Thermal stability of the coaxially electrospun fibers was analyzed using thermogravimetric analysis(TGA), differential scanning calorimetry(DSC) and differential thermogravimetric analysis(DTA). Complete evaporation of solvent and gelatin grafting over PHB fibers was confirmed through attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR). The coaxially electrospun fibers exhibited competent tensile properties for skin regeneration with high surface area and porosity. In vitro degradation studies proved the stability of fibers and its potential applications in tissue engineering. The fibers supported the growth of human dermal fibroblasts and keratinocytes with normal morphology indicating its potential as a scaffold for skin regeneration. - Highlights: • Coaxial electrospinning was employed to develop core-shell fibers of PHB and gelatin. • The scaffold has competent physicochemical properties. • Developed scaffold will have high impact as a dermal substitute in skin regeneration

  10. Tio2 Nanoparticles Coated With Porphyrin Dye Thin Film As Fluorescence Gas Sensor

    This research explores the possibility of using fluorescence technique to detect the presence of volatile organic compounds based on a single sensing material. The material used was TiO2 nanoparticles coated with porphyrin dye. The TiO2 nanoparticles colloid is in a sol-gel form synthesized from titanium (IV) ethoxide in ethanol with addition of potassium chloride (KCl) as stabilizer. TiO2 nanoparticles were then coated with porphyrin dye, Manganese (III) 5,10,15,20 tetra (4-pyridyl)-21H, 23H porphine chloride tetrakis (meta chloride). The coated nanoparticles were deposited on quartz substrate using self-assembly through dip coating technique. The sensing properties of the thin film toward volatile organic compounds; ethanol, acetone, cyclohexane and 2-propanol were studied using luminescence spectrometer. It was found that the thin film produced different emission spectra peaks for different volatile organic compounds (VOCs). Hence, it eases chemical identification process and potentially be use as fluorescence gas sensor. (author)

  11. Methodology optimization for quantification of total phenolics and individual phenolic acids in sweetpotato (Ipomoea batatas L.) roots.

    Padda, M S; Picha, D H

    2007-09-01

    Phenolic acids are one of the several classes of naturally occurring antioxidant compounds found in sweetpotatoes. Simplified, robust, and rapid methodologies were optimized to quantify total and individual phenolic acids in sweetpotato roots. Total phenolic acid content was quantified spectrophotometrically using both Folin-Denis and Folin-Ciocalteu reagents. The Folin-Ciocalteu reagent gave an overestimation of total phenolic acids due to the absorbance of interfering compounds (that is, reducing sugars and ascorbic acid). Individual phenolic acids were quantified by high-performance liquid chromatography (HPLC) using the latest in column technology. Four reversed-phase C18 analytical columns with different properties (dimensions, particle size, particle shape, pore size, and carbon load) were compared. Three different mobile phases using isocratic conditions were also evaluated. A column (4.6 x 150 mm) packed with 5-microm spherical silica particles of pore size 110 A combined with 14% carbon load provided the best and fast separation of individual phenolic acids (that is, chlorogenic acid, caffeic acid, and 3 isomers of dicaffeoylquinic acid) with a total analysis time of less than 7 min. Among the 3 mobile phases tested, a mobile phase consisting of 1% (v/v) formic acid aqueous solution: acetonitrile: 2-propanol, pH 2.5 (70:22:8, v/v/v) gave adequate separation. Among the solvents tested, aqueous mixtures (80:20, solvent:water) of methanol and ethanol provided higher phenolic acid extraction efficiency than the aqueous mixture of acetone. PMID:17995640

  12. Simulated moving bed separation of tocopherol homologues: simulation and experiments

    Yu-bin L(U); Bao-gen SU; Yi-wen YANG; Qi-long REN; Ping-dong WU

    2009-01-01

    Chromatograms of tocopherol homologues were obtained by a column of analytical size(inner diameter(ID)0.46 cm cm× 10 cm)packed with silica gel.Adsorption isotherms and film mass-transfer coefficient were estimated from the chromatograms by using a general rate model.which considers axial dispersion,external mass-transfer and intraparticle diffusion.Based on the obtained isotherms and mass-transfer coefficient.the separation process of tocopherol homologues on simulated moving impurities was separated on an SMB equipment.The SMB equipment was composed of 8 columns of ID 2 cm× 10 cm.with 2 columns in each section.The solid phase was silica gel,and the mobile phase was n-hexane/2-propanol(99/1 by volume).γ-and δ-tocopherols of purity greater than 98% were obtained with recovery greater than 98%.The effects of operating conditions (flow rates and switching time)on the performance of SMB were studied by both simulation and experiments.It was found that all the simulation results were quite close to the experimental results.We conclude that process development and optimization of operating conditions of SMB by simulation are feasible.

  13. Enhanced bioactivity of ZnO nanoparticles-an antimicrobial study

    Padmavathy, Nagarajan; Vijayaraghavan, Rajagopalan [School of Science and Humanities-Materials Division, VIT University, Vellore - 632 014, Tamil Nadu (India)], E-mail: rvijayaraghavan@vit.ac.in

    2008-07-01

    In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO{sub 3}){sub 2} and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles.

  14. Identification of volatile markers in potato brown rot and ring rot by combined GC-MS and PTR-MS techniques: study on in vitro and in vivo samples.

    Blasioli, Sonia; Biondi, Enrico; Samudrala, Devasena; Spinelli, Francesco; Cellini, Antonio; Bertaccini, Assunta; Cristescu, Simona M; Braschi, Ilaria

    2014-01-15

    Ralstonia solanacearum (Rs) and Clavibacter michiganensis subsp. sepedonicus (Cms) are the bacterial causal agents of potato brown and ring rot, respectively, and are included in the A2 list of quarantine pathogens in Europe. Identification by GC-MS analysis of volatile organic compounds from Rs or Cms cultured on different nutrient media was performed. GC-MS and PTR-MS analysis were carried out also on unwounded potato tubers infected with the same pathogens. Infected tubers were produced by experimental inoculations of the plants. In in vitro experiments, Rs or Cms emitted volatile compounds, part of which were specific disease markers of potato (2-propanol and 3-methylbutanoic acid), mainly originating from bacterial metabolism (i.e., amino acid degradation, carbohydrate and fatty acid oxidation). In potato tubers, pathogen metabolism modified the volatile compound pattern emitted from healthy samples. Both bacteria seem to accelerate metabolic processes ongoing in potatoes and, in the case of Rs, disease markers (1-hepten-3-ol, 3,6-dimethyl-3-octanone, 3-ethyl-3-methylpentane, 1-chloroctane, and benzothiazole) were identified. PMID:24313381

  15. Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

    Min Sup Kim

    2012-01-01

    Full Text Available We describe here the preparation of poly(caprolactone (PCL-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing 30~50% (wt/wt chitin were enhanced compared with PCL-only mats. In vitro studies showed that the viability of human dermal fibroblasts (HDFs for up to 7 days in culture was higher on composite (OD value: 1.42±0.09 than on PCL-only (0.51±0.14 nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.

  16. Bimodal fibrous structures for tissue engineering: Fabrication, characterization and in vitro biocompatibility.

    Tiwari, Arjun Prasad; Joshi, Mahesh Kumar; Kim, Jeong In; Unnithan, Afeesh Rajan; Lee, Joshua; Park, Chan Hee; Kim, Cheol Sang

    2016-08-15

    We report for the first time a polycaprolactone-human serum albumin (PCL-HSA) membrane with bimodal structures comprised of spider-web-like nano-nets and conventional fibers via facile electro-spinning/netting (ESN) technique. Such unique controllable morphology was developed by electrospinning the blend solution of PCL (8wt% in HFIP 1,1,1,3,3,3,-Hexafluoro-2-propanol) and HSA (10wt% deionized water). The phase separation during electrospinning caused the formation of bimodal structure. Various processing factors such as applied voltage, feeding rate, and distance between nozzle tip and collector were found responsible for the formation and distribution of the nano-nets throughout the nanofibrous mesh. Field emission electron microscopy (FE-SEM) confirmed that the nano-nets were composed of interlinked nanowires with an ultrathin diameter (10-30nm). When compared with a pure PCL membrane, the membrane containing nano-nets was shown to have better support for cellular activities as determined by cell viability and attachment assays. These results revealed that the blending of albumin, a hydrophilic biomolecule, with PCL, a hydrophobic polymer, proves to be an outstanding approach to developing membranes with controlled spider-web-like nano-nets for tissue engineering. PMID:27179176

  17. Spectroscopic Studies on ZrO2 Modified with MoO3 and Activity for Acid Catalysis

    Zirconia modified with MoO3 was prepared by impregnation of powdered Zr(OH)4 with ammonium heptamolybdate aqueous solution followed by calcining in air at high temperature. Spectroscopic studies on prepared catalysts were performed by using FTIR, Raman, XRD, and DSC and by measuring surface area. Upon the addition of molybdenum oxide to zirconia up to 15 wt%, the specific surface area increased in proportion to the molybdate oxide content, while acidity measured by irreversible chemisorption of ammonia exhibited a maximum value at 3 wt% of MoO3. Since the ZrO2 stabilizes the molybdenum oxide species, for the samples equal to or less than 30 wt%, molybdenum oxide was well dispersed on the surface of zirconia and no phase of crystalline MoO3 was observed at any calcination temperature above 400 .deg. C. The catalytic activities for cumene dealkylation were roughly correlated with the acidity of catalysts measured by ammonia chemisorption method, while the catalytic activities for 2-propanol dehydration were not correlated with the acidity because weak acid sites are necessary for the reaction

  18. Photodegradation of phosmet in wool wax models and on sheep wool: determination of wool wax bound phosmet by means of isotope ratio mass spectrometry.

    Sinderhauf, Katrin; Schwack, Wolfgang

    2005-06-15

    The photochemical reactions of phosmet, an organophosphorus insecticide used for plant protection and for control of ectoparasites on productive livestock, were studied in the presence of wool wax. Induced by UV light, phosmet features numerous degradation pathways as well as photoaddition reactions with lipid structure moieties. In model irradiation experiments of phosmet in mixtures of solvents (cyclohexane, cyclohexene, 2-propanol) and fatty acid methyl esters (methyl stearate, methyl oleate, 12-hydroxymethyl stearate), both adjusted to the hydroxyl and iodine values of wool wax, half-lives were determined to be approximately 7 and 16 h, respectively. Irradiation of phosmet on crude sheep wool resulted in a degradation rate of 65% after 24 h. In tracer studies with stable isotope labeled phosmet ([15N]phosmet) in commercial lanolin and on raw sheep wool, employing a sunlight simulator and natural sunlight, wool wax bound phosmet was formed. After extraction and measurement by elemental analyzer/isotope ratio mass spectrometry, delta15N values of the phosmet-free wool wax fractions were notably increased as compared to the value of natural lanolin. Calculated from the delta15N values, an average of 13.9/15.6% (sunlight simulator/natural sunlight) was bound to wool wax lipids after irradiation of thin films of commercial lanolin. In experiments with sheep wool, 13.2 and 15.4%, respectively, were detected as wax-bound. PMID:15941329

  19. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a β hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an α hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  20. Determination of the mixture in a reaction of glycerol with hydrochloric acid by gas chromatography%气相色谱法测定甘油与盐酸反应过程的混合物

    尤小姿; 李华荣; 罗正鸿

    2009-01-01

    采用气相色谱方法分析了甘油与盐酸反应过程中的主要物质. 使用KB-WAX毛细管柱及FID检测器, 以乙二醇作内标和甲醇定容, 并用内标法计算. 结果表明, 在程序升温下, 气相色谱内标法能使GLY, DCP, CPD等几种物质达到基线分离, 该方法能满足测试要求.%In this paper, a simple gas chromatographic method for the identification of glycerol (GLY), 1,3-dichloropropanol-2-propanol,(DCP) and 3-chloro-1,2-propandiol (CPD) in GLY chlorination reaction is described. The results are detected by KB-WAX capillary column with a flame ionization detector (FID) and calculated by an internal stand method. Glycol is used as an internal standard, and the samples are diluted with methanol. This method is simple, rapid and the results are reliable.

  1. Fiber content of diet affects exhaled breath volatiles in fasting and postprandial state in a pilot crossover study.

    Raninen, Kaisa J; Lappi, Jenni E; Mukkala, Maria L; Tuomainen, Tomi-Pekka; Mykkänen, Hannu M; Poutanen, Kaisa S; Raatikainen, Olavi J

    2016-06-01

    Our pilot study examined the potential of exhaled breath analysis in studying the metabolic effects of dietary fiber (DF). We hypothesized that a high-fiber diet (HFD) containing whole grain rye changes volatile organic compound (VOC) levels in exhaled breath and that consuming a single meal affects these levels. Seven healthy men followed a week-long low-fiber diet (17 g/d) and HFD (44 g/d) in a randomized crossover design. A test meal containing 50 g of the available carbohydrates from wheat bread was served as breakfast after each week. Alveolar exhaled breath samples were analyzed at fasting state and 30, 60, and 120 minutes after this meal parallel to plasma glucose, insulin, and serum lipids. We used solid-phase microextraction and gas chromatography-mass spectrometry for detecting changes in 15 VOCs. These VOCs were acetone, ethanol, 1-propanol, 2-propanol, 1-butanol, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, 2-methylbutyric acid, hexanoic acid, acetoin, diacetyl, and phenol. Exhaled breath 2-methylbutyric acid in the fasting state and 1-propanol at 120 minutes decreased (P = .091 for both) after an HFD. Ingestion of the test meal increased ethanol, 1-propanol, acetoin, propionic acid, and butyric acid levels while reducing acetone, 1-butanol, diacetyl, and phenol levels. Both DF diet content and having a single meal affected breathVOCs. Exploring exhaled breath further could help to develop tools for monitoring the metabolic effects of DF. PMID:27188907

  2. Solubility and solution thermodynamics of sorbic acid in eight pure organic solvents

    Highlights: • The solubility of sorbic acid in eight pure organic solvents was experimentally determined. • Several solution thermodynamic properties of sorbic acid in eight pure organic solvents were calculated. • The experimental solubility data were correlated by five models. • The COSMO-RS model was employed to predict the solubility of sorbic acid in eight pure organic solvents. - Abstract: By the gravimetric method, the solubility of sorbic acid in eight solvents including ethanol, 2-propanol, methanol, 1-butanol, ethyl acetate, methyl tert-butyl ether, acetone and acetonitrile was determined over a temperature range from 285.15 to K at atmospheric pressure. For the temperature range investigated, the solubility of sorbic acid in the solvents increased with increasing temperature. The experimental values were correlated with the linear solvation energy relationship, modified Apelblat equation, λh equation, non-random two-liquid (NRTL) model, and Wilson model. On the other hand, the enthalpy, entropy and Gibbs free energy of dissolution were obtained from these solubility values by using the van’t Hoff and Gibbs equations. The excess enthalpy of solution was estimated on the basis of λh equation. Furthermore, the a priori predictive model COSMO-RS was employed to predict the solubility of sorbic acid in selected solvents and reasonable agreement with experimental values is achieved

  3. Transmission of low-energy electrons (0-15eV) through thin films of ethers, ketones, alcohols, and ice

    The transmission of low-energy electrons (0-15 eV) through 10-100 A films of ethers, ketones, alcohols, and ice has been studied. Structures are indicated by electron current Isub(t) transmitted through a thin film as a function of the incident electron energy Vsub(i), displayed as dIsub(t)/dVsub(i), vs. V sub(i). With increasing the film thickness, a decrease of the height of the first peak (due to injection of electrons in the film) and an appearance of a second peak are observed for ethers and alcohols. The energies of quasifree electron state Vsub(o) are determined by measuring the energy of the second peak from the first peak for solid diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-nonanol. For acetone, diethyl ketone, dimethyl sulfoxide, and ice, neither a decrease of the first peak nor an appearance of a second peak is observed, indicating that these compounds have negative Vsub(o) values. From the energy of the onsets of broad negative peaks appeared at asymptotically equls 14 eV for ethers and alcohols, the solid phase ionization energies Isub(s) and the polarization energies of cations P+ by the solid media are determined. (author)

  4. Preparation of Pt Au/C and Pt Au Bi/C electrocatalysts using electron beam irradiation for ethanol electro-oxidation in alkaline medium

    Pt Au/C (50:50) and PtAuBi/C electrocatalysts with Pt:Au:Bi atomic ratios of 50:40:10, 50:30:20 and 50:10:40 were prepared in water/2-propanol using electron beam irradiation. The materials were characterized by X-ray diffraction (XRD) and the electro-oxidation of ethanol was studied by chronoamperometry at room temperature. The X-ray diffraction measurements for all electrocatalysts prepared showed four peaks, which are associated with the planes of the face-centered cubic (fcc) structure characteristic of Pt and Pt alloys. For PtAuBi/C it was also observed the presence of a mixture of BiPt alloys and bismuth phases. The average crystallite sizes for Pt/C, PtAu/C, PtAuBi/C (50:40:10), PtAuBi/C (50:30:20) and PtAuBi/C (50:10:40) were in the range of 2.0 - 4.0 nm. The activity of the electrocatalysts for ethanol oxidation in alkaline medium showed that PtAuBi/C (50:40:10) had a higher performance for ethanol oxidation compared to others electrocatalysts prepared. (author)

  5. Effect of hydrogen bonding and complexation with metal ions on the fluorescence of luotonin A.

    Miskolczy, Zsombor; Biczók, László

    2013-05-01

    Fluorescence characteristics of a biologically active natural alkaloid, luotonin A (LuA), were studied by steady-state and time-resolved spectroscopic methods. The rate constant of the radiationless deactivation from the singlet-excited state diminished by more than one order of magnitude when the solvent polarity was changed from toluene to water. Dual emission was found in polyfluorinated alcohols of large hydrogen bond donating ability due to photoinitiated proton displacement along the hydrogen bond. In CH2Cl2, LuA produced both 1 : 1 and 1 : 2 hydrogen-bonded complexes with hexafluoro-2-propanol (HFIP) in the ground state. Photoexcitation of the 1 : 2 complex led to protonated LuA, whose fluorescence appeared at a long wavelength. LuA served as a bidentate ligand forming 1 : 1 complexes with metal ions in acetonitrile. The stability of the complexes diminished in the series of Cd(2+) > Zn(2+) > Ag(+), and upon competitive binding of water to the metal cations. The effect of chelate formation on the fluorescent properties was revealed. PMID:23487318

  6. Anoxic radiation protection of bacterial spores in suspension

    Several compounds (nine alcohols, sodium formate, and CO2 gas) have been tested for an ability to alter the anoxic radiation sensitivity of Bacillus megaterium spores, irradiated in suspension. Some of the additives protected (allyl alcohol, ethanol, glycerol, methanol, 1-propanol, 2-propanol, sodium formate and CO2); some did not (1-amyl alcohol, benzyl alcohol, and t-butanol). A correlation exists between anoxic radiation protection and the ability of the additive to react with a water-derived radical and form a radical at the α-hydroxy position. Only those additives that form a radical at this site showed an ability to protect. As a test of the relevance of this correlation between radiation protection and the formation of an α-hydroxy radical, OH competition experiments were run between methanol and t-amyl alcohol. These results showed that methanol partially loses its ability to protect when the competition for OH favors t-amyl alcohol about 4.3:1. These initial results suggest that the correlation is significant, although the exact mechanisms for protection are not known

  7. Diamond-like carbon films deposited on three-dimensional shape substrate model by liquid electrochemical technique

    He, Y.Y. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Zhang, G.F. [School of Materials Science and Engineering, Dalian University of Technology, 116024, Dalian China (China); Zhao, Y.; Liu, D.D. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Cong, Y., E-mail: congyan@ciomp.ac.cn [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Buck, V. [Thin Film Technology Group, Faculty of Physics, University Duisburg-Essen and CeNIDE, 47057 Duisburg (Germany)

    2015-09-01

    Diamond-like carbon (DLC) films were deposited on three-dimensional (3D) shape substrate model by electrolysis of 2-propanol solution at low temperature (60 °C). This 3D shape model was composed of a horizontally aligned stainless steel wafer and vertically aligned stainless steel rods. Morphology and microstructure of the films were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy, respectively. The results suggested there were only differences in film uniformity and thickness for two kinds of samples. The hydrogenated amorphous carbon films deposited on horizontally aligned substrate were smooth and homogeneous. And the film thickness of DLC films gained on the vertical substrates decreased along vertical direction. It is believed that bubble formation could enhance nucleation on the wetted capillary area. This experiment shows that deposition of DLC films by liquid phase deposition on 3D shape conductive substrates is possible. - Highlights: • DLC film is expected to be deposited on complex surface/shape substrate. • DLC film is deposited on 3D shape substrate by liquid electrochemical method. • Horizontal substrate is covered by smooth and homogeneous DLC films. • Film thickness decreases along vertical direction due to boiling effect.

  8. Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

    Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P43212, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified. Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P43212, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation

  9. Fluidity of pea root plasma membranes under altered gravity

    Klymchuk, D. O.; Baranenko, V. V.; Vorobyova, T. V.; Dubovoy, V. D.

    This investigation aims to determine whether clinorotation 2 rev min of pea Pisum sativum L seedlings induces the alterations in the physical-chemical properties of cellular membranes including the plasma membrane fluidity The last is an important regulator of functional activity of membrane enzymes The plasma membranes were isolated by aqueous two-phase partitioning from roots of 6-day old pea seedlings The membrane fluidity was examined by fluorescence spectroscopy using pyrene probe The plasma membrane vesicles with known protein concentration were added to the incubation buffer to a final concentration of 50 mu g of protein per ml A small amount by 1 mu l of pyrene solution in 2-propanol was added to the incubation mixture to a final probe concentration 5 mu M at constant mixing Fluorescence spectra were measured using a Perkin-Elmer LS-50 spectrofluorometer Perkin-Elmer England Pyrene was excited at 337 nm and fluorescence intensity of monomers I M and excimers I E were measured at 393 and 470 nm respectively The I E I M ratios were 0 081 pm 0 003 and 0 072 pm 0 004 in preparations obtained from clinorotated and the control seedlings respectively This fact indicates that rotation on the clinostat increases the membrane fluidity Compared with controls clinorotated seedlings have also showed a reduced growth and a higher level of total unsaturated fatty acids determined by gas chromatography The factors that influence on the fluidity of membrane lipids in bilayer appear to be the

  10. Oxygen Storage Capacity and Oxygen Mobility of Co-Mn-Mg-Al Mixed Oxides and Their Relation in the VOC Oxidation Reaction

    María Haidy Castaño

    2015-05-01

    Full Text Available Co-Mn-Mg-Al oxides were synthesized using auto-combustion and co-precipitation techniques. Constant ratios were maintained with (Co + Mn + Mg/Al equal to 3.0, (Co + Mn/Mg equal to 1.0 and Co/Mn equal to 0.5. The chemical and structural composition, redox properties, oxygen storage capacity and oxygen mobility were analyzed using X-ray fluorescence (XRF, X-ray diffraction (XRD, Raman spectroscopy, scanning electron microscopy (SEM, temperature-programmed reduction of hydrogen (H2-TPR, oxygen storage capacity (OSC, oxygen storage complete capacity (OSCC and isotopic exchange, respectively. The catalytic behavior of the oxides was evaluated in the total oxidation of a mixture of 250 ppm toluene and 250 ppm 2-propanol. The synthesis methodology affected the crystallite size, redox properties, OSC and oxide oxygen mobility, which determined the catalytic behavior. The co-precipitation method got the most active oxide in the oxidation of the volatile organic compound (VOC mixture because of the improved mobility of oxygen and ability to favor redox processes in the material structure.

  11. An organic solvent-stable lipase from a newly isolated Staphylococcus aureus ALA1 strain with potential for use as an industrial biocatalyst.

    Ben Bacha, Abir; Moubayed, Nadine Ms; Al-Assaf, Alaa

    2016-05-01

    In this study, a new strain, ALA1, was identified as Staphylococcus aureus by biochemical tests, and its 16S ribosomal DNA sequence was isolated from dromedary milk. ALA1 lipase production was optimized in shake flask experiments and measured with varying pH (3-11), temperature (20-55 °C) and substrate concentrations. The maximum lipase production was recorded at pH 8 and 30 °C for up to 30 H of culture period for the S. aureus ALA1 strain. Among the substrates tested, selected carbon sources, xylose, nitrogen source, yeast extract, and olive oil (1%) were suitable for maximizing lipase production. The effects of surfactants were investigated and showed that Tween 20, Tween 80, and Triton X-100 prevented lipase production. Interestingly, isolate ALA1 was able to grow in high concentrations of benzene or toluene (up to 50% (v/v)). Moreover, the lipolytic activity of the S. aureus ALA1 lipase was stimulated by diethyl ether, whereas almost 100% of S. aureus ALA1 lipase activity was retained in 25% acetone, acetonitrile, benzene, 2-propanol, ethanol, methanol, or toluene. Because of its stability in organic solvent, the S. aureus ALA1 lipase was used as a biocatalyst to synthesize high levels of added value molecules. S. aureus ALA1 lipase could be considered as an ideal choice for applications in detergent formulations because of its high stability and compatibility with various surfactants, oxidizing agents, and commercial detergents. PMID:25828848

  12. Production of selective membranes using plasma deposited nanochanneled thin films

    Rodrigo Amorim Motta Carvalho

    2006-12-01

    Full Text Available The hydrolization of thin films obtained by tetraethoxysilane plasma polymerization results in the formation of a nanochanneled silicone like structure that could be useful for the production of selective membranes. Therefore, the aim of this work is to test the permeation properties of hydrolyzed thin films. The films were tested for: 1 permeation of polar organic compounds and/or water in gaseous phase and 2 permeation of salt in liquid phase. The efficiency of permeation was tested using a quartz crystal microbalance (QCM technique in gas phase and conductimetric analysis (CA in liquid phase. The substrates used were: silicon for characterization of the deposited films, piezoelectric quartz crystals for tests of selective membranes and cellophane paper for tests of permeation. QCM analysis showed that the nanochannels allow the adsorption and/or permeation of polar organic compounds, such as acetone and 2-propanol, and water. CA showed that the films allow salt permeation after an inhibition time needed for hydrolysis of the organic radicals within the film. Due to their characteristics, the films can be used for grains protection against microorganism proliferation during storage without preventing germination.

  13. A robust whole-cell biocatalyst that introduces a thermo- and solvent-tolerant lipase into Aspergillus oryzae cells: characterization and application to enzymatic biodiesel production.

    Adachi, Daisuke; Koh, FookHee; Hama, Shinji; Ogino, Chiaki; Kondo, Akihiko

    2013-05-10

    To develop a robust whole-cell biocatalyst that works well at moderately high temperature (40-50°C) with organic solvents, a thermostable lipase from Geobacillus thermocatenulatus (BTL2) was introduced into an Aspergillus oryzae whole-cell biocatalyst. The lipase-hydrolytic activity of the immobilized A. oryzae (r-BTL) was highest at 50°C and was maintained even after an incubation of 24-h at 60°C. In addition, r-BTL was highly tolerant to 30% (v/v) organic solvents (dimethyl carbonate, ethanol, methanol, 2-propanol or acetone). The attractive characteristics of r-BTL also worked efficiently on palm oil methanolysis, resulting in a nearly 100% conversion at elevated temperature from 40 to 50°C. Moreover, r-BTL catalyzed methanolysis at a high methanol concentration without a significant loss of lipase activity. In particular, when 2 molar equivalents of methanol were added 2 times, a methyl ester content of more than 90% was achieved; the yield was higher than those of conventional whole-cell biocatalyst and commercial Candida antarctica lipase (Novozym 435). On the basis of the results regarding the excellent lipase characteristics and efficient biodiesel production, the developed whole-cell biocatalyst would be a promising biocatalyst in a broad range of applications including biodiesel production. PMID:23608501

  14. Picosecond pulse radiolysis study of primary reactions in solutions

    Following the discovery of ionizing radiations and their chemical effects, it was important to study and comprehend the formation mechanisms of short lived free radicals and molecular products. In order to perform such studies, researchers and research groups worked on developing tools allowing both formation and detection of those species at short time scales. Nowadays, pulse radiolysis imposed itself as a fundamental and efficient tool allowing scientists to probe chemical effects as well as reaction mechanisms in studied media. The Laboratoire de Chimie Physique d'Orsay 'LCP' is an interdisciplinary laboratory hosting the platform of fast kinetics known as 'ELYSE'. Due to its femtosecond laser and its picosecond electron accelerator, we have the possibility to study chemical effects of ionizing radiations interaction with media at ultrashort times up to ∼5 ps.Knowing that we are interested in primary reactions induced in aqueous media by ionizing radiations, ELYSE represents the essential tool in performing our studies. The obtained results concern:- First direct determination of hydroxyl radical 'HO*' radiolytic yield as function of time at picosecond time scale;- Direct effect of ionizing radiation in highly concentrated aqueous solutions as well as investigation of the ultrafast electron transfer reaction between solute molecules and positive holes 'H2O*+' formed upon water radiolysis;- Study at room temperature of electron transfer reaction between solvated electron (electron donor) and organic solutes (electron acceptors) en viscous medium;- Study at room temperature of electron's solvation dynamics in ethylene glycol and 2-propanol. (author)

  15. Electrospun silk fibroin-hydroxybutyl chitosan nanofibrous scaffolds to biomimic extracellular matrix.

    Zhang, Kuihua; Qian, Yongfang; Wang, Hongsheng; Fan, Linpeng; Huang, Chen; Mo, Xiumei

    2011-01-01

    Silk fibroin (SF)-hydroxybutyl chitosan (HBC) blend nanofibrous scaffolds were fabricated using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and trifluoroacetic acid (TFA) as solvents to biomimic the native ECM by electrospinning. SEM results showed that the average nanofibrous diameter increased when the content of HBC was raised from 20% to 100%. Whereas water contact angle measurements confirmed that SF/HBC nanofibrous scaffolds with different weight ratios were of good hydrophilicity. Both the tensile strength and the elongation at break were improved obviously when the weight ratio of SF to HBC was 20:80. (13)C-NMR clarified that SF and HBC molecules existed in H-bond interactions, but HBC did not induce SF conformation to transform from random coil form to β-sheet structure. Moreover, the use of genipin vapour not only induced conformation of SF to convert from random coil to β-sheet structure but also acted as a cross-linking agent for SF and HBC. Cell viability studies demonstrated that SF/HBC nanofibrous scaffolds presented good cellular compatibility. Thus, electrospun SF/HBC blended nanofibres may provide an ideal biomimic tissue-engineering scaffold. PMID:20615313

  16. Acid Lipase from Candida viswanathii: Production, Biochemical Properties, and Potential Application

    Alex Fernando de Almeida

    2013-01-01

    Full Text Available Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield ( g/h. Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield ( of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties.

  17. Acid lipase from Candida viswanathii: production, biochemical properties, and potential application.

    de Almeida, Alex Fernando; Tauk-Tornisielo, Sâmia Maria; Carmona, Eleonora Cano

    2013-01-01

    Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U) was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield (Y L/S = 1.381 g/g), lipase yield (Y L/S = 6.892 U/g), and biomass productivity (P X = 0.282 g/h). Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield (Y L/S ) of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties. PMID:24350270

  18. Degradation of phorbol 12,13-diacetate in aqueous solution by gamma irradiation

    Kongmany, Santi; Furuta, Masakazu; Matsuura, Hiroto; Okuda, Shuichi; Imamura, Kiyoshi; Maeda, Yasuaki

    2014-12-01

    Phorbol esters (PEs) are highly toxic compounds that cause skin irritation, inflammation, and tumor promotion upon contact with humans or animals. These compounds are naturally present in Jatropha curcas L. To promote the use of J. curcas seed oil in bio-diesel production industries and reduce environmental concerns, it is necessary to find methods of degrading PEs. In this study, the degradation of phorbol 12,13-diacetate (PDA), as a representative PE, in aqueous solution at a concentration of 10 mg/L by 60Co-γ-irradiation was investigated. The results demonstrate that PDA was effectively degraded by this treatment and the degradation efficiency increased with the absorbed dose within the range of 0.5-3 kGy. Complete degradation of PDA was achieved at a dose of 3 kGy. In the presence of radical scavengers (i.e., methanol, tert-butanol, 2-propanol), reactive species from water radiolysis were scavenged, and significant inhibition of PDA degradation was observed at absorbed doses less than 1 kGy. In the presence of nitrous oxide, the generation of hydroxyl radicals (rad OH) was promoted during gamma irradiation and PDA degradation was drastically enhanced.

  19. Production of (R-3-Quinuclidinol by E. coli Biocatalysts Possessing NADH-Dependent 3-Quinuclidinone Reductase (QNR or bacC from Microbacterium luteolum and Leifsonia Alcohol Dehydrogenase (LSADH

    Nobuya Itoh

    2012-10-01

    Full Text Available We found two NADH-dependent reductases (QNR and bacC in Microbacterium luteolum JCM 9174 (M. luteolum JCM 9174 that can reduce 3-quinuclidinone to optically pure (R-(−-3-quinuclidinol. Alcohol dehydrogenase from Leifsonia sp. (LSADH was combined with these reductases to regenerate NAD+ to NADH in situ in the presence of 2-propanol as a hydrogen donor. The reductase and LSADH genes were efficiently expressed in E. coli cells. A number of constructed E. coli biocatalysts (intact or immobilized were applied to the resting cell reaction and optimized. Under the optimized conditions, (R-(−-3-quinuclidinol was synthesized from 3-quinuclidinone (15% w/v, 939 mM giving a conversion yield of 100% for immobilized QNR. The optical purity of the (R-(−-3-quinuclidinol produced by the enzymatic reactions was >99.9%. Thus, E. coli biocatalysis should be useful for the practical production of the pharmaceutically important intermediate, (R-(−-3-quinuclidinol.

  20. Synthesis and Anticancer Activity of Some New S-Glycosyl and S-Alkyl 1,2,4-Triazinone Derivatives

    Hosam A. Saad

    2011-07-01

    Full Text Available A series of S-glycosyl and S-alkyl derivatives of 4-amino-3-mercapto-6-(2-(2-thienylvinyl-1,2,4-triazin-5(4H-one (1 were synthesized using different halo compounds such as preacetylated sugar bromide, 4-bromobutylacetate, 2-acetoxyethoxy-methyl bromide, 3-chloropropanol, 1,3-dichloro-2-propanol, epichlorohydrin, allyl bromide, propargyl bromide, phthalic and succinic acids in POCl3. The structures of the synthesized compounds have been deduced from their elemental analysis and spectral (IR, 1H-NMR, and 13C-NMR data. Some of the synthesized compounds were screened as anticancer agents. Significant anticancer activities were observed in vitro for some members of the series, and compounds 4-Amino-3-(3-hydroxypropylthio-6-(2-(2-thienylvinyl-1,2,4-triazin-5(4H-one (12 and 3-(4-Oxo-3-(2-(2-thienylvinyl-4H-[1,3,4]thiadiazolo-[2,3-c][1,2,4]tr-iazin-7-ylpropanoic acid (18 are active cytotoxic agents against different cancer cell lines.

  1. Enhanced bioactivity of ZnO nanoparticles-an antimicrobial study

    In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO3)2 and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles

  2. Determination of CMPO using HPLC-UV.

    Elias, Gracy; Groenewold, Gary S; Mincher, Bruce J; Mezyk, Stephen P

    2012-06-22

    Octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) is an extractant proposed for selective separation of radionuclide metals from used nuclear fuel solutions using solvent extraction. Radiolysis reactions can degrade CMPO and reduce separation performance and hence methods for measuring the concentration of CMPO are needed. A novel high performance liquid chromatography (HPLC) method was developed for measuring CMPO in dodecane that featured a low pH buffer, octanol as a co-solvent with 2-propanol, and ultraviolet (UV) detection. Validation data indicated that the HPLC-UV method for CMPO determination provided good linearity, sensitivity, accuracy and precision. Method performance was evaluated using CMPO samples that had undergone radiolysis, and the results showed a decrease in CMPO concentration and the appearance of degradation products. The degradation products were identified using electrospray ionization mass spectrometry, which also showed formation of CMPO-nitric acid complexes that account for the apparent loss of CMPO in an acidic environment, independent of irradiation. PMID:22595518

  3. Photodegradation of estrone enhanced by dissolved organic matter under simulated sunlight

    Caupos, Emilie

    2011-05-01

    In the present work the degradation of estrone (E1) a natural estrogenic hormone has been studied under simulated solar irradiation. The photodegradation of E1 has been investigated in the absence and in the presence of 7.7-8.9 mg L-1 of dissolved organic carbon (DOC), under solar light simulation with irradiance approximating that of the sun. DOC extracts from different origins have been used. Half-lives ranging between 3.9 h and 7.9 h were observed. Results indicated that E1 was photodegraded even in the absence of DOC. The presence of DOC was found to enhance the degradation of E1. Experiments performed with the addition of reactive species scavengers (azide ions and 2-propanol) have shown that these two species play a significant role in the photodegradation. Some experiments have been performed with a DOC previously submitted to solar irradiation. Changes in optical and physico-chemical properties of DOC strongly affect its photoinductive properties, and hence its efficiency on E1 degradation. A part of the study consisted in the investigation of photoproducts structures. Five photoproducts were shown by chromatographic analysis: one arising from direct photolysis and the four others from DOC photoinduced degradation. © 2011 Elsevier Ltd.

  4. A Simple Method of Obtaining Spherical Nanosilica from Rice Husk

    Mohammed Noushad

    2012-01-01

    Full Text Available This paper describes the synthesis of nanosilica from rice husk. Synthesis was done by precipitation using different acids, namely, orthophosphoric acid and nitric acid which yielded nanosilica. The effect of different acids and different solvents (polar and non-polar on the size and degree of agglomeration of the silica particles were studied. When precipitation was done without the use of solvents, the silica particles  obtained were non-spherical in shape, whereas, when precipitation was done using polar solvents (ethanol or 2-propanol, the silica particles were spherical. The use of non-polar solvents (toluene and diethyl ether resulted in silica particles that were irregular in shape and in the case of orthophosphoric acid, a high degree of agglomeration was also noted. The degree of agglomeration was less when orthophosphoric acid was used with polar solvents as compared to nitric acid in conjunction with polar solvents. As regards the size, it ranged from approximately 70nm to 400nm when either acid was used in conjunction with polar solvents. When non-polar solvents were used, the silica particles were irregular in shape and the particle size was not estimated.

  5. Magnetically responsive enzyme powders

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction

  6. Identification of Wet-Spinning and Post-Spin Stretching Methods Amenable to Recombinant Spider Aciniform Silk.

    Weatherbee-Martin, Nathan; Xu, Lingling; Hupe, Andre; Kreplak, Laurent; Fudge, Douglas S; Liu, Xiang-Qin; Rainey, Jan K

    2016-08-01

    Spider silks are outstanding biomaterials with mechanical properties that outperform synthetic materials. Of the six fibrillar spider silks, aciniform (or wrapping) silk is the toughest through a unique combination of strength and extensibility. In this study, a wet-spinning method for recombinant Argiope trifasciata aciniform spidroin (AcSp1) is introduced. Recombinant AcSp1 comprising three 200 amino acid repeat units was solubilized in a 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)/water mixture, forming a viscous α-helix-enriched spinning dope, and wet-spun into an ethanol/water coagulation bath allowing continuous fiber production. Post-spin stretching of the resulting wet-spun fibers in water significantly improved fiber strength, enriched β-sheet conformation without complete α-helix depletion, and enhanced birefringence. These methods allow reproducible aciniform silk fiber formation, albeit with lower extensibility than native silk, requiring conditions and methods distinct from those previously reported for other silk proteins. This provides an essential starting point for tailoring wet-spinning of aciniform silk to achieve desired properties. PMID:27387592

  7. Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent

    Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin

    2008-02-01

    Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

  8. Inactivation of Lactobacillus rhamnosus GG by fixation modifies its probiotic properties.

    Markowicz, C; Kubiak, P; Grajek, W; Schmidt, M T

    2016-01-01

    Probiotics are microorganisms that have beneficial effects on the host and are safe for oral intake in a suitable dose. However, there are situations in which the administration of living microorganisms poses a risk for immunocompromised host. The objective of this study was to evaluate the influence of several fixation methods on selected biological properties of Lactobacillus rhamnosus GG that are relevant to its probiotic action. Fixation of the bacterial cells with ethanol, 2-propanol, glutaraldehyde, paraformaldehyde, and heat treatment resulted in a significant decrease of alkaline phosphatase, peroxidase, and β-galactosidase activities. Most of the fixation procedures reduced bacterial cell hydrophobicity and increased adhesion capacity. The fixation procedures resulted in a different perception of the bacterial cells by enterocytes, which was shown as changes in gene expression in enterocytes. The results show that some procedures of inactivation allow a fraction of the enzymatic activity to be maintained. The adhesion properties of the bacterial cells were enhanced, but the response of enterocytes to fixed cells was different than to live bacteria. Inactivation allows maintenance and modification of some of the properties of the bacterial cells. PMID:26634746

  9. Determination of calcium stearate in polyolefin samples by gas chromatographic technique after performing dispersive liquid-liquid microextraction.

    Ranji, Ali; Ghorbani Ravandi, Mahboobeh; Farajzadeh, Mir Ali

    2008-05-01

    In this study, a gas chromatographic method is presented for the determination of calcium stearate after its conversion to stearic acid in a polymeric matrix. A solution of hydrochloric acid in 2-propanol is used as an extracting solvent of calcium stearate and its converter to stearic acid. For stearic acid preconcentration before its injection to a separation system, a recently presented extraction method, dispersive liquid-liquid microextraction, using carbon tetrachloride as an extracting solvent is used. Finally, 1 microL of the organic phase collected at the bottom of a conical test tube after centrifuging is injected into a gas chromatograph (GC) for quantification. This method has a relatively broad linear dynamic range (50 - 2000 mg/L) with a limit of detection (LOD) of 15 mg/L for stearic acid in solution. The LOD of the proposed method in a polymeric sample using 10 mg of polymer is 60 ppm as calcium stearate. Some effective parameters, such as the time and temperature of heating, the concentration of hydrochloric acid and the volume of distilled water, were studied. PMID:18469468

  10. Radiation oxidation of phenol in the presence of petrochemical wastewater components

    Radiolytical decomposition of phenol was investigated at 60Co gamma irradiation (1-2 Gy * s-1, ≤ 10 kGy) of pre- and continuously aerated aqueous solutions at concentrations of phenol 1-100 mg * dm-3 and in the presence of sodium hydroxide, sulphuric acid, sodium and ferrous sulphate, formaldehyde, 2-propanol, n-hexane, xylene, benzene, and commercial gasoline. From the decomposition rate at doses 50-400 Gy, a phenomenological model of linear relation between the dose acquired for 37% decomposition (D37), initial concentration (g * m-3) of phenol (p0) and of an admixture (s0) was confirmed in the form D37 = 52ftr(p0 + feqs0), where f's are constants which can be attributed to the relative transformation resistance of phenol towards the OH radicals in given matrix (ftr, for pure water ftr = 1) and relative acceptor capacity of competing substrate (feq). In real wastewaters, the efficient decrease of phenols content may be substantially lower than that in the model solutions, obviously due to radiation oxidation of aromates, as proved by irradiation of aqueous solutions of benzene. Technical and economical feasibility of the process is discussed. (author) 27 refs.; 9 figs.; 1 tab

  11. Amine functionalized radiation-induced grafted water hyacinth fibers for Pb2+, Cu2+ and Cr3+ uptake

    Madrid, Jordan F.; Nuesca, Guillermo M.; Abad, Lucille V.

    2014-04-01

    An amine group containing fibrous adsorbent was prepared by reaction of grafted water hyacinth fibers with ethylenediamine. Glycidyl methacrylate (GMA) was grafted onto water hyacinth fibers using gamma radiation induced graft polymerization through simultaneous grafting technique and this was used as base material for producing the amine type adsorbents. The conversion of the epoxy group from GMA into amine group was investigated. The concentration of ethylenediamine solution that gave the highest amine functional group density was 50% by volume in 2-propanol. The amine functionalized water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy (EDX). Information derived from these analyses confirms the successful conversion of the epoxy group. The amine-type adsorbent was evaluated for its uptake of Pb2+, Cu2+ and Cr3+ from aqueous solutions. The initial concentration of the metal ions and pH of the solutions were found to influence the amount of metal ions adsorbed by the amine-type adsorbent. The kinetics of adsorption was observed to follow Lagergren's first order equation. Results of ion sorption studies indicate that gamma radiation-induced grafting and subsequent chemical modification improved the ion sorption behaviour of water hyacinth fibers.

  12. Fast gas chromatography and negative-ion chemical ionization tandem mass spectrometry for forensic analysis of cannabinoids in whole blood.

    Thomas, Aurélien; Widmer, Christèle; Hopfgartner, Gérard; Staub, Christian

    2007-11-01

    The present work describes a fast gas chromatography/negative-ion chemical ionization tandem mass spectrometric assay (Fast GC/NICI-MS/MS) for analysis of tetrahydrocannabinol (THC), 11-hydroxy-tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH) in whole blood. The cannabinoids were extracted from 500 microL of whole blood by a simple liquid-liquid extraction (LLE) and then derivatized by using trifluoroacetic anhydride (TFAA) and hexafluoro-2-propanol (HFIP) as fluorinated agents. Mass spectrometric detection of the analytes was performed in the selected reaction-monitoring mode on a triple quadrupole instrument after negative-ion chemical ionization. The assay was found to be linear in the concentration range of 0.5-20 ng/mL for THC and THC-OH, and of 2.5-100 ng/mL for THC-COOH. Repeatability and intermediate precision were found less than 12% for all concentrations tested. Under standard chromatographic conditions, the run cycle time would have been 15 min. By using fast conditions of separation, the assay analysis time has been reduced to 5 min, without compromising the chromatographic resolution. Finally, a simple approach for estimating the uncertainty measurement is presented. PMID:17913432

  13. Formation and absorption spectrum of copper nanoparticles from the radiolytic reduction of Cu(CN)2-

    Colloidal copper particles (20--100 nm) are formed in the γ-irradiation of aqueous solutions of KCu(CN)2, which also contain methanol or 2-propanol as OH scavenger. The radiation chemical yield is of the order of 0.1 Cu atoms formed per 100 eV absorbed radiation energy and decreases with increasing concentration of excess KCN. A reduction mechanism is proposed, in which the hydrated electron reacts with Cu(CN)2-, whereas organic radicals attack a copper-1 species, possibly colloidal Cu2O, present in low concentration by partial hydrolysis of Cu(CN)2-. Free copper atoms do not appear as intermediates in this mechanism. The optical absorption spectrum of Cu particles of different size is also reported; it contains the plasmon band in the 560--580 nm region and a UV band at 222 nm and becomes flatter with increasing particle size. The copper particles have almost spherical shape when formed at high irradiation dose rates but exhibit very pronounced polyhedra and rodlike contributions at low-dose rates

  14. Oxidation and β-Alkylation of Alcohols Catalysed by Iridium(I) Complexes with Functionalised N-Heterocyclic Carbene Ligands.

    Jiménez, M Victoria; Fernández-Tornos, Javier; Modrego, F Javier; Pérez-Torrente, Jesús J; Oro, Luis A

    2015-12-01

    The borrowing hydrogen methodology allows for the use of alcohols as alkylating agents for CC bond forming processes offering significant environmental benefits over traditional approaches. Iridium(I)-cyclooctadiene complexes having a NHC ligand with a O- or N-functionalised wingtip efficiently catalysed the oxidation and β-alkylation of secondary alcohols with primary alcohols in the presence of a base. The cationic complex [Ir(NCCH3 )(cod)(MeIm(2- methoxybenzyl))][BF4 ] (cod=1,5-cyclooctadiene, MeIm=1-methylimidazolyl) having a rigid O-functionalised wingtip, shows the best catalyst performance in the dehydrogenation of benzyl alcohol in acetone, with an initial turnover frequency (TOF0 ) of 1283 h(-1) , and also in the β-alkylation of 2-propanol with butan-1-ol, which gives a conversion of 94 % in 10 h with a selectivity of 99 % for heptan-2-ol. We have investigated the full reaction mechanism including the dehydrogenation, the cross-aldol condensation and the hydrogenation step by DFT calculations. Interestingly, these studies revealed the participation of the iridium catalyst in the key step leading to the formation of the new CC bond that involves the reaction of an O-bound enolate generated in the basic medium with the electrophilic aldehyde. PMID:26493780

  15. Quantitative evaluation of size selective precipitation of Mn-doped ZnS quantum dots by size distributions calculated from UV/Vis absorbance spectra

    We demonstrate the quantitative evaluation of the sharp classification of manganese-doped zinc sulfide (ZnS:Mn) quantum dots by size selective precipitation. The particles were characterized by the direct conversion of absorbance spectra to particle size distributions (PSDs) and high-resolution transmission electron micrographs (HRTEM). Gradual addition of a poor solvent (2-propanol) to the aqueous colloid led to the flocculation of larger particles. Though the starting suspension after synthesis had an already narrow PSD between 1.5 and 3.2 nm, different particle size fractions were subsequently isolated by the careful adjustment of the good solvent/poor solvent ratio. Moreover, due to the fact that for the analysis of the classification results the size distributions were available, an in-depth understanding of the quality of the distinct classification steps could be achieved. From the PSDs of the feed, as well as the coarse and the fine fractions with their corresponding yields determined after each classification step, an optimum after the first addition of poor solvent was identified with a maximal separation sharpness κ as high as 0.75. Only by the quantitative evaluation of classification results leading to an in-depth understanding of the relevant driving forces, a future transfer of this lab scale post-processing to larger quantities will be possible.

  16. Ligand centered radical pathway in catechol oxidase activity with a trinuclear zinc-based model: Synthesis, structural characterization and luminescence properties

    Pal, Sukanta; Chowdhury, Biswajit; Patra, Moumita; Maji, Milan; Biswas, Bhaskar

    2015-06-01

    A new trinuclear zinc(II) complex, [Zn3(L)(NCS)2](NO3)2·CH3OH·H2O (1), of a (N,O)-donor compartmental Schiff base ligand (H2L = N,N‧-bis(3-methoxysalicylidene)-1,3-diamino-2-propanol), has been synthesized in crystalline phase. The zinc(II) complex has been characterized by elemental analysis, IR spectroscopy, UV-Vis spectroscopy, powder X-ray diffraction study (PXRD), 1H NMR, EI mass spectrometry and thermogravimetric analysis. PXRD revealed that 1 crystallizes in P - 1 space group with a = 9.218 Å, b = 10.849 Å, c = 18.339 Å, with unit cell volume is 2179.713 (Å)3. Fluorescence spectra in methanolic solution reflect that intensity of emission for 1 is much higher compared to H2L and both the compounds exhibit good fluorescence properties. The complex 1 exhibits significant catalytic activities of biological relevance, viz. catechol oxidase. In methanol, it efficiently catalyzes the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to corresponding quinone via formation of a dinuclear species as [Zn2(L)(3,5-DTBC)]. Electron Paramagnetic Resonance (EPR) experiment suggests generation of radicals in the presence of 3,5-DTBC and it may be proposed that the radical pathway is probably responsible for conversion of 3,5-DTBC to 3,5-DTBQ promoted by complex of redox-innocent Zn(II) ion.

  17. High-Quality Perovskite Films Grown with a Fast Solvent-Assisted Molecule Inserting Strategy for Highly Efficient and Stable Solar Cells.

    Yuan, Shuai; Qiu, Zhiwen; Gao, Chaomin; Zhang, Hailiang; Jiang, Yanan; Li, Cuncheng; Yu, Jinghua; Cao, Bingqiang

    2016-08-31

    The performance of organolead halide perovskites based solar cells has been enhanced dramatically due to the morphology control of the perovskite films. In this paper, we present a fast solvent-assisted molecule inserting (S-AMI) strategy to grow high-quality perovskite film, in which the methylammonium iodide/2-propanol (MAI/IPA) solution is spin-coated onto a dimethylformamide (DMF) wetted mixed lead halide (PbX2) precursor film. The DMF can help the inserting of MAI molecules into the PbX2 precursor film and provide a solvent environment to help the grain growth of the perovskite film. The perovskite film grown by the S-AMI approach shows large and well-oriented grains and long carrier lifetime due to the reduced grain boundary. Solar cells constructed with these perovskite films yield an average efficiency over 17% along with a high average fill factor of 80%. Moreover, these unsealed solar cell devices exhibit good stability in an ambient atmosphere. PMID:27526617

  18. Microemulsion System for Topical Delivery of Thai Mango Seed Kernel Extract: Development, Physicochemical Characterisation and Ex Vivo Skin Permeation Studies

    Jiraporn Leanpolchareanchai

    2014-10-01

    Full Text Available A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar “Fahlun” was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93% in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment.

  19. Large Mesopore Generation in an Amorphous Silica-Alumina by Controlling the Pore Size with the Gel Skeletal Reinforcement and Its Application to Catalytic Cracking

    Hiroyuki Nasu

    2012-09-01

    Full Text Available Tetraethoxy orthosilicate (TEOS was used not only as a precursor of silica, but also as an agent which reinforces the skeleton of silica-gel to prepare an aerogel and resultant silica and silica-alumina with large pore size and pore volume. In this gel skeletal reinforcement, the strength of silica aerogel skeleton was enhanced by aging with TEOS/2-propanol mixed solution to prevent the shrink of the pores. When silica aerogel was reinforced by TEOS solution, the pore diameter and pore volume of calcined silica could be controlled by the amount of TEOS solution and reached 30 nm and 3.1 cm3/g. The results from N2 adsorption measurement indicated that most of pores for this silica consisted of mesopores. Silica-alumina was prepared by the impregnation of an aluminum tri-sec-butoxide/2-butanol solution with obtained silica. Mixed catalysts were prepared by the combination of β-zeolite (26 wt% and prepared silica-aluminas with large mesopore (58 wt% and subsequently the effects of their pore sizes on the catalytic activity and the product selectivity were investigated in catalytic cracking of n-dodecane at 500 °C. The mixed catalysts exhibited not only comparable activity to that for single zeolite, but also unique selectivity where larger amounts of branched products were formed.

  20. Degradation of phorbol 12,13-diacetate in aqueous solution by gamma irradiation

    Phorbol esters (PEs) are highly toxic compounds that cause skin irritation, inflammation, and tumor promotion upon contact with humans or animals. These compounds are naturally present in Jatropha curcas L. To promote the use of J. curcas seed oil in bio-diesel production industries and reduce environmental concerns, it is necessary to find methods of degrading PEs. In this study, the degradation of phorbol 12,13-diacetate (PDA), as a representative PE, in aqueous solution at a concentration of 10 mg/L by 60Co-γ-irradiation was investigated. The results demonstrate that PDA was effectively degraded by this treatment and the degradation efficiency increased with the absorbed dose within the range of 0.5–3 kGy. Complete degradation of PDA was achieved at a dose of 3 kGy. In the presence of radical scavengers (i.e., methanol, tert-butanol, 2-propanol), reactive species from water radiolysis were scavenged, and significant inhibition of PDA degradation was observed at absorbed doses less than 1 kGy. In the presence of nitrous oxide, the generation of hydroxyl radicals (·OH) was promoted during gamma irradiation and PDA degradation was drastically enhanced. - Highlights: • PDA in aqueous solution was effectively degraded by gamma irradiation. • Hydroxyl radical mainly contributed to PDA degradation. • Intermediate product produced from PDA degradation was further decomposed. • Gamma irradiation process can be useful for degrading phorbol esters in water

  1. Nanomaterials for the cleaning and pH adjustment of vegetable-tanned leather

    Baglioni, Michele; Bartoletti, Angelica; Bozec, Laurent; Chelazzi, David; Giorgi, Rodorico; Odlyha, Marianne; Pianorsi, Diletta; Poggi, Giovanna; Baglioni, Piero

    2016-02-01

    Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on aging and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable-tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study, the cleaning of historical leather samples was optimized by confining an oil-in-water nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using scanning electron microscopy, controlled environment dynamic mechanical analysis, and infrared spectroscopy. The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

  2. Hydrogen-transfer and charge-transfer in photochemical and radiation induced reactions. Progress report, November 1, 1975--October 31, 1976

    The relative importance of light absorption, quenching of triplet, and hydrogen transfer repair has been examined in retardation by mercaptans of photoreduction of aromatic ketones by alcohols. In the reduction of benzophenone by 2-propanol, retardation is efficient and, after correction for the first two effects, is due entirely to hydrogen-transfer repair, as indicated by deuterium labeling. In reduction of acetophenone by α-methylbenzyl alcohol, repair by hydrogen transfer is also operative. In reduction of benzophenone by benzhydrol, retardation is less efficient and is due to quenching, as the ketyl radical does not abstract hydrogen from mercaptan rapidly in competition with coupling. Deuterium isotope effects are discussed in terms of competitive reactions. Photoreduction of benzophenone by 2-butylamine and by triethylamine is retarded by aromatic mercaptans and disulfides. Of the retardation not due to light absorption and triplet quenching by the sulfur compounds, half is due to hydrogen-transfer repair, as indicated by racemization and deuterium labeling. The remainder is attributed to quenching by the sulfur compound of the charge-transfer-complex intermediate. Photoreduction by primary and secondary amines, but not by tertiary amines, is accelerated by aliphatic mercaptans. The acceleration is attributed to catalysis of hydrogen transfer by the mercaptan in the charge-transfer complex. The effect is large in hydrocarbon solvent, less in polar organic solvents and absent in water

  3. The effect of alkali metal on the surface properties of potassium doped Au-Beta zeolites

    Sobczak, Izabela, E-mail: sobiza@amu.edu.pl [A. Mickiewicz University, Faculty of Chemistry, Grunwaldzka 6, 60-780 Poznan (Poland); Rydz, Michal; Ziolek, Maria [A. Mickiewicz University, Faculty of Chemistry, Grunwaldzka 6, 60-780 Poznan (Poland)

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► Interaction of gold with K leads to the change of electronic state and redox properties of gold. ► The amount of potassium incorporated into Au-zeolites determines the size of gold particles. ► K(0.2 wt.%)/Au-Beta exhibits the best performance in decomposition of N{sub 2}O and removal of Bu{sub 2}S. -- Abstract: Beta zeolite was applied as support for gold introduced by gold-precipitation method and potassium added by impregnation or adsorption. The effect of zeolite composition and the amount of potassium introduced on the surface properties of the final materials was considered. Moreover, the interaction of gold and potassium species was found to be related to the adsorptive and catalytic behaviour of zeolites in NO reduction with propene and deodorization. K/Au-Beta(Impregnated) exhibits the best performance in the above mentioned processes because of the small gold particles (between 2 and 5 nm) and interaction of gold with potassium species leading to the change of electronic properties of the surface (the appearance of cationic gold species). Potassium added as a promoter improves the catalytic properties of Au-zeolite in N{sub 2}O decomposition and also in deodorization (increase of the ability to dibutyl sulphide oxidation). The catalysts prepared were characterized by XRD, XPS, UV–vis, TEM, pyridine adsorption combined with FTIR and test reaction (2-propanol transformation).

  4. Combined AC electroosmosis and dielectrophoresis for controlled rotation of microparticles.

    Walid Rezanoor, Md; Dutta, Prashanta

    2016-03-01

    Electrorotation is widely used for characterization of biological cells and materials using a rotating electric field. Generally, multiphase AC electric fields and quadrupolar electrode configuration are needed to create a rotating electric field for electrorotation. In this study, we demonstrate a simple method to rotate dielectrophoretically trapped microparticles using a stationary AC electric field. Coplanar interdigitated electrodes are used to create a linearly polarized nonuniform AC electric field. This nonuniform electric field is employed for dielectrophoretic trapping of microparticles as well as for generating electroosmotic flow in the vicinity of the electrodes resulting in rotation of microparticles in a microfluidic device. The rotation of barium titanate microparticles is observed in 2-propanol and methanol solvent at a frequency below 1 kHz. A particle rotation rate as high as 240 revolutions per minute is observed. It is demonstrated that precise manipulation (both rotation rate and equilibrium position) of the particles is possible by controlling the frequency of the applied electric field. At low frequency range, the equilibrium positions of the microparticles are observed between the electrode edge and electrode center. This method of particle manipulation is different from electrorotation as it uses induced AC electroosmosis instead of electric torque as in the case of electrorotation. Moreover, it has been shown that a microparticle can be rotated along its own axis without any translational motion. PMID:27014394

  5. Effect of water miscible organic solvents on p-nitrophenol hydroxylase (CYP2E1 activity in rat liver microsomes

    Pranali G Patil

    2015-01-01

    Full Text Available Organic solvents used for solubilization of the substrates/NCEs are known to affect the activity of cytochrome P450 enzymes. Further, this effect varies with the solvents used, the substrates and CYP450 isoforms in question. In the present study, we have investigated the effect of ten commonly used water miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, dimethyl sulphoxide, N,N-dimethyl formamide, dioxane and polyethylene glycol 400 on p-nitrophenol hydroxylase activity at 0, 0.1, 0.25, 0.5, 0.75 and 1% v/v concentration in rat liver microsomes. All the solvents studied showed concentration dependent inhibition of the p-nitrophenol hydroxylase activity except acetonitrile which showed activation of the activity at concentration range studied. Out of ten solvents studied, dioxane was found to be the most inhibitory solvent (inhibition >90% at 0.25% v/v concentration. Overall, solvents like dimethyl sulphoxide, dimethyl formamide and dioxane appeared to be unsuitable for characterizing p-nitrophenol hydroxylase (CYP2E1-mediated reactions due to a high degree of inhibition. On the other hand, methanol and acetonitrile at concentrations <0.5% v/v appeared to be appropriate solvents for substrate solubilization while evaluating CYP2E1-mediated catalysis. The results of this study imply that caution should be exercised while choosing solvents for dissolution of substrate during enzyme studies in liver microsomes.

  6. Methanosarcina subterranea sp. nov., a methanogenic archaeon isolated from a deep subsurface diatomaceous shale formation.

    Shimizu, Satoru; Ueno, Akio; Naganuma, Takeshi; Kaneko, Katsuhiko

    2015-04-01

    A methanogenic archaeon, strain HC-2(T), was isolated from a deep diatomaceous shale formation. The strain grew on methanol, monomethylamine, dimethylamine, trimethylamine and dimethylsulphide, but not on acetate, H2/CO2, formate, 2-propanol, 2-butanol or cyclopentanol. Cells were Gram-stain-negative, non-motile, and coccus-like, 0.9-1.4 µm in diameter, and occurred singly, in pairs, or as aggregates. The strain grew at 10-40 °C (optimum 35 °C), pH 5.9-7.4 (optimum pH 6.6-6.8) and in 0-0.6 M NaCl (optimum 0.1-0.2 M). The genomic DNA G+C content was 41.5 mol% and the 16S rRNA gene sequence was closely related to those of Methanosarcina lacustris DSM 13486(T) (99.1%) and Methanosarcina siciliae DSM 3028(T) (98.3%). Values for DNA-DNA hybridization with these strains were less than 30%. The phenotypic and phylogenetic features of HC-2(T) indicate that it represents a novel species of the genus Methanosarcina , for which the name Methanosarcina subterranea sp. nov. is proposed. The type strain is HC-2(T) ( = DSM 22503(T) = JCM 15540(T) = NBRC 102578(T)). PMID:25604340

  7. Gene-specific amplicons from metagenomes as an alternative to directed evolution for enzyme screening: a case study using phenylacetaldehyde reductases.

    Itoh, Nobuya; Kazama, Miki; Takeuchi, Nami; Isotani, Kentaro; Kurokawa, Junji

    2016-06-01

    Screening gene-specific amplicons from metagenomes (S-GAM) is a highly promising technique for the isolation of genes encoding enzymes for biochemical and industrial applications. From metagenomes, we isolated phenylacetaldehyde reductase (par) genes, which code for an enzyme that catalyzes the production of various Prelog's chiral alcohols. Nearly full-length par genes were amplified by PCR from metagenomic DNA, the products of which were fused with engineered par sequences at both terminal regions of the expression vector to ensure proper expression and then used to construct Escherichia coli plasmid libraries. Sequence- and activity-based screening of these libraries identified different homologous par genes, Hpar-001 to -036, which shared more than 97% amino acid sequence identity with PAR. Comparative characterization of these active homologs revealed a wide variety of enzymatic properties including activity, substrate specificity, and thermal stability. Moreover, amino acid substitutions in these genes coincided with those of Sar268 and Har1 genes, which were independently engineered by error-prone PCR to exhibit increased activity in the presence of concentrated 2-propanol. The comparative data from both approaches suggest that sequence information from homologs isolated from metagenomes is quite useful for enzyme engineering. Furthermore, by examining the GAM-based sequence dataset derived from soil metagenomes, we easily found amino acid substitutions that increase the thermal stability of PAR/PAR homologs. Thus, GAM-based approaches can provide not only useful homologous enzymes but also an alternative to directed evolution methodologies. PMID:27419059

  8. Morphological Effect of CNT/TiO2 Nanocomposite Photoelectrodes Dye-Sensitized Solar Cell on Photovoltaic Performance with Various Annealing Temperatures

    Mohd Zikri Razali

    2015-01-01

    Full Text Available This research focused on the fabrication of dye-sensitized solar cell based on a photoanode of carbon nanotube/titanium dioxide (CNT/TiO2 nanocomposite photoanode synthesized through acid-catalyzed sol-gel method. The results show the improvement of the chemical and electrical properties of the solar cells annealed at different temperatures. The CNT/TiO2 colloidal solution was synthesized using titanium tetraisopropoxide and CNT/2-propanol solution. The thin films were doctor-bladed on a fluorine tin oxide glass before being annealed at 550, 650, and 750°C. The field emission scanning electron microscopy morphological images show that the thin films were homogenously distributed and maintained their spherical structures. The X-ray diffraction patterns show that the films consisted of anatase and rutile phases with large crystallite sizes due to temperature increment. The atomic force microscopy analysis presents the thin film roughness in terms of root mean square roughness. The photovoltaic performance was analyzed using IV curve and electrochemical impedance spectroscopy (EIS. The thin films annealed at 750°C had the highest energy conversion efficiency at 5.23%. The EIS analysis estimated the values of the effective electron lifetime (τeff, effective electron diffusion coefficient, effective electron diffusion (Ln, and effective recombination rate constant (keff. A large τeff, small keff, and longer Ln can improve photovoltaic performance efficiency.

  9. Crystallization, data collection and phasing of two digestive lysozymes from Musca domestica

    The digestive lysozymes 1 and 2 from M. domestica were crystallized by vapour diffusion. The crystallographic data were processed to a maximum resolution of 1.9 Å in both cases. Lysozymes are mostly known for their defensive role against bacteria, but in several animals lysozymes have a digestive function. Here, the initial crystallographic characterization of two digestive lysozymes from Musca domestica are presented. The proteins were crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium sulfate or PEG/2-propanol as the precipitant. X-ray diffraction data were collected to a maximum resolution of 1.9 Å using synchrotron radiation. The lysozyme 1 and 2 crystals belong to the monoclinic space group P21 (unit-cell parameters a = 36.52, b = 79.44, c = 45.20 Å, β = 102.97°) and the orthorhombic space group P21212 (unit-cell parameters a = 73.90, b = 96.40, c = 33.27 Å), respectively. The crystal structures were solved by molecular replacement and structure refinement is in progress

  10. Authentication of fattening diet of Iberian pigs according to their volatile compounds profile from raw subcutaneous fat.

    Narváez-Rivas, M; Pablos, F; Jurado, J M; León-Camacho, M

    2011-02-01

    The composition of volatile components of subcutaneous fat from Iberian pig has been studied. Purge and trap gas chromatography-mass spectrometry has been used. The composition of the volatile fraction of subcutaneous fat has been used for authentication purposes of different types of Iberian pig fat. Three types of this product have been considered, montanera, extensive cebo and intensive cebo. With classification purposes, several pattern recognition techniques have been applied. In order to find out possible tendencies in the sample distribution as well as the discriminant power of the variables, principal component analysis was applied as visualisation technique. Linear discriminant analysis (LDA) and soft independent modelling by class analogy (SIMCA) were used to obtain suitable classification models. LDA and SIMCA allowed the differentiation of three fattening diets by using the contents in 2,2,4,6,6-pentamethyl-heptane, m-xylene, 2,4-dimethyl-heptane, 6-methyl-tridecane, 1-methoxy-2-propanol, isopropyl alcohol, o-xylene, 3-ethyl-2,2-dimethyl-oxirane, 2,6-dimethyl-undecane, 3-methyl-3-pentanol and limonene. PMID:21072505

  11. Osmotic coefficients and apparent molar volumes of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid in alcohols

    Highlights: • Physical and osmotic properties of [HMim][TfO] in alcohols are reported. • Apparent molar properties and osmotic coefficients were obtained. • Apparent molar volumes were fitted using a Redlich–Meyer type equation. • The osmotic coefficients were modeled with the Extended Pitzer and the MNRTL models. -- Abstract: In this work, density for the binary mixtures of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate in alcohols (1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol) was measured at T = 323.15 K and atmospheric pressure. From this property, the corresponding apparent molar volumes were calculated and fitted to a Redlich–Meyer type equation. For these mixtures, the osmotic and activity coefficients, and vapor pressures of these binary systems were also determined at the same temperature using the vapor pressure osmometry technique. The experimental osmotic coefficients were modeled by the Extended Pitzer model of Archer. The parameters obtained in this correlation were used to calculate the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures

  12. Osmotic and apparent molar properties of binary mixtures alcohol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid

    Highlights: ► Osmotic and physical properties of binary mixtures {alcohol + [BMim][TfO]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer model. -- Abstract: In this work, physical properties (densities and speeds of sound) for the binary systems {1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate} were experimentally measured from T = (293.15 to 323.15) K and at atmospheric pressure. These data were used to calculate the apparent molar volume and apparent molar isentropic compression which were fitted to a Redlich–Meyer type equation. This fit was used to obtain the corresponding apparent molar properties at infinite dilution. On the other hand, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The Extended Pitzer model of Archer was employed to correlate the experimental osmotic coefficients. From the parameters obtained in the correlation, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated

  13. Development of fast and robust multiresidual LC-MS/MS method for determination of pharmaceuticals in soils.

    Golovko, Oksana; Koba, Olga; Kodesova, Radka; Fedorova, Ganna; Kumar, Vimal; Grabic, Roman

    2016-07-01

    The aim of this study was to develop a simple extraction procedure and a multiresidual liquid chromatography-tandem mass spectrometry method for determination of a wide range of pharmaceuticals from various soil types. An extraction procedure for 91 pharmaceuticals from 13 soil types, followed by liquid chromatography-tandem mass spectrometry analysis, was optimized. The extraction efficiencies of three solvent mixtures for ultrasonic extraction were evaluated for 91 pharmaceuticals. The best results were obtained using acetonitrile/water (1/1 v/v with 0.1 % formic acid) followed by acetonitrile/2-propanol/water (3/3/4 v/v/v with 0.1 % formic acid) for extracting 63 pharmaceuticals. The method was validated at three fortification levels (10, 100, and 1000 ng/g) in all types of representative soils; recovery of 44 pharmaceuticals ranged between 55 and 135 % across all tested soils. The method was applied to analyze actual environmental samples of sediments, soils, and sludge, and 24 pharmaceuticals were found above limit of quantification with concentrations ranging between 0.83 ng/g (fexofenadine) and 223 ng/g (citalopram). PMID:27044290

  14. Ideal Gas thermodynamic properties of simple alkanols

    The ideal gas thermodynamic properties (C /SUP o/ /SUB p/ , S /SUP o/ (T)-S0(O) and H /SUP o/ (T)-H /SUP o/ (0)) of methanol (CH3OH), ethanol (C2H5OH), 1-propanol (CH3CH2CH2OH), and 2-propanol ((CH3)2CHOH) over the temperature range 0 to 1500 K at 1.01325-bar (1-atm) pressure are calculated by the statistical mechanical method, employing the recent molecular and spectroscopic constants. The internal rotational contributions to the thermodynamic properties caused by the presence of -CH3,-C2H5, and -OH rotors in these molecules are evaluated using an internal rotational partition function formed by the summation of internal rotational energy levels for each rotor. In the calculation of the thermodynamic properties of ethanol (g) and 1-propanol (g), we adopted a molecular model that the vapor of each compound contains an equilibrium mixture of trans and gauche isomers. The existence of such isomers was observed spectroscopically in recent years. Our calculated results, such as C /SUP o/ /SUB p/ and S /SUP o/ (T)-S /SUP o/ (0), agree with available experimental values

  15. Effect of the temperature on the physical properties of the pure ionic liquid 1-ethyl-3-methylimidazolium methylsulfate and characterization of its binary mixtures with alcohols

    Highlights: • Physical properties of the pure [EMim][MSO4] ionic liquid. • Physical and excess properties of its binary mixtures with alcohols. • The excess properties were fitted using the Redlich–Kister equation. • The effect of temperature on the VE, and KS,mE was analyzed. - Abstract: Experimental density, speed of sound, refractive index and viscosity data of the pure ionic liquid 1-ethyl-3-methylimidazolium methylsulfate, [EMim][MSO4], were measured as a function of temperature from T = (293.15 to 343.15) K, every 5 K, and atmospheric pressure. Density, speed of sound and refractive index data were satisfactorily correlated with a linear equation, while viscosity data were fitted to the Vogel–Fulcher–Tamman (VFT) equation. Besides, from the experimental density values, the thermal expansion coefficient, α, was calculated. Furthermore, density and speed of sound for the binary systems of {methanol, or ethanol, or 1-propanol, or 2-propanol, or 1-butanol, or 1-pentanol + [EMim][MSO4]} were experimentally determined over the whole composition range, at T = (288.15, 298.15 and 308.15) K and p = 0.1 MPa. These properties were used to calculate the corresponding excess molar volumes and excess molar isentropic compressions, which were satisfactorily fitted to the Redlich–Kister equation. Finally, a comparison with available literature data was also carried out and the obtained results are discussed in terms of interactions and structure factors in these binary mixtures

  16. Is there any sense to investigate volumetric and acoustic properties of more binary mixtures containing Ionic Liquids?

    Highlights: • Calculations of excess quantities of binary mixtures of IL + molecular solvent. • Analysis of excess properties for mixtures in order to find some regularities. • Balankina’s functions as tool to systematize excesses of IL + solvent mixtures. • Discussion of calculated absolute and relative excesses. • Prediction of absolute and relative excesses for similar binary systems. - Abstract: The excess speed of sound, excess molar volume and excess molar isentropic compressibility of 52 binary mixtures containing Ionic Liquids at T = 298.15 K were calculated using selected literature speed of sound and density data. The second components were alcohols: methanol, or ethanol, or 1-propanol, or 2-propanol, or 1-butanol or other solvents: acetone, acetonitrile, tetrahydrofuran, dichloromethane and dimethylsulfoxide. The Balankina’s relative excesses, Xbal, i.e. the ratios between excess and ideal quantities XE/Xid were also determined to reduce the structural impact of pure components to absolute excesses. Analysis of quantities determined shows some patterns for concentration dependences of large groups of mixtures; thus, the scheme for influence of anion or cation of Ionic Liquids and solvent on Balankina’s relative excesses was proposed. It seems that presented analysis provide the knowledge about absolute and relative excess quantities for other mixtures without doing the experimental work. It is also visible that analysis of excess molar quantities and Xbal parameters can support the interpretation of interactions which occur between Ionic Liquids and solvent

  17. Evaluation of thermodynamic properties of fluid mixtures by PC-SAFT model

    Experimental and calculated partial molar volumes (V¯m,1) of MIK with (♦) 2-PrOH, (♢) 2-BuOH, (●) 2-PenOH at T = 298.15 K. (—) PC-SAFT model. - Highlights: • Densities and viscosities of the mixtures (MIK + 2-alkanols) were measured. • PC-SAFT model was applied to correlate the volumetric properties of binary mixtures. • Agreement between experimental data and calculated values by PC-SAFT model is good. - Abstract: Densities and viscosities of binary mixtures of methyl isobutyl ketone (MIK) with polar solvents namely, 2-propanol, 2-butanol and 2-pentanol, were measured at 7 temperatures (293.15–323.15 K) over the entire range of composition. Using the experimental data, excess molar volumes VmE, isobaric thermal expansivity αp, partial molar volumes V¯m,i and viscosity deviations Δη, have been calculated due to their importance in the study of specific molecular interactions. The observed negative and positive values of deviation/excess parameters were explained on the basis of the intermolecular interactions occur in these mixtures. The Perturbed Chain Statistical Association Fluid Theory (PC-SAFT) has been used to correlate the volumetric behavior of the mixtures

  18. Rotational Spectra of Hydrogen Bonded Networks of Amino Alcohols

    Zhang, Di; Zwier, Timothy S.

    2014-06-01

    The rotational spectra of several different amino alcohols including D/L-allo-threoninol, 2-amino-1,3-propanediol and 1,3-diamino-2-propanol over the 6.5-18.5 GHz range have been investigated under jet-cooled conditions using chirped-pulsed Fourier transform microwave spectroscopy. Despite the small size of these molecules, a great variety of conformations have been observed in the molecular expansion. While the NH2 group is typically thought of as a H-bond acceptor, it often acts both as acceptor and donor in forming H-bonded networks. With three adjacent H-bonding substituents (a combination of OH and NH2 groups), many different hydrogen bonding patterns are possible, including H-bonded chains and H-bonded cycles. Since many of these structures differ primarily by the relative orientation of the H-atoms, the analysis of these rotational spectra are challenging. Only through an exhaustive conformational search and the comparison with the experimental rotational constants, nuclear quadrupolar splittings, and line strengths are we able to understand the complex nature of these interactions. The ways in which the presence and number of NH2 groups affects the relative energies, and distorts the structures will be explored.

  19. Osmotic coefficients of alcoholic mixtures containing BMpyrDCA: Experimental determination and correlation

    Graphical abstract: - Highlights: • Osmotic coefficients of alcohols with BMpyrDCA ionic liquid are determined. • Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. - Abstract: The vapour pressure osmometry technique (VPO) has been used to obtain the osmotic coefficients of the binary mixtures of the primary and secondary alcohols 1-propanol, 2-propanol, 1-butanol, 2-butanol and 1-pentanol with the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, BMpyrDCA. From these coefficients, the corresponding activity coefficients and vapour pressures of the mixtures have been also determined. The results have been discussed in terms of solute–solvent and ion–ion interactions and have been compared with those taken from literature in order to analyse the influence of the anion or cation constituting the ionic liquid. For the treatment of the experimental data, the Extended Pitzer model of Archer and the MNRTL model have been applied, obtaining standard deviations from the experimental osmotic coefficients lower than 0.015 and 0.065, respectively. From the parameters obtained with the Extended Pitzer model or Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures have been calculated

  20. Vapour pressures and osmotic coefficients of binary mixtures containing alcohol and pyrrolidinium-based ionic liquids

    Highlights: • Osmotic coefficients of alcohols with pyrrolidinium ILs are determined. • Experimental data were correlated with extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. -- Abstract: The osmotic and activity coefficients and vapour pressures of mixtures containing primary (1-propanol, 1-butanol and 1-pentanol) and secondary (2-propanol and 2-butanol) alcohols with pyrrolidinium-based ionic liquids (1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide, C4MpyrNTf2, and 1-butyl-1-methyl pyrrolidinium trifluoromethanesulfonate, C4MpyrTFO) have been experimentally determined at T = 323.15 K. For the experimental measurements, the vapour pressure osmometry technique has been used. The results on the influence of the structure of the alcohol and of the anion of the ionic liquid on the determined properties have been discussed and compared with literature data. For the correlation of the osmotic coefficients obtained, the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model were applied. The mean molal activity coefficients and the excess Gibbs energy for the studied mixtures were calculated from the parameters obtained in the correlation

  1. Amine functionalized radiation-induced grafted water hyacinth fibers for Pb2+, Cu2+ and Cr3+ uptake

    An amine group containing fibrous adsorbent was prepared by reaction of grafted water hyacinth fibers with ethylenediamine. Glycidyl methacrylate (GMA) was grafted onto water hyacinth fibers using gamma radiation induced graft polymerization through simultaneous grafting technique and this was used as base material for producing the amine type adsorbents. The conversion of the epoxy group from GMA into amine group was investigated. The concentration of ethylenediamine solution that gave the highest amine functional group density was 50% by volume in 2-propanol. The amine functionalized water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy(EDX). Information derived from these analyses confirms the successful conversion of the epoxy group. The amine type adsorbent was evaluated for its uptake of Pb2+, Cu2+ and Cr3+ from aqueous solutions. The initial concentration of the metal ions and pH of the solutions were found to influence the amount of metal ions adsorbed by the amine-type adsorbent. The kinetics of adsorption was observed to follow Lagergen's first order equation. Results of ion sorption studies indicate that gamma radiation-induced grafting and subsequent chemical modification improved the ion sorption behaviour of water hyacinth fibers. (Author)

  2. Platinum-Niobium(V Oxide/Carbon Nanocomposites Prepared By Microwave Synthesis For Ethanol Oxidation

    Virginija KEPENIENĖ

    2016-05-01

    Full Text Available In the present work, Pt nanoparticles were deposited by means of microwave synthesis on the primary carbon supported Nb2O5 composite which was prepared in two different ways: (A by dispersion of Nb2O5 and carbon with the mass ratio equal to 1:1 in a 2-propanol solution by ultrasonication for 30 min. with further desiccation of the mixture and (B by heating the Nb2O5/C composite obtained according to the procedure (A at 500 °C for 2 h. The transmission electron microscopy was used to determine the shape and the size of catalyst particles. X-ray diffraction and inductively coupled plasma optical emission spectroscopy were employed to characterize the structure and composition of the synthesized catalysts. The electrocatalytic activity of the synthesized catalysts towards the oxidation of ethanol in an alkaline medium was investigated by means of cyclic voltammetry.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.8609

  3. PHOTOREDUCTIVE SEQUESTRATION OF CO2 TO FORM C1 PRODUCTS AND FUEL

    Theodore Mill; Haruthai Tungudomwongsa

    2003-03-13

    Analytical methods for determining formic and oxalic acids, formaldehyde and methanol have been evaluated and/or optimized for measuring products from photoreduction of CO{sub 2} in illuminated, aqueous suspensions of photocatalysts. An electrophoretic analysis method can detect aqueous formate and oxalate ions at 3 and 1 {micro}M respectively. Recalibration of the Nash formaldehyde determination shows that as little as 0.5 {micro}M can be detected spectrally. Several experiments using suspensions of TiO{sub 2}, SrTiO{sub 3} and SrTiO{sub 3} with Cr and Sb were tested in CO{sub 2} saturated solutions. No formate was detected in most experiments. However adding 2-propanol to a CO{sub 2}/TiO{sub 2} suspension gave significant amounts of formate and some formaldehyde by blocking the re-oxidation of formate by semiconductor holes. Loss of C{sub 1} products by re-oxidation is probably an important process limiting the accumulation of formate, formaldehyde and methanol.

  4. Photochemical-spectrofluorimetric method for the determination of benzoylurea insecticides: applications in river water samples and in technical formulations.

    Gil-Garcia, M D; Martínez-Galera, M; López-López, T; Martínez-Vidal, J L; Mahedero, M C; Salinas, F

    2001-01-26

    Ultraviolet (UV) irradiation was used to obtain fluorescent photoproducts from four non-fluorescent benzoylurea (BU) insecticides (flufenoxuron (FLF), lufenuron (LUF), hexaflumuron (HF) and triflumuron (TRF)). The effect of solvent, pH (in aqueous solutions), organic solvent percentage and UV irradiation time on the excitation and emission wavelengths and fluorescence intensity were investigated. The largest fluorescence signals and the shortest UV irradiation time were obtained in methanol, ethanol and 2-propanol. Linear calibration graphs were established in the interval between 0.025 and 1.000 microg ml(-1) from FLF and TRF and between 0.050 and 1.000 microg ml(-1) from LUF and HF with regression coefficients larger than 0.99. A method based on the use of the first-derivative of the spectra of photoproducts was applied to the determination of BU insecticides in river water samples and in technical formulations. The mean recoveries ranged from 95.0% to 110.0% in river water samples and from 92.0% to 101.0% in technical formulations, according to the compound. A preconcentration step, using LLE, allowed to reach the concentration levels established by the EU directive for pesticides in drinking water. PMID:18968181

  5. A method for the determination of theophylline in serum by isotope dilution mass spectrometry

    A method for the determination of theophylline in human serum by the isotope dilution/mass spectrometric technique is described. As an internal standard labelled (1,3-15N2-2-13C)theophylline is added to the serum sample. The analyte and internal standard are extracted with chloroform/2-propanol (90:10) and converted to the trimethylsilyl derivatives. The extraction and silylation procedures are checked by adding theophylline and internal standard in various concentrations to blank serum and determining the recovery. The trimethylsilyl derivatives of labelled and non-labelled theophylline are separated and detected by GC-MS with the mass spectrometer set to m/z 252 and 255. The amounts of theophylline in the serum are calculated from the isotope ratios measured by selected ion monitoring. The accuracy, precision and recovery of this GC-MS method are presented and discussed. The coefficient of variation determined from duplicate samples was less than 2.5%. The detection limit was 10 ng/ml at a signal-to-noise ratio of 3:1. (orig.)

  6. A method for the determination of theophylline in serum by isotope dilution mass spectrometry

    Susanto, F.; Humfeld, S.; Niederau, C.M.; Reinauer, H. (Dept. of Clinical Biochemistry, Duesseldorf Univ. (Germany))

    1992-12-01

    A method for the determination of theophylline in human serum by the isotope dilution/mass spectrometric technique is described. As an internal standard labelled (1,3-[sup 15]N[sub 2]-2-[sup 13]C)theophylline is added to the serum sample. The analyte and internal standard are extracted with chloroform/2-propanol (90:10) and converted to the trimethylsilyl derivatives. The extraction and silylation procedures are checked by adding theophylline and internal standard in various concentrations to blank serum and determining the recovery. The trimethylsilyl derivatives of labelled and non-labelled theophylline are separated and detected by GC-MS with the mass spectrometer set to m/z 252 and 255. The amounts of theophylline in the serum are calculated from the isotope ratios measured by selected ion monitoring. The accuracy, precision and recovery of this GC-MS method are presented and discussed. The coefficient of variation determined from duplicate samples was less than 2.5%. The detection limit was 10 ng/ml at a signal-to-noise ratio of 3:1. (orig.).

  7. Preliminary assessment of mutagenic and anti-mutagenic potential of some aminoalkanolic derivatives of xanthone by use of the Vibrio harveyi assay.

    Słoczyńska, Karolina; Waszkielewicz, Anna Maria; Marona, Henryk

    2014-07-01

    The Vibrio harveyi assay was used to evaluate mutagenic and anti-mutagenic effects of four new aminoalkanolic derivatives of xanthone with anticonvulsant activity, to select the potentially safe compounds for further in vivo studies in animal models. The study showed that at a concentration of 40 ng/ml the test compounds were not mutagenic. Additionally, two of the investigated compounds, namely the (R,S)-N-methyl-1-amino-2-propanol derivative of 6-methoxyxanthone (compound III) and the (R)-N-methyl-2-amino-1-butanol derivative of 7-chloroxanthone (compound IV) were strong inhibitors of the mutagenicity induced by 4-nitroquinoline-N-oxide (4-NQO) in V. harveyi strains BB7M and BB7XM. The inhibition percentages for compound IV were 49 (in BB7M) and 69 (in BB7XM), whereas for compound III these percentages were 47 (in BB7M) and 42 (in BB7XM), respectively. The present study demonstrates that four bioactive derivatives of xanthone display no mutagenic activity in the V. harveyi assay. In addition, compounds III and IV demonstrated considerable anti-mutagenic activity in this test. Based on the results obtained here, these compounds could be selected for further studies in animal models, while compounds III and IV should be tested further for their anti-mutagenic properties. PMID:24769486

  8. Stereoselective Separation and Acute Toxicity of Tau-Fluvalinate to Zebrafish

    Qi Jia

    2015-01-01

    Full Text Available Tau-fluvalinate (TFLV is one of the most potent chiral synthetic pyrethroids to control a wide range of pests in agricultural fields, especially in apiary. In this study, two stereoisomers of TFLV were fully separated by high-performance liquid chromatography (HPLC with a semipreparative chiral column using cellulose-tris(3,5-dimethylphenylcarbamate as chiral stationary phase and n-hexane and 2-propanol (96/4, v/v as mobile phase at a flow rate of 2.5 mL min−1. The (+-stereoisomer was first eluted by detecting with an optical rotation detector. After obtaining pure single stereoisomer of TFLV, acute toxicities of each isomer and TFLV standard to zebrafish were evaluated. The results showed that the (+-stereoisomer exhibited 273.4 times higher toxicity than the (−-stereoisomer and 6.7 times higher than TFLV standard, according to their LC50 values at 96 h after exposure. This indicates that the toxicity of TFLV mainly originates from (+-stereoisomer. These results are very helpful to prepare single stereoisomer of chiral pesticides and evaluate their different toxicological effects to aquatic organisms.

  9. Crystallization and preliminary X-ray characterization of two thermostable DNA nucleases

    Two thermostable DNA nucleases from archaea were crystallized in different space groups; the crystals were suitable for X-ray analysis. Temperature-tolerant organisms are an important source to enhance the stability of enzymes used in biotechnological processes. The DNA-cleaving enzyme exonuclease III from Escherichia coli is used in several applications in gene technology. A thermostable variant could expand the applicability of the enzyme in these methods. Two homologous nucleases from Archaeoglobus fulgidus (ExoAf) and Methanothermobacter thermoautrophicus (ExoMt) were studied for this purpose. Both enzymes were crystallized in different space groups using (poly)ethylene glycols, 2,4-methyl pentandiol, dioxane, ethanol or 2-propanol as precipitants. The addition of a 10-mer DNA oligonucleotide was important to obtain monoclinic crystals of ExoAf and ExoMt that diffracted to resolutions better than 2 Å using synchrotron radiation. The crystal structures of the homologous proteins can serve as templates for genetic engineering of the E. coli exonuclease III and will aid in understanding the different catalytic properties of the enzymes

  10. Crystallization and preliminary characterization of three different crystal forms of human saposin C heterologously expressed in Pichia pastoris

    Three different crystal forms were obtained of human saposin C. The structures could not be determined by molecular replacement using known solution structures of the protein as search models, supporting the notion of a highly flexible protein. The amphiphilic saposin proteins (A, B, C and D) act at the lipid–water interface in lysosomes, mediating the hydrolysis of membrane building blocks by water-soluble exohydrolases. Human saposin C activates glucocerebrosidase and β-galactosylceramidase. The protein has been expressed in Pichia pastoris, purified and crystallized in three different crystal forms, diffracting to a maximum resolution of 2.5 Å. Hexagonal crystals grew from 2-propanol-containing solution and contain a single molecule in the asymmetric unit according to the Matthews coefficient. Orthorhombic and tetragonal crystals were both obtained with pentaerythritol ethoxylate and are predicted to contain two molecules in the asymmetric unit. Attempts to determine the respective crystal structures by molecular replacement using either the known NMR structure of human saposin C or a related crystal structure as search models have so far failed. The failure of the molecular-replacement method is attributed to conformational changes of the protein, which are known to be required for its biological activity. Crystal structures of human saposin C therefore might be the key to mapping out the conformational trajectory of saposin-like proteins

  11. Crystallization and preliminary characterization of three different crystal forms of human saposin C heterologously expressed in Pichia pastoris

    Schultz-Heienbrok, Robert [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Remmel, Natascha; Klingenstein, R. [Kekule-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn (Germany); Rossocha, Maksim [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Sandhoff, Konrad [Kekule-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn (Germany); Saenger, Wolfram [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Maier, Timm, E-mail: timm.maier@mol.biol.ethz.ch [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Institute for Molecular Biology and Biophysics, Swiss Federal Institute of Technology, ETH Zürich (Switzerland)

    2006-02-01

    Three different crystal forms were obtained of human saposin C. The structures could not be determined by molecular replacement using known solution structures of the protein as search models, supporting the notion of a highly flexible protein. The amphiphilic saposin proteins (A, B, C and D) act at the lipid–water interface in lysosomes, mediating the hydrolysis of membrane building blocks by water-soluble exohydrolases. Human saposin C activates glucocerebrosidase and β-galactosylceramidase. The protein has been expressed in Pichia pastoris, purified and crystallized in three different crystal forms, diffracting to a maximum resolution of 2.5 Å. Hexagonal crystals grew from 2-propanol-containing solution and contain a single molecule in the asymmetric unit according to the Matthews coefficient. Orthorhombic and tetragonal crystals were both obtained with pentaerythritol ethoxylate and are predicted to contain two molecules in the asymmetric unit. Attempts to determine the respective crystal structures by molecular replacement using either the known NMR structure of human saposin C or a related crystal structure as search models have so far failed. The failure of the molecular-replacement method is attributed to conformational changes of the protein, which are known to be required for its biological activity. Crystal structures of human saposin C therefore might be the key to mapping out the conformational trajectory of saposin-like proteins.

  12. Characterization of a Membrane Interface for Analysis of Air Samples Using Time-of-flight Mass Spectrometry

    In the present study, we constructed a membrane inlet assembly for selective permeation of volatile airborne organic compounds for subsequent analysis by time-of-flight mass spectrometry. The time-dependent diffusion of analytes through a 75 μm thick polydimethylsiloxane membrane was measured by monitoring the ion signal after a step change in the sample concentration. The results fit well to a non-steady-state permeation equation. The diffusion coefficient, response time, and sensitivity were determined experimentally for a range of polar (halogenated) and nonpolar (aromatic) compounds. We found that the response times for several volatile organic compounds were greatly influenced by the alkyl chain length as well as the size of the substituted halogen atoms. The detection limits for benzene, ethylbenzene, and 2-propanol were 0.2 ppm, 0.1 ppm, and 3.0 ppm by volume, respectively, with a linear dynamic range greater than three orders of magnitude. These results indicate that the membrane inlet/time-of-flight mass spectrometry technique will be useful for a wide range of applications, particularly for in situ environmental monitoring

  13. Natural organic matter and sunlight accelerate the degradation of 17ss-estradiol in water

    Nanomolar concentrations of steroid hormones such as 17β-estradiol can influence the reproductive development and sex ratios of invertebrate and vertebrate populations. Thus their release into surface and ground waters from wastewater facilities and agricultural applications of animal waste is of environmental concern. Many of these compounds are chromophoric and susceptible to photolytic degradation. High intensity UV-C radiation has been demonstrated to degrade some of these compounds in engineered systems. However, the degradation efficacy of natural solar radiation in shallow fresh waters is less understood. Here photolytic experiments with 17β-estradiol demonstrated modest photodegradation (∼ 26%) when exposed to simulated sunlight between 290 and 720 nm. Photodegradation significantly increased (∼ 40-50%) in the presence of 2.0-15.0 mg/l of dissolved organic carbon (DOC) derived from humic acids of the Suwannee River, GA. However, rates of photodegradation reached a threshold at approximately 5.0 mg/l DOC. Observed suppression of photolysis in the presence of a radical inhibitor (i.e. 2-propanol) indicated that a significant proportion of the degradation was due to radicals formed from the photolysis of DOC. Although photodegradation was greatest in full sunlight containing UV-B (290-320 nm), degradation was also detected with UV-A (320-400 nm) and visible light (400-720 nm) alone

  14. Calcium phosphate/microgel composites for 3D powderbed printing of ceramic materials.

    Birkholz, Mandy-Nicole; Agrawal, Garima; Bergmann, Christian; Schröder, Ricarda; Lechner, Sebastian J; Pich, Andrij; Fischer, Horst

    2016-06-01

    Composites of microgels and calcium phosphates are promising as drug delivery systems and basic components for bone substitute implants. In this study, we synthesized novel composite materials consisting of pure β-tricalcium phosphate and stimuli-responsive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-vinylimidazole) microgels. The chemical composition, thermal properties and morphology for obtained composites were extensively characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, IGAsorp moisture sorption analyzer, thermogravimetric analysis, granulometric analysis, ESEM, energy dispersive X-ray spectroscopy and TEM. Mechanical properties of the composites were evaluated by ball-on-three-balls test to determine the biaxial strength. Furthermore, initial 3D powderbed-based printing tests were conducted with spray-dried composites and diluted 2-propanol as a binder to evaluate a new binding concept for β-tricalcium phosphate-based granulates. The printed ceramic bodies were characterized before and after a sintering step by ESEM. The hypothesis that the microgels act as polymer adhesive agents by efficient chemical interactions with the β-tricalcium phosphate particles was confirmed. The obtained composites can be used for the development of new scaffolds. PMID:25870955

  15. Synthesis and swelling behavior of polyurethane networks based on hyperbranched polymer

    Džunuzović Jasna V.

    2011-01-01

    Full Text Available A series of six polyurethane (PU networks was synthesized from BoltornR hydroxy-functional hyperbranched polyester (HBP of the second pseudo generation as a crosslinking agent, α,ω- dihydroxy-(ethylene oxide-poly(dimethylsiloxane-ethylene oxide (EO-PDMS-EO and 4,4’- methylenediphenyl diisocyanate, by a two-step polymerization in solution. Each sample of the prepared PUs had different EO-PDMS-EO content. The chemical structure of the synthesized networks was analyzed by FTIR spectroscopy. The influence of the EO-PDMS-EO content and type of the solvent on the swelling behavior of the PUs in 2-propanol and toluene was investigated. During the swelling measurements certain amount of sol fractions was extracted from the PUs by solvents. According to the 1H NMR results, sol fractions are mainly composed of the soluble hyperbranched PU, formed during the polymerization by partial modification of the end hydroxyl groups of HBP with NCO-terminated prepolymer synthesized in the first step of the reaction. Chains of the so reacted prepolymer can then fold back and form cyclic products by reaction of the free -NCO group from the NCO-terminated prepolymer with free -OH group of HBP. As the EO-PDMS-EO content increases the amount of the sol fractions and swelling degree also increased, indicating that networks with lower EO-PDMS-EO content are more crosslinked and have higher solvent resistance.

  16. Fabrication and Intermolecular Interactions of Silk Fibroin/Hydroxybutyl Chitosan Blended Nanofibers

    Xiu-Mei Mo

    2011-03-01

    Full Text Available The native extracellular matrix (ECM is composed of a cross-linked porous network of multifibril collagens and glycosaminoglycans. Nanofibrous scaffolds of silk fibroin (SF and hydroxybutyl chitosan (HBC blends were fabricated using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP and trifluoroacetic acid (TFA as solvents to biomimic the native ECM via electrospinning. Scanning electronic microscope (SEM showed that relatively uniform nanofibers could be obtained when 12% SF was blended with 6% HBC at the weight ratio of 50:50. Meanwhile, the average nanofibrous diameter increased when the content of HBC in SF/HBC blends was raised from 20% to 100%. Fourier transform infrared spectra (FTIR and 13C nuclear magnetic resonance (NMR showed SF and HBC molecules existed in hydrogen bonding interactions but HBC did not induce conformation of SF transforming from random coil form to β-sheet structure. X-ray diffraction (XRD confirmed the different structure of SF/HBC blended nanofibers from both SF and HBC. Thermogravimetry-Differential thermogravimetry (TG-DTG results demonstrated that the thermal stability of SF/HBC blend nanofibrous scaffolds was improved. The results indicated that the rearrangement of HBC and SF molecular chain formed a new structure due to stronger hydrogen bonding between SF and HBC. These electrospun SF/HBC blended nanofibers may provide an ideal tissue engineering scaffold and wound dressing.

  17. Development and characterization of coaxially electrospun gelatin coated poly (3-hydroxybutyric acid) thin films as potential scaffolds for skin regeneration

    Nagiah, Naveen [Bioproducts Lab, Central Leather Research Institute, Adyar, Chennai (India); Madhavi, Lakshmi; Anitha, R. [CavinKare Research Centre, Ekkattuthangal, Chennai (India); Anandan, C. [National Aerospace Laboratory, Banglore (India); Srinivasan, Natarajan Tirupattur, E-mail: naveen.nagiah@gmail.com [Conducting Polymers Lab, Department of Physics, Indian Institute of Technology Madras, Chennai (India); Sivagnanam, Uma Tirichurapalli, E-mail: suma67@gmail.com [Bioproducts Lab, Central Leather Research Institute, Adyar, Chennai (India)

    2013-10-01

    The morphology of fibers synthesized through electrospinning has been found to mimic extracellular matrix. Coaxially electrospun fibers of gelatin (sheath) coated poly (3-hydroxybutyric acid) (PHB) (core) was developed using 2,2,2 trifluoroethanol(TFE) and 1,1,1,3,3,3 hexafluoro-2-propanol(HFIP) as solvents respectively. The coaxial structure and coating of gelatin with PHB fibers was confirmed through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Thermal stability of the coaxially electrospun fibers was analyzed using thermogravimetric analysis(TGA), differential scanning calorimetry(DSC) and differential thermogravimetric analysis(DTA). Complete evaporation of solvent and gelatin grafting over PHB fibers was confirmed through attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR). The coaxially electrospun fibers exhibited competent tensile properties for skin regeneration with high surface area and porosity. In vitro degradation studies proved the stability of fibers and its potential applications in tissue engineering. The fibers supported the growth of human dermal fibroblasts and keratinocytes with normal morphology indicating its potential as a scaffold for skin regeneration. - Highlights: • Coaxial electrospinning was employed to develop core-shell fibers of PHB and gelatin. • The scaffold has competent physicochemical properties. • Developed scaffold will have high impact as a dermal substitute in skin regeneration.

  18. Synthesis and characterization of mesoporous TiO{sub 2} assembled as microspheres

    Beitollahi, Ali, E-mail: beitolla@iust.ac.i [Nanomaterial Research Group, Dept. of Metallurgy and Materials Eng., Iran University of Science and Technology (IUST), Narmak, Farjam, Tehran (Iran, Islamic Republic of); Daie, Amir Hossein Haj [Nanomaterial Research Group, Dept. of Metallurgy and Materials Eng., Iran University of Science and Technology (IUST), Narmak, Farjam, Tehran (Iran, Islamic Republic of); Samie, Leyla [Nanomaterial Research Group, Dept. of Metallurgy and Materials Eng., Iran University of Science and Technology (IUST), Narmak, Farjam, Tehran (Iran, Islamic Republic of); Research Institute of Petroleum Industries, Tehran (Iran, Islamic Republic of); Akbarnejad, Mohammad Mehdi [Research Institute of Petroleum Industries, Tehran (Iran, Islamic Republic of)

    2010-02-04

    In the work presented here, we report the successful synthesis of highly porous (219 m{sup 2}/g) mesostructured titania powder assembled as microspheres of uniform wormlike channels of {approx}6-7 nm widths by spray pyrolysis of a titania sol prepared by templating approach using P123 pluronic block copolymer (BC). This method involves the preparation of a Ti{sup 4+}-sol containing titanium tertraisopropoxide (TTIP), pluronic BC P123, 2-propanol, acetyl acetonate (ACAC) and hydrochloric acid (HCl) as well as H{sub 2}O followed by spray pyrolysis of the obtained sol into the hot zone of a pre-heated reactor at 800 deg. C, 900 deg. C and 1000 deg. C. For all of these pyrolyzed samples, the formation of anatase as the major phase along with rutile as the minor one could be confirmed. The appearance of wormlike mesopores rather than highly ordered cubic or hexagonal mesostructures is related to the lack of appropriate drying conditions normally applied to induce self assembly as well as formation of rather large titania crystallite sizes.

  19. A new sol-gel processing routine without chelating agents for preparing highly transparent solutions and nanothin films: engineering the role of chemistry to design the process

    Ashiri, Rouholah

    2015-01-01

    The great sensitivity of titanium alkoxides to hydrolysis makes their sol-gel transformation very fast and thus difficult to control. A method was proposed to alleviate this drawback. Preparation of highly transparent solutions and nanothin films is another objective of the present research. Employing nanoemulsion method and optimizing the processing conditions, a clear solution of well-dispersed nanosized particles was obtained. With the proposed process BaTiO3 precursor sols and nanothin films with enhanced optical transparency towards the visible were prepared. The optimal formulation of the sol consists of acetic acid, barium acetate, 2-propanol, TTIP and deionized water with 6:1:1:1:150 M ratios, respectively. It was found that the reduction of the temperature in the initial stage of mixing of precursors controls the size of the forming species and accordingly improves the stability and transparency of the sol. The results also showed that the applied modifications and optimizations significantly downsize the particles within the sol to the nanometric scale and accordingly result in a significant improvement in the optical response of the products.

  20. Microemulsion system for topical delivery of thai mango seed kernel extract: development, physicochemical characterisation and ex vivo skin permeation studies.

    Leanpolchareanchai, Jiraporn; Padois, Karine; Falson, Françoise; Bavovada, Rapepol; Pithayanukul, Pimolpan

    2014-01-01

    A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar "Fahlun") was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM) was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w) system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol) at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93%) in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment. PMID:25347456

  1. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone

  2. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    Vajnhandl, Simona [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)]. E-mail: simona.vajnhandl@uni-mb.si; Le Marechal, Alenka Majcen [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)

    2007-03-06

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone.

  3. Determining indoor air quality and identifying the origin of odour episodes in indoor environments

    Eva Gallego; Xavier Roca; Jose Francisco Perales; Xavier Guardino

    2009-01-01

    A methodology for identifying volatile organic compounds (VOC) and determining air quality of indoor air has been developed. The air samples are collected using pump samplers by the inhabitants when they perceive odorous and/or discomfort episodes. Glass multi-sorbent tubes are connected to the pump samplers for the retention of VOC. The analysis is performed by automatic thermal desorption (ATD) coupled with gas chromatography-mass spectrometry (GC/MS). This methodology can be applied in cases of sick building syndrome (SBS) evaluation, in which building occupants experience a series of varied symptoms that appear to be linked to time spent in the building. Chemical pollutants concentrations (e.g., VOC) have been described to contribute to SBS. To exemplify the methodology, a qualitative determination and an evaluation of VOC present were performed in a dwelling where the occupants experienced the SBS symptoms. Higher total VOC (TVOC) value was detected in episodes in indoor air (1.33 ( 1.53 mg/m3) compared to outdoor air (0.71 ( 0.46 mg/m3). The concentrations of individual VOCs, such as ethanol, acetone, isopropanol, 1-butanol, acetic acid, acetonitrile and 1-metoxy-2-propanol, were also higher than the expected for a standard dwelling. The external source of VOC was found to be a not declared activity of storage and manipulation of solvents located at the bottom of a contiguous building.

  4. Highly ordered mesoporous TiO2-Fe2O3 mixed oxide synthesized by sol-gel pathway: an efficient and reusable heterogeneous catalyst for dehalogenation reaction.

    Patra, Astam K; Dutta, Arghya; Bhaumik, Asim

    2012-09-26

    Highly ordered two-dimensional (2D) hexagonal TiO(2)-Fe(2)O(3) mixed-oxide material MFT-1, which is composed of very tiny nanoparticles, is synthesized using sodium dodecylsulfate (SDS) as a structure-directing agent. Interestingly, synthesis of an ordered mesophase was not possible using SDS as a template for mesoporous pure Fe(2)O(3) or TiO(2) phases. This mesoporous iron-titanium mixed-oxide material has been characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N(2) sorption, ultraviolet-visible light diffuse reflectance spectroscopy (UV-vis DRS) studies. N(2) sorption analysis revealed high surface areas (126-385 m(2) g(-1)) and narrow pore size distributions (3.1-3.4 nm) for different samples. UV-vis DRS spectra and wide-angle powder XRD patterns indicate that the material is composed of α-Fe(2)O(3) and anatase TiO(2) phases. This TiO(2)-Fe(2)O(3) mixed-oxide material can act as a very efficient and reusable catalyst in the dehalogenation of aromatic chloride-, bromide-, and iodide-tolerating -F, -CN, -CH(3), -OCH(3) and -NO(2) functional groups in the aromatic ring using 2-propanol as the dispersion medium. PMID:22939382

  5. Enhanced bioactivity of ZnO nanoparticles—an antimicrobial study

    Nagarajan Padmavathy and Rajagopalan Vijayaraghavan

    2008-01-01

    Full Text Available In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO32 and NaOH. The products were characterized by x-ray diffraction (XRD analysis, transmission electron microscopy (TEM and photoluminescence (PL spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles.

  6. Enhanced bioactivity of ZnO nanoparticles—an antimicrobial study

    Padmavathy, Nagarajan; Vijayaraghavan, Rajagopalan

    2008-07-01

    In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO3)2 and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles.

  7. A simple and sensitive spectrofluorimetric method for analysis of some nitrofuran drugs in pharmaceutical preparations.

    Belal, Tarek Saied

    2008-09-01

    A simple, rapid, selective and sensitive spectrofluorimetric method was described for the analysis of three nitrofuran drugs, namely, nifuroxazide (NX), nitrofurantoin (NT) and nitrofurazone (NZ). The method involved the alkaline hydrolysis of the studied drugs by warming with 0.1 M sodium hydroxide solution then dilution with distilled water for NX or 2-propanol for NT and NZ. The formed fluorophores were measured at 465 nm (lambda (Ex) 265 nm), 458 nm (lambda (Ex) 245 nm) and 445 nm (lambda (Ex) 245 nm) for NX, NT and NZ, respectively. The reaction pathway was discussed and the structures of the fluorescent products were proposed. The different experimental parameters were studied and optimized. Regression analysis showed good correlation between fluorescence intensity and concentration over the ranges 0.08-1.00, 0.02-0.24 and 0.004-0.050 microg ml(-1) for NX, NT and NZ, respectively. The limits of detection of the method were 8.0, 1.9 and 0.3 ng ml(-1) for NX, NT and NZ, respectively. The proposed method was validated in terms of accuracy, precision and specificity, and it was successfully applied for the assay of the three nitrofurans in their different dosage forms. No interference was observed from common pharmaceutical adjuvants. The results were favorably compared with those obtained by reference spectrophotometric methods. PMID:18246413

  8. Electrophoretic deposition of ZnO nanostructures: Au nanoclusters on Si substrates induce self-assembled nanowire growth

    Sandoval, Claudia [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Marin, Oscar [CONICET – LAFISO, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Real, Silvina [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Comedi, David [CONICET – LAFISO, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Tirado, Mónica, E-mail: mtirado@herrera.unt.edu.ar [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina)

    2014-09-15

    Highlights: • ZnO nanowires were grown on silicon substrate by electrophoretic deposition technique without use a porous template. • The growth was induced by Au nanoclusters and was performed at room temperature. • The photoluminescence spectrum for the nanowires obtained shows a broad UV-blue excitonic emission peak and a low emission in the green region. - Abstract: The present work reports the self-assembled growth of ZnO nanowires on silicon substrate with nanometer sized Au clusters using electrophoretic deposition technique at room temperature without a sacrificial template. A colloidal suspension of ≈5 nm sized ZnO nanoparticles dispersed in 2-propanol was used (nanoparticle bandgap of 3.47 eV as determined from absorbance measurements). The results show that the Au nanoclusters on the silicon substrate induce the self-assembly of the ZnO nanoparticles into vertically aligned ZnO nanowires. This effect is tentatively explained as being due to increased electric field intensities near the Au nanoclusters during the electrophoretic deposition. Photoluminescence measurements reveal the presence of quantum confined excitons and a relatively low concentration of deep defects in the nanowires. The electric field guided growth of semiconductor nanostructures at room temperature has great industrial potential as it minimizes production costs and enables the use of substrate materials not withstanding high temperatures.

  9. The effect of nitroimidazole and nitroxyl radiosensitizers on the post-irradiation synthesis of DNA

    The modification of DNA damage by three radiosensitizing drugs, present during γ-irradiation of hypoxic Chinese hamster cells, was investigated. Both 2-methyl-5-nitroimidazole-1-ethanol (metronidazole) and 1-(2-nitro-1-imidazole)-3-methoxy-2-propanol (Ro-07-0582) were found to cause large increases in the yield of DNA single-strand breaks (SSB); triacetoneamine-N-oxyl (TAN) was found to have only a small effect on SSB production. The three drugs tested did not inhibit the rejoining of SSB. A pulse label and chase procedure was used to examine post-irradiation DNA synthesis. TAN present during irradiation under hypoxia was found to cause interruptions in subsequent DNA synthesis. Metronidazole and Ro-07-0582 had no effect on post-irradiation DNA synthesis. In addition, the effects of pre- and post-irradiation exposure to TAN were investigated, since these treatments have shown increased cell-killing in survival studies. TAN pre- and post-treatments were found to have no significant effect on subsequent DNA synthesis. (author)

  10. Separation of alcohol-water mixtures using salts

    Card, J. C.; Farrell, L. M.

    1982-04-01

    Use of a salt (KF or Na/sub 2/SO/sub 4/) to induce phase separation of alcohol-water mixtures was investigated in three process flowsheets to compare operating and capital costs with a conventional distillation process. The process feed was the Clostridia fermentation product, composed of 98 wt % water and 2 wt % solvents (70% 1-butanol, 27% 2-propanol, and 3% ethanol). The design basis was 150 x 10/sup 6/ kg/y of solvents. Phase equilibria and tieline data were obtained from literature and experiments. Three separation-process designs were developed and compared by an incremental economic analysis (+-30%) with the conventional separation technique using distillation alone. The cost of salt recovery for recycle was found to be the critical feature. High capital and operating costs make recovery of salt by precipitation uneconomical; however, a separation scheme using multiple-effect evaporation for salt recovery has comparable incremental capital costs ($1.72 x 10/sup 6/ vs $1.76 x 10/sup 6/) and lower incremental operating costs ($2.14 x 10/sup 6//y vs $4.83 x 10/sup 6//y) than the conventional separation process.

  11. Algorithms for GPU-based molecular dynamics simulations of complex fluids: Applications to water, mixtures, and liquid crystals.

    Kazachenko, Sergey; Giovinazzo, Mark; Hall, Kyle Wm; Cann, Natalie M

    2015-09-15

    A custom code for molecular dynamics simulations has been designed to run on CUDA-enabled NVIDIA graphics processing units (GPUs). The double-precision code simulates multicomponent fluids, with intramolecular and intermolecular forces, coarse-grained and atomistic models, holonomic constraints, Nosé-Hoover thermostats, and the generation of distribution functions. Algorithms to compute Lennard-Jones and Gay-Berne interactions, and the electrostatic force using Ewald summations, are discussed. A neighbor list is introduced to improve scaling with respect to system size. Three test systems are examined: SPC/E water; an n-hexane/2-propanol mixture; and a liquid crystal mesogen, 2-(4-butyloxyphenyl)-5-octyloxypyrimidine. Code performance is analyzed for each system. With one GPU, a 33-119 fold increase in performance is achieved compared with the serial code while the use of two GPUs leads to a 69-287 fold improvement and three GPUs yield a 101-377 fold speedup. PMID:26174435

  12. Extraction and separation of zinc and cadmium chlorides by TOPO from mixed media

    The effect of water-miscible alcohols and acetone on the extraction and separation of Cd and Zn chlorides by TOPO was systematically investigated. The maximum extraction of Zn chloride with 0.1 M TOPO decreases in the order: acetone> methanol> ethanol> 2-propanol> 2-butanol. For alcohols, the sequence of decreasing extractability is thus parallel to the order of their dielectric constants. This can be explained by the increase of HCl extraction by TOPO in the same direction. The presence of additives in the polar phase prevents the formation of a bulky white precipitate encountered during extraction of Zn Cl2 from pure aqueous solutions. A decrease of Cd chloride extraction was generally noticed in presence of additives; this is more noticeable for the longer chain alcohols. The highest separation factor (E) for Zn Cl2 and Cd Cl2 in 0.4 M HCl is obtained from 30% methanol (13.8 compared to about 3.8 in absence of methanol) and from 10-20% acetone where it reaches 30

  13. Increased Electrochemical Oxidation Rate of Alcohols in Alkaline Media on Palladium Surfaces Electrochemically Modified by Antimony, Lead, and Tin

    Several adatoms (M = Sb, Sn, or Pb) were added to Pd nanoparticles and examined for the electrochemical oxidation of ethanol, 1-propanol, 2-propanol, ethylene glycol, propylene glycol, and glycerol. We observed a significant increase in oxidation rate on Pd-M for each of the adatoms in each of the fuels. For example, the oxidation rate of ethanol was 1.5 times greater on Pd-Pb and Pd-Sn as compared with the oxidation rate on Pd after 10 minutes of oxidation. However, even more notable is the behavior observed by the polyhydric alcohols that exhibit sluggish reaction kinetics even in alkaline media. For example, the oxidation rate of propylene glycol on Pd-Pb was observed to be 21 times greater than the oxidation rate on Pd after 10 minutes, and it was still 7.1 times greater after 12 hours. These results show particular promise for the potential of efficiently oxidizing bulkier and higher energy density alcohols in the alkaline direct liquid fuel cell. All three bimetallic surfaces induced an increase in oxidation rate with all alcohols as compared to the monometallic Pd. Based on analysis of our results, we attribute a significant amount of the increase in oxidation rate to the bifunctional effect and suggest a lesser role is played by the electronic effect

  14. Natural organic matter and sunlight accelerate the degradation of 17ss-estradiol in water

    Leech, Dina M. [Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557 (United States)], E-mail: dmleech@email.unc.edu; Snyder, Matthew T.; Wetzel, Robert G. [Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2009-03-01

    Nanomolar concentrations of steroid hormones such as 17{beta}-estradiol can influence the reproductive development and sex ratios of invertebrate and vertebrate populations. Thus their release into surface and ground waters from wastewater facilities and agricultural applications of animal waste is of environmental concern. Many of these compounds are chromophoric and susceptible to photolytic degradation. High intensity UV-C radiation has been demonstrated to degrade some of these compounds in engineered systems. However, the degradation efficacy of natural solar radiation in shallow fresh waters is less understood. Here photolytic experiments with 17{beta}-estradiol demonstrated modest photodegradation ({approx} 26%) when exposed to simulated sunlight between 290 and 720 nm. Photodegradation significantly increased ({approx} 40-50%) in the presence of 2.0-15.0 mg/l of dissolved organic carbon (DOC) derived from humic acids of the Suwannee River, GA. However, rates of photodegradation reached a threshold at approximately 5.0 mg/l DOC. Observed suppression of photolysis in the presence of a radical inhibitor (i.e. 2-propanol) indicated that a significant proportion of the degradation was due to radicals formed from the photolysis of DOC. Although photodegradation was greatest in full sunlight containing UV-B (290-320 nm), degradation was also detected with UV-A (320-400 nm) and visible light (400-720 nm) alone.

  15. Determination of alcohol compounds using corona discharge ion mobility spectrometry

    HAN Hai-yan; HUANG Guo-dong; JIN Shun-ping; ZHENG Pei-chao; XU Guo-hua; LI Jian-quan; WANG Hong-mei; CHU Yan-nan

    2007-01-01

    Ion mobility spectrometry (IMS) is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions (H2O)nH+ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions (H2O)nH+. The mixture of these alcohols, including two isomers, has been detected, and the result shows that they can also be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional 63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L.

  16. Synthesis of Highly Ordered Hydrothermally Stable Mesoporous Niobia Catalysts by Atomic Layer Deposition

    Pagan-Torres, Yomaira J; Gallo, Jean Marcel R; Wang, Dong; Pham, Hien N; Libera, J.A.; Marshall, Christopher L; Elam, Jeffrey W.; Datye, Abhaya K; Dumesic, James A

    2011-10-07

    A new class of mesoporous niobia catalysts has been synthesized by atomic layer deposition (ALD) of niobia within the pores of a mesoporous silica (SBA-15). Mesoporous materials after ALD cycles of niobia maintained the structural organization of SBA-15. Increasing loadings of niobia cause a decrease in the surface area, pore volume, and pore diameter due to the conformal coating of niobia within the pores. Materials containing 10, 19, and 30 cycles show remarkable hydrothermal stability, with minimal change in porosity and structural properties upon treatment in liquid water at 473 K. The mesoporous niobia material produced by 19 cycles has been studied as an acid catalyst for the gas-phase dehydration of 2-propanol, and for the dehydration of 2-butanol in both the gas and liquid phases, showing catalytic activity superior to commercial niobia (HY-340) per mass of material. Furthermore, deposition of Pd nanoparticles on this material consisting of SBA-15 coated with 19 cycles of niobia leads to a bifunctional catalyst for the transformation of γ-valerolactone to pentanoic acid, showing better stability versus time-on-stream compared to a conventional catalyst consisting of Pd supported on HY-340.

  17. Photocatalytic reduction of vanadium(V) in TiO2 suspension: Chemometric optimization and application to wastewaters

    Highlights: • Photocatalytic reduction of harmful vanadium(V) to vanadium(IV) is studied in water. • Quantitative conversion is achieved under sunlight. • Natural organic matter acts as electron donor allowing rapid vanadium(V) reduction. • The procedure is effective for remediation of vanadium(V)-contaminated wastewaters. -- Abstract: The photocatalytic reduction of V(V) to V(IV) over TiO2 in aqueous solution is presented. Experiments were undertaken on air-equilibrated water spiked with V(V) (0.6–20 mg L−1), under UV-A or solar light. A chemometric study was performed to optimize the reduction yield, by considering the most important variables recognized to affect the photocatalytic process. Among pH, irradiation time and catalyst concentration, the two latter proved to be determinant. The good yields achieved (up to 98%), along with the possibility of working in aerated solution, make this procedure simple, rapid and efficient. Although a deep insight on the photochemical mechanisms was beyond our scope, the role of electron donors was investigated, proving the efficiency of 2-propanol, citric acid and formic acid in the acceleration and improvement of V(V) conversion. After irradiation, total vanadium and aqueous V(V) and V(IV) after solid-phase separation on Chelex-100 resin, were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). The procedure was applied to contaminated wastewaters, combining remediation and possible vanadium recovery as V(IV)

  18. Reaction of CO with Ta(eta5-C5Me5)Me4. Intramolecular reductive coupling of carbon monoxide via an eta2-acetone intermediate

    Ta(eta5-C5Me5)Me4 (1) reacts rapidly with 1 mol of CO at 250C to give (in 80% yield) an eta2-acetone complex, monomeric (2). Its IR spectrum shows a peak at 1200/cm which may be described as an oxytantallacyclopropane complex. Since its 1H and 13C NMR spectra show only three types of methyl groups, and since the peak for the acetone methyl group broadens significantly at -800C in toluene-d8 in the 270-MHz 1H NMR spectrum, it is suggested that the molecule has a ground state pseudo-tetragonal-pyramidal geometry which rearranges rapidly under most conditions. Acetone is produced when 2 is treated with oxygen, but bound acetone does not exchange readily with free acetone-d6. Eta2-acetone is reduced to 2-propanol when 2 is treated with water; 2 mol of methane are also formed. The reaction of 1 with enriched 13CO gave Ta(eta5-C5Me5)(0 = 13CMe2)Me2 (2-13C). The peak suspected as upsilon/sub C-O/ at 1200/cm in 2 shifts to 1180/cm in 2-13C. No intermediate was detected between 1 and 2 in low temperature 13C NMR experiments

  19. Volumetric and viscometric properties of binary mixtures of {methyl tert-butyl ether (MTBE) + alcohol} at several temperatures and p = 0.1 MPa: Experimental results and application of the ERAS model

    Highlights: → Binary mixtures of MTBE + alcohol have been studied. → Volumetric and viscometric properties have been determined at several temperatures. → Excess molar volumes have been used to test the applicability of the ERAS model. → The results are discussed in terms of chemical and structural effects. - Abstract: Densities and viscosities of binary mixtures of {methyl tert-butyl ether (MTBE) + methanol, or +ethanol, or +1-propanol, or +2-propanol, or +1-butanol, or +1-pentanol, or +1-hexanol} have been determined as a function of composition at several temperatures and atmospheric pressure. The temperatures studied were (293.15, 298.15, 303.15, and 308.15) K. The experimental results have been used to calculate the excess molar volume (VmE) and viscosity deviation (Δη). Both VmE and Δη values were negative over the entire range of mole fraction for all temperatures and systems studied. Moreover, the VmE values have been used to test the applicability of the Extended Real Associated Solution (ERAS) model.

  20. Solubilities of some organic solutes in 1-ethyl-3-methylimidazolium acetate. Chromatographic measurements and predictions from COSMO-RS

    Highlights: ► New solubility data are reported. ► Two experimental procedures for measuring solubilities are used. ► The experimental results from both procedures are compared. ► Experiments are compared with the theoretical calculations. - Abstract: Infinite-dilution activity coefficients and Henry’s constants for several organic solutes in 1-ethyl-3-methylimidazolium acetate [EMIM][Ac] were measured from T = 313 K to T = 413 K using two types of gas–liquid chromatography columns: packed columns and an open tubular wall-coated (OTWC) column. The organic solutes include n-hexane, 1-hexene, cyclohexane, heptane, benzene, toluene, ethyl acetate, tetrahydrofuran, 1,4-dioxane, acetonitrile, nitromethane, 1,2-methoxyethane, 1-propanol, 2-propanol, t-butanol and t-amyl alcohol. Results using packed columns are in good agreement with those using the OTWC column. However, there is a useful advantage associated with an OTWC column: for solutes such as alcohols, that have strong interactions with the stationary phase, measurements are faster due to their shorter retention time compared to those in packed columns.

  1. Magnetically responsive enzyme powders

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  2. Extraction and separation of zinc and cadmium chlorides by TOPO from mixed media

    The effect of water-miscible alcohols and acetone on the extraction and separation of Cd and Zn chlorides by TOPO was systematically investigated. The maximum extraction of Zn chloride with 0.1 M TOPO decreases in the order: acetone > methanol > ethanol > 2-propanol > 2-butanol. For alcohols, the sequence of decreasing extractability is thus parallel to the order of their dielectric constants. This can be explained by the increase of HCl extraction by TOPO in the same direction. The presence of additives in the polar phase prevents the formation of a bulky white precipitate encountered during extraction of ZnCl2 from pure aqueous solutions. A decrease of Cd chloride extraction was generally noticed in presence of additives; this is more noticeable for the longer chain alcohols. The highest separation factor (E) for ZnCl2 and CdCl2 in 0.48 M HCl is obtained from 30% methanol (13.8 compared to about 3.8 in absence of methanol) and from 10-20% acetone where it reaches 30. (author)

  3. Factors controlling volatile organic compounds in dwellings in Melbourne, Australia.

    Cheng, M; Galbally, I E; Molloy, S B; Selleck, P W; Keywood, M D; Lawson, S J; Powell, J C; Gillett, R W; Dunne, E

    2016-04-01

    This study characterized indoor volatile organic compounds (VOCs) and investigated the effects of the dwelling characteristics, building materials, occupant activities, and environmental conditions on indoor VOC concentrations in 40 dwellings located in Melbourne, Australia, in 2008 and 2009. A total of 97 VOCs were identified. Nine VOCs, n-butane, 2-methylbutane, toluene, formaldehyde, acetaldehyde, d-limonene, ethanol, 2-propanol, and acetic acid, accounted for 68% of the sum of all VOCs. The median indoor concentrations of all VOCs were greater than those measured outdoors. The occupant density was positively associated with indoor VOC concentrations via occupant activities, including respiration and combustion. Terpenes were associated with the use of household cleaning and laundry products. A petroleum-like indoor VOC signature of alkanes and aromatics was associated with the proximity of major roads. The indoor VOC concentrations were negatively correlated (P < 0.05) with ventilation. Levels of VOCs in these Australian dwellings were lower than those from previous studies in North America and Europe, probably due to a combination of an ongoing temporal decrease in indoor VOC concentrations and the leakier nature of Australian dwellings. PMID:25788118

  4. Synthesis, characterization and application of naïve and nano-sized titanium dioxide as a photocatalyst for degradation of methylene blue

    Arpita Pandey

    2015-09-01

    Full Text Available In the present work, photocatalytic degradation of methylene blue has been carried out using naïve titanium dioxide, nano-sized titanium dioxide and H2O2 under visible light. The catalysts, naïve and nano-sized titanium dioxide were prepared by the sol–gel method. Characterization of synthesized catalysts has been done by scanning electron microscopy (SEM, X-ray diffraction (XRD and UV–Visible spectroscopy. The rate of degradation of dye was monitored spectrophotometrically by measuring absorbance of dye at regular time intervals. The effect of various parameters such as pH, concentration of dye, amount of catalyst, amount of H2O2 and light intensity on the rate of reaction has been studied. Various parameters like chemical oxygen demand (COD, conductance, pH, TDS, salinity and dissolved oxygen (DO for the reaction mixture have also been determined. A tentative mechanism for degradation of dye has been proposed involving ·−OH radical as an oxidant. The participation of ·−OH radical has been confirmed by using 2-propanol (scavenger as the rate of reaction was drastically reduced in its presence.

  5. Gamma-irradiated carboxymethyl kappa-carrageenan nano gels as potential drug delivery system

    This study aims to produce, characterize and assess the potential of gamma-irradiated carboxymethyl kappa-carrageenan nano gels for drug delivery system. The carboxy methylation of κ-carrageenan was carried out in 2 propanol, activated with appropriate amount of 16N sodium hydroxide and reacted with monochloroacetic acid as etherifying agent. The carboxymethyl κ-carrageenan was further subjected to gamma-irradiation followed by the formation of nano gels. In this study, nano gels were prepared from gamma irradiated carboxymethyl κ-carrageenan encapsulating a model redox indicator (methylene blue, neutral, with a pH range of 6.0-7.6), using reverse microemulsions combined with thermally induced gelation. Nano gels were characterized through Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Differential Thermal Analysis. In vitro drug loading and in vitro drug release studies were done. It was found that gamma-irradiated carboxymethyl κ-carrageenan has the potential for drug delivery system, prolonged release in particular. Furthermore, it was proven that the loading capacity,as well as the amount of drug release, increases with the dose of gamma-irradiated carboxymethyl κ-carrageenan nano gels. No significant interaction effect was seen among the different dose of gamma-irradiated carboxymethyl κ-carrageenan nano gels; a significant increase in the methylene blue release was observed with time. (author)

  6. Design and construction of a compact end-station at NSRRC for circular-dichroism spectra in the vacuum-ultraviolet region.

    Liu, Szu Heng; Lin, Yi Hung; Huang, Liang Jen; Luo, Shiang Wen; Tsai, Wan Lin; Chiang, Su Yu; Fung, Hok Sum

    2010-11-01

    A synchrotron-radiation-based circular-dichroism end-station has been implemented at beamline BL04B at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan for biological research. The design and performance of this compact end-station for measuring circular-dichroism spectra in the vacuum-ultraviolet region are described. The linearly polarized light from the beamline is converted to modulated circularly polarized light with a LiF photoelastic modulator to provide a usable wavelength region of 130-330 nm. The light spot at the sample position is 5 mm × 5 mm at a slit width of 300 µm and provides a flux greater than 1 × 10(11) photons s(-1) (0.1% bandwidth)(-1). A vacuum-compatible cell made of two CaF(2) windows has a variable path length from 1.3 µm to 1 mm and a temperature range of 253-363 K. Measured CD spectra of (1S)-(+)-10-camphorsulfonic acid and proteins demonstrated the ability of this system to extend the wavelength down to 172 nm in aqueous solution and 153 nm in hexafluoro-2-propanol. PMID:20975221

  7. Diastereo- and Enantioselective Iridium Catalyzed Coupling of Vinyl Aziridines with Alcohols: Site-Selective Modification of Unprotected Diols and Synthesis of Substituted Piperidines.

    Wang, Gang; Franke, Jana; Ngo, Chinh Q; Krische, Michael J

    2015-06-24

    The chiral cyclometalated π-allyliridium ortho-C,O-benzoate complex (R)-Ir-VIb derived from [Ir(cod)Cl]2, allyl acetate, 4-cyano-3-nitro-benzoic acid, and (R)-MeO-BIPHEP catalyzes the coupling of N-(p-nitrophenylsulfonyl) protected vinyl aziridine 3a with primary alcohols 1a-1l to furnish branched products of C-C bond formation 4a-4l with good levels of anti-diastereo- and enantioselectivity. In the presence of 2-propanol, but under otherwise identical conditions, vinyl aziridine 3a and aldehydes 2a-2l engage in reductive coupling to furnish an equivalent set of adducts 4a-4l with roughly equivalent levels of anti-diastereo- and enantioselectivity. Using enantiomeric iridium catalysts, vinyl aziridine 3a reacts with unprotected chiral 1,3-diols 1m-1o in a site-selective manner to deliver the diastereomeric products of C-allylation syn-4m, -4n, -4o and anti-4m, -4n, -4o, respectively, with good isolated yields and excellent levels of catalyst-directed diastereoselectivity. These adducts were directly converted to the diastereomeric 2,4,5-trisubstituted piperidines syn-5m, -5n, -5o and anti-5m, -5n, -5o. PMID:26074091

  8. Crystallization and preliminary X-ray analysis of AzoR (azoreductase) from Escherichia coli

    The crystallization and preliminary X-ray analysis of AzoR (azoreductase) have been performed. AzoR (azoreductase), an FMN-dependent NADH-azo compound oxidoreductase from Escherichia coli, has been crystallized in the presence of FMN by the sitting-drop vapour-diffusion method using 2-propanol as a precipitant. AzoR catalyzes the reductive cleavage of azo groups. The crystals were found to diffract X-rays to beyond 1.8 Å resolution using a synchrotron-radiation source. The crystals belonged to the tetragonal space group P42212, with unit-cell parameters a = b = 92.2, c = 51.9 Å. The crystals are expected to contain one subunit of the homodimer in the asymmetric unit (VM = 2.6 Å3 Da−1) and to have a solvent content of 51.6%. Data sets were also collected from heavy-atom derivatives for use in phasing. As a result, crystals soaked in a solution containing K2PtCl4 for 23 d were found to be reasonably isomorphous to the native crystals and the presence of Pt atoms could be confirmed. The data sets from the native crystals and the K2PtCl4-derivatized crystals are being evaluated for use in structure determination by single isomorphous replacement with anomalous scattering

  9. Sonochemically synthesized mono and bimetallic Au-Ag reduced graphene oxide based nanocomposites with enhanced catalytic activity.

    Neppolian, Bernaurdshaw; Wang, Chang; Ashokkumar, Muthupandian

    2014-11-01

    Graphene oxide (GO) supported Ag and Au mono-metallic and Au-Ag bimetallic catalysts were synthesized using a sonochemical method. Bimetallic catalysts containing different weight ratios of Au and Ag were loaded onto GO utilizing a low frequency horn-type ultrasonicator. High frequency ultrasonication was used to efficiently reduce Ag(I) and Au(III) ions in the presence of polyethylene glycol and 2-propanol. Transmission electron microscopy (TEM-EDX) and X-ray photoelectron spectroscopy were used to analyze the morphology, size, shape and chemical oxidation states of the prepared metallic catalysts on GO. The catalytic efficiency of the prepared catalysts were compared using 4-nitrophenol (4-NP) reduction reaction and the subsequent formation of 4-aminophenol (4-AP) that was also monitored using UV-vis spectrophotometry. The results revealed that Au-Ag-GO bimetallic catalysts showed high activity for the conversion of 4-NP to 4-AP than their monometallic counterparts. Amongst different weight ratios (1:1, 1:2 and 2:1) between Au and Ag, the 1:2 (Au:Ag) catalyst exhibited very good catalytic performance for the conversion of 4-NP to 4-AP. A total reduction of 4-NP took place within a short period of time if Au-GO was reduced first followed by Ag reduction, whereas a lower reduction rate was observed if Ag-GO was reduced first. The same trend was observed for all the ratios of bimetallic catalysts prepared by this method. The initial unfavorable reduction potential of Ag(I) is likely to be responsible for the above order. It was found that applying dual frequency ultrasonication was a highly effective way of preparing bimetallic catalysts requiring relatively low levels of added chemicals and producing bimetallic catalysts with GO with improved catalytic efficiency. PMID:24582660

  10. Determination of cocaine and its metabolites in plasma by porous membrane-protected molecularly imprinted polymer micro-solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Sánchez-González, Juan; García-Carballal, Sara; Cabarcos, Pamela; Tabernero, María Jesús; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-06-17

    A selective molecularly imprinted polymer synthesized for the selective retention of cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] was used as a solid adsorbent for assessing cocaine abuse by plasma analysis. The MIP beads (50mg) were loaded inside a cone shaped device made of a polypropylene (PP) membrane for micro-solid-phase extraction (μ-SPE). High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used for quantifying the analytes after MIP-μ-SPE. The best retention capabilities were reached when loading plasma samples (within the 0.1-5.0mL range), previously adjusted to pH 5.5 by orbital-horizontal shaking (150rpm, 50°C) for 10min. Analyte elution was achieved by subjecting the MIP-μ-SPE device to ultrasound (37kHz, 325W) with 10mL of dichloromethane/2-propanol/ammonium hydroxide (76:20:4) for 8min. After eluate evaporation to dryness and re-dissolution in 100μL of mobile phase, the MIP-μ-SPE method yielded a pre-concentration factor of 50. Precision was assessed by intra-day and inter-day assays, and accuracy (intraday and inter-day analytical recovery, as well as the analysis of a BTMF 1/11-B control serum sample) show that the developed method is highly precise and accurate. In addition, the limits of detection, ranging from 0.061ngmL(-1) for COC to 0.87ngmL(-1) for BZE, were low enough for confirmative conclusions regarding cocaine abuse. The method was used for screening/quantifying cocaine and metabolites in plasma samples from poly-drug abusers. PMID:27207577

  11. Titania modification with a ruthenium(II) complex and gold nanoparticles for photocatalytic degradation of organic compounds.

    Zheng, Shuaizhi; Wei, Zhishun; Yoshiiri, Kenta; Braumüller, Markus; Ohtani, Bunsho; Rau, Sven; Kowalska, Ewa

    2016-01-01

    Titania of fine anatase nanoparticles (ST01) was modified successively with two components, i.e., a ruthenium(II) complex with phosphonic anchoring groups [Ru(bpy)2(4,4'-(CH2PO3H2)2bpy)](2+) bpy = 2,2'-bipyridine (Ru(II)CP) and gold nanoparticles (Au). Various compositions of two titania modifiers were investigated, i.e., Au, Au + Ru(II)CP, Au + 0.5Ru(II)CP, Ru(II)CP, 0.5Ru(II)CP and 0.25Ru(II)CP, where Au and Ru(II)CP correspond to 0.81 mol% and 0.34 mol% (with respect to titania), respectively. In the case of hybrid photocatalysts, the sequence of modification (ruthenium(II) complex adsorption or gold deposition) was investigated to check its influence on the resultant properties and thus photocatalytic performance. Diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM) were applied to characterize the structural properties of the prepared photocatalysts, which confirmed the successful introduction of modifiers of the ruthenium(II) complex and/or gold NPs. Different distributions of gold particle sizes and chemical compositions were obtained for the hybrid photocatalysts prepared with an opposite sequence. It was found that photocatalytic activities depended on the range of used irradiation (UV/vis or vis) and the kind of modifier in different ways. Gold NPs improved the photocatalytic activities, while Ru(II)CP inhibited the reactions under UV/vis irradiation, i.e., methanol dehydrogenation and acetic acid degradation. Oppositely, Ru(II)CP greatly enhanced the photocatalytic activities for 2-propanol oxidation under visible light irradiation. PMID:26661372

  12. Synthesis 1-(5-oxohexyl)-3,7-dimethyl-xanthyne labelled with tritium into 8 position from purinic ring

    This paper presents the work on synthesis of 1-(5-oxohexyl)-3,7-dimethyl-xanthyne labelled with tritium into 8 position from purinic ring. The obtaining of tritium labelled compound is realized by initial labelling of theobromine with tritium into 8 position and by coupling the purinic derivative to 1-Br-5-hexanone. Theobromine-8- 3 H was obtained by the bromination of theobromine with elementary bromine and after that the bromine was substituted with tritium i.e.: C7H8O2N4 theobromine Br2/(-HBr) C7H7O2N4 Br (8-Br-theobromine) (3 H2/cat)/(-KOH) C7H73 HO2N4 (theobromine-8- 3 H). Theobromine-8- 3 H was purified by thin layer chromatography with a solvent system i.e. n-BuOH:AcOH:H2O (4:1:1, v/v/v) and characterized radiochemically. It was then diluted by unlabelled theobromine to specific activity of 50 mCi/g. After dilution, theobromine-8-3 H was coupled to 1-Br-5-hexanone i.e.: C7H73 HO2N4 (theobromine-8- 3 H) + Br-(CH2)4-CO-CH3 (1-Br-5-hexanone) (NaOH)/(CH3OH) C13 H173 HO3N4 (1-(5-oxohexyl)- 3,7-dimethyl-xanthine-8- 3 H). The raw compound was purified by recrystallization from 2-propanol and it was characterized radiochemically. (authors)

  13. Cloning, recombinant expression and biochemical characterisation of novel esterases from Bacillus sp. associated with the marine sponge Aplysina aerophoba.

    Karpushova, A; Brümmer, F; Barth, S; Lange, S; Schmid, R D

    2005-04-01

    Two novel esterases (EstB1 and EstB2) were isolated from a genomic library of Bacillus sp. associated with the marine sponge Aplysina aerophoba. EstB1 shows low identity (26-44%) with the published hydrolases of the genus Bacillus, whereas EstB2 shows high identity (73-74%) with the carboxylesterases from B. cereus and B. anthracis. Both esterases were efficiently expressed in Escherichia coli under the control of T7 promoter using the vector pET-22b(+). Recombinant EstB1 was purified in a single step to electrophoretic homogeneity by IMAC. A method for the refolding of inclusion bodies formed by the recombinant EstB2 was established to obtain active enzyme. Substrate specificity of the two enzymes towards p-nitrophenyl and methyl esters and the respective kinetic parameters K(m) and V(max) were determined. The temperature optima of EstB1 and EstB2 were determined to be in the range of 30-50 degrees C and 20-35 degrees C, respectively. The pH optima were found to be in the range of 6.5-7.5 and 6.5-8.0, respectively. Both enzymes showed the highest stability in up to 50% (v/v) DMSO followed by methanol, ethanol and 2-propanol. The influence of high NaCl and KCl concentrations was tested. The inhibition effect of 10-50 mM Zn(2+) and 50 mM Mg(2+) and Ca(2+) ions was observed for both esterases. One to five millimolar PMSF deactivated the enzymes, whereas beta-mercaptoethanol, DTT and EDTA had no effect on the enzymes activity. PMID:15614567

  14. Synthesis of levan in water-miscible organic solvents.

    Castillo, E; López-Munguía, A

    2004-10-19

    The synthesis of levan using a levansucrase from a strain of Bacillus subtilis was studied in the presence of the water-miscible solvents: acetone, acetonitrile and 2-methyl-2-propanol (2M2P). It was found that while the enzyme activity is only slightly affected by acetone and acetonitrile, 2M2P has an activating effect increasing the total activity 35% in 40-50% (v/v) 2M2P solutions at 30 degrees C. The enzyme is highly stable in water at 30 degrees C; however, incubation in the presence of 15 and 50% (v/v) 2M2P reduced the half-life time to 23.6 and 1.8 days, respectively. This effect is reversed in 83% 2M2P, where a half-life time of 11.8 days is observed. The presence of 2M2P in the system increases the transfer/hydrolysis ratio of levansucrase. As the reaction proceeds with 10% (w/v) sucrose in 50/50 water/2M2P sucrose is converted to levan and an aqueous two-phase system (2M2P/Levan) is formed and more sucrose can be added in a fed batch mode. It is shown that high molecular weight levan is obtained as an hydrogel and may be easily recovered from the reaction medium. However, when high initial sucrose concentrations (40% (w/v) in 50/50 water/2M2P) are used, an aqueous two-phase system (2M2P/sucrose) is induce, where the synthesized levan has a similar molecular weight distribution as in water and remains in solution. PMID:15464614

  15. Visible light-sensitive yellow TiO2-x N x and Fe-N co-doped Ti1-y Fe y O2-x N x anatase photocatalysts

    Nitrogen substituted yellow colored anatase TiO2-x N x and Fe-N co-doped Ti1-y Fe y O2-x N x have been easily synthesized by novel hydrazine method. White anatase TiO2-δ and N/Fe-N-doped samples are semiconducting and the presence of ESR signals at g ∼1.994-2.0025 supports the oxygen vacancy and g∼4.3 indicates Fe3+ in the lattice. TiO2-x N x has higher conductivity than TiO2-x and Fe/Fe-N-doped anatase and the UV absorption edge of white TiO2-x extends in the visible region in N, Fe and Fe-N co-doped TiO2, which show, respectively, two band gaps at ∼3.25/2.63, ∼3.31/2.44 and 2.8/2.44 eV. An activation energy of ∼1.8 eV is observed in Arrhenius log resistivity vs. 1/T plots for all samples. All TiO2 and Fe-doped TiO2 show low 2-propanol photodegradation activity but have significant NO photodestruction capability, both in UV and visible regions, while standard Degussa P-25 is incapable in destroying NO in the visible region The mid-gap levels that these N and Fe-N-doped TiO2 consist may cause this discrepancy in their photocatalytic activities. - Graphical abstract: DRS of TiO2, N/Fe-N doped TiO2

  16. Crystal optimization and preliminary diffraction data analysis of the Smad1 MH1 domain bound to a palindromic SBE DNA element

    Crystals of palindromic SBE DNA-bound Smad1 MH1 domain diffracting to 2.7 Å resolution have been obtained. The bone morphogenetic protein (BMP) signalling pathway regulates diverse processes such as cell differentiation, anterior/posterior axis specification, cell growth and the formation of extra-embryonic tissues. The transcription factor Smad1 relays the BMP signal from the cytoplasm to the nucleus, where it binds short DNA-sequence motifs and regulates gene expression. However, how Smad1 selectively targets particular genomic regions is poorly understood. In order to understand the physical basis of the specific interaction of Smad1 with DNA and to contrast it with the highly homologous but functionally distinct Smad3 protein, the DNA-binding Mad-homology 1 (MH1) domain of Smad1 was cocrystallized with a 17-mer palindromic Smad-binding element (SBE). The extensive optimizations of the length, binding-site spacing and terminal sequences of the DNA element in combination with the other crystallization parameters necessary for obtaining diffraction-quality crystals are described here. A 2.7 Å resolution native data set was collected at the National Synchrotron Radiation Research Centre, Taiwan, from crystals grown in a solution containing 0.2 M ammonium tartrate dibasic, 20% PEG 3350, 3% 2-propanol and 10% glycerol. The data set was indexed and merged in space group P222, with unit-cell parameters a = 73.94, b = 77.49, c = 83.78 Å, α = β = γ = 90°. The solvent content in the unit cell is consistent with the presence of two Smad1 MH1 molecules bound to the duplex DNA in the asymmetric unit

  17. Formation of 8-hydroxy(deoxy)guanosine and generation of strand breaks at guanine residues in DNA by singlet oxygen

    Singlet molecular oxygen (1O2) was generated in aqueous solution (H2O or D2O) at 37 C by the thermal dissociation of the endoperoxide of 3,3'-(1,4-naphthylidene) dipropionate (NDPO2). Guanosine and deoxyguanosine quench 1O2 with overall quenching rate constants of 6.2 x 106 M-1 s-1 and 5.2 x 106 M-1 s-1, respectively. Reaction with 1O2 results in the formation of 8-hydroxyguanosine (8-OH-Guo) and 8-hydroxydeoxyguanosine (8-OH-dGuo), respectively, with a yield of 1.5% at 1 mM substrate with an NDPO2 concentration of 40 mM; a corresponding 8-hydroxy derivative is not formed from deoxyadenosine. in D2O the yield of 8-OH-Guo is 1.5-fold that in H2O. Sodium azide suppresses 8-OH-Guo and 8-OH-dGuo production. in contrast, the hydroxyl radical scavengers, tert-butanol, 2-propanol, or sodium formate, do not decrease the production of the 8-OH derivatives. The formation of 8-OH derivatives is significantly increased (2-5-fold) by thiols such as dithiothreitol, glutathione, cysteine, and cysteamine. With use of a plasmid containing a fragment of the mouse metallothionein 1 promoter (pMTP3') and a novel end-labeling technique, the position of 1O2-induced single-strand breaks in DNA was examined. Strand breaks occur selectively at dGuo; no major differences (hot spots) were observed between individual guanines

  18. Induction of DNA strand breaks by RSU-1069, a nitroimidazole-aziridine radiosensitizer

    [2-14C]-RSU-1069 [1-(2-nitro-1-imidazolyl)-3-(1-aziridino)-2-propanol], either as a parent or following radiation reduction, binds to calf thymus DNA in vitro. Radiation-reduced RSU-1069 binds to a greater extent and more rapidly than the parent compound. RSU-1137, a non-aziridino analogue of RSU-1069, binds following radiation reduction. Radiation-reduced misonidazole exhibits binding ratios a thousand-fold less than those of reduced RSU-1069. Both parent and reduced RSU-1069 cause single strand breaks (ssbs) in pSV2 gpt plasmid DNA with the reduced compound causing a greater number of breaks. Parent and reduced RSU-1137 and misonidazole do not cause ssbs. It is inferred that the aziridine moiety present in both parent and reduced RSU-1069 is required for ssb production. RSU-1069 reacts with inorganic phosphate probably via nucleophilic ring-opening of the aziridine fragment. Incubation of plasmid DNA with reduced RSU-1069 in the presence of either phosphate or deoxyribose-5-phosphate at concentrations greater than 0.35 mol dm-3 prevents strand breakage, whereas 1.2 mol dm-3 deoxyribose does not protect against strand breakage formation. It is proposed that the observed binding to DNA occurs via the aziridine and the reduced nitro group of RSU-1069 and that these two have different target sites. Binding to DNA via the reduced nitro group may serve to increase aziridine attack due to localization at or near its target. (author)

  19. Mesenchymal stromal cell-derived extracellular matrix influences gene expression of chondrocytes

    Decellularized extracellular matrix (ECM) has recently gained a lot of interest as an instructive biomaterial for regenerative medicine applications. In this study, the ability of adult human mesenchymal stem cell (hMSC)-derived ECM to rescue the phenotype of osteoarthritic (OA) chondrocytes and to further stimulate the differentiation of healthy (HL) chondrocytes was evaluated. ECMs were prepared by decellularizing hMSCs cultured in basic medium (BM) and chondrogenic medium (CM). The obtained ECM was then combined with a polymeric solution of Poly (ε-caprolactone) (PCL) dissolved in 1, 1, 1, 3, 3, 3-hexafluoro-2-propanol (HFIP) and electrospun meshes were fabricated. Electrospun ECM scaffolds were characterized using scanning electron microscopy (SEM) and picrosirius red staining was used to confirm the presence of collagen. OA and HL chondrocytes were cultured on scaffolds containing hMSC ECM in BM or CM and compared to PCL electrospun scaffolds without ECM. Metabolic activity and chondrogenic gene expression were assessed by Alamar blue assay and quantitative PCR (qPCR) analysis, respectively. The ECM presence resulted in a significant difference in chondrocyte metabolic activity compared to PCL scaffolds alone. HL chondrocytes cultured for 21 days in chondrogenic medium on electrospun scaffolds containing hMSC ECM from BM showed a significant increase in collagen II and aggrecan expression compared to hMSC ECM from CM and PCL scaffolds without ECM incorporation. No significant influence of hMSC ECM presence on the chondrogenic signature of OA chondrocytes was found. The influence of decellularized hMSC ECM on HL chondrocytes suggests that hMSC-derived ECM scaffolds are promising candidates for cartilage tissue engineering applications. (paper)

  20. Phototransformations of non-toxic antioxidants, the derivatives of 1,2-dihydroquinolines, in homogeneous and micellar solutions

    T. D. Nekipelova

    1999-01-01

    Full Text Available Reactions of transient species photogenerated from 6-R-2,2,4-trimethyl-1,2-dihydroquinolines (TMDQ are very sensitive to medium variation. In anhydrous organic solvents, aminyl radicals were generated. They decay in the reaction of dimerization with the second-order rate constant decreasing in a row heptane>benzene>2-propanol. When passing from organic solvents to water, methanol, and water-alcohol solutions, the kinetics and the direction of the reaction crucially change. As a result of the photolysis, the product of the addition of a solvent to the double bond of heterocycle, 4-hydroxy- or 4-methoxy-6-R-2,2,4- tetramethyl-1,2,3,4-tetrahydroquinoline is formed in water and methanol, respectively. The transformation is a complex reaction, and the formation of excited transient species is followed by a sequence of first-order and pseudo-first-order reactions. Unlike the photolysis in anhydrous organic solvents, the reaction in water and methanol does not involve aminyl radicals. In aqueous solutions, the first-order rate constants for the decay of transient species are higher in acidic and neutral solutions. At the pH close to pKa of the transient species, it drops, indicating that the neutral form is less reactive. The same product is formed over the whole range of pH. For the anionic surfactant (SDS in acidic and alkaline solutions, the apparent rate constant in the micellar solutions is lower than that in the aqueous (negative micellar catalysis. At the medium pH, a positive micellar catalysis is observed, and the rate constant of the decay depends linearly on the concentration of TMDQ in the micelles, indicative of the direct reaction between TMDQ and the cationic transient species.

  1. Determination of aqueous fullerene aggregates in water by ultrasound-assisted dispersive liquid-liquid microextraction with liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry.

    Chen, Hsin-Chang; Ding, Wang-Hsien

    2012-02-01

    A simple and solvent-minimized method for the determination of three aqueous fullerene aggregates (nC₆₀, nC₇₀, and aqueous [6,6]-phenyl C₆₁ butyric acid methyl ester (nPCBM)) in water samples is described. The method involves the use of ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled liquid chromatography-tandem mass spectrometry with atmospheric pressure photoionization (LC-APPI-MS/MS). The parameters affecting the extraction efficiency of the analytes from water samples were systematically investigated and the conditions optimized. The best extraction conditions involved the rapid injection of a mixture of 1.0 mL of 2-propanol (as a disperser solvent) and 10 μL of benzyl bromide (as an extraction solvent) into 10 mL of an aqueous solution (pH 10.0) containing 1% sodium chloride in a conical bottom glass tube. After ultrasonication for 1.0 min and centrifugation at 5000 pm (10 min), the sedimented phase 5.0 μL was directly injected into the LC-APPI-MS/MS system. The limits of quantification (LOQs) were 150, 60 and 8 ng L⁻¹ for nPCBM, nC₆₀ and nC₇₀, respectively. The precision for these analytes, as indicated by relative standard deviations (RSDs), were less than 12% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 70 and 86%. A standard addition method was used to quantitate three aqueous fullerene aggregates, and the concentrations of these aqueous fullerene aggregates were determined to be in the range from n.d. to 130 ng L⁻¹ in various environmental samples including municipal influent and effluent samples, industrial wastewater samples, and surface water samples. PMID:22209304

  2. Indoor air quality in hair salons: Screening of volatile organic compounds and indicators based on health risk assessment

    de Gennaro, Gianluigi; de Gennaro, Lucrezia; Mazzone, Antonio; Porcelli, Francesca; Tutino, Maria

    2014-02-01

    Volatile organic compounds (VOCs) are common ingredients in cosmetic products which can impact human health. This study monitored 12 hairdressing salons in order to assess the individual exposure of the people working in or frequenting these environments as well as identify the main products or activities responsible for the presence of these compounds. In each site halogenated, oxygenated, aliphatic and aromatic compounds were monitored during the work week with diffusive samplers suitable for thermal desorption and analysed using GC-MS. The study of indoor-outdoor concentration ratios and a knowledge of the composition of most of the products, whether ecological or traditional, used in the hair salons verified the presence of compounds linked to hairdressing activities. In particular, compounds widely used in products for hair care as spray lacquer and foam (butane), shampoo, balms, hair masks and oils (camphene, camphor, limonene, eucalyptol, alpha pinene, 1-methoxy-2-propanol, n-butanol and menthol), and hair dye (benzyl alcohol, isopropanol, limonene, hexane and methyl ethyl ketone) were found at much higher levels inside rather than outside the salons (mean I/O > 10). The importance of this finding is linked to the potential health hazards of some of the VOCs detected. Integrated indicators of health risk were proposed in this study to assess the criticality level and rank the investigated environments accordingly. The results of this study indicate that the level of VOC concentrations was most affected by the type of products used while the size of the environment, the efficiency of air exchange and the number of customers had less impact on those levels.

  3. Pervaporation from a dense membrane: roles of permeant-membrane interactions, Kelvin effect, and membrane swelling.

    Sharma, Ashutosh; Thampi, Sumesh P; Suggala, Satyanarayana V; Bhattacharya, Prashant K

    2004-05-25

    Dense polymeric membranes with extremely small pores in the form of free volume are used widely in the pervaporative separation of liquid mixtures. The membrane permeation of a component followed by its vaporization on the opposite face is governed by the solubility and downstream pressure. We measured the evaporative flux of pure methanol and 2-propanol using dense membranes with different free volumes and different affinities (wettabilities and solubilities) for the permeant. Interestingly, the evaporative flux for different membranes vanished substantially (10-75%) below the equilibrium vapor pressure in the bulk. The discrepancy was larger for a smaller pore size and for more wettable membranes (higher positive spreading coefficients). This observation, which cannot be explained by the existing (mostly solution-diffusion type) models ofpervaporation, suggests an important role for the membrane-permeant interactions in nanopores that can lower the equilibrium vapor pressure. The pore sizes, as estimated from the positron annihilation, ranged from 0.2 to 0.6 nm for the dry membranes. Solubilities of methanol in different composite membranes were estimated from the Flory-Huggins theory. The interaction parameter was obtained from the surface properties measured by the contact angle goniometry in conjunction with the acid-base theory of polar surface interactions. For the membranes examined, the increase in the "wet" pore volume due to membrane swelling correlates almost linearly with the solubility of methanol in these membranes. Indeed, the observations are found to be consistent with the lowering of the equilibrium vapor pressure on the basis of the Kelvin equation. Thus, a higher solubility or selectivity of a membrane also implies stronger permeant-membrane interactions and a greater retention of the permeant by the membrane, thus decreasing its evaporative flux. This observation has important implications for the interpretation of existing experiments and in

  4. Separation of several alcohol-benzene mixtures by pervaporation through styrene graft polyethylene membranes

    The permeation of pure liquids, such as methanol, ethanol, 1-propanol, 2-propanol and benzene, and the permeability and selectivity of 50 vol% binary mixtures of these alcohols and benzene were investigated by pervaporation technique. The used membranes (21%, 40%, and 72% graftings) were obtained by graft polymerization of styrene to polyethylene film (thickness 10 μm) by γ-radiation. The permeation rates of each of these alcohols and benzene were measured by pervaporation through the graft membranes. Those of these alcohols were very small as well as those through the original membrane. On the other hand, the permeabilities for benzene through the graft membranes were larger than that through the original membrane. The temperature dependence of the permeation rate for benzene was expressed by Arrhenius-type relationships, and the apparent activation energies were calculated to be 10.7 (21%), 10.2 (40%) and 10.0 (72%) kcal/mol. In the permeation of 50 vol% several alcohol-benzene mixtures, the permeabilities through the graft membranes were also larger than that through the original membrane, and increased with the grafting. The temperature dependence of the permeation for these mixtures was showed by Arrhenius relationships, and the apparent activation energies were calculated to be in the range of 8.4∼11.0 kcal/mol. The separation factors of the graft membranes calculated from composition of the permeates were always smaller than that of the original membrane, but became larger with increase of molecular volume of alcohol in alcohol-benzene mixtures. (author)

  5. Physico-chemical properties of Pd nanoparticles produced by Pulsed Laser Ablation in different organic solvents

    Cristoforetti, Gabriele, E-mail: gabriele.cristoforetti@cnr.it [National Institute of Optics, Research Area of National Research Council, Via G. Moruzzi 1, 56124 Pisa (Italy); Pitzalis, Emanuela; Spiniello, Roberto [Institute of Chemistry of OrganoMetallic Compounds, Research Area of National Research Council, Via G. Moruzzi 1, 56124 Pisa (Italy); Ishak, Randa [Department of Chem. Eng. And Material Science, University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy); Giammanco, Francesco [Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Muniz-Miranda, Maurizio; Caporali, Stefano [Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy)

    2012-01-15

    Palladium nanoparticles are arousing an increasing interest because of their strong activity in heterogeneous catalysis in a wide range of reactions. Driven by the interest of producing Pd nanoparticles to be deposited for catalysis over hydrophobic supports, we investigated their synthesis via Pulsed Laser Ablation in Liquid in several organic solvents, as acetone, ethanol, 2-propanol, toluene, n-hexane. The colloids were produced by using a Nd:YAG ns laser and without the addition of surfactant agents. The morphology, composition, stability and oxidation state of the obtained nanoparticles were investigated by TEM-EDS analysis, UV-vis spectroscopy, X-ray Photoelectron Spectroscopy and micro-Raman spectroscopy. The results evidence that the nature of the solvent influences both the yield and the physico-chemical properties of the produced nanoparticles. While in acetone and alcohols spheroidal, non aggregated and stable particles are obtained, in case of toluene and n-hexane few unstable particles surrounded by a gel-like material are produced. Raman/XPS measurements suggest the presence of amorphous or graphitic carbon onto crystalline Pd nanoparticles, which could have hindered their growth and determined the observed smaller sizes if compared to nanoparticles produced in water. The stability of Pd colloids obtained in acetone and alcohols was attributed to adsorbed anions like enolates or alcoholates; non polar solvents like toluene and n-hexane, unable to give rise to adsorbed anionic species, cannot provide any stabilization to the palladium nanoparticles. XPS analyses also evidenced a partial oxidation of particles surface, with a ratio Pd{sup 2+}:Pd{sup 0} of 1:2.5 and 1:4 in acetone and ethanol, respectively.

  6. The effect of extracellular pH on radiosensitization by misonidazole and acidic or basic analogues

    Using hypoxic Chinese hamster v79 cells in vitro, misonidazole (1 mmol dm-3) gave an enhancement ratio (e.r.) of 1.6 which remained unchanged over the pHsub(e) range of 3.8-9.5. Control hypoxic survival curves in the absence of sensitizer (also) remained essentially unchanged over this pHsub(e) range. These results contrast with those seen for 0.1 mmol dm-3 Ro 03-8799 (1-(2-nitro-1-imidazolyl)-3-N-piperidino-2-propanol), a base with pKsub(a)=8.9): the ER increased from 1.4 to 2.1 as pHsub(e) increased from 5.6 to 8.4. However, with the weaker bases, Ro 03-8800 and nimorazole (morpholino derivatives with pKsub(a)=6.3 and 5.2 respectively) the e.r. remained constant over a wide pHsub(e) range. Nitroimidazoles substituted with acidic functions gave decreasing sensitization with increasing pHsub(e). For azomycin (pKsub(a)=7.2) at 1 mmol dm-3 the e.r. decreased from 1.9 at pHsub(e) 4 to 1.0 at pHsub(e) 9. The effect of the proton conductor carbonyl cyanide-3-chlorophenylhydrazone (CCCP, 10 μmol dm-3) on radiosensitization by Ro 03-8799 (0.1 mmol dm-3) and misonidazole (1.0 mmol dm-3) was also studied. At pHsub(e) 6.67 the e.r. for Ro 03-8799 was increased from 1.36 to 1.76 by the presence of CCCP, whereas at pHsub(e) 7.33 the e.r. was unchanged. In contrast the e.r. for misonidazole was unchanged at pHsub(e) 6.65 and 7.33. (author)

  7. Oxygen tension, cellular respiration, and redox state as variables influencing the cytotoxicity of the radiosensitizer misonidazole

    The colony-forming ability of Chinese hamster ovary (CHO) cells that wre incubated in the presence of 10 mM misonidazole [1-(2-nitro-1-imidazolyl)-3-methoxy-2-propanol, MIS)] at intermediate O2 levels was studied using stirred cell suspensions gassed with gas mixtures containing 0.1 to 2% O2. During the treatment, the O2 tension in solution was directly monitored using a Clark-type O2-sensing electrode. Survival studies were also done with KCN-inhibited CHO cells and a respiration-deficient cell line. In all cases, the O2 probe measurements indicated that substantially lower O2 levels were present in solution relative to the gas phase due to cellular O2 consumption. The results of the simultaneous O2 level-survival assessments indicated: (1) Very low levels of O2 were effective in inhibiting MIS toxicity. Less than 200 ppM (2 x 10-7 M) O2 was sufficient to reduce the maximal rate of killing by 50% for 10 mM MIS. (2) With the respiration-deficient cell line, the O2 dependence for MIS toxicity could be investigated under conditions where a constant O2 level could be maintained throughout the incubation and confirmed conclusion number (2). (3) KCN was found to enhance drug toxicity at all nonzero O2 levels. These results suggest MIS toxicity is mediated by an interplay of O2 level, respiration rate, and redox state of the cell. (4) MIS caused a time-dependent decrease in cellular O2 utilization rates, after substantial cell killing, which appeared to be responsible for the rise in O2 tension and reduced rate of killing by MIS noted at longer incubation times (6 to 12 hr)

  8. Wet vs. Dry Dispersion Methods for Multiwall Carbon Nanotubes in the High Graphite Content Phenolic Resin Composites for Use as Bipolar Plate Application

    Graphical abstract: MWCNTs are utilized to improve the properties of the phenolic resin composites. The composite with 1.0 wt% of MWCNTs prepared by dry method provides the highest electrical conductivity and optimum mechanical properties which meets the DOE material requirements for bipolar plates in PEMFC. - Highlights: • MWCNTs are utilized to improve the properties of the phenolic resin composites. • Wet and dry nanoparticle dispersion methods are explored to disperse MWCNTs in high content of graphite/phenolic composites. • The dry method is a proper method for high filler content composite preparation. • The composites with 1.0 wt% of the MWCNTs provide the highest electrical conductivity, flexural strength and tensile strength. • The composites meet the DOE requirement for use as bipolar plates in PEMFC. - Abstract: The preparation of multiwalled carbon nanotubes (MWCNTs) - reinforced graphite/phenolic resin composites is studied. The high electrical conductivity is needed in the composites for the bipolar plates in proton exchange membrane fuel cell (PEMFC) application, so upto 80% by weight of graphite was employed in the composites. The mechanical properties of the composites are found to diminish with this high filler content. The wet and dry nanoparticle dispersion methods are explored in order to disperse MWCNTs in the composites in order to strengthen them. For wet method, MWCNTs are dispersed in 2-propanol via ultrasonication and then mixed with graphite and phenolic resin by dry ball milling. For dry method, all components are mixed only by dry ball milling. After mixing, the composites are fabricated into sheets by hot compression molding. It is found that the dry method is a proper method for preparing composites with high filler content. The composite with 1.0 wt% of MWCNTs prepared by dry method provides highest electrical conductivity and optimum mechanical properties which meets the DOE material requirement for bipolar plates in

  9. Yarrowia lipolytica NCIM 3589, a tropical marine yeast, degrades bromoalkanes by an initial hydrolytic dehalogenation step.

    Vatsal, Aakanksha; Zinjarde, Smita S; Kumar, Ameeta Ravi

    2015-04-01

    The widespread industrial use of organobromines which are known persistent organic pollutants has led to their accumulation in sediments and water bodies causing harm to animals and humans. While degradation of organochlorines by bacteria is well documented, information regarding degradation pathways of these recalcitrant organobromines is scarce. Hence, their fates and effects on the environment are of concern. The present study shows that a tropical marine yeast, Yarrowia lipolytica NCIM 3589 aerobically degrades bromoalkanes differing in carbon chain length and position of halogen substitution viz., 2-bromopropane (2-BP), 1-bromobutane (1-BB), 1,5 dibromopentane (1,5-DBP) and 1-bromodecane (1-BD) as seen by an increase in cell mass, release of bromide and concomitant decrease in concentration of brominated compound. The amount of bromoalkane degraded was 27.3, 21.9, 18.0 and 38.3 % with degradation rates of 0.076, 0.058, 0.046 and 0.117/day for 2-BP, 1-BB, 1,5-DBP and 1-BD, respectively. The initial product formed respectively were alcohols viz., 2-propanol, 1-butanol, 1-bromo, 5-pentanol and 1-decanol as detected by GC-MS. These were further metabolized to fatty acids viz., 2-propionic, 1-butyric and 1-decanoic acid eventually leading to carbon dioxide formation. Neither higher chain nor brominated fatty acids were detected. An inducible extracellular dehalogenase responsible for removal of bromide was detected with activities of 21.07, 18.82, 18.96 and 26.67 U/ml for 2-BP, 1-BB, 1,5-DBP and 1-BD, respectively. We report here for the first time the proposed aerobic pathway of bromoalkane degradation by an eukaryotic microbe Y. lipolytica 3589, involving an initial hydrolytic dehalogenation step. PMID:25708590

  10. Nitrite Reduction to Nitrous Oxide and Ammonia by TiO2 Electrons in a Colloid Solution via Consecutive One-Electron Transfer Reactions.

    Goldstein, Sara; Behar, David; Rajh, Tijana; Rabani, Joseph

    2016-04-21

    The mechanism of nitrite reduction by excess electrons on TiO2 nanoparticles (eTiO2(-)) was studied under anaerobic conditions. TiO2 was loaded with up to 75 electrons per particle, induced by γ-irradiation of acidic TiO2 colloid solutions containing 2-propanol. Time-resolved kinetics and material analysis were performed, mostly at 1.66 g L(-1) TiO2. At relatively low nitrite concentrations (R = [eTiO2(-)]o/[nitrite]o > 1.5), eTiO2(-) decays via two consecutive processes; at higher concentrations, only one decay step is observed. The stoichiometric ratio Δ[eTiO2(-)]/[nitrite]o of the faster process is about 2. This process involves the one-electron reduction of nitrite, forming the nitrite radical (k1 = (2.0 ± 0.2) × 10(6) M(-1) s(-1)), which further reacts with eTiO2(-) (k2) in competition with its dehydration to nitric oxide (NO) (k3). The ratios k2/k3 = (3.0 ± 0.5) × 10(3) M(-1) and k2 > 1 × 10(6) M(-1) s(-1) were derived from kinetic simulations and product analysis. The major product of this process is NO. The slower stage of the kinetics involves the reduction of NO by eTiO2(-), and the detailed mechanism of this process has been discussed in our earlier publication. The results reported in this study suggest that several intermediates, including NO and NH2OH, are adsorbed on the titanium nanoparticles and give rise to inverse dependency of the respective reaction rates on the TiO2 concentration. It is demonstrated that the reduction of nitrite by eTiO2(-) yields mainly N2O and NH3 via consecutive one-electron transfer reactions. PMID:27050805

  11. Classical Keggin Intercalated into Layered Double Hydroxides: Facile Preparation and Catalytic Efficiency in Knoevenagel Condensation Reactions.

    Jia, Yueqing; Fang, Yanjun; Zhang, Yingkui; Miras, Haralampos N; Song, Yu-Fei

    2015-10-12

    The family of polyoxometalate (POM) intercalated layered double hydroxide (LDH) composite materials has shown great promise for the design of functional materials with numerous applications. It is known that intercalation of the classical Keggin polyoxometalate (POM) of [PW12 O40 ](3-) (PW12 ) into layered double hydroxides (LDHs) is very unlikely to take place by conventional ion exchange methods due to spatial and geometrical restrictions. In this paper, such an intercalated compound of Mg0.73 Al0.22 (OH)2 [PW12 O40 ]0.04 ⋅0.98 H2 O (Mg3 Al-PW12 ) has been successfully obtained by applying a spontaneous flocculation method. The Mg3 Al-PW12 has been fully characterized by using a wide range of methods (XRD, SEM, TEM, XPS, EDX, XPS, FT-IR, NMR, BET). XRD patterns of Mg3 Al-PW12 exhibit no impurity phase usually observed next to the (003) diffraction peak. Subsequent application of the Mg3 Al-PW12 as catalyst in Knoevenagel condensation reactions of various aldehydes and ketones with Z-CH2 -Z' type substrates (ethyl cyanoacetate and malononitrile) at 60 °C in mixed solvents (V2-propanol :Vwater =2:1) demonstrated highly efficient catalytic activity. The synergistic effect between the acidic and basic sites of the Mg3 Al-PW12 composite proved to be crucial for the efficiency of the condensation reactions. Additionally, the Mg3 Al-PW12 -catalyzed Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate demonstrated the highest turnover number (TON) of 47 980 reported so far for this reaction. PMID:26337902

  12. Response of the bacterium Cupriavidus metallidurans CH34 to space flight conditions.

    Leys, N.; Wattiez, R.; Rosier, C.; de Boever, P.; Baatout, S.; Mergeay, M.

    Background When man goes to space inevitably microbes hitchhike along some needed others unwanted Knowledge is required to understand the behaviour of bacteria in spaceflight conditions Aim The aim of this work was to investigate the physiological and metabolic response and adaptation of the environmental model bacterium Cupriavidus metallidurans CH34 to space flight conditions The strain was grown in the International Space Station ISS during 2 separated Soyuz missions MESSAGE 1 2 experiments and in the Rotating Wall Vessel RWV mimicking microgravity on ground Results It was clear that pre- in- and post-flight incubation conditions are critical in spaceflight experiments and should be controlled monitored and taken into account as much as possible when comparing space flight with ground grown cells Distinct changes in physiology and metabolism were observed in the cell cultures grown in space flight when compared to correct ground control cultures A total of 12 proteins over-produced in space conditions were identified and divided in functional groups One group are proteins that protect the cell against physical damage such as heat-shock GrpE UspA and oxidative agents AhpC TrxB DpsA Another group of proteins is probably involved in a metabolic pathway to produce the energy-rich Acetyl-CoA Ald ExaC LpsJ CaiA with the help of a de carboxylase AcxABC Higher concentrations of this group of proteins were also detected in cells grown with acetone or 2-propanol as

  13. Evaluation of a virucidal quantitative carrier test for surface disinfectants.

    Rabenau, Holger F; Steinmann, Jochen; Rapp, Ingrid; Schwebke, Ingeborg; Eggers, Maren

    2014-01-01

    Surface disinfectants are part of broader preventive strategies preventing the transmission of bacteria, fungi and viruses in medical institutions. To evaluate their virucidal efficacy, these products must be tested with appropriate model viruses with different physico-chemical properties under conditions representing practical application in hospitals. The aim of this study was to evaluate a quantitative carrier assay. Furthermore, different putative model viruses like adenovirus type 5 (AdV-5) and different animal parvoviruses were evaluated with respect to their tenacity and practicability in laboratory handling. To evaluate the robustness of the method, some of the viruses were tested in parallel in different laboratories in a multi-center study. Different biocides, which are common active ingredients of surface disinfectants, were used in the test. After drying on stainless steel discs as the carrier, model viruses were exposed to different concentrations of three alcohols, peracetic acid (PAA) or glutaraldehyde (GDA), with a fixed exposure time of 5 minutes. Residual virus was determined after treatment by endpoint titration. All parvoviruses exhibited a similar stability with respect to GDA, while AdV-5 was more susceptible. For PAA, the porcine parvovirus was more sensitive than the other parvoviruses, and again, AdV-5 presented a higher susceptibility than the parvoviruses. All parvoviruses were resistant to alcohols, while AdV-5 was only stable when treated with 2-propanol. The analysis of the results of the multi-center study showed a high reproducibility of this test system. In conclusion, two viruses with different physico-chemical properties can be recommended as appropriate model viruses for the evaluation of the virucidal efficacy of surface disinfectants: AdV-5, which has a high clinical impact, and murine parvovirus (MVM) with the highest practicability among the parvoviruses tested. PMID:24475079

  14. Evaluation of a virucidal quantitative carrier test for surface disinfectants.

    Holger F Rabenau

    Full Text Available Surface disinfectants are part of broader preventive strategies preventing the transmission of bacteria, fungi and viruses in medical institutions. To evaluate their virucidal efficacy, these products must be tested with appropriate model viruses with different physico-chemical properties under conditions representing practical application in hospitals. The aim of this study was to evaluate a quantitative carrier assay. Furthermore, different putative model viruses like adenovirus type 5 (AdV-5 and different animal parvoviruses were evaluated with respect to their tenacity and practicability in laboratory handling. To evaluate the robustness of the method, some of the viruses were tested in parallel in different laboratories in a multi-center study. Different biocides, which are common active ingredients of surface disinfectants, were used in the test. After drying on stainless steel discs as the carrier, model viruses were exposed to different concentrations of three alcohols, peracetic acid (PAA or glutaraldehyde (GDA, with a fixed exposure time of 5 minutes. Residual virus was determined after treatment by endpoint titration. All parvoviruses exhibited a similar stability with respect to GDA, while AdV-5 was more susceptible. For PAA, the porcine parvovirus was more sensitive than the other parvoviruses, and again, AdV-5 presented a higher susceptibility than the parvoviruses. All parvoviruses were resistant to alcohols, while AdV-5 was only stable when treated with 2-propanol. The analysis of the results of the multi-center study showed a high reproducibility of this test system. In conclusion, two viruses with different physico-chemical properties can be recommended as appropriate model viruses for the evaluation of the virucidal efficacy of surface disinfectants: AdV-5, which has a high clinical impact, and murine parvovirus (MVM with the highest practicability among the parvoviruses tested.

  15. Mechanistic Insight into Peroxydisulfate Reactivity: Oxidation of the cis,cis-[Ru(bpy)2(OH2)]2O(4+) "Blue Dimer".

    Hurst, James K; Roemeling, Margo D; Lymar, Sergei V

    2015-06-18

    One-electron oxidation of the μ-oxo dimer (cis,cis-[Ru(III)(bpy)2(OH2)]2O(4+), {3,3}) to {3,4} by S2O8(2-) can be described by three concurrent reaction pathways corresponding to the three protic forms of {3,3}. Free energy correlations of the rate constants, transient species dynamics determined by pulse radiolysis, and medium and temperature dependencies of the alkaline pathway all suggest that the rate-determining step in these reactions is a strongly nonadiabatic dissociative electron transfer within a precursor ion pair leading to the {3,4}|SO4(2-)|SO4(•-) ion triple. As deduced from the SO4(•-) scavenging experiments with 2-propanol, the SO4(•-) radical then either oxidizes {3,4} to {4,4} within the ion triple, effecting a net two-electron oxidation of {3,3}, or escapes in solution with ∼25% probability to react with additional {3,3} and {3,4}, that is, effecting sequential one-electron oxidations. The reaction model presented also invokes rapid {3,3} + {4,4} → 2{3,4} comproportionation, for which kcom ∼5 × 10(7) M(-1) s(-1) was independently measured. The model provides an explanation for the observation that, despite favorable energetics, no oxidation beyond the {3,4} state was detected. The indiscriminate nature of oxidation by SO4(•-) indicates that its fate must be quantitatively determined when using S2O8(2-) as an oxidant. PMID:25819370

  16. Pt/Al/sub 2/O/sub 3/- carbon nanocomposite as a catalyst for fuel cells

    Catalysts comprising platinum nanoparticles (Pt NPs) on carbon support are used in fuel cells for the hydrogen and electricity production by electrochemical oxidation of methanol. However, the catalyst is not the best in terms of its performance. Considering role of the support as significant towards efficiency and durability of the catalyst, there is need for introducing novel support materials to replace carbon alone. Deposition of various metallic NPs on ceramic-carbon (hybrid) supports has been reported to improve thermal, mechanical, electrical and chemical properties of different types of catalyst. In search of better performing catalysts for proton exchange membrane fuel cells (PEMFCs), hybrid supports having different ceramic materials should be synthesized. In this regard Pt/Al/sub 2/O/sub 3/-Carbon (nanocomposites) have been synthesized and applied as promising catalysts in the PEMFCs; results obtained for the nanocomposites were compared with Pt/carbon and Pt/Al/sub 2/O/sub 3/. Vulcan carbon was purified and functionalized prior to use; presence of oxygen containing functional groups on carbon was established from the FTIR spectrum, Hybrid support (1:8 by weight ratio of ceramic and carbon) were already prepared in aqueous 2-propanol employing sonication method on to which Pt NPs (10% by weight in all the cases) were deposited by simple chemical reduction of PtCl/sub 4/ by NaBH/sub 4/ under controlled conditions. The catalysts were subjected to various characterization techniques like TGA (for thermal stability), EDX (for chemical composition), SEM (for surface morphology) and XRD (for cell-shape and -volume, material density and average crystalline size). Catalysts efficiencies for the methanol oxidation were investigated through cyclic voltammetery (CV) by comparing electrochemical surface area, peak current, exchange current density and rate constant in the acidic and basic media. Pt/Al/sub 2/O/sub 3/-carbon exhibited better catalytic efficiencies

  17. Determination of thermodynamic properties of poly(cyclohexyl methacrylate)by inverse gas chromatography

    Ismet KAYA; Cigdem Yigit PALA

    2014-01-01

    In this work,some thermodynamic properties of poly( cyclohexyl methacrylate)were studied by inverse gas chromatography( IGC). For this purpose,the polymeric substance was coated on Chromosorb W and which was filled into a glass column. The retention times(tr)of the probes were determined from the interactions of poly(cyclohexyl methacrylate)with n-pentane,n-hexane,n-heptane,n-octane,n-decane, methanol,ethanol,2-propanol,butanol,acetone,ethyl methyl ketone,benzene,toluene and o-xylene by IGC technique. Then,the specific volume(V0g)was determined for each probe molecule. By using(1/T;lnV0g) graphics,the glass transition temperature of poly( cyclohexyl methacrylate)was found to be 373 K. The adsorp-tion heat under the glass transition temperature(ΔH a ),and partial molar heat of sorption above the glass tran-sition(ΔHS1 ),partial molar free energy of sorption(ΔGS1 )and partial molar entropy of sorption(ΔSS1 )belong-ing to sorption for every probe were calculated. The partial molar heat of mixing at infinite dilution(ΔH∞1 ), partial molar free energy of mixing at infinite dilution(ΔG∞1 ),Flory-Huggins interaction parameter(χ∞12 )and weight fraction activity coefficient(a1/w1)∞ values of polymer-solute systems were calculated at different col-umn temperatures. The solubility parameters(δ2 )of the polymer were obtained by IGC technique.

  18. Screening study of SFC critical method parameters for the determination of pharmaceutical compounds.

    Dispas, Amandine; Lebrun, Pierre; Sacré, Pierre-Yves; Hubert, Philippe

    2016-06-01

    Nowadays, supercritical fluid chromatography is commonly presented as a promising alternative technique in the field of separation sciences. Nevertheless the selection of chromatographic conditions and sample preparation of pharmaceutical compounds remain a challenge and peak distortion was previously highlighted. The main objective of the present work was to evaluate the impact of different critical method parameters (CMPs), i.e. stationary phase, mobile phase composition and injection solvent nature. The experiments were performed considering two groups of antimalarial molecules: one group with neutral/apolar compounds and the other one with salt form of polar compounds. In this context, another objective was to propose a suitable sample solvent for quantitative analysis. The interest of new generation stationary phase to obtain good peak shape and the interest to tune the mobile phase composition were demonstrated. During this study, design of experiments and desirability function approach enabled to highlight optimal chromatographic conditions in order to maximise peak capacity and to get acceptable value of symmetry factor. Regarding sample injection solvent composition, some counterintuitive results were observed: solvents closer to the mobile phase polarity (i.e heptane or 2-propanol/heptane mixture) did not provide best results in terms of peak symmetry. In addition, acetonitrile and short aliphatic alcohols offered an interesting alternative as injection solvent: toxicity of solvents used is clearly reduced and better quantitative performances could be expected while keeping high peak capacity and symmetric sharp peaks. Finally, the quantitative performances were evaluated by the method validation for the quantitative determination of quinine sulfate in a pharmaceutical formulation. These better understandings on critical method parameters led SFC to be an even more promising technique in the field of the analysis of pharmaceutical compounds. PMID:27105334

  19. Physico-chemical properties of Pd nanoparticles produced by Pulsed Laser Ablation in different organic solvents

    Palladium nanoparticles are arousing an increasing interest because of their strong activity in heterogeneous catalysis in a wide range of reactions. Driven by the interest of producing Pd nanoparticles to be deposited for catalysis over hydrophobic supports, we investigated their synthesis via Pulsed Laser Ablation in Liquid in several organic solvents, as acetone, ethanol, 2-propanol, toluene, n-hexane. The colloids were produced by using a Nd:YAG ns laser and without the addition of surfactant agents. The morphology, composition, stability and oxidation state of the obtained nanoparticles were investigated by TEM-EDS analysis, UV-vis spectroscopy, X-ray Photoelectron Spectroscopy and micro-Raman spectroscopy. The results evidence that the nature of the solvent influences both the yield and the physico-chemical properties of the produced nanoparticles. While in acetone and alcohols spheroidal, non aggregated and stable particles are obtained, in case of toluene and n-hexane few unstable particles surrounded by a gel-like material are produced. Raman/XPS measurements suggest the presence of amorphous or graphitic carbon onto crystalline Pd nanoparticles, which could have hindered their growth and determined the observed smaller sizes if compared to nanoparticles produced in water. The stability of Pd colloids obtained in acetone and alcohols was attributed to adsorbed anions like enolates or alcoholates; non polar solvents like toluene and n-hexane, unable to give rise to adsorbed anionic species, cannot provide any stabilization to the palladium nanoparticles. XPS analyses also evidenced a partial oxidation of particles surface, with a ratio Pd2+:Pd0 of 1:2.5 and 1:4 in acetone and ethanol, respectively.

  20. Rapid Synthesis and Antiviral Activity of (Quinazolin-4-YlaminoMethyl-Phosphonates Through Microwave Irradiation

    Baoan Song

    2012-06-01

    Full Text Available This study describes the simple synthesis of new (quinazolin-4-ylamino methylphosphonates via microwave irradiation. Substituted-2-aminobenzonitrile reacted with 1,1-dimethoxy-N,N-dimethylmethanamine at a reflux condition to obtain N'-(substituted-2-cyanophenyl-N,N-dimethylformamidine (1. The subsequent reaction of this intermediate product with α-aminophosphonate (2 in a solution containing glacial acetic acid in 2-propanol through microwave irradiation resulted in the formation of (quinazolin-4-ylaminomethyl-phosphonate derivatives 3a to 3x, which were unequivocally characterized by the spectral data and elemental analysis. The influence of the reaction conditions on the yield of 3a was investigated to optimize the synthetic conditions. The relative optimal conditions for the synthesis of 3a include a 1:1 molar ratio of N’-(2-cyanophenyl-N,N-dimethylformamidine to diethyl amino(phenylmethylphosphonate and a 4:1 volume ratio of isopropanol to HOAc in the solvent mixture, at a reaction temperature of 150 °C, with a microwave power of 100 W and a corresponding pressure of 150 psi for 20 min in the microwave synthesizer. The yield of 3a was approximately 79%, whereas those of 3b to 3x were approximately 77% to 86%. Some of the synthesized compounds displayed weak to good anti-Tobacco mosaic virus (TMV activity.

  1. Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system

    Serna-Galvis, Efraím A.; Silva-Agredo, Javier [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Giraldo-Aguirre, Ana L. [Grupo de Diseño y Formulación de Medicamentos, Cosméticos y Afines (DYFOMECO), Facultad de Química Farmacéutica, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Torres-Palma, Ricardo A., E-mail: ricardo.torres@udea.edu.co [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2015-08-15

    Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20–60 W), dissolved gas (air, Ar and He), pH (3–11) and initial concentration of fluoxetine (2.9–162.0 μmol L{sup −1}). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe{sup 2+}) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. - Highlights: • The pharmaceutical fluoxetine was effectively eliminated upon ultrasonic action. • Ultrasonic power, dissolved gas, pH and concentration of fluoxetine were evaluated. • Fe{sup 2+}, sodium nitrate or nitric acid had a positive effect on the FLX degradation. • More hydrophobic or volatile compounds than fluoxetine diminished the efficiency. • A sonochemical-biological combined process led to the total mineralization of FLX.

  2. Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

    Jambon, C

    1962-07-01

    After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

  3. Effect of alcohol vapor treatment on electrical and optical properties of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) films for indium tin oxide-free organic light-emitting diodes

    Graphical abstract: - Highlights: • A simple alcohol vapor treatment (AVT) technique was applied to enhance the conductivity of PEDOT:PSS films. • Alcohols with one OH group can improve conductivity of PEDOT:PSS films by this technique. • Mechanism of conductivity enhancement of PEDOT:PSS films by AVT method was explained. • ITO-free OLEDs were fabricated using highly conductive AVT PEDOT:PSS films standalone anode. - Abstract: A simple alcohol vapor treatment (AVT) technique was proposed to improve the conductivity of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films. In this technique, various alcohols, i.e. methanol, ethanol, 2-propanol and ethylene glycol, were applied to treat the surface of the films formed and then they were annealed. The sheet resistance of PEDOT:PSS films was significantly reduced from 130 kΩ/sq to 60 Ω/sq when treated with methanol vapor. The investigation of the vertical resistance of the films showed that the sample treated with methanol vapor displayed the lowest resistance as well. The mechanism of conductivity enhancement of PEDOT:PSS films through AVT method was explained by surface phase images, UV and IR spectra of PEDOT:PSS films. Optical transmittance spectrum of treated films exhibited that AVT has even enhanced the optical transmittance slightly. Improvement in the morphology, electrical and optical properties of PEDOT:PSS films prompted their applications as a transparent anode in the fabrication of ITO-free organic light-emitting diodes (OLEDs). The OLED manufactured based on methanol-treated PEDOT:PSS films demonstrated the highest luminance

  4. Effect of the temperature on the physical properties of pure 1-propyl 3-methylimidazolium bis(trifluoromethylsulfonyl)imide and characterization of its binary mixtures with alcohols

    Highlights: ► The temperature dependence of the physical properties of [PMim][NTf2] was studied. ► Physical properties of its binary mixtures with alcohols were determined at 298.15 K. ► The thermal expansion coefficient of the pure ionic liquid was calculated. ► The heat capacity of the pure ionic liquid at 298.15 K was determined. ► The excess properties of binary mixtures were adjusted with Redlich–Kister equation. - Abstract: In this paper, physical properties of a high purity sample of the ionic liquid 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [PMim][NTf2], and its binary mixtures with methanol, ethanol, 1-propanol, and 2-propanol were measured at atmospheric pressure. The temperature dependence of density, refractive index and speed of sound (293.15 to 343.15) K and dynamic viscosity (298.15 to 343.15) K were studied at atmospheric pressure by conventional techniques for the pure ionic liquid. For its mixtures with alcohols, density, speed of sound, and refractive index were measured at T = 298.15 K over the whole composition range. The thermal expansion coefficient of the [PMim][NTf2] was calculated from the experimental results using an empirical equation, and values of the excess molar volume, excess refractive index, and excess molar isentropic compressibility for the binary systems at the above mentioned temperature, were calculated and fitted to the Redlich–Kister equation. The heat capacity of the pure ionic liquid at T = 298.15 K was determined using DSC.

  5. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    Delmau, L.H.

    2002-10-08

    This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

  6. Amine functionalized radiation-induced grafted water hyacinth fibers for Pb2+, Cu2+ and Cr3+ uptake

    An amine group containing fibrous adsorbent was prepared by reaction of grafted water hyacinth fibers with ethylenediamine. Glycidyl methacrylate (GMA) was grafted onto water hyacinth fibers using gamma radiation induced graft polymerization through simultaneous grafting technique and this was used as base material for producing the amine type adsorbents. The conversion of the epoxy group from GMA into amine group was investigated. The concentration of ethylenediamine solution that gave the highest amine functional group density was 50% by volume in 2-propanol. The amine functionalized water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy (EDX). Information derived from these analyses confirms the successful conversion of the epoxy group. The amine-type adsorbent was evaluated for its uptake of Pb2+, Cu2+ and Cr3+ from aqueous solutions. The initial concentration of the metal ions and pH of the solutions were found to influence the amount of metal ions adsorbed by the amine-type adsorbent. The kinetics of adsorption was observed to follow Lagergren's first order equation. Results of ion sorption studies indicate that gamma radiation-induced grafting and subsequent chemical modification improved the ion sorption behaviour of water hyacinth fibers. - Highlights: • RIGP and amination imparted higher ion sorption capacity to water hyacinth fibers. • The epoxy group of grafted glycidyl methacrylate was reacted with ethylenediamine. • TGA, ATR-FTIR and EDX analysis confirmed successful amine functionalization. • The amine type fibrous adsorbent has higher affinity for Cu2+ and Pb2+ than Cr3+

  7. PHOTOREDUCTIVE SEQUESTRATION OF CO2 TO FORM C1 PRODUCTS AND FUEL

    Theodore Mill; Haruthai Tungudomwongsa

    2003-08-25

    Analytical methods for determining formic, acetic and oxalic acids, formaldehyde, and methanol have been evaluated and/or optimized for measuring products from photoreduction of CO{sub 2} in illuminated, aqueous suspensions of photocatalysts. An electrophoresis anion separation method (CIA) can detect aqueous formate and oxalate ions at 22 and 17 {micro}M (1 ppm), respectively. Recalibration of the Nash formaldehyde determination shows that as little as 10 {micro}M (0.3 ppm) can be detected spectrally. Several experiments using suspensions of Pt/TiO{sub 2}, SrTiO{sub 3}, and SrTiO{sub 3} with Cr and Sb were illuminated in CO{sub 2} saturated solutions. No acids were detected in most experiments using CIA; however, ion chromatography (IC) was able to detect formate and acetate at low {micro}M (sub ppm) concentrations in several experiments using Pt/TiO{sub 2} and SrTiO{sub 3} in sunlight and with xenon uv light. Analysis for methanol by gas chromatography showed that not more than 2 ppm methanol could have formed and probably less. Adding 0.6 mM 2-propanol to an irradiated CO{sub 2}/TiO{sub 2} suspension led to formation of 550 {micro}M formate, but no formaldehyde, probably because re-oxidation of formate by semiconductor holes was competitively blocked. Loss of C{sub 1} products at higher concentrations by re-oxidation may be an important process, limiting the accumulation of products. Preliminary estimates were made of the physical size of a solar CO{sub 2} photoreduction unit large enough to reduce the CO{sub 2} produced from a 1000 MW coal-fired electricity plant. A perfectly efficient system could be as small as 2 to 3 km{sup 2}.

  8. Toluene promotes lid 2 interfacial activation of cold active solvent tolerant lipase from Pseudomonas fluorescens strain AMS8.

    Yaacob, Norhayati; Mohamad Ali, Mohd Shukuri; Salleh, Abu Bakar; Rahman, Raja Noor Zaliha Raja Abdul; Leow, Adam Thean Chor

    2016-07-01

    The utilization of cold active lipases in organic solvents proves an excellent approach for chiral synthesis and modification of fats and oil due to the inherent flexibility of lipases under low water conditions. In order to verify whether this lipase can function as a valuable synthetic catalyst, the mechanism concerning activation of the lid and interacting solvent residues in the presence of organic solvent must be well understood. A new alkaline cold-adapted lipase, AMS8, from Pseudomonas fluorescens was studied for its structural adaptation and flexibility prior to its exposure to non-polar, polar aprotic and protic solvents. Solvents such as ethanol, toluene, DMSO and 2-propanol showed to have good interactions with active sites. Asparagine (Asn) and tyrosine (Tyr) were key residues attracted to solvents because they could form hydrogen bonds. Unlike in other solvents, Phe-18, Tyr-236 and Tyr-318 were predicted to have aromatic-aromatic side-chain interactions with toluene. Non-polar solvent also was found to possess highest energy binding compared to polar solvents. Due to this circumstance, the interaction of toluene and AMS8 lipase was primarily based on hydrophobicity and molecular recognition. The molecular dynamic simulation showed that lid 2 (residues 148-167) was very flexible in toluene and Ca(2+). As a result, lid 2 moves away from the catalytic areas, leaving an opening for better substrate accessibility which promotes protein activation. Only a single lid (lid 2) showed the movement following interactions with toluene, although AMS8 lipase displayed double lids. The secondary conformation of AMS8 lipase that was affected by toluene observed a reduction of helical strands and increased coil structure. Overall, this work shows that cold active lipase, AMS8 exhibits distinguish interfacial activation and stability in the presence of polar and non-polar solvents. PMID:27474867

  9. Pharmacokinetics of mitomycin C in dogs: application of a high-performance liquid chromatographic assay.

    Barbhaiya, R H; Papp, E A; Van Harken, D R; Smyth, R D

    1984-09-01

    A normal-phase high-performance liquid chromatographic (HPLC) assay was developed for the determination of mitomycin C in plasma and urine. The method involves extraction of mitomycin C from plasma or urine into ethyl acetate-2-propanol-chloroform (70:15:15) with UV detection at 365 nm. Quantitation was performed with an internal standard (porfiromycin) by the peak height ratio method. Excellent correlation was obtained between the HPLC assay and the established microbiological cup-plate bioassay. The pharmacokinetics of mitomycin C were investigated in beagle dogs following a 1-mg/kg iv (22-mg/m2) bolus dose. The plasma mitomycin C concentration versus time data were analyzed by using an open three-compartment model. The average volume of distribution was 1.90 L or 17% of body weight for the central compartment and 7.7 L or 68% of body weight for the terminal elimination phase. The volumes of distribution at steady state, calculated by model-dependent and -independent methods, compared very well with each other and were 6.5 L or 58% of body weight. Total body clearance averaged 112 mL/min, and the mean terminal plasma half-life was 53 min. The 0-24-h urinary excretion of intact mitomycin C accounted for 19% of the dose. The terminal half-life and percent urinary recovery of mitomycin C in dogs is similar to that in humans. Based on these observations, the dog appears to be a good model for studying the disposition of mitomycin C. PMID:6436466

  10. Hypoxia-dependent retinal toxicity of bioreductive anticancer prodrugs in mice.

    Lee, A E; Wilson, W R

    2000-02-15

    The bioreductive anticancer prodrug CI-1010 ((2R)-1-[(2-bromoethyl)amino]-3-(2-nitro-1H-imidazol-1-yl)-2-propanol hydrobromide) is an alkylating nitroimidazole which shows selective toxicity against hypoxic cells in murine tumors, but causes extensive apoptosis in the outer retina in rodents and monkeys. This irreversible retinal toxicity has terminated preclinical development of CI-1010. We have investigated whether such toxicity is due to physiological hypoxia in the retina, and whether it is a general feature of hypoxia-selective bioreductive drugs. Retinal damage was quantified by morphometric analysis of histological sections following treatment of female C57Bl6 mice. Both CI-1010 and tirapazamine (TPZ, 1,2,4-benzotriazin-3-amine 1,4-dioxide), a bioreductive drug in Phase III clinical trial, caused a time and dose-dependent loss of photoreceptor cells of the outer retina following administration of single intraperitoneal doses. The lesion caused by TPZ was qualitatively similar to that with CI-1010, but was less severe at equivalent fractions of the maximum tolerated dose (as defined by lethality). With both bioreductive drugs, lesion severity was increased if animals breathed 10% O(2) for 3 h after drug administration, while breathing 95% O(2)/5% CO(2) was protective. Other hypoxia-selective bioreductive drugs tested (the quinone porfiromycin, the anthraquinone N-oxide AQ4N and the nitrogen mustard prodrugs SN 23816 and SN 25341) did not cause retinal damage at their maximum tolerated doses. This study suggests that the retinal toxicity of bioreductive drugs might be avoided by manipulation of tissue hypoxia using 95% O(2)/5% CO(2), although this intervention could suppress antitumor activity. The finding that not all bioreductive drugs cause retinal toxicity suggests this toxicity can be avoided through appropriate drug design. PMID:10662604

  11. High-performance plastic platinized counter electrode via photoplatinization technique for flexible dye-sensitized solar cells.

    Fu, Nian-Qing; Fang, Yan-Yan; Duan, Yan-Dong; Zhou, Xiao-Wen; Xiao, Xu-Rui; Lin, Yuan

    2012-11-27

    A photoplatinization technique was proposed to deposit Pt on a thin TiO(2) layer modified indium tin oxide-coated polyethylene naphthalate (ITO/PEN) substrate at low temperature (about 50 °C after 1 h of UV irradiation) for the first time. The fabrication process includes coating and hydrolyzing the tetra-n-butyl titanate to form a TiO(2)-modified layer and the photoplatinization of the modified substrate in H(2)PtCl(6)/2-propanol precursor solution under UV irradiation. The obtained platinized electrodes were used as counter electrodes (CE) for flexible dye-sensitized solar cells (FDSCs). The well-optimized platinized electrode showed high optical transmittance, up to 76.5% between 400 and 800 nm (T(av)), and the charge transfer resistance (R(ct)) was as low as 0.66 Ω cm(2). A series of characterizations also demonstrated the outstanding chemical/electrochemical durability and mechanical stability of the platinized electrode. The FDSCs with TiO(2)/Ti photoanodes and the obtained CEs achieved a power conversion efficiency (PCE) up to 8.12% under rear-side irradiation (AM 1.5 illumination, 100 mW cm(-2)). The obtained CEs were also employed in all-plastic bifacial DSCs. When irradiated from the rear side, the bifacial FDSC yielded a PCE of 6.26%, which approached 90% that of front-side irradiation (6.97%). Our study revealed that, apart from serving as a functional layer for deposition of Pt, the thin TiO(2) layer modification on ITO/PEN substrates also played an important role in improving the transparency and the mechanical properties of the CE. The effect of the thickness of the TiO(2) layer for Pt coating on the performance of the CE was also investigated. PMID:23039879

  12. Wetting transition and pretransitional thin films in binary liquids: alcohol/perfluoromethylcyclohexane mixtures studied by x-ray reflectivity

    In this study the wetting transition at the liquid-vapour interface of binary organic liquid mixtures has been investigated by x-ray reflectivity. Mixtures of various isomeric alcohols with perfluoromethylcyclohexane (PFMC) served as model systems, with alcohol carbon numbers ranging from 1 to 4. Remarkably different pretransitional behaviour of the thin films below the wetting temperature was observed, which could be classified according to the carbon number. At two-phase coexistence, no pretransitional thin films could be detected for methanol and ethanol, whereas thin-to-thick-film transitions were found for propanol and butanol and their isomers. For 1-propanol and 2-propanol, the surface of the upper, alcohol-rich phase of the gravity-separated mixture displays a wetting transition at Tw = 31.5 deg. C and 38.3 deg. C, respectively, where the thickness of a PFMC-rich film jumps from less than 25 A to values exceeding the experimental resolution of about 1200 A. For 1-butanol, 2-butanol and i-butanol, we found pretransitional film thicknesses increasing up to 100 A, with wetting transitions at Tw = 45.0 deg. C, 34.2 deg. C and 40.1 deg. C, respectively. In the single-phase region, the study of adsorption isotherms above Tw revealed novel behaviour of the adsorbed PFMC-rich film. We observed both a growing film thickness and a significantly changing composition as the coexistence line was approached. Nevertheless, the variation of the excess adsorption with distance from coexistence could still be described by a power law. (author)

  13. Antioxidation Properties and Surface Interactions of Polyvinylpyrrolidone-Capped Zerovalent Copper Nanoparticles Synthesized in Supercritical Water.

    Morioka, Takuya; Takesue, Masafumi; Hayashi, Hiromichi; Watanabe, Masaru; Smith, Richard L

    2016-01-27

    Zerovalent copper nanoparticles (CuNPs) (diameter, 26.5 ± 9 nm) capped with polyvinylpyrrolidone (PVP) were synthesized in supercritical water at 400 °C and 30 MPa with a continuous flow reactor. The PVP-capped CuNPs were dispersed in distilled water, methanol, ethanol, 1-propanol, 2-propanol, butanol, and their mixed solvents to study their long-term stability. Temporal variation of UV-vis spectra and surface plasmon resonance were measured and showed that ethanol, the propanols, and butanol solvents provided varying degrees of oxidative protection for Cu(0). Fourier transform infrared spectroscopy showed that PVP adsorbed onto the surface of the CuNPs with a pyrrolidone ring of PVP even if the CuNPs were oxidized. Intrinsic viscosities of PVP were higher for solvents that provided antioxidation protection than those that give oxidized CuNPs. In solvents that provided Cu(0) with good oxidative protection (ethanol, the propanols, and butanol), PVP polymer chains formed large radii of gyration and coil-like conformations in the solvents so that they were arranged uniformly and orderly on the surface of the CuNPs and could provide protection of the Cu(0) surface against dissolved oxygen. In solvents that provided poor oxidative protection for Cu(0) (water, alcohol-water mixed solvents with 30% water), PVP polymer chains had globular-like conformations due to their relatively high hydrogen-bonding interactions and sparse adsorption onto the CuNP surface. Antioxidative properties of PVP-capped CuNPs in a solvent can be ascribed to the conformation of PVP polymer chains on the Cu(0) particle surface that originates from the interaction between polymer chains and its interaction with the solvent. PMID:26716468

  14. p-Aminophenylacetic acid-mediated synthesis of monodispersed titanium oxide hybrid microspheres in ethanol solution.

    Zhang, Hongye; Xie, Yun; Liu, Zhimin; Tao, Ranting; Sun, Zhenyu; Ding, Kunlun; An, Guimin

    2009-10-15

    Monodispersed TiO2 hybrid microspheres were prepared via the hydrolysis of titanium isopropoxide (TTIP) in ethanol solution containing p-aminophenylacetic acid (APA). The effects of the APA:TTIP molar ratio, water content, reaction time and reaction temperature on the morphology of the resultant spheres were investigated. The products were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. It was demonstrated that the diameters of the resultant TiO2 spheres could be tuned in the range of 380-800 nm by changing the APA:TTIP molar ratio (1:3 to 3:1) and water content (1-3 v/v%) in the reaction medium, and that increasing the APA:TTIP molar ratio led to larger TiO2 hybrid spheres while increasing the water content decreased their size. The loading content of APA in the hybrid spheres could reach 20 wt.% as they were prepared with the APA:TTIP ratio of 3:1. The possible formation mechanism of the hybrid spheres was also investigated. It was found that APA slowed down the hydrolysis rate of the titanium precursor so that resulted in the formation of the TiO2 spheres. In addition, the APA present in TiO2 spheres acted as a reducing agent to in situ convert HAuCl4 into metallic Au on the surface of the TiO2 spheres. The catalytic activity of the resultant Au/APA-TiO2 composite was examined using transfer hydrogenation of phenylacetone with 2-propanol, and it was indicated that the catalyst displayed high efficiency for this reaction. PMID:19616218

  15. Synthesis of Biodiesel from the Oily Content of Marine Green Alga Ulva fasciata

    The present study is focused on the chemical transformation of oils derived from the marine green alga Ulva fasciata Delile to biodiesel. The transesterification of algal oil was performed with a variety of alcohols using Na metal and NaOH as catalysts. Transesterification of algal oil by mechanical stirring yielded significant biodiesel within an hour at 60 degree C with NaOH and at room temperature with Na metal. In addition, microwave irradiated transesterification produced significant amount of biodiesel with NaOH and Na metal within 1-5 minutes. However, reaction of sodium metal in microwave oven was highly exothermic and uncontrollable that could also damage the radiation source. The reactivity order of alcohols was found to be methanol > ethanol > benzyl alcohol > 1-propanol > 1-butanol > 1-pentanol > 1-hexanol > 2-propanol. Isopropyl alcohol was found to be least reactive due to steric hindrance. Benzyl alcohol was found to be more reactive than 1-propyl alcohol due to the electron withdrawing effect of benzene ring. The highest % conversion of FAME and FAEE were found to be 97% and 98% respectively using Na metal through mechanical stirring. Biodiesel production was confirmed by thin layer chromatography (TLC). Furthermore, the fuel properties including density, kinematics viscosity, high heating value, acid value, free fatty acid (%), cloud point and pour point of U. fasciata oil and all the esters were determined and compared with the standard limits of biodiesel. Fatty acid methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 1-pentyl and 1-hexyl esters showed the fuel properties within the biodiesel standard limits therefore all of them were considered as the substitute of biodiesel. On the other hand, the fuel properties of benzyl ester were found to be above the limits of biodiesel specifications and thus it could not be considered as biodiesel. This research article will be helpful to overcome the current challenges of energy crisis, global warming and

  16. Efficacy of ethanol-based hand foams using clinically relevant amounts: a cross-over controlled study among healthy volunteers

    Marschall Sigunde

    2010-03-01

    Full Text Available Abstract Background Foams containing 62% ethanol are used for hand decontamination in many countries. A long drying time may reduce the compliance of healthcare workers in applying the recommended amount of foam. Therefore, we have investigated the correlation between the applied amount and drying time, and the bactericidal efficacy of ethanol foams. Methods In a first part of tests, four foams (Alcare plus, Avagard Foam, Bode test foam, Purell Instant Hand Sanitizer containing 62% ethanol, which is commonly used in U.S. hospitals, were applied to 14 volunteers in a total of seven variations, to measure drying times. In a second part of tests, the efficacy of the established amount of foam for a 30 s application time of two foams (Alcare plus, Purell Instant Hand Sanitizer and water was compared to the EN 1500 standard of 2 × 3 mL applications of 2-propanol 60% (v/v, on hands artificially contaminated with Escherichia coli. Each application used a cross-over design against the reference alcohol with 15 volunteers. Results The mean weight of the applied foam varied between 1.78 and 3.09 g, and the mean duration to dryness was between 37 s and 103 s. The correlation between the amount of foam applied and time until hands felt dry was highly significant (p 10-reduction: 3.05 ± 0.45 and Alcare plus (3.58 ± 0.71 was significantly less effective than the reference disinfection (4.83 ± 0.89 and 4.60 ± 0.59, respectively; p 10-reduction of 2.39 ± 0.57. Conclusions When using 62% ethanol foams, the time required for dryness often exceeds the recommended 30 s. Therefore, only a small volume is likely to be applied in clinical practice. Small amounts, however, failed to meet the efficacy requirements of EN 1500 and were only somewhat more effective than water.

  17. Final Report for CRADA Agreement , AL-C-2006-01 with Microsens Biotechnologies: Detection of the Abnormal Prion Protein in Blood by Improving the Extraction of this Protein

    Schmerr, Mary Jo

    2009-03-31

    Several conditions were examined to optimize the extraction protocol using Seprion beads for the abnormal prion protein. Different combinations of water, hexafluro-2-propanol and formic acid were used. The results of these extraction protocols showed that the magnetic beads coated with Seprion reagents were subject to degradation, themselves, when the extraction conditions that would solubilize the abnormal prion protein were used. These compounds caused interference in the immunoassay for the abnormal prion protein and rendered these protocols incompatible with the assay systems. In an attempt to overcome this problem, another approach was then used. The coated beads were used as an integral part of the assay platform. After washing away denaturing agents, the beads with the 'captured' abnormal prion were incubated directly in the immunoassay, followed by analysis by the capillary electrophoresis. When a capillary electrophoresis electro-kinetic separation was attempted, the beads disturbed the analysis making it impossible to interpret. A pressure separation method was then developed for capillary electrophoresis analysis. When 20 samples, 5 of which were positive were analyzed, the assay identified 4 of the 5 positives and had no false positives. When a larger number of samples were analyzed the results were not as good - there were false positives and false negatives. It was then observed that the amount of beads that were loaded was dependent upon how long the beads were allowed to settle before loading them into the capillary. This resulted in unacceptable variations in the results and explained that when large numbers of samples were evaluated the results were not consistent. Because the technical difficulties with using the Seprion beads could not be overcome at this time, another approach is underway that is outside of the scope of this CRADA. No further agreements have been developed. Because the results were not favorable, no manuscripts were

  18. Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system

    Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20–60 W), dissolved gas (air, Ar and He), pH (3–11) and initial concentration of fluoxetine (2.9–162.0 μmol L−1). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe2+) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. - Highlights: • The pharmaceutical fluoxetine was effectively eliminated upon ultrasonic action. • Ultrasonic power, dissolved gas, pH and concentration of fluoxetine were evaluated. • Fe2+, sodium nitrate or nitric acid had a positive effect on the FLX degradation. • More hydrophobic or volatile compounds than fluoxetine diminished the efficiency. • A sonochemical-biological combined process led to the total mineralization of FLX

  19. A combined experimental and computational investigation of excess molar enthalpies of (nitrobenzene + alkanol) mixtures

    Highlights: • Excess molar enthalpies for the binary mixtures of nitrobenzene + alkanols mixtures were measured. • The infinite dilution excess partial molar enthalpies were calculated using the ab initio methods. • The PCM calculations were performed. • The computed excess partial molar enthalpies at infinite dilution were compared to experimental results. - Abstract: Excess molar enthalpies (HmE) for the binary mixtures of {(nitrobenzene + ethanol), 1-propanol, 2-propanol, 1-butanol and 2-butanol} have been measured over the entire composition range at ambient pressure (81.5 kPa) and temperature 298 K using a Parr 1455 solution calorimeter. From the experimental results, the excess partial molar enthalpies (HiE) and excess partial molar enthalpies at infinite dilution (HiE,∞) were calculated. The excess molar enthalpies (HmE) are positive for all {nitrobenzene (1) + alkanol (2)} mixtures over the entire composition range. A state-of-the-art computational strategy for the evaluation of excess partial molar enthalpies at infinite dilution was followed at the M05-2X/6-311++G∗∗ level of theory with the PCM model. The experimental excess partial molar enthalpies at infinite dilution have been compared to the computational data of the ab initio in liquid phase. Integrated experimental and computational results help to clarify the nature of the intermolecular interactions in {nitrobenzene (1) + alkanol (2)} mixtures. The experimental and computational work which was done in this study complements and extends the general research on the computation of excess partial molar enthalpy at infinite dilution of binary mixtures

  20. Mn(2+)-mediated homogeneous Fenton-like reaction of Fe(III)-NTA complex for efficient degradation of organic contaminants under neutral conditions.

    Li, Yifan; Sun, Jianhui; Sun, Sheng-Peng

    2016-08-01

    In this work, we report a novel Mn(2+)-mediated Fenton-like process based on Fe(III)-NTA complex that is super-efficient at circumneutral pH range. Kinetics experiments showed that the presence of Mn(2+) significantly enhanced the effectiveness of Fe(III)-NTA complex catalyzed Fenton-like reaction. The degradation rate constant of crotamiton (CRMT), a model compound, by the Fe(III)- NTA_Mn(2+) Fenton-like process was at least 1.6 orders of magnitude larger than that in the absence of Mn(2+). Other metal ions such as Ca(2+), Mg(2+), Co(2+) and Cu(2+) had no impacts or little inhibitory effect on the Fe(III)-NTA complex catalyzed Fenton-like reaction. The generation of hydroxyl radical (HO) and superoxide radical anion (O2(-)) in the Fe(III)-NTA_Mn(2+) Fenton-like process were suggested by radicals scavenging experiments. The degradation efficiency of CRMT was inhibited significantly (approximately 92%) by the addition of HO scavenger 2-propanol, while the addition of O2(-) scavenger chloroform resulted in 68% inhibition. Moreover, the results showed that other chelating agents such as EDTA- and s,s-EDDS-Fe(III) catalyzed Fenton-like reactions were also enhanced significantly by the presence of Mn(2+). The mechanism involves an enhanced generation of O2(-) from the reactions of Mn(2+)-chelates with H2O2, indirectly promoting the generation of HO by accelerating the reduction rate of Fe(III)-chelates to Fe(II)- chelates. PMID:27070388