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Sample records for mixed solvent water-di-ethanolamine-methanol

  1. Thermodynamic modelling of the absorption of acid gas in mixed solvent (water-di-ethanolamine-methanol); Modelisation thermodynamique de l'absorption des gaz acides dans un solvant mixte (eau-diethanolamine-methanol)

    Energy Technology Data Exchange (ETDEWEB)

    Habchi tounsi, K.N.

    2003-10-01

    This work is related to the development of new processes about gas sweetening with mixed solvent coupling a chemical one (aqueous solution of di-ethanolamine) and a physical one (Methanol). These systems are electrolyte solutions constituted by ions and molecular species related each others by chemical reactions. This work is also relevant to the problematic of solvent mixtures (water-methanol). In a first stage we focus our interest over the measurement of original data covering a large experimental interval: five compositions in condition of pressures and temperatures up to 30 and 120 deg C respectively. In a second stage the simultaneous representation of chemical and phase equilibrium was successfully realised. The non stoichiometric method is used for the determination of chemical equilibrium. The heterogeneous method (Peng Robinson + NRTL electrolyte) is used for the representation of vapour liquid equilibrium. (author)

  2. Molecular Thermodynamic Modeling of Mixed Solvent Solubility

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

    2010-01-01

    A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from...... nearly ideal to strongly nonideal. The database covers a temperature range from 293 to 323 K. Comparisons with available data and other existing solubility methods show that the method successfully describes a variety of observed mixed solvent solubility behaviors using solute−solvent parameters from...

  3. Modeling of Salt Solubilities in Mixed Solvents

    DEFF Research Database (Denmark)

    Chiavone-Filho, O.; Rasmussen, Peter

    2000-01-01

    A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric...... constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt...

  4. Modeling of Salt Solubilities in Mixed Solvents

    DEFF Research Database (Denmark)

    Chiavone-Filho, O.; Rasmussen, Peter

    2000-01-01

    A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric...... constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt...

  5. Mixed Solvent Reactive Recrystallization of Sodium Carbonate

    NARCIS (Netherlands)

    Gaertner, R.S.

    2005-01-01

    Investigation of the reactive recrystallization of trona (sodium sesquicarbonate) and sodium bicarbonate to sodium carbonate (soda) in a mixed solvent led to the design of several alternative, less energy consumptive, economically very attractive process routes for the production of soda from all pr

  6. Dynamics around solutes and solute-solvent complexes in mixed solvents.

    Science.gov (United States)

    Kwak, Kyungwon; Park, Sungnam; Fayer, M D

    2007-09-04

    Ultrafast 2D-IR vibrational echo experiments, IR pump-probe experiments, and FT-IR spectroscopy of the hydroxyl stretch of phenol-OD in three solvents, CCl4, mesitylene (1, 3, 5 trimethylbenzene), and the mixed solvent of mesitylene and CCl4 (0.83 mole fraction CCl4), are used to study solute-solvent dynamics via observation of spectral diffusion. Phenol forms a complex with Mesitylene. In the mesitylene solution, there is only complexed phenol; in the CCl4 solution, there is only uncomplexed phenol; and in the mixed solvent, both phenol species are present. Dynamics of the free phenol in CCl4 or the mixed solvent are very similar, and dynamics of the complex in mesitylene and in the mixed solvent are very similar. However, there are differences in the slowest time scale dynamics between the pure solvents and the mixed solvents. The mixed solvent produces slower dynamics that are attributed to first solvent shell solvent composition variations. The composition variations require a longer time to randomize than is required in the pure solvents, where only density variations occur. The experimental results and recent MD simulations indicate that the solvent structure around the solute may be different from the mixed solvent's mole fraction.

  7. Solvent

    OpenAIRE

    Hamida Y. Mostafa; Ebaa A. El-Shamy; Amal S. Farag; Nadia G. Kandile

    2013-01-01

    Neat ethylacetoacetate (EAA) and its mixtures with a co-solvent and an anti-solvent have been studied for refining of heavy wax distillate fraction to produce substantially non-carcinogenic base oil. The co-solvent and anti-solvent used are dipropylene glycol (DPG) and ethylene glycol (EG) respectively. The solubility characteristics of the main solvent and its mixed solvent systems were studied. Selection of the optimum solvent mixture and extraction variables has been studied. The effect of...

  8. Method for Predicting Solubilities of Solids in Mixed Solvents

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O'Connell, J. P.

    2009-01-01

    A method is presented for predicting solubilities of solid solutes in mixed solvents, based on excess Henry's law constants. The basis is statistical mechanical fluctuation solution theory for composition derivatives of solute/solvent infinite dilution activity coefficients. Suitable approximations...... are made for a single parameter characterizing solute/solvent interactions. Comparisons with available data show that the method is successful in describing a variety of observed mixed solvent solubility behavior, including nearly ideal systems with small excess solubilities, systems with solute......-independent excess solubilities, and systems deviating from these simple rules. Successful predictions for new solvent mixtures cat? be made using limited data from other mixtures....

  9. NMR microscopy of tissue in organic and mixed solvents

    OpenAIRE

    Macura Slobodan; Mishra Prasanna K.; Gamez Jeffrey D.; Pirko Istvan

    2013-01-01

    We propose to use organic and mixed solvents for nuclear magnetic resonance microscopy of fixed tissue as a means for improving image information content. NMR properties of some standard solvents (methanol, acetone, DMSO) and solvents in use for tissue processing in pathology (xylenes, paraffin, ‘Clearify’) have been measured, reviewed, and analyzed. It was found that DMSO and paraffin are very useful solvents that provide images of better quality than thos...

  10. NMR microscopy of tissue in organic and mixed solvents

    Directory of Open Access Journals (Sweden)

    Macura Slobodan

    2013-01-01

    Full Text Available We propose to use organic and mixed solvents for nuclear magnetic resonance microscopy of fixed tissue as a means for improving image information content. NMR properties of some standard solvents (methanol, acetone, DMSO and solvents in use for tissue processing in pathology (xylenes, paraffin, ‘Clearify’ have been measured, reviewed, and analyzed. It was found that DMSO and paraffin are very useful solvents that provide images of better quality than those obtained in water (neutralized formalin buffer. This is illustrated on the formalin fixed mouse brain sections imaged at 16.4 teslas (700 MHz.

  11. Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Sue B. [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry

    2016-10-31

    The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

  12. Mixed solvent system for treating acidic gas

    Energy Technology Data Exchange (ETDEWEB)

    Capobianco, P.J.; Butwell, K.F.; Kossakowski, E.J.

    1987-11-10

    This invention discloses mixtures of alkyl dialcohol amines and mono alkyl ethers of polyethylene glycols which are useful in removing acidic gases from gaseous mixtures. The solvent mixtures contain between 1.5 N and 5.0 N methyl diethanolamine (MDEA), 10 to 40 percent water and the balance is methoxytriglycol (MTG). The overall heat of reaction of the solution is typically less than 500 BTU/lb CO/sub 2/, and remains as a single liquid phase during normal gas scrubber operating conditions.

  13. Divalent Cu, Cd, and Pb Biosorption in Mixed Solvents

    Directory of Open Access Journals (Sweden)

    M. H. Al-Qunaibit

    2009-01-01

    Full Text Available Dead dried Chlorella vulgaris was studied in terms of its performance in binding divalent copper, cadmium, and lead ions from their aqueous or 50% v/v methanol, ethanol, and acetone solutions. The percentage uptake of cadmium ions exhibited a general decrease with decrease in dielectric constant values, while that of copper and lead ions showed a general decrease with increase in donor numbers. Uptake percentage becomes less sensitive to solvent properties the larger the atomic radius of the biosorbed ion, and uptake of copper was the most affected. FT-IR analyses revealed stability of the biomass in mixed solvents and a shift in vibrations of amide(I and (II, carboxylate, glucose ring, and metal oxygen upon metal binding in all media. ΔνCOO values (59–69 cm−1 confirmed bidentate metal coordination to carboxylate ligands. The value of νasCOO increased slightly upon Cu, Cd, and Pb biosorption from aqueous solutions indicating lowering of symmetry, while a general decrease was noticed in mixed solvents pointing to the opposite. M–O stretching frequencies increased unexpectedly with increase in atomic mass as a result of solvent effect on the nature of binding sites. Lowering polarity of the solvent permits variations in metal-alga bonds strengths; the smaller the metal ion, the more affected.

  14. Prediction of Corrosion of Alloys in Mixed-Solvent Environments

    Energy Technology Data Exchange (ETDEWEB)

    Anderko, Andrzej [OLI Systems Inc. Morris Plains (United States); Wang, Peiming [OLI Systems Inc. Morris Plains (United States); Young, Robert D. [OLI Systems Inc. Morris Plains (United States); Riemer, Douglas P. [OLI Systems Inc. Morris Plains (United States); McKenzie, Patrice [OLI Systems Inc. Morris Plains (United States); Lencka, Malgorzata M. [OLI Systems Inc. Morris Plains (United States); Babu, Sudarsanam Suresh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Angelini, Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2003-06-05

    Corrosion is much less predictable in organic or mixed-solvent environments than in aqueous process environments. As a result, US chemical companies face greater uncertainty when selecting process equipment materials to manufacture chemical products using organic or mixed solvents than when the process environments are only aqueous. Chemical companies handle this uncertainty by overdesigning the equipment (wasting money and energy), rather than by accepting increased risks of corrosion failure (personnel hazards and environmental releases). Therefore, it is important to develop simulation tools that would help the chemical process industries to understand and predict corrosion and to develop mitigation measures. To create such tools, we have developed models that predict (1) the chemical composition, speciation, phase equilibria, component activities and transport properties of the bulk (aqueous, nonaqueous or mixed) phase that is in contact with the metal; (2) the phase equilibria and component activities of the alloy phase(s) that may be subject to corrosion and (3) the interfacial phenomena that are responsible for corrosion at the metal/solution or passive film/solution interface. During the course of this project, we have completed the following: (1) Development of thermodynamic modules for calculating the activities of alloy components; (2) Development of software that generates stability diagrams for alloys in aqueous systems; these diagrams make it possible to predict the tendency of metals to corrode; (3) Development and extensive verification of a model for calculating speciation, phase equilibria and thermodynamic properties of mixed-solvent electrolyte systems; (4) Integration of the software for generating stability diagrams with the mixed-solvent electrolyte model, which makes it possible to generate stability diagrams for nonaqueous or mixed-solvent systems; (5) Development of a model for predicting diffusion coefficients in mixed-solvent electrolyte

  15. An electrolyte CPA equation of state for mixed solvent electrolytes

    DEFF Research Database (Denmark)

    Maribo-Mogensen, Bjørn; Thomsen, Kaj; Kontogeorgis, Georgios M.

    2015-01-01

    that the predictive capabilities could be improved through the development of an electrolyte equation of state. In this work, the Cubic Plus Association (CPA) Equation of State is extended to handle mixtures containing electrolytes by including the electrostatic contributions from the Debye-Hückel and Born terms...... depression. Finally, the model is applied to predict VLE, LLE, and SLE in aqueous salt mixtures as well as in mixed solvents....

  16. Thermodynamics of Ion Pair of Magnesium Sulfate in Mixed Solvent

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction Magnesium sulfate is an archetypal 2-2 salt that plays a central role in defining the characteristics of higher valent electrolyte solutions and its solution has been widely used to test various theories of strong electrolyte behavior and to develop models of ion association in solution[1]. Up to now, the ion pairs of magnesium sulfate in an aqueous solution have been widely investigated by using different experimental techniques, such as conductometry[2] , cryoscopy[3] , potentiometry[4] ,solubility[5] and Raman spectrometry[6]. However, to our knowledge, no measurement of the standard association constant of the ion pairs, [MgSO4] 0 in a glucosewater mixed solvent is available.

  17. Solubility of β-cyclodextrin in different mixed solvents

    Institute of Scientific and Technical Information of China (English)

    Yu Yong; Li Jiguang; Sun Yan; Liang Qianqing; Peng Xiaoming; Liu Yansheng; Hu Yufeng

    2008-01-01

    The solubility of β-cyclodextrin(β-CD)in ionic liquid/N,N-dimethyl-acetamide(IL/DMAC)mixed solvent and in LiCl/DMAC mixed solvent was investigated at 323.15 K and 353.15 K.The results showed that the solubility of β-CD in IL/DMAC system increased with increasing temperature,but decreased in LiCl/DMAC system.β-CD had the highest solubility in IL/DMAC system with[Cl]- or[Br]- anions.The solubility of β-CD in LiCl/DMAC system was lower than that in IL/DMAC system with [Cl]- or[Br]- anions but higher than that in IL/DMAC system with weak-coordinated anions(e.g[BF4]- or[PF6]-).The effects of substituent groups(benzyl and butyl)of cation and the structure of cations on β-cyclodextrin solubility were also investigated.

  18. Mixed organic solvents induce renal injury in rats.

    Directory of Open Access Journals (Sweden)

    Weisong Qin

    Full Text Available To investigate the injury effects of organic solvents on kidney, an animal model of Sprague-Dawley (SD rats treated with mixed organic solvents via inhalation was generated and characterized. The mixed organic solvents consisted of gasoline, dimethylbenzene and formaldehyde (GDF in the ratio of 2:2:1, and were used at 12,000 PPM to treat the rats twice a day, each for 3 hours. Proteinuria appeared in the rats after exposure for 5-6 weeks. The incidences of proteinuria in male and female rats after exposure for 12 weeks were 43.8% (7/16 and 25% (4/16, respectively. Urinary N-Acetyl-β-(D-Glucosaminidase (NAG activity was increased significantly after exposure for 4 weeks. Histological examination revealed remarkable injuries in the proximal renal tubules, including tubular epithelial cell detachment, cloud swelling and vacuole formation in the proximal tubular cells, as well as proliferation of parietal epithelium and tubular reflux in glomeruli. Ultrastructural examination found that brush border and cytoplasm of tubular epithelial cell were dropped, that tubular epithelial cells were partially disintegrated, and that the mitochondria of tubular epithelial cells were degenerated and lost. In addition to tubular lesions, glomerular damages were also observed, including segmental foot process fusion and loss of foot process covering on glomerular basement membrane (GBM. Immunofluorescence staining indicated that the expression of nephrin and podocin were both decreased after exposure of GDF. In contrast, increased expression of desmin, a marker of podocyte injury, was found in some areas of a glomerulus. TUNEL staining showed that GDF induced apoptosis in tubular cells and glomerular cells. These studies demonstrate that GDF can induce both severe proximal tubular damage and podocyte injury in rats, and the tubular lesions appear earlier than that of glomeruli.

  19. Selecting water-alcohol mixed solvent for synthesis of polydopamine nano-spheres using solubility parameter

    OpenAIRE

    Jiang, Xiaoli; Wang, Yinling; Li, Maoguo

    2014-01-01

    The solvent plays an important role in a given chemical reaction. Since most reaction in nature occur in the mixed-solvent systems, a comprehensive principle for solvent optimization was required. By calculating the Hansen solubility parameters (HSP) distance Ra , we designed a model experiment to explore the influence of mixed solvents on the chemical synthesis. The synthesis of polydopamine (PDA) in the water-alcohol system was chosen as model. As predicted, the well-dispersed PDA spheres w...

  20. Selecting water-alcohol mixed solvent for synthesis of polydopamine nano-spheres using solubility parameter

    Science.gov (United States)

    Jiang, Xiaoli; Wang, Yinling; Li, Maoguo

    2014-08-01

    The solvent plays an important role in a given chemical reaction. Since most reaction in nature occur in the mixed-solvent systems, a comprehensive principle for solvent optimization was required. By calculating the Hansen solubility parameters (HSP) distance Ra, we designed a model experiment to explore the influence of mixed solvents on the chemical synthesis. The synthesis of polydopamine (PDA) in the water-alcohol system was chosen as model. As predicted, the well-dispersed PDA spheres were obtained in selected solvents with smaller Ra values: methanol/water, ethanol/water and 2-propanol/water. In addition, the mixed solvent with smaller Ra values gave a higher conversion of dopamine. The strategy for mixed solvent selection is might be useful to choose optimal reaction media for efficient chemical synthesis.

  1. Selecting water-alcohol mixed solvent for synthesis of polydopamine nano-spheres using solubility parameter

    Science.gov (United States)

    Jiang, Xiaoli; Wang, Yinling; Li, Maoguo

    2014-01-01

    The solvent plays an important role in a given chemical reaction. Since most reaction in nature occur in the mixed-solvent systems, a comprehensive principle for solvent optimization was required. By calculating the Hansen solubility parameters (HSP) distance Ra, we designed a model experiment to explore the influence of mixed solvents on the chemical synthesis. The synthesis of polydopamine (PDA) in the water-alcohol system was chosen as model. As predicted, the well-dispersed PDA spheres were obtained in selected solvents with smaller Ra values: methanol/water, ethanol/water and 2-propanol/water. In addition, the mixed solvent with smaller Ravalues gave a higher conversion of dopamine. The strategy for mixed solvent selection is might be useful to choose optimal reaction media for efficient chemical synthesis. PMID:25317902

  2. Regeneration of mixed solvent by electrodialysis: selective removal of chloride and sulfate

    NARCIS (Netherlands)

    Gärtner, R.S.; Wilhelm, F.G.; Witkamp, G.J.; Wessling, Matthias

    2005-01-01

    The applicability of electrodialysis for the selective removal of sulfate and chloride ions from a mixed solvent solution of sodium carbonate is investigated. The mixed solvent consists of 70 wt.% ethylene glycol and 30 wt.% water. Six different ion exchange membranes, the homogeneous membranes

  3. Excited state charge transfer reaction in (mixed solvent + electrolyte) systems: Role of reactant-solvent and reactant-ion interactions

    Indian Academy of Sciences (India)

    Harun Al Rasid Gazi; Ranjit Biswas

    2011-05-01

    Fluorescence spectroscopic techniques have been used to study the excited state intramolecular charge transfer reaction of 4-(1-azetidinyl)benzonitrile (P4C) in two sets of mixed solvents, (1-propanol + ethyl acetate) and (propylene carbonate + acetonitrile), in the absence and presence of a strong electrolyte, lithium perchlorate. These two sets of mixed solvent systems represent binary solvent mixtures of low and high polarities, respectively. Density, sound velocity and viscosity measurements indicate that these two mixed solvent systems are structurally different. Stronger ion-reactant interaction is evidenced in the mole fraction independence of emission frequencies in electrolyte solutions of low polar binary solvent mixtures. For both these mixtures, the reaction driving force (- ) decreases with increase in mole fraction of the relatively less polar solvent component of the mixture. Interestingly, - increases significantly on addition of electrolyte in low polar mixtures and exhibits mixture composition dependence but, in contrast, - in high polar mixtures does not sense variation in mixture composition in presence of electrolyte. This insensitivity to mixture composition for high polar mixtures is also observed for the measured reaction time constant. In addition, the reaction time constant does not sense the presence of electrolyte in the high polar solvent mixtures. The reaction time constant in low polar mixtures, which becomes faster on addition of electrolyte, lengthens on increasing the mole fraction of the relatively less polar solvent component of the mixture. These observations have been qualitatively explained in terms of the measured solvent reorganization energy and reaction driving force by using expressions from the classical theory of electron transfer reaction.

  4. 1/6TH SCALE STRIP EFFLUENT FEED TANK-MIXING RESULTS USING MCU SOLVENT

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E

    2006-02-01

    The purpose of this task was to determine if mixing was an issue for the entrainment and dispersion of the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) solvent in the Defense Waste Processing Facility (DWPF) Strip Effluent Feed Tank (SEFT). The MCU strip effluent stream containing the Cs removed during salt processing will be transferred to the DWPF for immobilization in HLW glass. In lab-scale DWPF chemical process cell testing, mixing of the solvent in the dilute nitric acid solution proved problematic, and the Savannah River National Laboratory (SRNL) was requested to perform scaled SEFT mixing tests to evaluate whether the problem was symptomatic of the lab-scale set-up or of the solvent. The solvent levels tested were 228 and 235 ppm, which represented levels near the estimated DWPF solvent limit of 239 ppm in 0.001M HNO{sub 3} solution. The 239 ppm limit was calculated by Norato in X-CLC-S-00141. The general approach for the mixing investigation was to: (1) Investigate the use of fluorescent dyes to aid in observing the mixing behavior. Evaluate and compare the physical properties of the fluorescent dyed MCU solvents to the baseline Oak Ridge CSSX solvent. Based on the data, use the dyed MCU solvent that best approximates the physical properties. (2) Use approximately a 1/6th linear scale of the SEFT to replicate the internal configuration for DWPF mixing. (3) Determine agitator speed(s) for scaled testing based on the DWPF SEFT mixing speed. (4) Perform mixing tests using the 1/6th SEFT and determine any mixing issues (entrainment/dispersion, accumulation, adhesion) through visual observations and by pulling samples to assess uniformity. The mixing tests used MCU solvent fabricated at SRNL blended with Risk Reactor DFSB-K43 fluorescent dye. This dyed SRNL MCU solvent had equivalent physical properties important to mixing as compared to the Oak Ridge baseline solvent, blended easily with the MCU solvent, and provided an excellent visual aid.

  5. Psychomotor Effects of Mixed Organic Solvents on Rubber Workers

    Directory of Open Access Journals (Sweden)

    O Aminian

    2014-04-01

    Full Text Available Background: Exposure to organic solvents is common among workers.Objective: To assess neurobehavioral effects of long-term exposure to organic solvents among rubber workers in Tehran, Iran.Methods: Across-sectional study was conducted on 223 employees of a rubber industry. The participants completed a data collection sheet on their occupational and medical history, and demographic characteristics including age, work experience, education level; they performed 6 psychiatric tests on the neurobehavioral core test battery (NCTB that measure simple reaction time, short-term memory (digit span, Benton, eye-hand coordination (Purdue pegboard, pursuit aiming, and perceptual speed (digit symbol.Results: Workers exposed and not exposed to organic solvents had similar age and education distribution. The mean work experience of the exposed and non-exposed workers was 5.9 and 4.4 years, respectively. The exposed workers had a lower performance compared to non-exposed workers in all psychomotor tests. After controlling for the confounders by logistic regression analysis, it was found that exposure to organic solvents had a significant effect on the results of digit symbols, digit span, Benton, aiming, and simple reaction time tests. No significant effect was observed in pegboard test.Conclusion: Occupational exposure to organic solvent can induce subtle neurobehavioral changes among workers exposed to organic solvents; therefore, periodical evaluation of the central nervous system by objective psychomotor tests is recommended among those who are chronically exposed to organic solvents.

  6. Modeling of wettability alteration during spontaneous imbibition of mutually soluble solvents in mixed wet fractured reservoirs

    NARCIS (Netherlands)

    Chahardowli, M.; Bruining, J.

    2014-01-01

    Mutually-soluble solvents can enhance oil recovery both in mixed-wet fractured reservoirs. When a partially waterwet matrix is surrounded by an immiscible wetting phase in the fracture, spontaneous imbibition is the most important production mechanism. Initially, the solvent moves with the imbibing

  7. Liquid-liquid equilibrium extraction of ethanol with mixed solvent for bioethanol concentration

    Institute of Scientific and Technical Information of China (English)

    Hiroaki Habaki; Haihao Hu; Ryuichi Egashira

    2016-01-01

    The extraction of ethanol with the solvents of aldehydes mixed with m-xylene was studied for the bioethanol concentration process. Furfural and benzaldehyde were selected as extraction solvents, with which the solubility of water is smal , expecting large distribution coefficient of ethanol. The liquid–liquid two-phase region was the largest with m-xylene solvent, followed by benzaldehyde and furfural. The region of two liquid–liquid phase be-came larger with the mixed solvent of m-xylene and furfural than that with furfural solvent. The NRTL model was applied to the ethanol–water–furfural–m-xylene system, and the model could well express the liquid–liquid equilibrium of the system. For any solvent used in this study, the separation selectivity of ethanol relative to water decreased as the distribution coefficient of ethanol increased. The separation selectivity with m-xylene was the largest among the employed solvents, but the distribution coefficient was the smal est. The solvent mix-ture of furfural and m-xylene showed relatively high distribution coefficient of ethanol and separation selectivity, even in the higher mass fraction of m-xylene in the solvent phase. The ethanol extraction with a countercurrent multistage extractor by a continuous operation was simulated to evaluate the extraction performance. The ethanol content could be concentrated in the extract phase with relatively small number of extraction stages but low yield of ethanol was obtained.

  8. Phase behavior and second osmotic virial coefficient for competitive polymer solvation in mixed solvent solutions.

    Science.gov (United States)

    Dudowicz, Jacek; Freed, Karl F; Douglas, Jack F

    2015-11-21

    We apply our recently developed generalized Flory-Huggins (FH) type theory for the competitive solvation of polymers by two mixed solvents to explain general trends in the variation of phase boundaries and solvent quality (quantified by the second osmotic virial coefficient B2) with solvent composition. The complexity of the theoretically predicted miscibility patterns for these ternary mixtures arises from the competitive association between the polymer and the solvents and from the interplay of these associative interactions with the weak van der Waals interactions between all components of the mixture. The main focus here lies in determining the influence of the free energy parameters for polymer-solvent association (solvation) and the effective FH interaction parameters {χαβ} (driving phase separation) on the phase boundaries (specifically the spinodals), the second osmotic virial coefficient B2, and the relation between the positions of the spinodal curves and the theta temperatures at which B2 vanishes. Our classification of the predicted miscibility patterns is relevant to numerous applications of ternary polymer solutions in industrial formulations and the use of mixed solvent systems for polymer characterization, such as chromatographic separation where mixed solvents are commonly employed. A favorable comparison of B2 with experimental data for poly(methyl methacrylate)/acetonitrile/methanol (or 1-propanol) solutions only partially supports the validity of our theoretical predictions due to the lack of enough experimental data and the neglect of the self and mutual association of the solvents.

  9. Solvent sorting in (mixed solvent + electrolyte) systems: Time-resolved fluorescence measurements and theory

    Indian Academy of Sciences (India)

    Harun Al Rasidgazi; Hemant K Kashyap; Ranjit Biswas

    2015-01-01

    In this manuscriptwe explore electrolyte-induced modification of preferential solvation of a dipolar solute dissolved in a binary mixture of polar solvents. Composition dependence of solvation characteristics at a fixed electrolyte concentration has been followed. Binary mixtures of two different polarities have been employed to understand the competition between solute-ion and solute-solvent interactions. Time-resolved fluorescence Stokes shift and anisotropy have been measured for coumarin 153 (C153) in moderately polar (ethyl acetate + 1-propanol) and strongly polar (acetonitrile + propylene carbonate) binary mixtures at various mixture compositions, and in the corresponding 1.0M solutions of LiClO4. Both the mixtures show red shifts in C153 absorption and fluorescence emission upon increase of mole fraction of the less polar solvent component in presence of the electrolyte. In addition, measured average solvation times become slower and rotation times faster for the above change in the mixture composition. A semi-molecular theory based on solution density fluctuations has been developed and found to successfully capture the essential features of the measured Stokes shift dynamics of these complex multi-component mixtures. Dynamic anisotropy results have been analyzed by using both Stokes-Einstein-Debye (SED) and Dote-Kivelson-Schwartz (DKS) theories. The importance of local solvent structure around the dissolved solute has been stressed.

  10. Density and viscosity of magnesium sulphate in formamide + ethylene glycol mixed solvents

    Indian Academy of Sciences (India)

    A Ali; A K Nain; N Kumar; M Ibrahim

    2002-10-01

    Densities () and viscosities () of different strengths of magnesium sulphate (MgSO4) in varying proportions of formamide (FA) + ethylene glycol as mixed solvents were measured at room temperature. The experimental values of and were used to calculate the values of the apparent molar volume, (), partial molar volume, (°) at infinite dilution, - and $B$-coefficients of the Jones-Dole equation and free energies of activation of viscous flow, ($\\Delta \\mu^{0\\ast}_{1}$) and ($\\Delta \\mu^{0\\ast}_{2}$), per mole of solvent and solute respectively. The behaviour of these parameters suggests strong ion-solvent interactions in these systems and also that MgSO4 acts as structure-maker in FA + ethylene glycol mixed solvents.

  11. Solvent effect on intramolecular electron transfer rates of mixed-valence biferrocene monocation derivatives.

    Science.gov (United States)

    Masuda, Y; Shimizu, C

    2006-06-01

    Intramolecular electron transfer (ET) rates in various solvents of mixed-valence biferrocene monocation (Fe(II), Fe(III)) and the 1',1' ''-diiodo and 1',1' ''-diethyl derivatives (respectively abbreviated as BFC(+), I(2)BFC(+), and Et(2)BFC(+)) were determined by means of the spin-lattice relaxation times of the protons, taking into account the local magnetic field fluctuation caused by the electron hopping between the two ferrocene units. We also determined the ET rates of a mixed-valence diferrocenylacetylene monocation (DFA(+)) in order to examine the effect of the insertion of an acetylene bridge between the two ferrocene units. The insertion of the bridge decreased the ET rate, while the effect of substitution on the cyclopentadienyl rings on the rate was minor. The observed rates for each mixed-valence monocation in various solvents did not correlate with the reorganization energies, but we did find a significant contribution of the solvent dynamics. The observed rates were considerably higher than those expected on the basis of the Sumi-Marcus-Nalder model in which the solvents were regarded as dielectric continua. The slope of the logarithm plot of the pre-exponential factors in various solvents for each mixed-valence monocation versus the inverse of the longitudinal dielectric relaxation times of the solvents was significantly smaller than unity, and the slope for DFA(+) was larger than those for BFC(+), I(2)BFC(+), and Et(2)BFC(+). These results were ascribed to a partial contribution of the dielectric friction to the dynamics along the solvent coordinate; the extent of the contribution decreased with a reduction in the ET distance. For the dynamics along the solvent coordinate of the ET reactions in methanol, the observed rates indicated an important contribution by the minor dielectric relaxation components with faster relaxation times, rather than the major component with an extraordinarily long relaxation time.

  12. 信息动态%Mixed Solvent Induced Dewetting of Polystyrene Thin Film

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    We investigated the dewetting process of PS film induced by mixed solvent of water and acetone with the method of OM and AFM. By changing the proportion between acetone and water in the mixed solvent,it was found that on the hydrophilic substrate, with the decreasing of volume fraction of acetone, first R-exp ( t/(Υ)), then R-t, and at last R-t0.76. Besides, when the volume fraction of acetone in mixed solvent further decreased, the dewetting mechanism changed from nucleation and growth to penetration-replacement. While on hydrophobic substrate, first R-exp ( t/(Υ)), then R-t, at last R-t0.72, and the mechanism of hole growth was still nucleation and growth mechanism. But the slippage effect of PS was valid on both hydrophilic substrate and hydrophobic substrate.

  13. Reverse Schreinemakers Method for Experimental Analysis of Mixed-Solvent Electrolyte Systems

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Thomsen, Kaj; Stenby, Erling Halfdan

    2009-01-01

    from determining the composition of salt mixtures by pH titration are discussed, and the derived method significantly improves the obtained result from titration. Furthermore, the method reduces the required experimental work needed for analysis of phase composition. The method is applicable to multi......A method based on Schreinemakers's tie-line theory of 1893 is derived for determining the composition and phase amounts in solubility experiments for multi-solvent electrolyte systems. The method uses the lever rule in reverse compared to Schreinemakers's wet residue method, and is therefore called...... the reverse Schreinemakers (RS) method. The method is based on simple mass balance principles similar to the wet residues method. It allows for accurate determination of the mixed-solvent phase composition even though part of the solvent may precipitate as complexes between solvent and salt. Discrepancies...

  14. Preparation of Soybean Protein Concentrate with Mixed Solvents of Hexane-Aqueous Alcohol

    Institute of Scientific and Technical Information of China (English)

    Zhang Weinong; Liu Dachuan

    2002-01-01

    Preparation of soybean proteinconcentrate with the mixed solvents of hexane-aqueous alcohol was studied in this paper Theoptimum technology parameters were obtainedby orthogonal tests. The results of experimentsshowed that the qualities of the product weregood not only on taste and color, but also onhigh solubility-NSI value was 48.80%.

  15. Solid-Liquid Equilibria of Succinic Acid in Cyclohexanone, Cyclohexanol and Their Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    FAN Lihua; MA Peisheng; SONG Weiwei

    2007-01-01

    Solubilities were measured for succinic acid dissolved in cyclohexanone, cyclohexanol and 5 of their mixed solvents at the temperature range from 291.85 K to 358.37 K using a dynamic method. The solubility data were regressed by λh equation, withthe average absolute relative deviation 3.47%. The binary interaction parameter is 0.306 7 for the mixed solvent of cyclohexanone and cyclohexanol was determined by correlating the experimental solubilities with the modified λh equation. When the binary interaction parameter was determined, it can be used to extrapolate the solubilities of succinic acid in mixed solvents of cyclohexanone and cyclohexanol at any proportion. The average absolute relative deviation was 7.69% by using the modified λh equation to correlate the solubility data, however, the average absolute relative deviation was 8.89% by using NRTL equation to correlate the solubility data. The results show that the accuracy of the modified λh equation is better than that of the NRTL equation for the solubility of succinic acid in the 5 mixed solvents of cyclohexanone and cyclohexanol.

  16. Effects of the Water in Mixed Solvent on the Epoxidation Reaction of Propylene with TS-1 Catalyst

    Institute of Scientific and Technical Information of China (English)

    苏泉声; 王彪; 张玉梅; 王华平

    2001-01-01

    The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of methanol/water.

  17. Spectrophotometric determination of the acidity constants of calcon in water and mixed water–organic solvents

    Directory of Open Access Journals (Sweden)

    MOHAMMAD MAZLOUM-ARDAKANI

    2009-02-01

    Full Text Available The acid–base properties of calcon (1-(2-hydroxy-1-naphthylazo-2-naphthol-4-sulfonic acid in water and mixed water–organic solvents at 25 °C at an ionic strength of 0.10 M are studied by a multiwavelength spectrophotometric method. The organic solvents used were the amphiprotic (methanol, dipolar aprotic (dimethylsulfoxide, and low basic aprotic (acetonitrile. To evaluate the pH absorbance data, a resolution method based on the combination of soft- and hard-modeling was applied. The acidity constants of all related equilibria were estimated using the whole spectral fitting of the collected data to an established factor analysis model. The data analysis program Datan was applied for determination of the acidity constants. The corresponding pKa values were determined in water and mixed water–organic solvents. Linear relationship between the acidity constants and the mole fraction of the different sol-vents in the mixtures exist. The effect of solvent properties on acid–base behavior is discussed.

  18. Effects of Assistant Solvents and Mixing Intensity on the Bromination Process of Butyl Rubber

    Institute of Scientific and Technical Information of China (English)

    王伟; 邹海魁; 初广文; 向阳; 彭晗; 陈建峰

    2014-01-01

    A slow bromination process of butyl rubber (IIR) suffers from low efficiency and low selectivity (S) of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%(by volume) dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product (xA1s) of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r·min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed (RPB) reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.

  19. VISCOMETRIC INVESTIGATIONS OF POLYVINYLPYRROLIDONE IN MIXED SOLVENTS AND WITH VARYING TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    Omar Melad; Omar Abu-Tiem; Rajai Baraka

    2005-01-01

    The viscosity behavior of polyvinylpyrrolidone (PVP) has been determined at 25℃ in mixed solvents comprising water/dimethylformamide (DMF) and water /methanol (MeOH). Analysis of the data has considered the PVP as being both host and guest polymer in solution. The intrinsic viscosity of PVP in DMF is higher than in water and in MeOH, but also increases in a mixed solvent with high water content because of the effect of polymer-solvent interactions. It was also found that the intrinsic viscosity of PVP at finite concentration, [ηPVP]c decreases with an increase in the concentration of PVP in solution. The viscosity behavior of PVP in a mixed solvent is affected by the concentration-dependent intermolecular excluded volume effect, which can be quantitatively expressed by the parameter, bY, which reflects the shrinkage of PVP chain coils, resulting in a decrease of [ηPVP]c . The effect of temperature on the viscosity behavior of PVP in MeOH shows that the interaction parameter increases up to a maximum value, and then decreases after a certain temperature.

  20. Supramolecular solvent-based vortex-mixed microextraction: determination of glucocorticoids in water samples.

    Science.gov (United States)

    Qin, Hui; Qiu, Xiaoyan; Zhao, Jiao; Liu, Mousheng; Yang, Yaling

    2013-10-11

    Glucocorticoids contamination has become a big environmental issue in China and other developing countries, due to increasing needs in medical prescription and farming. However, no highly sensitive and precise methods have been reported to quantify glucocorticoids so far. In the past several years, supramolecular solvent-based vortex-mixed microextraction (SS-BVMME) has been shown to be effective. However, the mechanism of SS-BVMME is still unknown. In this report, a novel method has been proposed for rapid quantification of trace amount of glucocorticoids, beclomethasone dipropionate (BD), hydrocortisone butyrate (HB) and nandrolone phenylpropionate (NPP) in water samples from the Green Lake. This method is simple, safe and cost effective. It contains two steps: supramolecular solvent-based vortex-mixed microextraction (SS-BVMME) technique and high performance liquid chromatography (HPLC) analysis. First, ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) and n-butanol were mixed to form the supramolecular solvent. After mixing the supramolecular solvent with an aqueous sample to test, a homogenous mixture was formed immediately. BD, HB and NPP were then extracted based on their binding interactions, particularly hydrogen bond formed between their hydroxyl group and the supramolecular solvent. The overall process of sample preparation took only 20min and more than 5 samples could be simultaneously prepared. The minimum detectable concentrations of samples in this method were 0.09925, 0.5429 and 2.428ngmL(-1) for BD, HB and NPP, respectively. Product recoveries ranged from 88% to 103% with relative standard deviations from 0.6% to 4%. For the first time, we report that hydrogen bond plays a key role in SS-BVMME. We also improve the sensitivity significantly to quantify glucocorticoids, which may greatly benefit environmental safety management in China.

  1. PVTx measurements of the N-methylpyrrolidone/methanol mixed solvent: cubic and SAFT EOS analyses.

    Science.gov (United States)

    Aparicio, Santiago; García, Begoña; Alcalde, Rafael; Davila, María J; Leal, José M

    2006-04-06

    The PVTx behavior for the x N-methylpyrrolidone (NMP) + (1 - x) methanol compressed liquid solvent is reported over the full composition range and within wide pressure and temperature ranges. The derived excess properties were analyzed in terms of structural effects and intermolecular interactions and revealed strong H-bonding heteroassociations between the two components. The cubic equations of state by Soave (SRK), Peng-Robinson (PR), Patel-Teja (PT), and Sako-Wu-Prausnitz (SWP), and the statistical associating fluid theory (SAFT) equation of state, combined with a number of selected mixing rules, were used to correlate and predict the behavior of both the pure components and mixed solvent. While the classical cubic equations of state were not successful in describing the properties of this system, the SWP equation of state and the SAFT yielded reasonably good results.

  2. Synthesis of MgO Nanoparticles by Solvent Mixed Spray Pyrolysis Technique for Optical Investigation

    Directory of Open Access Journals (Sweden)

    K. R. Nemade

    2014-01-01

    Full Text Available Solvent mixed spray pyrolysis technique has attracted a global interest in the synthesis of nanomaterials since reactions can be run in liquid state without further heating. Magnesium oxide (MgO is a category of the practical semiconductor metal oxides, which is extensively used as catalyst and optical material. In the present study, MgO nanoparticles were successfully synthesized using a solvent mixed spray pyrolysis. The X-ray diffraction pattern confirmed the formation of MgO phase with an excellent crystalline structure. Debye-Scherrer equation is used for the determination of particle size, which was found to be 9.2 nm. Tunneling electron microscope analysis indicated that the as-synthesized particles are nanoparticles with an average particle size of 9 nm. Meanwhile, the ultraviolet-visible spectroscopy of the resulting product was evaluated to study its optical property via measurement of the band gap energy value.

  3. Solvent mixing effects on the electrode characteristics of secondary Li/TiS2 cells

    Science.gov (United States)

    Matsuda, Y.; Morita, M.; Takata, K.-I.

    1984-09-01

    Charge-discharge characteristics of Li negative and TiS2 positive electrodes have been studied in LiBF4 solutions of tetrahydrofuran (THF), 1,3-dioxolane (DOL), and their mixture. Solvent mixing effects on the charge-discharge characteristics were investigated. Charge-discharge potentials at the Li electrode in THF-DOL/LiBF4 were more stable than those in THF/LiBF4 and DOL/LiBF4, and they showed the least variation with the cycles. Ionic behavior in the solutions is discussed through the data of current-potential curves of the electrodes and electrolytic conductivity of the solutions. With respect to the TiS2 electrode, charging efficiency in THF was seemingly the best, but the efficiency variation with the cycle in DOL-THF was very small. It was concluded that advantages of solvent mixing should be evaluated totally in Li/TiS2 cells.

  4. Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Vinayak Kabadi

    2007-03-17

    The main objective of this research was to measure heat of dissolution of CO{sub 2} in carefully mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture process, and for better understanding of the thermodynamics of CO{sub 2}-Alkanolamine systems. An experimental set-up has been designed using the Isothermal Micro Calorimeter for measuring the solubilities and enthalpies of CO{sub 2} in mixed solvents made of MEA, MDEA, PZ, KF and water. All the measurements were done at temperatures 15, 40, and 75 C by maintaining a constant pressure of 100 psig. A detailed study has been done on the variation of solubilities and enthalpies over a wide range of temperatures, pressures and concentrations, by extracting the information from the literature.

  5. Preparation of Soybean Protein Concentrate with Mixed Solvents of Hexane-Aqueous Alcohol

    Institute of Scientific and Technical Information of China (English)

    ZhangWeinong; LiuDachuan

    2002-01-01

    Preparation of soybean protein concentrate with the mixed solvents of hexane-aqueous alcohol was studied in this paper.The optimum technology parameters were obtained by orthogonal tests.The results of experiments showed that the qualities of the product were good not only on taste of the product were good not only on tasted and color,but also on high solubility-NSI value was 48.80%.

  6. Effect of Mixed Solvents and Additives on the Habit Modification of 6-APA Crystals

    Institute of Scientific and Technical Information of China (English)

    GONG Junbo; WANG Jingkang; WEI Hongyuan

    2005-01-01

    6-aminopenicillanic acid (6-APA) crystals obtained under different physical and chemical conditions of the solutions may present different habits. The habits of diamond-shaped plates are desirable compared with other habits of 6-APA crystals. To obtain ideal 6-APA crystals, the effects of the mixed solvents and additives on 6-APA crystal habits were investigated. Ethanol or acetone was used as the organic solvent, and impurities existing in the 6-APA purification process were used as the additives. 6-APA growth habits were changed when the concentrations of ethanol, acetone or phenyl acetic acid were increased to exceed their critical concentration. The observed results show that the dominant face on 6-APA crystals was identified to be {020}, but the overall habit was controlled by the relative growth rates of the {101} and {002} faces. Crystal growth rates and habits can be appreciably changed by specific adsorption of additives on crystal faces.In some cases solvent molecules can act in a similar way and may be regarded as bulk additives. The effects of additives and organic solvents on 6-APA crystal habits were the results of adsorption effect, which fitted the experimental results quite well.

  7. Dynamic Interactions of CdSe/ZnS Quantum Dots with Cyclic Solvents Probed by Femtosecond Four-Wave Mixing

    Directory of Open Access Journals (Sweden)

    Biju V.

    2013-03-01

    Full Text Available We studied dynamic interactions between CdSe/ZnS quantum dots (QDs and cyclic solvents probed by femtosecond four-wave mixing. We found that the dynamic interactions of QDs strongly depend on the existence of π-bonds in solvent molecules.

  8. Recrystallization and shape control of crystals of the organic dye acid green 27 in a mixed solvent.

    Science.gov (United States)

    Cong, Huai-Ping; Yu, Shu-Hong

    2007-01-01

    Recrystallization of the unstructured dye acid green 27 (AG27) in a mixed solvent of alcohol (ethanol or methanol) and water was systematically studied. The results demonstrated that AG27 crystals with uniform sizes and controllable shapes can be produced by simply changing the volume ratio of ethanol (or methanol) and deionized water (DIW). Rodlike and shuttlelike AG27 crystals can be selectively synthesized. The XRD analyses revealed the periodic structures of the organic crystals. Furthermore, crystallization in another mixed solvent of N,N-dimethylformamide (DMF) and DIW results in the formation of longer fibers with high aspect ratio, which further validates the remarkable effects of mixed solvent on the shape of the AG27 crystals. This method of recrystallization in a mixed solvent is expected to facilitate the synthesis of other functional organic crystals with unusual shapes.

  9. Mixed solvents for the optimization of morphology in solution-processed, inverted-type perovskite/fullerene hybrid solar cells.

    Science.gov (United States)

    Kim, Hak-Beom; Choi, Hyosung; Jeong, Jaeki; Kim, Seongbeom; Walker, Bright; Song, Seyeong; Kim, Jin Young

    2014-06-21

    We investigate mixed solvents of N,N-dimethylformamide (DMF) and γ-butyrolactone (GBL) to produce the smooth surface of a perovskite film and uniform crystal domains. This ideal morphology from mixed solvents enhances the power conversion efficiency to over 6% by improving the exciton dissociation efficiency and reducing the recombination loss at both interfaces of PEDOT:PSS/perovskite and perovskite/PCBM.

  10. Kinetic analysis of high-concentration isopropanol biodegradation by a solvent-tolerant mixed microbial culture.

    Science.gov (United States)

    Bustard, Mark T; Meeyoo, Vissanu; Wright, Phillip C

    2002-06-20

    The ability of a previously enriched microbial population to utilize isopropanol (IPA) as the sole carbon source within a minimal salts medium is studied. The advantage of prior enrichment procedures for the improvement of IPA biodegradation performance is demonstrated for an IPA concentration of up to 24 g L(-1). Results showing the interrelationship between temperature and substrate utilization and inhibition levels at temperatures of between 2 degrees C and 45 degrees C are examined. Models of inhibition based on enzyme kinetics are assessed via nonlinear analysis, in order to accurately represent the growth kinetics of this solvent-tolerant mixed culture. The model that best describes the data is the Levenspiel substrate inhibition model, which can predict the maximum substrate level above which growth is completely limited. This is the first report of IPA treatment of up to 24 g L(-1) by an aerobic solvent-tolerant population.

  11. Effect of Mixed Solvents Consisting of Water and Organic Solvent on Preparation of Medium-Responsive Grafted Cellulose Film by Means of Photografting

    Directory of Open Access Journals (Sweden)

    Irwan Ginting-Suka

    2006-11-01

    Full Text Available Cellulose having a medium-responsive function were synthesized by photografting of methacrylic acid (MAA on regenerated cellulose film (thickness = 20 µm at 60°C using mixed solvent consisting of water and organic solvents such as acetone and methanol. Xanthone was used as photoinitiator by coating on the film surfaces. A maximum percentage of grafting was observed at a certain concentration of organic solvent. MAA-grafted cellulose films produced showing homogeneous distribution of grafted chains, which was examined by scanning electron microscopy. The modified films also exhibit medium responsive character, it shrinks in acidic and swells in basic solution. Moreover, the grafted film exhibited the ability to absorb copper ion, which was not influenced by the solvent used in grafting processes.

  12. Effect of solvent on complexation between Y3+ cation and 4,13-diaza-18-crown-6 in some binary mixed non-aqueous solvents

    Science.gov (United States)

    Mohammadi, M.; Rounaghi, G. H.; Mohajeri, M.; Karimian, F.

    2014-10-01

    The complexation reaction of 4,13-diaza-18-crown-6 (DA18C6) with Y3+ cation was studied in some binary mixed solvent solutions of acetonitrile (AN) with methanol (MeOH), ethanol (EtOH), 2-propanol (2-PrOH) and methyl acetate (MeOAc) at different temperatures by conductometric method. The obtained data show that in all studied solutions the stoichiometry of the complex formed between DA18C6 and Y3+ cation is 1: 1 [ML], but in the case of pure MeOAc, a 2: 1 [ML2] complex is formed in solution upon addition of the ligand to the metal salt solution, and further addition of the ligand results in formation of a M2L2 complex in solution. This results show that the stoichiometry of the composition of the macrocyclic complexes may be affected by the nature of the solvent system. The results obtained in this study show that the stability constant of the resulting 1: 1 [ML] complex in the binary solvent solutions decreases in the order: AN-MeOAc > AN-2PrOH > AN-MeOH > AN-EtOH. A non-linear relationship was observed between the stability constant (log K f ) of [Y(DA18C6)]3+ complex with the composition of the binary mixed solvent solutions. The corresponding standard thermodynamic parameters ( H° c , Δ S° c ) for 1: 1 [ML] complexation reaction between DA18C6 and Y3+ cation were obtained from temperature dependence of the stability constant of the complex. The results show that, in all solvent systems, the (DAI8C6.Y)3+ complex is entropy stabilized, but from enthalpy point of view, depending on the solvent system, it is stabilized or destabilized and the result show that the values of both thermodynamic quantities change with the nature and composition of the binary mixed solvent solutions.

  13. Mixed-solvent thermal synthesis and magnetic properties of flower-like microstructured nickel

    Institute of Scientific and Technical Information of China (English)

    Aerpati Yimamu; Sadeh Beysen; Dengfeng Peng; Yierpan Aierken

    2012-01-01

    Flower-like microstructured nickel was synthesized by a facile mixed-solvent thermal process.The structure,morphology,and magnetic properties of the reaction products were investigated,respectively,by X-ray diffraction (XRD),scanning electron microscopy (SEM),and vibrating sample magnetometry (VSM).The results showed that the products consisted of a face-centered cubic (fcc) structure with lattice constant of α =3.524A.The average diameter of flower-like microstructured nickel was about 5 μm and the thickness of a single flake was about 100nm.Magnetic measurement showed that these powders exhibited ferromagnetic characteristics.

  14. Tunable and rapid self-assembly of block copolymers using mixed solvent vapors

    Science.gov (United States)

    Park, Woon Ik; Tong, Sheng; Liu, Yuzi; Jung, Il Woong; Roelofs, Andreas; Hong, Seungbum

    2014-11-01

    Pattern generation of well-controlled block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) is important for applications in sub-20 nm nanolithography. We used mixed solvents of dimethylformamide (DMF) and toluene to control the morphology as well as the time to achieve the targeted morphology via self-assembly of BCPs. By precisely controlling the volume ratio of DMF and toluene, well-ordered line, honeycomb, circular hole, and lamellar nanostructures were obtained from a cylinder-forming poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) BCP with high χ. Furthermore, a well-aligned 12 nm line pattern was successfully achieved in the guiding template within one minute using the mixed solvents. This practical method may also be applicable to self-assembly of other BCPs, providing more opportunities for the next-generation sub-10 nm lithography applications.Pattern generation of well-controlled block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) is important for applications in sub-20 nm nanolithography. We used mixed solvents of dimethylformamide (DMF) and toluene to control the morphology as well as the time to achieve the targeted morphology via self-assembly of BCPs. By precisely controlling the volume ratio of DMF and toluene, well-ordered line, honeycomb, circular hole, and lamellar nanostructures were obtained from a cylinder-forming poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) BCP with high χ. Furthermore, a well-aligned 12 nm line pattern was successfully achieved in the guiding template within one minute using the mixed solvents. This practical method may also be applicable to self-assembly of other BCPs, providing more opportunities for the next-generation sub-10 nm lithography applications. Electronic supplementary information (ESI) available: PDF material includes morphological transition of SV42 BCP (Fig. S1), metal-oxide line and hole structures (Fig. S2), time-evolution of self-assembled SV42 BCP using pure

  15. Monetite formed in mixed solvents of water and ethylene glycol and its transformation to hydroxyapatite.

    Science.gov (United States)

    Ma, Ming-Guo; Zhu, Ying-Jie; Chang, Jiang

    2006-07-27

    Agglomerated nanorods of hydroxyapatite have been synthesized using monetite as a precursor in a NaOH solution. Monetite consisting of nanosheets has been successfully synthesized by a one-step microwave-assisted method using CaCl(2).2.5H(2)O, NaH(2)PO(4), and sodium dodecyl sulfate (SDS) in water/ethylene glycol (EG) mixed solvents. The effects of the molar ratio of water to EG and the reaction time on the products were investigated. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectrometry (FTIR).

  16. Cation-π Interaction between the Aromatic Organic Counterion and DTAB Micelle in Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    DENG,Dong-Shun(邓东顺); LI,Hao-Ran(李浩然); LIU,Di-Xia(刘迪霞); HAN,Shi-Jun(韩世钧)

    2004-01-01

    The cation-π interaction between the aromatic organic counterion potassium hydrogen phthalate (KHP) and DTAB micelle in aqueous mixture of EG was investigated, using the techniques of conductivity measurements, UV absorption spectrum and NMR spectrum. The conductivity and UV spectrum studies were with respect to the effect of KHP on DTAB and that of DTAB micelle on KHP, respectively. According to the chemical shift changes of the aromatic ring and the surfactant methylene protons, it can be assumed that KHP penetrated into DTAB micelle with its carboxylic group protruding out of the micellar surface. And the strength of the interaction became weaker with the content of EG in the mixed solvent increasing.

  17. Ultrasmooth Perovskite Film via Mixed Anti-Solvent Strategy with Improved Efficiency.

    Science.gov (United States)

    Yu, Yu; Yang, Songwang; Lei, Lei; Cao, Qipeng; Shao, Jun; Zhang, Sheng; Liu, Yan

    2017-02-01

    Most antisolvents employed in previous research were miscible with perovskite precursor solution. They always led to fast formation of perovskite even if the intermediate stage existed, which was not beneficial to obtain high quality perovskite films and made the formation process less controllable. In this work, a novel ethyl ether/n-hexane mixed antisolvent (MAS) was used to achieve high nucleation density and slow down the formation process of perovskite, producing films with improved orientation of grains and ultrasmooth surfaces. These high quality films exhibited efficient charge transport at the interface of perovskite/hole transport material and perovskite solar cells based on these films showed greatly improved performance with the best power conversion efficiency of 17.08%. This work also proposed a selection principle of MAS and showed that solvent engineering by designing the mixed antisolvent system can lead to the fabrication of high-performance perovskite solar cells.

  18. Evaporative assembly of MEH-PPV rings using mixed solvents at the air/water interface.

    Science.gov (United States)

    Chao, Kung-Po; Biswal, Sibani L

    2014-04-22

    Controlling the morphology of conjugated polymers has recently attracted considerable attention because of their applications in photovoltaic (PV) devices and organic light-emitting diodes (OLEDs). Here, we describe the self-assembly of a common conjugated polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), into ringlike structures via solvent evaporation on an air/water interface. The films are monitored using Brewster angle microscopy (BAM) and transferred onto a solid substrate by either the Langmuir-Blodgett (LB) or the Langmuir-Schaefer (LS) method and further characterized by atomic force microscopy (AFM). The morphology of the MEH-PPV thin film at the air/water interface can be controlled by the spreading solvent. By mixing solvents of varying spreading coefficients and evaporation rates, such as chloroform and chlorobenzene, MEH-PPV can be assembled into micrometer-sized ring structures. The optical properties of these MEH-PPV ring structures are also characterized. Lastly, MEH-PPV can be used as a soft template to organize microscale structures of nanoparticles.

  19. Preparation and performance study of a novel liquid scintillator with mixed solvent as the matrix

    Science.gov (United States)

    Zheng, Zhanlong; Zhu, Jiayi; Luo, Xuan; Xu, Yewei; Zhang, Qianfeng; Zhang, Xing; Bi, Yutie; Zhang, Lin

    2017-04-01

    A novel liquid scintillator with the mixed solvent as the matrix was prepared for obtaining a good comprehensive performance. In this ternary liquid scintillator, the combination of 20% pseudocumene (PC) and 80% linear-alkyl benzene (LAB) by volume was chosen as the mixed solvent, and 2,5-diphenyloxazole (PPO) and 1,4-bis(2-Methylstyryl) benzene (bis-MSB) were as the primary fluor and wavelength shifter, respectively. The optimum prescription was obtained with regard to the light yield. Some characterizations based on the optimal formulation were conducted. The fluorescence emission spectra and wavelength-dependent optical attenuation length of the sample were measured by the fluorescence spectrophotometer and an UV-Vis spectrometer, respectively. The light yield was characterized by adopting the home-made optical platform device. The decay time was tested by adopting the time-correlated single photon counting (TCSPC) technique featured in high dynamic range of several orders of magnitude in light intensity. The experimental test results showed that the sample had a fairly good comprehensive performance.

  20. Precursor- route ZnO films from mixed casting solvent for high performance aqueous electrolyte- gated transistors

    OpenAIRE

    Grell, M.; Althagafi, T.M.; Algarni, S.A.; Al Naim, A.; Mazher, J.

    2015-01-01

    We significantly improved the properties of semiconducting zinc oxide (ZnO) films resulting from the thermal conversion of a soluble precursor, zinc acetate (ZnAc), by using a mixed casting solvent for the precursor. ZnAc dissolves more readily in a 1:1 mix of ethanol (EtOH) and acetone than in either pure EtOH, pure acetone, or pure isopropanol, and ZnO films converted from mixed solvent cast ZnAc are more homogeneous. When gated with a biocompatible electrolyte, phosphate buffered saline (P...

  1. Combined effects of exposure to occupational noise and mixed organic solvents on blood pressure in car manufacturing company workers.

    Science.gov (United States)

    Attarchi, Mirsaeed; Golabadi, Majid; Labbafinejad, Yasser; Mohammadi, Saber

    2013-02-01

    Recent studies suggest that occupational exposures such as noise and organic solvents may affect blood pressure. The aim of this study was to investigate interaction of noise and mixed organic solvents on blood pressure. Four hundred seventy-one workers of a car manufacturing plant were divided into four groups: group one or G1 workers exposed to noise and mixed organic solvents in the permitted limit or control group, G3 exposed to noise only, G2 exposed to solvents only, and G4 workers exposed to noise and mixed organic solvents at higher than the permitted limit or co-exposure group. Biological interaction of two variables on hypertension was calculated using the synergistic index. The workers of co-exposure group (G4), noise only group (G3), and solvents only group (G2) had significantly higher mean values of SBP and DBP than workers of control group (G1) or office workers (P car manufacturing company workers and co-exposure to noise and a mixture of solvents has an additive effect in this regard. Therefore appropriate preventive programs in these workers recommended. Copyright © 2012 Wiley Periodicals, Inc.

  2. Preferential solvation and solvation shell composition of free base and protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin in aqueous organic mixed solvents.

    Science.gov (United States)

    Farajtabar, Ali; Jaberi, Fatemeh; Gharib, Farrokh

    2011-12-01

    The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale (E(T)) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO.

  3. Preferential solvation and solvation shell composition of free base and protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin in aqueous organic mixed solvents

    Science.gov (United States)

    Farajtabar, Ali; Jaberi, Fatemeh; Gharib, Farrokh

    2011-12-01

    The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale ( ET) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO.

  4. Transport of Indium, Gallium and Thallium Metal Ions Through Chromatographic Fiber Supported Solid Membrane in Acetylacetone Containing Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    Abaji Gaikwad

    2011-01-01

    The transport of metal ions of indium, gallium and thallium from source solution to receiving phase through the chromatographic fiber supported solid membrane in the acetylacetone (HAA) containing mixed solvent system has been explored. The fibers supported solid membranes were prepared with chemical synthesis from cellulose fibers and citric acid with the carboxylic acid ion exchange groups introduced. The experimental variables, such as concentration of metal ions (10^-2 to 10^-4 mol.L^-1) in the source solution, mixed solvent composition [for exampl, e, acetylacetone, (2,4-pentanedione), (HAA) 20% (by volume), 1,4-dioxane 10% to 60% and HC1 0.25 to 2 mol.L^-1] in the receiving phase and stirring speed (50-130 r.min ) of the bulk source and receiving phase, were explored. The efficiency of mixed solvents for the transport of metal ions from the source to receiving phase through the fiber supported solid membrane was evaluated. The combined ion exchange solvent extraction (CIESE) was observed effective for the selective transport of thallium, indium and gallium metal ions through fiber supported solid membrane in mixed solvents. The oxonium salt formation in the receiving phase enhances thallium, indium and gallium metal ion transport through solid membrane phase. The selective transport of thallium metal ions from source phase was observed from indium and gallium metal ions in the presence of hydrochloric acid in organic solvents in receiving phase. The separation of thallium metal ions from the binary mixtures of Be(II), Ti(IV), AI(III) Ca(II), Mg(II), K (I), La(III) and Y(III) was carried out in the mixed solvent system using cellulose fiber supported solid membrane.

  5. A mixed-solvent strategy for facile and green preparation of graphene by liquid-phase exfoliation of graphite

    Science.gov (United States)

    Yi, Min; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

    2012-08-01

    A versatile and scalable mixed-solvent strategy, by which two mediocre solvents could be combined into good solvents for exfoliating graphite, is demonstrated for facile and green preparation of graphene by liquid-phase exfoliation of graphite. Mild sonication of crystal graphite powder in a mixture of water and alcohol could yield graphene nanosheets, which formed a highly stable suspension in the mixed solvents. The graphene yield was estimated as 10 wt%. The optimum mass fraction of ethanol in water-ethanol mixtures and isopropanol in water-isopropanol mixtures was experimentally determined as 40 and 55 % respectively, which could be roughly predicted by the theory of Hansen solubility parameters. Statistics based on atomic force microscopic analysis show that up to 86 % of the prepared nanosheets were less than 10-layer thick with a monolayer fraction of 8 %. High resolution transmission electron microscopy, infrared spectroscopy, X-ray diffraction, and Raman spectrum analysis of the vacuum-filtered films suggest the graphene sheets to be largely free of defects and oxides. The proposed mixed-solvent strategy here extends the scope for liquid-phase processing graphene and gives researchers great freedom in designing ideal solvent systems for specific applications.

  6. SYNTHESIS AND CHARACTERIZATION OF CELLULOSE-SILICA COMPOSITE FIBER IN ETHANOL/WATER MIXED SOLVENTS

    Directory of Open Access Journals (Sweden)

    Ning Jia

    2011-04-01

    Full Text Available Cellulose-silica composite fiber samples have been successfully synthesized using cellulose solution, tetraethoxysilane, and NH3•H2O in ethanol/water mixed solvents at room temperature for 24 h. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in a solvent mixture of N,N-dimethylacetamide (DMAc/lithium chloride (LiCl. The effect of the tetraethoxysilane concentration on the product was investigated. The products were characterized by X-ray powder diffraction (XRD, thermogravimetric analysis (TG, differential scanning calorimetric analysis (DSC, scanning electron microscopy (SEM, Fourier transform infrared spectrometry (FT-IR, energy-dispersive X-ray spectrum (EDS, and cross polarization magic angle spinning (CP/MAS solid state 13C-NMR. The morphology of the cellulose-silica composite fiber was investigated by SEM, while their composition was established from EDS measurements combined with the results of FT-IR spectral analysis and XRD patterns. The XRD, FT-IR and EDS results indicated that the obtained product was cellulose-silica composite fiber. The SEM micrographs showed that the silica particles were homogeneously dispersed in the cellulose fiber. The CP/MAS solid state 13C-NMR results indicated that the silica concentration had an influence on the crystallinity of the cellulose. This method is simple for preparation of cellulose-based composites.

  7. Inhibition of positronium formation by nitroso spin trap scavengers in methanol-water mixed solvents

    Energy Technology Data Exchange (ETDEWEB)

    Levay, Bela [Department of Nuclear Chemistry, Eoetvoes Lorand University, Budapest (Hungary)]. E-mail: levay@para.chem.elte.hu; Boros, Marton [Department of Nuclear Chemistry, Eoetvoes Lorand University, Budapest (Hungary)

    2004-10-25

    The positron annihilation lifetime spectroscopy (PALS) is used to study the effect of nitroso spin trap scavengers on the positronium (Ps) yields in methanol-water mixed solvents. Nitrosobenzene (NOB), N,N-dimethyl-4-nitroso-aniline (DMNA) and tert-nitroso-butane (tNOBu) are investigated. These compounds have been found to be good Ps inhibitors. The numerical values of the Ps inhibition coefficients ({sigma}) exhibit similar trend to those of the reaction rate constants of o-Ps (k{sub p}) and solvated electron (k{sub e}) for the same compounds and increase in the same order: tNOBuDMNANOB. Solvent composition dependence of {sigma} for both DMNA and NOB shows strong correlation with that of the reaction of es- with nitrobenzene, that is a scavenger similar to NOB. The Ps inhibition capacity of nitroso compounds decreases with increasing temperature reflecting that the activation energy of the Ps formation reaction is greater than that of the electron scavenging one.

  8. Mixed-solvent thermal synthesis of porous LiFePO4.

    Science.gov (United States)

    Pei, Zhenzhao; Zhang, Xia; Gao, Xiang

    2013-04-01

    Porous structure LiFePO4 with pore size from 2 to 15 nm was successfully synthesized in mixed solvents system of glycol and water. By changing stirring time from 5 to 60 min, LiFePO4 morphologies were adjusted and percentage of porous LiFePO4 was higher and higher in sequence. Stirring time is the key cause of controlling morphologies of final products for its influence on diffusion rate of the initial formed particles of final products. Through adjusting this factor, products with specific morphologies and functions can be obtained. The morphologies and microstructures were observed by transmission electron microscopy (TEM), and the phase composition was verified by X-ray diffraction (XRD). This synthetic method provides a new route to obtain porous structure materials.

  9. A high-performance theory for thermodynamic study of solvation in mixed solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei Behbehani, G. [Department of Chemistry, Imam Khomeini International University Qazvin Iran, Imam Khomeini Street, Qazvin (Iran, Islamic Republic of)], E-mail: grb402003@yahoo.com; Waghorne, W.E. [School of Chemistry and Chemical Biology, UCD, Dublin 4 (Ireland)

    2008-11-20

    The enthalpies of transfer, {delta}H{sub t}{sup {theta}}, of the solutes from pure solvent A to mixtures of A and a second solvent B were studied by isothermal titration calorimetry and analysed in terms of the new extended solvation theory. These data are considered in terms of the new developed solvation theory including variable ({alpha}n + {beta}N), the net effect of the solute on the solvent-solvent bonding and is positive if there is a net breaking or weakening of solvent-solvent bonds.

  10. Specific solute solvent interactions and dual fluorescence of electron donor substituted bis-pyrazoquinoline in binary mixed solvents

    Science.gov (United States)

    Rotkiewicz, Krystyna; Rettig, Wolfgang; Köhler, Gottfried; Rechthaler, Karl; Danel, Andrzej; Grabka, Danuta

    2004-12-01

    Some extended electron donor and acceptor substituted π-electron systems, composed of a dimethyl- or diethylanilino (DMA or DEA, respectively) group as electron donor and bis-pyrazoloquinoline (DPPQ) or bis-pyrazolopyridine (DMPP) derivatives as acceptors, were studied with the aim to elucidate the contributions of various solute interactions with solvent molecules upon intramolecular charge separation. Steady state and time resolved fluorescence studies were performed for DMA-DPPQ, DMA-DMPP and DEA-DMPP in alcohols and their binary mixtures with heptane. The decay kinetics of the fluorescence of DMA-DPPQ was also studied in neat 1-propanol in dependence of the temperature between 170 and 293 K. Several different fluorescent species, which were ascribed to different complexes with alcohol molecules, contribute to the fluorescence of the various compounds in these binary mixtures and account for the complex fluorescence decay. A simplified consecutive model is proposed to explain the decay behaviour of the excited species.

  11. Thermodynamic method for obtaining the solubilities of complex medium-sized chemicals in pure and mixed solvents

    DEFF Research Database (Denmark)

    Abildskov, Jens; O'Connell, J.P.

    2005-01-01

    This paper extends our previous simplified approach to using group contribution methods and limited data to determine differences in solubility of sparingly soluble complex chemicals as the solvent is changed. New applications include estimating temperature dependence and the effect of adding...... cosolvents forming strongly nonideal aqueous mixtures and including immiscibility. The method optimally selects a 'reference solvent' from limited data, which effectively eliminates the need for pure-solute properties and minimizes the impact of their uncertainties. The technique also decreases the number...... of adjustable parameters to be determined by data reduction, by using an efficient experimental and mathematical regularization strategy to find their values. The approach has been established for pure and mixed solvent systems, and the resulting models have been employed in some cosolvent design problems...

  12. Effect of Mixed Solvent on Fabrication, Morphology and Monodispersity of Microspheres with Hydrophobic Poly(butyl methacrylate) Shells

    Institute of Scientific and Technical Information of China (English)

    XIAO Xincai; LU Cheng

    2012-01-01

    Monodisperse microspheres (mean diameter 200-300 nm) with polystyrene cores and poly(acrylamide-co-buty1 methacrylate) shells were prepared by using a free radical polymerization method.Moreover,the effect of mixed solvent on the preparation,morphology and monodispersity was investigated.The experimental results showed that solubility parameter of butyl methacrylate and solvent affected mainly the molding of monodisperse core-shell microspheres.When the microspheres were fabricated in a sequential synthesis process,addition of hydrophilic and organic solvent including butyl methacrylate led to spherical degree of the particles becoming worse,and the mean diameter of the microspheres decreased and the monodispersity became better with increasing the crosslinker methylenebisacrylamide dosage.

  13. The effect of organic solvent, temperature and mixing time on the production of oil from Moringa oleifera seeds

    Science.gov (United States)

    Ghazali, Q.; Yasin, N. H. M.

    2016-06-01

    The effect of three different organic solvent, temperature and mixing time on the production of oil from M.oleifera seeds were studied to evaluate the effectiveness in obtaining the high oil yield based on the percentage of oil production. The modified version of Soxhlet extraction method was carried out to extract the oil from M.oleifera seeds by using hexane, heptane and ethanol as the organic solvent. Among the three solvents, it is found that heptane yield higher oil from M.oleifera seeds with maximum oil yield of 36.37% was obtained followed by hexane and ethanol with 33.89% and 18.46%, respectively. By using heptane as a solvent, the temperature (60oC, 70oC, 80oC) and mixing time (6 h, 7 h, and 8 h) were investigated to ensure the high oil yield over the experimental ranges employed and high oil yield was obtained at 600C for 6 h with percentage oil yield of 36.37%. The fatty acid compositions of M.oleifera seeds oil were analyzed using Gas Chromatography/Mass Spectrometry (GC-MS). The main components of fatty acid contained in the oil extracted from M.oleifera seeds was oleic acid, followed by palmitic acid and arachidic acid, and small amount of behenic acid and margaric acid.

  14. Complexation study of cryptand 222 with lanthanum(III) cation in binary mixed non-aqueous solvents

    Science.gov (United States)

    Dolatshahi, S.; Rounaghi, G. H.; Tarahomi, S.

    2013-10-01

    Conductometric titrations have been performed in some binary solvent solutions of acetonitrile (AN), 1,2-dichloroethane (DCE), ethylacetate (EtOAc) and methylacetate (MeOAc) with methanol (MeOH), at 288, 298, 308, and 318 K to give the complex stability constant and the thermodynamic parameters for the complexation of lanthanum(III) cation with 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]-hexacosane (cryptand 222). The stability constant of the resulting 1:1 complex at each temperature was determined from computer fitting of the conductance-mole ratio data. The results revealed that, the stoichiometry and the stability order of (cryptand 222 · La)3+ complex changes with the nature and also the composition of the solvent system. A non-linear relationship was observed between the stability constant (log K f) of (cryptand 222 · La)3+ complex versus the composition of the binary mixed solvents. Thermodynamically, the complexation of lanthanum(III) cation with the cryptand 222, is mainly entropy governed and the values of these parameters are influenced by the nature and composition of the binary mixed solvent solutions.

  15. Solvents Production from a Mixture of Glucose and Xylose by Mixed Fermentation of Clostridium acetobutylicum and Saccharomyces cerevisiae.

    Science.gov (United States)

    Qi, Gao-Xiang; Xiong, Lian; Huang, Chao; Chen, Xue-Fang; Lin, Xiao-Qing; Chen, Xin-De

    2015-10-01

    To overcome the xylose utilization defect in ethanol fermentation by wide-type Saccharomyces cerevisiae and alleviate the carbon catabolite repression (CCR) in acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum, a novel mixed fermentation of S. cerevisiae and C. acetobutylicum was developed. When S. cerevisiae was inoculated 24 h earlier than C. acetobutylicum CH02, a higher solvents yield was achieved with 0.41 g/g, compared to 0.38 g/g in ABE fermentation, and when S. cerevisiae and C. acetobutylicum CH02 were inoculated simultaneously, a higher productivity was achieved with 0.32 g/L/h, compared to 0.15 g/L/h in ABE fermentation. The total solvents yield was improved by the high ethanol yield from glucose. The CCR in mixed fermentation was alleviated when glucose was utilized quickly by S. cerevisiae, and therefore, the productivity was improved. This study suggests that mixed fermentation is an effective solvents production method from a mixture of glucose and xylose.

  16. Influence of water content in mixed solvent on surface morphology, wettability, and photoconductivity of ZnO thin films.

    Science.gov (United States)

    Zhao, Min; Shang, Fengjiao; Lv, Jianguo; Song, Ying; Wang, Feng; Zhou, Zhitao; He, Gang; Zhang, Miao; Song, Xueping; Sun, Zhaoqi; Wei, Yiyong; Chen, Xiaoshuang

    2014-01-01

    ZnO thin films have been synthesized by means of a simple hydrothermal method with different solvents. The effect of deionized water content in the mixed solvents on the surface morphology, crystal structure, and optical property has been investigated by scanning electron microscopy, X-ray diffraction, and UV-Vis spectrophotometer. A large number of compact and well-aligned hexagonal ZnO nanorods and the maximal texture coefficient have been observed in the thin film, which is grown in the mixed solvent with x = 40%. A lot of sparse, diagonal, and pointed nanorods can be seen in the ZnO thin film, which is grown in the 40-mL DI water solution. The optical band gap decreases firstly and then increases with the increase of x. Reversible wettability of ZnO thin films were studied by home-made water contact angle apparatus. Reversible transition between hydrophobicity and hydrophilicity may be attributed to the change of surface chemical composition, surface roughness and the proportion of nonpolar planes on the surface of ZnO thin films. Photocurrent response of ZnO thin films grown at different solvents were measured in air. The response duration of the thin film, which is grown in the solvent with x = 40%, exhibits a fast growth in the beginning but cannot approach the saturate current value within 100 s. The theoretical mechanism for the slower growth or decay duration of the photocurrent has been discussed in detail.

  17. Ions in mixed dielectric solvents: density profiles and osmotic pressure between charged interfaces.

    Science.gov (United States)

    Ben-Yaakov, Dan; Andelman, David; Harries, Daniel; Podgornik, Rudi

    2009-04-30

    The forces between charged macromolecules, usually given in terms of osmotic pressure, are highly affected by the intervening ionic solution. While in most theoretical studies the solution is treated as a homogeneous structureless dielectric medium, recent experimental studies concluded that, for a bathing solution composed of two solvents (binary mixture), the osmotic pressure between charged macromolecules is affected by the binary solvent composition. By adding local solvent composition terms to the free energy, we obtain a general expression for the osmotic pressure, in planar geometry and within the mean-field framework. The added effect is due to the permeability inhomogeneity and nonelectrostatic short-range interactions between the ions and solvents (preferential solvation). This effect is mostly pronounced at small distances and leads to a reduction in the osmotic pressure for macromolecular separations of the order 1-2 nm. Furthermore, it leads to a depletion of one of the two solvents from the charged macromolecules (modeled as planar interfaces). Lastly, by comparing the theoretical results with experimental ones, an explanation based on preferential solvation is offered for recent experiments on the osmotic pressure of DNA solutions.

  18. Coil-globule transition of macromolecules in mixed solvent: A semi-grand canonical molecular dynamics approach

    Science.gov (United States)

    Mukherji, Debashish; Kremer, Kurt

    2014-03-01

    Conformational transition of macromolecules in mixed solvents are intimately linked to large local concentration fluctuations of solvent components. The numerical studies in the field are limited to the closed boundary schemes, which, however, suffer from severe system size effects. To overcome this discrepancy, we have developed a semi-grand canonical molecular dynamics scheme for complex fluids. Our method makes use of the adaptive resolution scheme (AdResS) with a metropolis particle exchange criterion. In AdResS, an all-atom region, containing macromolecule, is coupled to a coarse-grained (CG) reservoir. The semi-grand canonical particle exchange is performed in the CG region. As the applications of the method, we study the concentration driven reentrant collapse and swelling transition of poly(N-isopropylacrylamide) (PNIPAm) and poly(N,N-diethylacrylamide) (PDEAm) in aqueous methanol and demonstrate the role of the delicate interplay of the different intermolecular interactions.

  19. Analysis of the Cybotactic Region of Two Renewable Lactone-Water Mixed-Solvent Systems that Exhibit Synergistic Kamlet-Taft Basicity.

    Science.gov (United States)

    Duereh, Alif; Sato, Yoshiyuki; Smith, Richard Lee; Inomata, Hiroshi

    2016-05-19

    Kamlet-Taft solvatochromic parameters (polarity, basicity, acidity) of hydrogen bond donor (HBD)/acceptor (HBA) mixed-solvent systems, water (H2O)-γ-valerolactone (GVL), methanol (MeOH)-GVL, ethanol (EtOH)-GVL, H2O-γ-butyrolactone (GBL), MeOH-GBL, and EtOH-GBL, were measured over their entire composition region at 25 °C using UV-vis spectroscopy. Basicity of H2O-GVL and H2O-GBL systems exhibited positive deviation from ideality and synergism in the Kamlet-Taft basicity values. The cybotactic region around each indicator in the mixed-solvent systems was analyzed with the preferential solvation model. Both H2O-GVL and H2O-GBL mixed-solvent systems were found to be completely saturated with mutual complex molecules and to have higher basicity than pure water because water prefers to interact with GVL or GBL molecules rather than with itself. Formation of H2O-GVL and H2O-GBL complex molecules via specific hydrogen bond donor-acceptor interactions were confirmed by infrared spectroscopy. In MeOH-GVL or MeOH-GBL mixed-solvent systems, MeOH molecules prefer self-interaction over that with GVL or GBL so that synergistic basicity was not observed. Synergistic basicity and basicity increase for various functional groups of ten mixed-solvent (water-HBA solvent) systems can be quantitatively explained by considering electrostatic basicity and a ratio of the partial excess HBA solvent basicity with the HBA solvent molar volume that correlate linearly with the preferential solvation model complex molecular parameter (f12/1). Analysis of the cybotactic region of indicators in aqueous mixtures with the preferential solvation model allows one to estimate the trends of mixed-solvent basicity.

  20. Impurity Distribution Behavior in Caprolactam Extraction with Environmentally Benign Mixed Solvents

    NARCIS (Netherlands)

    Delden, van M.L.; Drumm, C.; Kuipers, N.J.M.; Haan, de A.B.

    2006-01-01

    In a previous study a solvent mixture of heptane containing 40 mass % heptanol was selected as an alternative in the industrial extraction of caprolactam to replace benzene, toluene, or chlorinated hydrocarbons. This work reports the equilibrium distribution ratio of caprolactam and four model impur

  1. [Liver function of workers occupationally exposed to mixed organic solvents in a petrochemical industry].

    Science.gov (United States)

    Fernández-D'Pool, J; Oroño-Osorio, A

    2001-06-01

    A descriptive and cross sectional study was conducted to determine whether hepatic function changes in workers occupationally exposed to a mixture of organic solvents, were due to the exposure or confusing factors. A non random sample of 77 workers, operators and supervisors of the Olefin Plant I and II of a petrochemical industry in Maracaibo, Venezuela, was used. Their mean age was 29 +/- 7 years, and had at least one year of exposure to the solvents. This sample was compared with a group of employees of the administrative offices or control panel workers, with a mean age of 36 +/- 8 year and with similar anthropometric characteristics. Workers with a known history of liver disease, blood transfusions and diabetes mellitus were excluded of the study. In addition to a complete occupational disease medical history and a physical examination, serum samples were obtained to determine the activity of the aspartato aminotransferase (AST), alanin aminotransferase (ALT), gamma glutamiltransferase (GGT), alkaline phosphatase (AF), the concentration of the total bile acids (BAS), the surface antigen of hepatitis B(HbsAg) and the hepatitis A virus antibodies: AntiHAV-IgG and the AntiHAV-IgM. An urine sample was taken and analyzed by standard methodology to determine urinary phenols. The air concentrations of benzene, ethylbenzene, toluene and xylene were analyzed by gas chromathography. The serum activities of the liver enzymes, the concentration of bile acids and urinary phenols were not influenced by the exposure to the solvents. The increase of the activity of GGT was associated with obesity and alcohol consumption. The antibodies of the surface antigen of hepatitis A-IgM were normal in both groups and the antibodies for the antigen of hepatitis A-IgG presented a prevalence of 6% in the exposed group and 9% in the non exposed not being associated with liver abnormalities. The individual air concentrations of the solvents were below the environmentally permissible

  2. Enthalpy of mixing of methacrylic acid with organic solvents at 293 K

    Science.gov (United States)

    Sergeev, V. V.

    2016-03-01

    The enthalpies of mixing of binary systems of methacrylic acid with acetonitrile, benzene, hexane, 1,2-dichloroethane, and acetic acid are measured calorimetrically at 293 K and atmospheric pressure. The enthalpy of mixing of all the studied binary systems is positive over the range of concentrations.

  3. Heat capacity and density of potassium iodide solutions in mixed N-methylpyrrolidone-water solvent at 298.15 K

    Science.gov (United States)

    Novikov, A. N.

    2014-10-01

    The heat capacity and density of potassium iodide solutions in a mixed N-methylpyrrolidone (MP)-water solvent with a low content of the organic component are measured via calorimetry and densimetry at 298.15 K. Standard partial molal heat capacities and volumes of potassium iodide in MP-water mixtures are calculated. Standard heat capacities and volumes of potassium and iodide ions are determined. The character of the changes in heat capacity and volume are discussed on the basis of calculating additivity coefficients δ c and δ v upon the mixing of isomolal binary solutions KI-MP and KI-water, depending on the composition of the MP-H2O mixture and the concentration of the electrolyte.

  4. Apparent Molal Volumes of Sodium Fluoride in Mixed Aqueous-Ethanol Solvents

    Directory of Open Access Journals (Sweden)

    E. Gomaa

    2010-09-01

    Full Text Available The densities of different molal concentrations of sodium fluoride at ethanol-water mixtures, as solvent, have been measured over the whole composition range at three different temperatures, 293.15, 303.15 and 313.15oK. From the measured densities, the apparent and limiting molal volumes of the electrolytes have been evaluated. The limiting molal volumes for sodium and fluoride ions were estimated by splitting the ionic contributions as an asymmetric assumption.

  5. Semipermanent capillary coatings in mixed organic-water solvents for CE.

    Science.gov (United States)

    Diress, Abebaw G; Yassine, Mahmoud M; Lucy, Charles A

    2007-04-01

    This report describes the creation of semipermanent capillary coatings that are compatible with organic-water solvent systems in CE. The coatings are created by simply rinsing the fused-silica capillary with long double-chain cationic surfactants, such as dimethyl-ditetradecyl ammonium bromide (2C(14)DAB), dihexadecyldimethyl ammonium bromide (2C(16)DAB), and dimethyldioctadecyl ammonium bromide (2C(18)DAB). These surfactants generate semipermanent bilayer coatings on the capillary surface, which display a high degree of stability in buffers containing up to 60% v/v of organic solvents, such as methanol and ACN. The coating stability increases with increasing hydrophobicity of the surfactant, i.e., with increasing chain length. For instance, the EOF changes by only 1.2% in a 2C(18)DAB-coated capillary after 130 capillary volumes of rinsing with 60% v/v methanol containing buffer. The bilayer coatings allow separations to be performed without the need to regenerate the coating between runs or to maintain the EOF modifier in the run buffer. Rapid separations (organic solvent content is adjusted.

  6. Determination of Specific Refractive Index Increment (dn/dc)μ at a Constant Chemical Potential, for Solutions of Polymer in Mixed Solvents by the GPC Method

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-guo; LI Xiao-wen; CHENG Rong-shi

    2007-01-01

    A new chromatographic method is described for the determination of specific refractive index increment(dn/dc)μ at a constant chemical potential, for polymer/mixed solvent systems. In this method the (dn/dc) is obtained by measuring the areas of solvated-polymer peaks when the mixed solvent is used as an eluent. Values of(dn/dc)μ for the poly(dimethylsiloxane) (PDMS) -benzene-methanol system, determined by the proposed method are in good agreement with those determined by the conventional dialysis method. The new approach has the advantages of simplicity, fast speed, and high reproducibility. The experimental results for stearic acid-chloroform-methanol system show that this method can also be applied to nonpolymer/mixed solvent systems for the determination of (dn/dc)μ.

  7. Dependence of the enthalpies of alanyl-alanine dissolution on the composition of mixed water + acetone and water + DMSO solvents at 298.15 K

    Science.gov (United States)

    Smirnov, V. I.; Badelin, V. G.

    2015-08-01

    The enthalpies of dissolution of two dipeptides, DL-α-alanyl-β-alanine and β-alanyl-β-alanine, in mixed solvents H2O + acetone (AC) and H2O + dimethyl sulfoxide (DMSO) are measured via calorimetry at an organic component concentration of x 2 = 0-0.25 mole fraction at 298.15 K. The standard enthalpies of dissolution (Δsol H po) and the transfer (Δtr H po) of dipeptides from water to the mixed solvent and the enthalpic coefficients of pairwise interactions ( h xy ) with AC and DMSO molecules are calculated from these data. The effect the composition of aqueous organic mixtures has on the enthalpy characteristics of the dissolution of DL-α-alanyl-β-alanine and β-alanyl-β-alanine is considered. A comparative analysis of h xy values is performed for alanine dipeptides in the investigated mixed solvents.

  8. Microwave-assisted synthesis of spheroidal vaterite CaCO 3 in ethylene glycol-water mixed solvents without surfactants

    Science.gov (United States)

    Chen, Yinxia; Ji, Xianbing; Wang, Xiaobo

    2010-10-01

    Spheroidal vaterite CaCO 3 composed of irregular nanoparticals have been synthesized by a fast microwave-assisted method. The structures are fabricated by the reaction of Ca(CH 3COO) 2 with (NH 4) 2CO 3 at 90 °C in ethylene glycol-water mixed solvents without any surfactants. The diameters of the spheroidal vaterite CaCO 3 range from 1 to 2 μm, and the average size of the nanoparticals is about 70 nm. Bundle-shaped aragonite and rhombohedral calcite are also obtained by adjusting the experimental parameters. Our experiments show that the ratio of ethylene glycol to water, microwave power, reaction time, and two sources of ammonium ions and acetate anions are key parameters for the fabrication of spheroidal vaterite CaCO 3. A possible growth mechanism for the spheroidal structures has been proposed, which suggests that the spheroidal vaterite CaCO 3 is formed by an aggregation mechanism.

  9. Measurement and Correlation for Solubility of Diosgenin in Some Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    陈飞雄; 赵明蕊; 冯露; 任保增

    2014-01-01

    The solubility data of diosgenin in mixed systems of ethanol+1-propanol (1︰1), ethanol+1-butanol (1︰1), ethanol+isobutyl alcohol (1︰1), methanol+isobutyl alcohol (1︰1), methanol+isobutyl alcohol (1︰4), ethanol+1-pentanol (1︰1) and carbon tetrachloride were measured over the temperature range from 289.15 K to 334.15 K by a laser monitoring observation technique at atmospheric pressure, with all mixtures mixed by volume ratio. The Apelblat equation, the ideal solution model, and theλh equation are used to correlate the solubility data. The results show that the three models agree well with the experimental data, providing essential support for industrial design and further theoretical study.

  10. Explosive treatment of Illinois No.6 coal with a mixed solvent of water and cyclohexanol; Mizu-cyclohexanol kongo yozai ni yoru Illinois tan no bakusai shori

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, T.; Takada, H.; Asami, K.; Yano, M. [Osaka City University, Osaka (Japan). Faculty of Engineering

    1996-10-28

    Coal was treated at high temperature under high pressure in the binary system mixed solvent of water and organic solvent, and the solvent treated coal was liquefied. When the treated coal was treated again by the explosive method in which high temperature and pressure were released immediately, the oil yield was higher than that by the normal method in which high temperature and pressure were reduced gradually to room temperature and atmospheric pressure. In this study, an explosive treatment unit with increased scale of sample amount was newly fabricated. Illinois No.6 coal was treated by the explosive method in a mixed solvent of water and cyclohexanol using this unit. Changes in shape on the surface, specific surface area, and functional groups were analyzed. The explosively treated coal contained more amount of low boiling point components than the normally treated coal. It was suggested that the oil yield of explosively treated coal increased due to the liquefaction of these components during the successive hydrogenation process. For the explosively treated coal, micro pores were fractured by the rapid change in the volume of solvent molecules, and the specific surface area was smaller than that of the normally treated coal. When the treatment temperature was increased from 300{degree}C to 350{degree}C, specific surface areas of both the treated coals increased. 2 refs., 3 figs., 2 tabs.

  11. Conductometric study of complexation process between dibenzo-18-crown-6 and K+, Na+, and La3+ cations in some binary mixed non-aqueous solvents

    Science.gov (United States)

    Khoshnood, Razieh Sanavi; Teymoori, Mostafa; Hatami, Elaheh; Balanezhad, Azadeh Zafar

    2015-09-01

    The complexation reactions between K+, Na+, and La3+ cations and the macrocyclic ligand dibenzo-18-crown-6 (DB18C6) were studied in acetionitrile (AN)-dimethylformamide (DMF) binary mixtures. Also, the complexation of K+ and Na+ in 50% ethanol (EtOH)-50% DMF and 50% EtOH-50% AN binary mixtures was studied. The conductivity data show that the stochiometry of all the complexes is 1: 1. A non-linear behavior was observed for the log K f variation vs. composition of binary solvent, which was discussed in terms of heteroselective solvation and solvent-solvent interactions in binary solutions. It was found that the stability order of the complexes changes with composition of the mixed solvents. The stability sequence for AN-DMF (25 and 50 mol % DMF) solutions and pure AN at 25°C is [K(DB18C6)]+ > [Na(DB18C6)]+ > [La(DB18C6)]3+. However, at 75 mol % DMF it changes to [Na(DB18C6)]+ > [K(DB18C6)]+ > [La(DB18C6)]3+. The thermodynamical values (Δ H {/c po}, Δ S {/c po}) for these complexation reactions were determined from the temperature dependence of the stability constants. The thermodynamics of the complexation reactions is affected by the nature and composition of the mixed solvents.

  12. Characterization and optical properties of nano-ceria synthesized by surfactant-mediated precipitation technique in mixed solvent system

    Energy Technology Data Exchange (ETDEWEB)

    Sujana, M.G. [Institute of Minerals and Materials Technology, (Formerly RRL), Bhubaneswar, Orissa (India)], E-mail: mgsujana@gmail.com; Chattopadyay, K.K. [Department of Physics, Jadavpur University, Kolkata (India); Anand, S. [Institute of Minerals and Materials Technology, (Formerly RRL), Bhubaneswar, Orissa (India)

    2008-09-15

    Crystalline cerium oxide nanoparticles have been synthesized by surfactant-mediated precipitation technique in acetone/water mixed solvent system. The cerium nitrate hexahydrate as precursor and non-ionic surfactant Tween 80 were taken in acetone/water system and precipitated with ammonia at pH 10. The sample was then calcined for 2 h in the temperature range of 200-800 deg. C and characterized by X-ray diffraction (XRD), FTIR, BET surface area and TEM. It was found from XRD studies that the crystallite size increased with calcination temperature from 3 nm to 13 nm and the surface area was found to be 133 m{sup 2}/g for 400 deg. C calcined sample. The particle size obtained from high-resolution transmission electron microscope (HRTEM) was in the range of 4.5 nm with uniform shape and narrow particle size distribution. The diffraction pattern completely indexed with the cubic fluorite structure of CeO{sub 2}. The calcined cerium oxide nanoparticles showed strong UV absorption and room temperature photoluminescence (PL)

  13. Characterization and optical properties of nano-ceria synthesized by surfactant-mediated precipitation technique in mixed solvent system

    Science.gov (United States)

    Sujana, M. G.; Chattopadyay, K. K.; Anand, S.

    2008-09-01

    Crystalline cerium oxide nanoparticles have been synthesized by surfactant-mediated precipitation technique in acetone/water mixed solvent system. The cerium nitrate hexahydrate as precursor and non-ionic surfactant Tween 80 were taken in acetone/water system and precipitated with ammonia at pH 10. The sample was then calcined for 2 h in the temperature range of 200-800 °C and characterized by X-ray diffraction (XRD), FTIR, BET surface area and TEM. It was found from XRD studies that the crystallite size increased with calcination temperature from 3 nm to 13 nm and the surface area was found to be 133 m 2/g for 400 °C calcined sample. The particle size obtained from high-resolution transmission electron microscope (HRTEM) was in the range of 4.5 nm with uniform shape and narrow particle size distribution. The diffraction pattern completely indexed with the cubic fluorite structure of CeO 2. The calcined cerium oxide nanoparticles showed strong UV absorption and room temperature photoluminescence (PL).

  14. 3D investigation on polystyrene colloidal crystals by floatage self-assembly with mixed solvent via synchrotron radiation x-ray phase-contrast computed tomography

    Science.gov (United States)

    Fu, Yanan; Xie, Honglan; Deng, Biao; Du, Guohao; Xiao, Tiqiao

    2017-06-01

    The floatage self-assembly method was introduced with mixed solvent as the medium of polystyrene sphere suspension to fabricate the colloidal crystal. The three dimensional (3D) void system of the colloidal crystal was noninvasively characterized by synchrotron radiation phase-contrast computed tomography, and the quantitative image analysis was implemented aiming to the polystyrene sphere colloidal crystal. Comparing with gravity sedimentation method, the three samples fabricated from floatage self-assembly with mixed solvents have the lowest porosity, and when ethylene glycol and water were mixed with ratio of 1:1, the lowest porosity of 27.49% could be achieved, that has been very close to the minimum porosity of ordered 3D monodisperse sphere array (26%). In single slices, the porosities and fractal dimension for the voids were calculated. The results showed that two factors would significantly influence the porosity of the whole colloidal crystal: the first deposited sphere layer's orderliness and the sedimentation speed of the spheres. The floatage self-assembly could induce a stable close-packing process, resulted from the powerful nucleation force-lateral capillary force coupled with the mixed solvent to regulate the floating upward speed for purpose of matching the assembly rate.

  15. The micro-flow reaction system featured the liquid-liquid interface created with ternary mixed carrier solvents in a capillary tube.

    Science.gov (United States)

    Masuhara, Yuji; Jinno, Naoya; Hashimoto, Masahiko; Tsukagoshi, Kazuhiko

    2012-01-01

    A micro-flow reaction system was developed in which liquid-liquid interface was created based on the tube radial distribution of ternary mixed carrier solvents. The system was constructed from double capillary tubes having different inner diameters (100 and 250 µm i.d.). The smaller tube was inserted into the larger one through a T-type joint. The reaction of a protein with a fluorescence derivatizing reagent was adopted as a model. A water-acetonitrile mixture (3:1 volume ratio) including bovine serum albumin (hydrophilic) was delivered into the large tube from the inside through the small tube and an acetonitrile-ethyl acetate mixture (7:4 volume ratio) containing fluorescamine (hydrophobic) as a derivatizing reagent was delivered from the outside through the joint. Solutions were mixed through the double capillary tubes to promote ternary mixed carrier solvents (water-acetonitrile-ethyl acetate; 1:2:1 volume ratio). The liquid-liquid interface was created based on the tube radial distribution of ternary solvents in the larger tube. The derivatization reaction was performed in the larger, or reaction, tube in the micro-flow system. The fluorescence intensity of the fluorescamine-derivatized bovine serum albumin obtained by the system, which specifically included the kinetic liquid-liquid interface in the tube, was greater than that obtained through a batch reaction using a homogeneous solution of water-acetonitrile (1:2 volume ratio).

  16. Effects of Hydrogen-bonding Interaction and Polarity on Emission Spectrum of Naphthalene-Triethylamine in Mixed Solvent

    Institute of Scientific and Technical Information of China (English)

    XIE Guo-bin; Yoshimi Sueishi; Shunzo Yamamoto

    2004-01-01

    The effects of the protic and aprotic polar solvents on the emission spectrum of the naphthalene-triethylamine system in THF were studied under conditions of steady-state illumination. The fluorescence spectrum of the naphthalene-triethylamine system consists of two emission bands, the fluorescence band of naphthalene (band A, 329 nm) and the emission band of the exciplex(band B, 468 nm). The intensities of both the emission bands decrease with increasing the solvent polarity. The intensity of band B also decreases due to the hydrogen-bonding interaction between triethylamine and protic solvent, while that of band A increases. It is thus suggested that the quenching of naphthalene fluorescence by triethylamine in THF occurs through the charge transfer and electron transfer reactions. The spectral changes upon the increase of solvent polarity can be explained by the dependences of the equilibrium constant between exciplex and ion-pair and the rate constant for the electron transfer reaction from triethylamine to the excited naphthalene on the relative permittivity of solvent. It is shown that the formation of intermolecular hydrogen-bonding between triethylamine and protic solvent suppresses the quenching reaction by the decrease in free amine. Acetonitrile has only a polar effect and trichloroacetic acid only a hydrogen-bonding(or protonation) effect, while alcohols have both the effects. The effects of alcohols could be separated into the effects of solvent polarity and intermolecular hydrogen-bonding interaction quantitatively.

  17. Preparation and formation mechanism of BiOCl0.75I0.25 nanospheres by precipitation method in alcohol-water mixed solvents.

    Science.gov (United States)

    Wang, Xiaoning; Chen, Hongche; Li, Hongjing; Mailhot, Gilles; Dong, Wenbo

    2016-09-15

    BiOCl0.75I0.25 crystals with irregular three-dimensional (3D) flower-like and hierarchical nanosphere-like structures were successfully synthesized in different alcohol-water mixed solvents by precipitation method. The primary formation mechanism of BiOCl0.75I0.25 nanospheres was investigated by taking water, monohydric alcohols (ethanol and isopropanol), and polyhydric alcohols (ethylene glycol, diethylene glycol, and glycerol) as solvents in the synthesis process. The obtained BiOCl0.75I0.25 samples were characterized by powder X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and nitrogen adsorption. Results showed that the alcohol solvents with different physical and chemical properties used in the synthesis process performed significant functions in directing the morphology and surface pore structure of BiOCl0.75I0.25 crystals. Meanwhile, BiOCl0.75I0.25 synthesized in various solvents exhibited morphology-dependent adsorption and photocatalytic degradation abilities in removing p-hydroxyphenylacetic acid (p-HPA), which was used as a model pollutant, in aqueous solutions under simulated solar light (λ⩾290nm). In addition, the fabrication process of the crystal products was proposed through a series of time-dependent experiments.

  18. Solvent-Directed Switch of a Left-Handed 10/12-Helix into a Right-Handed 12/10-Helix in Mixed β-Peptides.

    Science.gov (United States)

    Thodupunuri, Prashanth; Katukuri, Sirisha; Ramakrishna, Kallaganti V S; Sharma, Gangavaram V M; Kunwar, Ajit C; Sarma, Akella V S; Hofmann, Hans-Jörg

    2017-02-17

    Present study describes the synthesis and conformational analysis of β-peptides from C-linked carbo-β-amino acids [β-Caa(l)] with a d-lyxo furanoside side chain and β-hGly in 1:1 alternation. NMR and CD investigations on peptides with an (S)-β-Caa(l) monomer at the N-terminus revealed a right-handed 10/12-mixed helix. An unprecedented solvent-directed "switch" both in helical pattern and handedness was observed when the sequence begins with a β-hGly residue instead of a (S)-β-Caa(l) constituent. NMR studies on these peptides in chloroform indicated a left-handed 10/12-helix, while the CD spectrum in methanol inferred a right-handed secondary structure. The NMR data for these peptides in CD3OH showed the presence of a right-handed 12/10-helix. NMR investigations in acetonitrile indicated the coexistence of both helix types. Quantum chemical studies predicted a small energy difference of 0.3 kcal/mol between the two helix types, which may explain the possibility of solvent influence. Examples for a solvent-directed switch of both the H-bonding pattern and the handedness of foldamer helices are rare so far. A comparable solvent effect was not found in the corresponding peptides with (R)-β-Caa(l) residues, where right-handed 12/10-helices are predominating.

  19. Improving the Performances of Random Copolymer Based Organic Solar Cells by Adjusting the Film Features of Active Layers Using Mixed Solvents

    Directory of Open Access Journals (Sweden)

    Xiangwei Zhu

    2015-12-01

    Full Text Available A novel random copolymer based on donor–acceptor type polymers containing benzodithiophene and dithienosilole as donors and benzothiazole and diketopyrrolopyrrole as acceptors was designed and synthesized by Stille copolymerization, and their optical, electrochemical, charge transport, and photovoltaic properties were investigated. This copolymer with high molecular weight exhibited broad and strong absorption covering the spectra range from 500 to 800 nm with absorption maxima at around 750 nm, which would be very conducive to obtaining large short-circuits current densities. Unlike the general approach using single solvent to prepare the active layer film, mixed solvents were introduced to change the film feature and improve the morphology of the active layer, which lead to a significant improvement of the power conversion efficiency. These results indicate that constructing random copolymer with multiple donor and acceptor monomers and choosing proper mixed solvents to change the characteristics of the film is a very promising way for manufacturing organic solar cells with large current density and high power conversion efficiency.

  20. Controlled Crystal Grain Growth in Mixed Cation-Halide Perovskite by Evaporated Solvent Vapor Recycling Method for High Efficiency Solar Cells.

    Science.gov (United States)

    Numata, Youhei; Kogo, Atsushi; Udagawa, Yosuke; Kunugita, Hideyuki; Ema, Kazuhiro; Sanehira, Yoshitaka; Miyasaka, Tsutomu

    2017-06-07

    We developed a new and simple solvent vapor-assisted thermal annealing (VA) procedure which can reduce grain boundaries in a perovskite film for fabricating highly efficient perovskite solar cells (PSCs). By recycling of solvent molecules evaporated from an as-prepared perovskite film as a VA vapor source, named the pot-roast VA (PR-VA) method, finely controlled and reproducible device fabrication was achieved for formamidinium (FA) and methylammonium (MA) mixed cation-halide perovskite (FAPbI3)0.85(MAPbBr3)0.15. The mixed perovskite was crystallized on a low-temperature prepared brookite TiO2 mesoporous scaffold. When exposed to very dilute solvent vapor, small grains in the perovskite film gradually unified into large grains, resulting in grain boundaries which were highly reduced and improvement of photovoltaic performance in PSC. PR-VA-treated large grain perovskite absorbers exhibited stable photocurrent-voltage performance with high fill factor and suppressed hysteresis, achieving the best conversion efficiency of 18.5% for a 5 × 5 mm(2) device and 15.2% for a 1.0 × 1.0 cm(2) device.

  1. Optically active mixed phthalocyaninato-porphyrinato rare-earth double-decker complexes: synthesis, spectroscopy, and solvent-dependent molecular conformations.

    Science.gov (United States)

    Zhang, Xiaomei; Muranaka, Atsuya; Lv, Wei; Zhang, Yuexing; Bian, Yongzhong; Jiang, Jianzhuang; Kobayashi, Nagao

    2008-01-01

    Reaction between the optically active metal-free phthalocyanine with a pi system with noncentrosymmetrical C(2) [corrected] symmetry ((S)- and (R)-H(2){Pc(OBNP)(2)}; OBNP=binaphthylphthalocyanine) and half-sandwich complexes [M(III)(acac)(TClPP)] (M=Y, Eu; TClPP=meso-tetrakis(4-chlorophenyl)porphyrinate; acac=acetylacetonate), which were generated in situ from [M(acac)(3)].n H(2)O and H(2)(TClPP) in n-octanol at reflux, provided the first optically active protonated mixed phthalocyaninato-porphyrinato rare-earth double-decker complexes [M(III)H{Pc(OBNP)(2)}(TClPP)] (M=Y, Eu) in good yield. In addition to electronic absorption spectroscopy and magnetic circular dichroism results, circular dichroism shows different spectroscopic features of these mixed-ring rare-earth double-decker compounds in different solvents, such as DMF and CHCl(3), which was well-reproduced on the basis of time-dependent density functional theory calculation results for the yttrium species (S)-[Y(III){Pc(OBNP)(2)}(Por)](-) (Por=porphyrinate, which is obtained by removing the four chlorophenyl groups from the TClPP ligand) in terms of the change in the rotation angle between the two macrocyclic ligands in the double-decker molecules. These results revealed the solvent-dependent nature of the molecular conformation of mixed-ring rare-earth double-decker complexes, which suggests a new way of tuning the optical and the electrochemical properties of sandwich-type bis(tetrapyrrole)-metal double-decker complexes in solution by changing the solvent.

  2. A solvent extraction approach to recover acetic acid from mixed waste acids produced during semiconductor wafer process.

    Science.gov (United States)

    Shin, Chang-Hoon; Kim, Ju-Yup; Kim, Jun-Young; Kim, Hyun-Sang; Lee, Hyang-Sook; Mohapatra, Debasish; Ahn, Jae-Woo; Ahn, Jong-Gwan; Bae, Wookeun

    2009-03-15

    Recovery of acetic acid (HAc) from the waste etching solution discharged from silicon wafer manufacturing process has been attempted by using solvent extraction process. For this purpose 2-ethylhexyl alcohol (EHA) was used as organic solvent. In the pre-treatment stage >99% silicon and hydrofluoric acid was removed from the solution by precipitation. The synthesized product, Na(2)SiF(6) having 98.2% purity was considered of commercial grade having good market value. The waste solution containing 279 g/L acetic acid, 513 g/L nitric acid, 0.9 g/L hydrofluoric acid and 0.030 g/L silicon was used for solvent extraction study. From the batch test results equilibrium conditions for HAc recovery were optimized and found to be 4 stages of extraction at an organic:aqueous (O:A) ratio of 3, 4 stages of scrubbing and 4 stages of stripping at an O:A ratio of 1. Deionized water (DW) was used as stripping agent to elute HAc from organic phase. In the whole batch process 96.3% acetic acid recovery was achieved. Continuous operations were successfully conducted for 100 h using a mixer-settler to examine the feasibility of the extraction system for its possible commercial application. Finally, a complete process flowsheet with material balance for the separation and recovery of HAc has been proposed.

  3. Effect of organic co-solvents on the solvation enthalpies of amino acids and dipeptides in mixed aqueous solutions

    Science.gov (United States)

    Badelin, V. G.; Tyunina, E. Yu.

    2011-09-01

    Transition enthalpies (Δtr H o) of substances from water to binary solutions were calculated at 298.15 K on the basis of standard dissolution enthalpies (Δsol H o) for six amino acids and five dipeptides in the mixtures of water with organic solvents of various chemical natures. The enthalpy pair coefficients of interaction h xy for biomolecules with organic component of mixture were estimated within the formalism of the McMillan-Mayer theory. The change in the character of the interaction of the components of solution was demonstrated in dependence on the physicochemical properties of the solvent and nature of the side radical of the dissolved bioorganic substance. Quantitative estimation of the type of interaction of the substance with the solvent was performed on the basis of correlation ratios relating the enthalpy characteristics of bioorganic substances to properties of organic cosolvents. It was shown that in the solutions under study, the effects of both the specific (mainly electron donor) and non-specific solvation of amino acids and peptides are observed.

  4. Use of tube radial distribution of ternary mixed carrier solvents for introduction of absorption reagent for metal ion separation and online detection into capillary.

    Science.gov (United States)

    Fujinaga, Satoshi; Jinno, Naoya; Hashimoto, Masahiko; Tsukagoshi, Kazuhiko

    2011-10-01

    When ternary mixed solvents consisting of water-hydrophilic/hydrophobic organic solvents are fed into a micro-space under laminar flow conditions, the solvent molecules are radially distributed in the micro-space. The specific fluidic behavior of the solvents is called the "tube radial distribution phenomenon (TRDP)". A novel capillary chromatography method was developed based on the TRDP that creates the inner major and outer minor phases in a tube, where the outer phase acts as a pseudo-stationary phase. This is called "tube radial distribution chromatography (TRDC)". In this study, Chrome Azurol S as an absorption reagent was introduced into the TRDC system for metal ion separation and online detection. The fused-silica capillary tube (75 μm id and 110 cm length) and water-acetonitrile-ethyl acetate mixture (3:8:4 volume ratio) including 20 mM Chrome Azurol S as a carrier solution were used. Metal ions, i.e. Co(II), Cu(II), Ni(II), Al(III), and Fe(III), as models were injected into the present TRDC system. Characteristic individual absorption characteristics and elution times were obtained as the result of complex formation between the metal ions and Chrome Azurol S in the water-acetonitrile-ethyl acetate mixture solution. The elution times of the metal ions were examined based on their absorption behavior; Co(II), Ni(II), Al(III), Fe(III), and Cu(II) were eluted in this order over the elution times of 4.7-6.8 min. The elution orders were determined from the molar ratios of metal ion to Chrome Azurol S and Irving-Williams series for bivalent metal ions. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. 混合溶剂提取杜仲籽油工艺研究%Study on Process of Mixed Solvent Extraction of Eucommia Seed Oil

    Institute of Scientific and Technical Information of China (English)

    黄诚; 尹红

    2014-01-01

    Eucommia seed was taken as raw material,using the mixed solvent of cyclohexane and petroleum ether as extraction solvent,Eucommia ulmoides seed oil extraction technology was studied.First of all,the influencing factors,such as solid-liquid ratio,solvent density,extraction temperature and extraction time were discussed,then further extraction process was optimized by orthogonal experiment.The results showed that the best process was liquid-solid ratio 1:8 (g/mL),solvent density 0.754 g/cm3,extraction temperature 60℃,extraction time 60 min,under this condition,the extraction rate reached 30.10%.%以杜仲籽为原料、环己烷和石油醚的混合溶液为提取溶剂,进行杜仲籽油提取工艺研究。对影响杜仲籽油提取得率的料液比、溶剂密度、提取温度、提取时间等单因素进行探讨,采用正交试验进一步对提取工艺进行优化。结果表明:提取杜仲籽油的最佳工艺为料液比1:8(g/mL)、溶剂密度为0.754 g/cm3、提取温度60益、提取时间60 min,在此条件下杜仲籽毛油提取得率为30.10%。

  6. Use of an in vitro model for the assessment of muscle damage from intramuscular injections: in vitro-in vivo correlation and predictability with mixed solvent systems.

    Science.gov (United States)

    Brazeau, G A; Fung, H L

    1989-09-01

    The potential of binary mixtures of propylene glycol-water, ethanol-water, and polyethylene glycol 400-water to cause skeletal muscle damage (myotoxicity) following intramuscular injection was examined with an in vitro model using the isolated rat muscle. At moderate concentrations (20-40%, v/v) of the organic cosolvent, the order of myotoxicity was propylene glycol greater than ethanol much greater than polyethylene glycol 400. The in vitro results were then compared with in vivo toxicity in rabbits after injection of normal saline, 40% (v/v) polyethylene glycol 400, 40% (v/v) propylene glycol, indocyanine green in normal saline, and indocyanine green in 40% (v/v) propylene glycol. Employing the area under the creatine kinase activity curve from 0 to 72 hr as the index of skeletal muscle damage, an excellent in vitro-in vivo correlation was observed. The basic myotoxicity relationships obtained from the binary cosolvent systems were then used to examine the myotoxicity of ternary organic cosolvent mixtures. Several mixed solvent systems with the same theoretical molar solubilization power for a model compound, diazepam, were selected to determine (1) if myotoxicity can be reduced by changing the composition of the ternary mixtures and (2) if myotoxicity of the individual components is additive. For the solvent systems containing propylene glycol, ethanol, and water, the total myotoxicity equaled the sum of the individual myotoxicity of each component. In contrast, for the solvent systems containing polyethylene glycol 400, the total myotoxicity was only half of the sum of individual toxicities. These results suggest that polyethylene glycol 400 in mixed cosolvent systems might have a protective effect on the myotoxicity generated by intramuscular injections.

  7. Elution behavior of lambda-DNA with ternary mixed carrier solvents in an open-tubular capillary under laminar flow conditions.

    Science.gov (United States)

    Nogami, Takahiro; Fujinaga, Satoshi; Jinno, Naoya; Hashimoto, Masahiko; Tsukagoshi, Kazuhiko

    2012-01-01

    An open-tubular capillary chromatography was developed based on the tube radial distribution of the ternary mixed carrier solvents that generated the inner and outer phases under laminar flow conditions. This is called "tube radial distribution chromatography" (TRDC). In this report, the elution behavior of lambda-DNA (48502 bp) as a biopolymer was examined by the TRDC system. The ternary mixture of water-acetonitrile-ethyl acetate, 15:3:2 or 3:8:4 volume ratio, as a carrier solution was fed into the capillary tube made of polytetrafluoroethylene (PTFE) or fused-silica. The mixture of hydrophobic 1-naphthol and hydrophilic lambda-DNA was subjected to the TRDC system using the water-rich carrier solution. Lambda-DNA and 1-naphthol were distributed between the inner and outer phases due to their hydrophilic and hydrophobic nature, and then eluted in this order, undergoing chromatographic separation. The mixture of hydrophilic 2,6-naphthalenedisulfonic acid and hydrophobic lambda-DNA that was treated with surfactants was also examined with the organic solvent-rich carrier solution. The modified hydrophobic DNA and 2,6-naphthalenedisulfonic acid were distributed and eluted in this order due to their nature.

  8. Thermal, spectroscopic, and solvent influence studies on mixed-ligand copper(II) complexes containing the bulky ligand: Bis[ N-( p-tolyl)imino]acenaphthene

    Science.gov (United States)

    El-Ayaan, Usama; Gabr, I. M.

    2007-05-01

    Four mixed-ligand copper(II) complexes containing the rigid bidentate nitrogen ligand bis[ N-( p-tolyl)imino]acenaphthene (abb. p-Tol-BIAN) ligand are reported. These complexes, namely [Cu( p-Tol-BIAN) 2](ClO 4) 21, [Cu( p-Tol-BIAN)(acac)](ClO 4) 2, [Cu( p-Tol-BIAN)Cl 2] 3 and [Cu( p-Tol-BIAN)(AcOH) 2](ClO 4) 24 (where acac, acetylacetonate and AcOH, acetic acid) have been prepared and characterized by elemental analysis, spectroscopic, magnetic and molar conductance measurements. ESR spectra suggest a square planar geometry for complexes 1 and 2. In complexes 3 and 4, a distorted tetrahedral arrangement around copper(II) centre was suggested. Solvatochromic behavior of all studied complexes indicates strong solvatochromism of their solutions. The observed solvatochromism is mainly due to the solute-solvent interaction between the chelate cation and the solvent molecules. Thermal properties and decomposition kinetics of all complexes are investigated. The kinetic parameters ( E, A, Δ H, Δ S and Δ G) of all thermal decomposition stages have been calculated using the Coats-Redfern and other standard equations.

  9. Kinetics of the Reaction of 2-Chloro-3,5-dinitrobenzotriflouride with Aniline in Toluene and Methanol-Toluene Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    Fathalla; Magda F.

    2012-01-01

    Kinetics of the reaction of 2-chloro-3,5-dinitrobenzotriflouride with aniline were studied in toluene, metha- nol-toluene binary solvents, benzene and chloroform. The reaction in toluene exhibits third-order kinetics consistent with aggregates of aniline. Thermodynamic parameters AH#, AS# and AG# are calculated and discussed for the reaction of 2-chloro-3,5-dinitrobenzotriflouride with aniline in methanol-toluene. Molecular complexes between aniline and the substrate are rejected spectrophotometricaly. The mechanism is studied and compared with the reac- tion in presence of pyridine. It shows an amine dependence and formation of homo and/or hetero mixed aggregates between aniline and pyridine i.e. dimer mechanism.

  10. Solvent-Free Selective Oxidation of Toluene with O2 Catalyzed by Metal Cation Modified LDHs and Mixed Oxides

    Directory of Open Access Journals (Sweden)

    Xiaoli Wang

    2016-01-01

    Full Text Available A series of metal cation modified layered-double hydroxides (LDHs and mixed oxides were prepared and used to be the selective oxidation of toluene with O2. The results revealed that the modified LDHs exhibited much higher catalytic performance than their parent LDH and the modified mixed oxides. Moreover, the metal cations were also found to play important roles in the catalytic performance and stabilities of modified catalysts. Under the optimal reaction conditions, the highest toluene conversion reached 8.7% with 97.5% of the selectivity to benzyldehyde; moreover, the catalytic performance remained after nine catalytic runs. In addition, the reaction probably involved a free-radical mechanism.

  11. Effect of methanol ratio in mixed solvents on optical properties and wettability of ZnO films by cathodic electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Miao; Xu, Kai; Jiang, Xishun; Yang, Lei; He, Gang; Song, Xueping [School of Physics and Material Science, Anhui University, Hefei 230601 (China); Sun, Zhaoqi, E-mail: szq@ahu.edu.cn [School of Physics and Material Science, Anhui University, Hefei 230601 (China); Lv, Jianguo, E-mail: lvjg1@163.com [School of Electronic and Information Engineering, Hefei Normal University, Hefei 230601 (China)

    2014-12-05

    Highlights: • Different surface morphologies of ZnO films were prepared by cathodic electrodeposition. • The surface morphologies are controlled through add different ratio methanol to electrolyte. • The morphology changes from nanorods with hexagonal structure to net-like nanostructure. • The wettability of films shows obvious change with increasing methanol ratio. • The maximum light-induced CA change has been observed with the methanol ratio of 0.8. - Abstract: ZnO thin films were prepared in the electrolyte with different methanol ratio by cathodic electrodeposition method. Microstructure, surface morphology, optical properties and wettability of the thin films were investigated by X-ray diffractometer, field-emission scanning electron microscope, ultraviolet–visible spectroscope, fluorescence spectrometer and water contact angle apparatus. Increase of methanol ratio in the solvents may restrain the (0 0 2) plane preferential orientation in some extent. Change of current density curves with the ratio of methanol in the solution play a vital role on electrochemical reaction kinetics, microstructure and/or surface morphology of ZnO thin films. With the methanol ratio increase from 0 to 0.8, the surface morphology changes from nanorods to net-like nanostructure. The adsorbed NO{sub 3}{sup −} ions on the polar planes hinder the crystal growth along the c-axis and redirect the growth direction along the nonpolar planes. The maximum and minimum band gaps have been obtained in the ZnO thin films with the methanol ratio of 0.4 and 0.6, respectively. Change of contact angle before UV irradiation may be related to surface morphology and oxygen vacancies. The maximum light-induced water contact angle change has been observed in the sample with the methanol ratio of 0.8. The results may be attributed to the higher surface roughness and net-like morphology.

  12. Inclusion Behavior of Chemical Modified β-cyclodextrin in Alcohol/Water Mixed Solvents%化学修饰环糊精在醇/水混合溶剂中的包结行为

    Institute of Scientific and Technical Information of China (English)

    解宏智; 吴世康

    2000-01-01

    A comparative study on the fluorescence behavior of the chemical modified β -cyclodextrin appended a N,N-dimethylamino-chalcone group (DMAC-CD) and the non-modified β-CD mixed with free dimethylamino-chalcone (DMAC+ CD) in alcohol/water mixed solvents have been carried out in this work.The fluorescence data obtained— — maximum peak wavelength and emission intensity— — indicates that the inclusion behavior of the above-mentioned systems is obviously different in mixed alcohol/water solvents.The solvent-induced multi-component complex formation and dissociation and the effect of polarity and size of alcohol used have been also studied carefully by variation of the fluorescence spectroscopic characters.The result indicates that the self-inclusion complex of DMAC-CD has a higher stability in mixed alcohol/water solvents than that in the DMAC + β -CD system.The obtained results and the observed phenomena have been discussed in details.

  13. Mixed

    Directory of Open Access Journals (Sweden)

    Pau Baya

    2011-05-01

    Full Text Available Remenat (Catalan (Mixed, "revoltillo" (Scrambled in Spanish, is a dish which, in Catalunya, consists of a beaten egg cooked with vegetables or other ingredients, normally prawns or asparagus. It is delicious. Scrambled refers to the action of mixing the beaten egg with other ingredients in a pan, normally using a wooden spoon Thought is frequently an amalgam of past ideas put through a spinner and rhythmically shaken around like a cocktail until a uniform and dense paste is made. This malleable product, rather like a cake mixture can be deformed pulling it out, rolling it around, adapting its shape to the commands of one’s hands or the tool which is being used on it. In the piece Mixed, the contortion of the wood seeks to reproduce the plasticity of this slow heavy movement. Each piece lays itself on the next piece consecutively like a tongue of incandescent lava slowly advancing but with unstoppable inertia.

  14. Toward mechanistic understanding of nuclear reprocessing chemistries by quantifying lanthanide solvent extraction kinetics via microfluidics with constant interfacial area and rapid mixing.

    Science.gov (United States)

    Nichols, Kevin P; Pompano, Rebecca R; Li, Liang; Gelis, Artem V; Ismagilov, Rustem F

    2011-10-05

    The closing of the nuclear fuel cycle is an unsolved problem of great importance. Separating radionuclides produced in a nuclear reactor is useful both for the storage of nuclear waste and for recycling of nuclear fuel. These separations can be performed by designing appropriate chelation chemistries and liquid-liquid extraction schemes, such as in the TALSPEAK process (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes). However, there are no approved methods for the industrial scale reprocessing of civilian nuclear fuel in the United States. One bottleneck in the design of next-generation solvent extraction-based nuclear fuel reprocessing schemes is a lack of interfacial mass transfer rate constants obtained under well-controlled conditions for lanthanide and actinide ligand complexes; such rate constants are a prerequisite for mechanistic understanding of the extraction chemistries involved and are of great assistance in the design of new chemistries. In addition, rate constants obtained under conditions of known interfacial area have immediate, practical utility in models required for the scaling-up of laboratory-scale demonstrations to industrial-scale solutions. Existing experimental techniques for determining these rate constants suffer from two key drawbacks: either slow mixing or unknown interfacial area. The volume of waste produced by traditional methods is an additional, practical concern in experiments involving radioactive elements, both from disposal cost and experimenter safety standpoints. In this paper, we test a plug-based microfluidic system that uses flowing plugs (droplets) in microfluidic channels to determine absolute interfacial mass transfer rate constants under conditions of both rapid mixing and controlled interfacial area. We utilize this system to determine, for the first time, the rate constants for interfacial transfer of all lanthanides, minus promethium, plus yttrium, under TALSPEAK

  15. Coaxial Electrospinning with Mixed Solvents: From Flat to Round Eudragit L100 Nanofibers for Better Colon-Targeted Sustained Drug Release Profiles

    Directory of Open Access Journals (Sweden)

    Deng-Guang Yu

    2014-01-01

    Full Text Available A modified coaxial electrospinning process was developed for creating drug-loaded composite nanofibers. Using a mixed solvent of ethanol and N,N-dimethylacetamide as a sheath fluid, the electrospinning of a codissolving solution of diclofenac sodium (DS and Eudragit L100 (EL100 could run smoothly and continuously without any clogging. A series of analyses were undertaken to characterize the resultant nanofibers from both the modified coaxial process and a one-fluid electrospinning in terms of their morphology, physical form of the components, and their functional performance. Compared with those from the one-fluid electrospinning, the DS-loaded EL100 fibers from the modified coaxial process were rounder and smoother and possessed higher quality in terms of diameter and distribution with the DS existing in the EL100 matrix in an amorphous state; they also provided a better colon-targeted sustained drug release profile with a longer release time period. The modified coaxial process not only can smooth the electrospinning process to prevent clogging of spinneret, but also is a useful tool to tailor the shape of electrospun nanofibers and thus endow them improved functions.

  16. Synthesis of Spherical TiO{sub 2}-SiO{sub 2} Particles by Mixed Solvent Method and Photocatalytic Degradation of Iso-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Un Yeon; Seo, Jin Seok; Lee, Jung Woon; Choi, Jin Hoon; Park, Hyung Sang [Department of Chemical Engineering, Sogang University, Seoul (Korea); Kim, Yong Ryul [Department of Chemical Engineering, Daejin University, Pochon (Korea); Yoo, Seung Joon [Faculty of Environmental and Chemical Engineering, Seonam University, Namwon (Korea); Yoon, Ho Sung [Division of Mineral Utilization and Materials, Korea Institute of Geology , Mining and Materials, Changwon (Korea)

    2001-02-01

    The physical properties which affect on the activity of photocatalysts are active site number and surface area, etc. Recently, to control these properties, 'Sol-Gel' Methods are used to synthesize photocatalysts. In this study, we synthesized spherical Tio{sub 2}-Sio{sub 2} photocatalysts by mixed solvent method, and analyzed the changes in morphology of the catalysts with synthesis conditions by SEM and the changes in physical properties of the particles and the variation of the crystal structure with Ti concentration and calcination temperature by TGA, BET, FT-IR and XRD. Then we investigated the effects of the physical properties and [Ti]/[Si] ratio on photocatalytic degradation of iso-propanol. The particle size was decreased with increasing HPC concentration and decreasing Ti concentration. The surface area of the catalysts was decreased by increasing Ti concentration and calcination temperature. As Ti concentration was increased, Ti-O-Si bond number was increased, and by calcination, the number was increased until 400 degree C, then decreased with increasing calcination temperature. The extent of photodegradation of isopropanol was higher as photocatalysts have more Ti, But the turnover frequency of the Ti was higher as the catalysts have less Ti. Because (Ti{sup 3+}-O{sup -}) number and the surface area of the photocatalysts are decreased by increasing calcination temperature, the photodegradation of organic material is decreased. 13 refs., 14 figs., 2 tabs.

  17. Mixed Ligand Complexes of N-Methyl-N-phenyl Dithiocarbamate: Synthesis, Characterisation, Antifungal Activity, and Solvent Extraction Studies of the Ligand.

    Science.gov (United States)

    Ekennia, Anthony C; Onwudiwe, Damian C; Ume, Cyril; Ebenso, Eno E

    2015-01-01

    A series of mixed ligand dithiocarbamate complexes with a general formula [ML2(py)2], where M = Mn(II), Co(II), Ni(II), and Cu(II), py = pyridine, and L = N-methyl-N-phenyl dithiocarbamate have been prepared and characterised by elemental analysis, FTIR and Uv spectroscopy, magnetic moment, and thermogravimetric and conductance analysis. The infrared spectra showed that symmetrical bidentate coordination occurred with the dithiocarbamate moiety through the sulfur atoms, while neutral monodentate coordination occurred through the nitrogen atom for the pyridine molecule in the complexes. The electronic spectra, elemental analysis, and magnetic moment results proved that the complexes adopted octahedral geometry. The conductance measurement showed that the complexes are nonelectrolytes proving their nonionic nature. The compounds were screened for three human pathogenic fungi: Aspergillus flavus, Aspergillus niger, and Candida albicans. The cobalt complex showed the best antifungal activity among the test compounds. Liquid-liquid extractive abilities of the ligand towards copper and nickel ions in different solvent media were investigated. The ligand showed a strong binding affinity towards the metals ions with an extractive efficiency of about 99%.

  18. Renewable Lignosulfonate-Assisted Synthesis of Hierarchical Nanoflake-Array-Flower ZnO Nanomaterials in Mixed Solvents and Their Photocatalytic Performance.

    Science.gov (United States)

    Li, Yue; Zuo, Hong-Fen; Guo, Yuan-Ru; Miao, Ting-Ting; Pan, Qing-Jiang

    2016-12-01

    With the assistance of sodium lignosulfonate, hierarchical nanoflake-array-flower nanostructure of ZnO has been fabricated by a facile precipitation method in mixed solvents. The sodium lignosulfonate amount used in our synthetic route is able to fine-tune ZnO morphology and an abundance of pores have been observed in the nanoflake-array-flower ZnO, which result in specific surface area reaching as high as 82.9 m(2) · g(-1). The synthesized ZnO exhibits superior photocatalytic activity even under low-power UV illumination (6 W). It is conjectured that both nanoflake-array structure and plenty of pores embedded in ZnO flakes may provide scaffold microenvironments to enhance photocatalytic activity. Additionally, this catalyst can be used repeatedly without a significant loss in photocatalytic activity. The low-cost, simple synthetic approach as well as high photocatalytic and recycling efficiency of our ZnO nanomaterials allows for application to treat wastewater containing organic pollutants in an effective way.

  19. Effect of f-electron configurations on the adsorption of trivalent f-elements on tertiary pyridine resin in hydrochloric acid/alcohol mixed solvents

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Atsushi; Suzuki, Tatsuya; Aida, Masao; Ohtake, Kouhei; Fujii, Yasuhiko; Itoh, Keisuke; Hara, Mitsuo; Mitsugashira, Toshiaki

    2004-07-14

    The separation of trivalent actinides (An) from lanthanides (Ln) is difficult because of their chemical similarities although it is necessary for various fields such as nuclear fuel-cycle process. In the present study, it was observed that the trivalent An (Am{sup 3+}, Cm{sup 3+} and Cf{sup 3+}) were adsorbed on tertiary pyridine type resins far more strongly than the Ln in HCl (LiCl solution)/methanol mixed solvents and the An were separated from the Ln by using a single separation process. On the other hand, the Dowex 1 x 8 showed no adsorption in the same conditions. Therefore, there is a possibility that the adsorption of An and Ln cations is caused by the complexation of the cations with the tertiary pyridine groups of the resins, not by the ionic interaction. There seems to be some relationship between the distribution coefficients (K{sub d}) of trivalent f-elements (i.e. An and Ln) and the f-electron configurations of their cations, and their ionic size.

  20. 可循环混合溶剂分离水稻秸秆纤维素%Isolation of Cellulose from Rice Straw with Recyclable Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    王伟; 姜曼; 朱世步; 周祚万

    2011-01-01

    粉碎的水稻秸秆经水煮和抽提预处理后,采用乙二醇(EG)和水的混合体系(体积比9:1)为溶剂,在酸或碱催化作用下,分离得到纤维素,同时回收木质素和半纤维素;对所得样品的组分含量、晶体结构、微观形貌等进行了分析.结果表明:经水煮和抽提预处理后,秸秆纤维束状结构变得疏松;在0.1mol/L的硫酸催化下,经混合溶剂处理所得样品的综纤维素含量达到86.59%(其中纤维素含量为83.09%),酸不溶木质素含量为3.70%;相同条件下,以0.1mol/L氢氧化钠为催化剂,所得样品中酸不溶木质素含量为4.21%.研究还发现,混合溶剂可高效回收并循环使用.基于实验结果和结论分析,对催化剂可能的作用机理解释为:在适当浓度的酸或碱作用下,木质素的重聚合被有效抑制,从而促进了其在混合溶剂中溶解,并使其从秸秆组织中分离.%It is of great importance to make full use of the biomasses such as straws with high value by environmental process. The cellulose was isolated from pulverized rice straw (RS) with mixed solvent of ethylene glycol (EG) and water in the presence of different catalysts,after pre-cooking and extracting with hot water, and the lignin and hemicelluloses were recovered in the same procedure. Structures and morphologies of the obtained samples were characterized by X-ray diffractometry (XRD), Fourier transform infrared (FT-IR) spectroscopy and environmental scanning electron microscopy (ESEM), the components were also analyzed. It is observed that the fibril bundles become loose after cooking and extracting with hot water. The related mixture solvent, in the presence of sulphuric acid (0. 1 mol/L) as catalyst, displayed a good effect for isolating the components from the rice straw. The obtained solid samples were detected to contain 86.59 % holocellulose (83.09% of which is cellulose), and 3. 70% lignin. As a comparison, the lignin could also be reduced to 4.21% with

  1. Study of complex formation process between 4′-nitrobenzo-18-crown-6 and yttrium(III cation in some binary mixed non-aqueous solvents using the conductometry method

    Directory of Open Access Journals (Sweden)

    Mahboobeh Vafi

    2017-07-01

    Full Text Available The complexation reaction between Y3+ cation and macrocyclic ligand, 4′-nitrobenzo-18-crown-6 (4′NB18C6, was studied in acetonitrile–methanol (AN–MeOH, acetonitrile–1,2-dichloroethane (AN–DCE, acetonitrile–dimethylformamide (AN–DMF and acetonitrile–ethylacetate (AN–EtOAc binary mixed solvent solutions at different temperatures using the conductometric method. The conductance data show that in most cases, the stoichiometry of the complex formed between 4′NB18C6 and Y3+ cation is 1:1 [M:L], but in the case of AN-DCE binary solution (mol% DCE = 50 at 15, 25 and 35 °C, a 2:1 [M2:L] and also a 2:2 [M2:L2] complexes are formed in solution. The results show that the stoichiometry of the complex formed between 4′NB18C6 and Y3+ cation changes with the composition of the mixed solvents and even with temperature. The stability constant of the 1:1 complex was determined using a computer program, GENPLOT. The stability order of (4′NB18C6.Y3+ complex in pure studied solvents at 25 °C was found to be: EtOAc > AN > MeOH > DMF and in the case of the mixed solvent solutions with 25 mol percent of AN at 25 °C was: AN-DCE > AN-EtOAc > AN-MeOH ∼ AN-DMF. The values of stability constant (logKf of (4′NB18C6.Y3+ complex which were obtained from conductometric data, show that the stability of the complex is not only affected by the nature and composition of the solvent system, but it is also influenced by the temperature. In all cases, a non-linear behavior is observed for changes of logKf of the (4′NB18C6.Y3+ complex versus the composition of the binary mixed solvents. The values of standard thermodynamic quantities (ΔH°c and ΔS°c for the complexation process which were obtained from temperature dependence of the stability constant of (4′NB18C6.Y3+ complex, show that depending on the solvent system, in most cases, the complex is enthalpy and also entropy stabilized, but in some cases, it is stabilized or

  2. Morphologic improvement of the PBDTTT-C and PC71BM blend film with mixed solvent for high-performance inverted polymer solar cells.

    Science.gov (United States)

    Chen, Hsin-Yi; Lin, Shang-Hong; Sun, Jen-Yu; Hsu, Chi-Hsing; Lan, Shiang; Lin, Ching-Fuh

    2013-12-06

    Tracing the evolution of the bulk heterojunction structure, a dramatic promotion in the efficiency of polymer solar cells has been obtained in recent years. The active layer morphology of low-bandgap polymer solar cells is one of the critical factors for high-efficiency performance. In the past, the relationship between morphology improvement and the device's characteristics (such as efficiency, fill factor and short-circuit current) in low-bandgap polymer solar cells has been studied intensively with regards to the conventional structure. Here we demonstrate the morphologic improvement of the poly[(4,8-bis-(2-ethylhexyloxy)-benzo[1,2-b;4,5-b']dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiopene)-2,6-diyl]/[6,6]-phenyl C71 butyric acid methyl ester (PBDTTT-C/PC71BM) blend film for inverted solar cells. By utilizing a mixed solvent of dichlorobenzene/chlorobenzene with (1,8-diiodooctane) additives, the device efficiency can be significantly enhanced, from 0.92% to 4.43%. This enhancement is attributed to active layer morphologic improvement promoting carrier transport. Furthermore, the thickness optimization of the active layer and the electron blocking layer MoO3 further contributes to efficiency. The device performance could be achieved with an efficiency as high as 5.35%, an open-circuit voltage of 0.70 V, a short-circuit current density of 13.5 mA cm(-2), and a fill factor of 57%.

  3. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum–classical approximation. II. Proton transfer reaction in non-polar solvent

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, H.; Yamada, A.; Okazaki, S., E-mail: okazaki@apchem.nagoya-u.ac.jp [Department of Applied Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2015-05-07

    The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum–classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute–solvent interactions.

  4. Platinum nanoparticles on carbon-nanotube support prepared by room-temperature reduction with H2 in ethylene glycol/water mixed solvent as catalysts for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Zheng, Yuying; Dou, Zhengjie; Fang, Yanxiong; Li, Muwu; Wu, Xin; Zeng, Jianhuang; Hou, Zhaohui; Liao, Shijun

    2016-02-01

    Polyol approach is commonly used in synthesizing Pt nanoparticles in polymer electrolyte membrane fuel cells. However, the application of this process consumes a great deal of time and energy, as the reduction of precursors requires elevated temperatures and several hours. Moreover, the ethylene glycol and its oxidizing products bound to Pt are difficult to remove. In this work, we utilize the advantages of ethylene glycol and prepare Pt nanoparticles through a room-temperature hydrogen gas reduction in an ethylene glycol/water mixed solvent, which is followed by subsequent harvesting by carbon nanotubes as electrocatalysts. This method is simple, facile, and time-efficient, as the entire room-temperature reduction process is completed in a few minutes. As the solvent changes from water to an ethylene glycol/water mix, the size of Pt nanoparticles varies from 10 to 3 nm and their shape transitions from polyhedral to spherical. Pt nanoparticles prepared in a 1:1 volume ratio mixture of ethylene glycol/water are uniformly dispersed with an average size of ∼3 nm. The optimized carbon nanotube-supported Pt electrocatalyst exhibits excellent methanol oxidation and oxygen reduction activities. This work demonstrates the potential use of mixed solvents as an approach in materials synthesis.

  5. Synthesis, structural and solvent influence studies on solvatochromic mixed-ligand copper(II) complexes with the rigid nitrogen ligand: bis[ N-(2,4,6-trimethylphenyl)imino]acenaphthene

    Science.gov (United States)

    El-Ayaan, Usama; Murata, Fumiko; El-Derby, Soheir; Fukuda, Yutaka

    2004-04-01

    Three mixed-ligand copper (II) complexes containing the rigid bidentate nitrogen ligand bis[ N-(2,4,6-trimethylphenyl)imino]acenaphthene (abbr. 2,4,6-Me 3C 6H 2-BIAN) and β-diketonate (dike) ligands are reported and characterized. These complexes namely, [Cu(dike)(2,4,6-Me 3C 6H 2-BIAN)]ClO 4 {where dike=acac (acetylacetonate), bzac (benzoylacetonate) or (dibm) dibenzoylmethanate}have been synthesized and characterized by elemental analysis, spectroscopic, magnetic and molar conductance measurements. In addition to their high solubility in various organic solvents, these three complexes show a color change on going from one solvent to another, that is, strong solvatochromism of their solutions. The observed solvatochromism is mainly due to the solute-solvent interaction between the chelate cation and the solvent molecules. Reported also are the X-ray crystal structures of the free 2,4,6-Me 3C 6H 2-BIAN ligand and the [Cu(acac)(2,4,6-Me 3C 6H 2-BIAN)]ClO 4 complex.

  6. Study on mixed solvent for separating ethanol and water by using batch extractive distillation%复合溶剂间歇萃取精馏乙醇-水的研究

    Institute of Scientific and Technical Information of China (English)

    李春利; 孙晶晶; 吕建华; 李玉杰; 靳红星; 龙梅

    2011-01-01

    A batch extractive distillation process for separating ethanol and water system was studied by employing N,N-dimethylfonnamide (DMF) , dimethyl sulfoxide (DMSO) and the mixture of them as solvents. The effects of different types of solvent, solvent rate, and reflux ratio on separation process were investigated. The results show that the most suitable mass ratio of DMSO to DMF in the mixed solvent is 7 :3; the separation effect is improved with the increasing of solvent rate and reflux ratio; under the conditions that the optimum value of solvent m( DMSO) : m( DMF) =7:3, reflux ratio is 2, and flow rate of solvent is 15 mL/min, the mass fraction of ethanol reaches 99.14% , which is improved by 3. 29% and 1. 71% than DMF and DMSO respectively; and the lowest unit consumption of solvent is 1.58 mL/mL.%采用N,N-二甲基甲酰胺和二甲基亚砜及其组成的复合溶剂为萃取剂,在间歇萃取精馏实验装置上研究了乙醇-水共沸体系的分离过程.实验考察了溶剂种类、溶剂流率、回流比等因素对分离效果的影响.实验结果表明:复合溶剂的最佳配比为7:3(二甲基亚砜与N,N-二甲基甲酰胺质量比);随着溶剂流率与回流比的增大,复合溶剂分离效果增强;在最佳配比下,当回流比为2,溶剂流率为15 mL/min时,乙醇的质量分数可达99.14%,比单一溶剂N,N-二甲基甲酰胺和二甲基亚砜分别提高了3.29%和1.71%,且单位产品溶剂消耗最低为1.58 mL/mL,此时复合溶剂间歇萃取精馏乙醇-水的综合效果最好.

  7. Synthesis of sol–gel silica particles in reverse micelles with mixed-solvent polar cores: tailoring nanoreactor structure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Bürglová, Kristýna; Hlaváč, Jan [Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry (Czech Republic); Bartlett, John R., E-mail: jbartlett@usc.edu.au [University of the Sunshine Coast, Faculty of Science, Health, Education and Engineering (Australia)

    2015-07-15

    In this paper, we describe a new approach for producing metal oxide nano- and microparticles via sol–gel processing in confined media (sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles), in which the chemical and physical properties of the polar aqueous core of the reverse micelles are modulated by the inclusion of a second polar co-solvent. The co-solvents were selected for their capacity to solubilise compounds with low water solubility and included dimethylsulfoxide, dimethylformamide, ethylene glycol, n-propanol, dimethylacetamide and N-methylpyrrolidone. A broad range of processing conditions across the sodium bis(2-ethylhexyl)sulfosuccinate/cyclohexane/water phase diagram were identified that are suitable for preparing particles with dimensions <50 to >500 nm. In contrast, only a relatively narrow range of processing conditions were suitable for preparing such particles in the absence of the co-solvents, highlighting the role of the co-solvent in modulating the properties of the polar core of the reverse micelles. A mechanism is proposed that links the interactions between the various reactive sites on the polar head group of the surfactant and the co-solvent to the nucleation and growth of the particles.

  8. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  9. 溶解度参数在混合溶剂处理铝塑复合物中的应用%Application of Mixed Solvent Solubility Parameter in the Separation of Aluminum and Plastic Composite

    Institute of Scientific and Technical Information of China (English)

    张素风; 梅星贤; 张璐璐

    2013-01-01

    Mixed solvents including benzene-ethanol-water, toluene-ethanol-water and styrene-ethanol-water were used as a separating agent to separate aluminum and plastic composite. The volume ratio of each component of the mixed solvent used for completely separating the aluminum and plastic composite was investigated; the solubility parameter range of the organic adhesive used in the composite could be obtained through calculating the solubility parameter of the mixed solvent. The results showed that the ideal range of solubility parameters of organic adhesive is 29.1 to 34.8; the required volume ratio of toluene is least when using toluene-ethanol-water solvent as the separating agent.%针对混合溶剂处理铝塑复合物工艺的研究,分别以苯-乙醇-水、甲苯-乙醇-水、苯乙烯-乙醇-水3种混合液作为分离剂进行铝塑分离实验.由于苯、甲苯、苯乙烯的溶解度参数相近,当铝塑完全分离时,考察不同分离剂各组分的体积比,通过混合溶剂溶解度参数计算公式得出各混合溶剂的溶解度参数.根据相似相溶原理,得出铝塑复合物间有机胶黏剂溶解度参数的理想范围.结果表明,3种混合溶剂处理铝塑复合物,当铝塑完全分离时,铝塑复合物间胶黏剂的溶解度参数范围为29.1 ~ 34.8;甲苯-乙醇-水混合溶剂作为分离剂,所需的甲苯体积比最小(20%).

  10. Supramolecular solvent-based extraction coupled with vortex-mixing for determination of palladium and silver in water samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Meng, Lifen; Cheng, Jiaxi; Yang, Yaling

    2014-01-01

    A simple and practical extraction method of supramolecular solvents (SUPRAS) was developed for separation and enrichment of trace amounts of palladium (Pd) and silver (Ag) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. The SUPRAS selected was made up of an aqueous solution containing tetrahydrofuran and nonanoic acid. Pd and Ag reacted with diethyldithiocarbamate to form hydrophobic chelates, which were extracted into the vesicles of SUPRAS. Different parameters such as the concentration of chelating agent, sample pH, supramolecular solvent and the effect of foreign ions were studied. Under the optimal conditions, the linear ranges of Pd and Ag were from 10 to 1,000 μg/L. The relative recoveries of Pd and Ag in tap and river water samples at the spiking level of 10 ug/mL ranged from 90.8 to 116%. The relative standard deviations were 3.6-4.0% (n = 9), the limits of detection were 2.8 and 1.9 μg/L and the enrichment factors were 36 and 18 for Pd and Ag, respectively. The quantification limits were 3.2 and 2.4 μg/L. The method was successfully applied to the determination of Pd and Ag in water samples.

  11. Optimization of Liquefaction Technology of Bagasse in Water-tetralin Mixed Solvents%甘蔗渣在水与四氢萘混合溶剂中的液化工艺优化实验

    Institute of Scientific and Technical Information of China (English)

    操江飞; 李存龙; 谢宁; 周欣欣; 洪亚明; 李志霞

    2014-01-01

    通过正交试验考察了蔗渣在水与四氢萘混合溶剂中液化过程的5个因素对蔗渣转化率的影响。蔗渣在混合溶剂中的优化工艺为:反应温度270℃、反应时间30 min、固液比(蔗渣与溶剂质量比)1:6、碱浸预处理NaOH用量4%、四氢萘用量(占总溶剂质量分数)50%。各因素的影响次序:NaOH用量>反应温度>四氢萘用量>固液比>反应时间。在此工艺条件下,蔗渣转化率可达到97.9%。实验结果表明,四氢萘部分取代液化溶剂中的水,可以有效提高蔗渣液化效率,同时降低反应温度及压力,促进实验操作条件的改善。%The effects of five factors on conversion rate during the liquefaction of bagasse in water-tetralin( W-T)mixed solvents were investigated by orthogonal test. The optimal conditions were reaction temperature 270℃,reaction time 30 min,mass ratio of bagasse to solvent 1:6,NaOH dosage in alkali-soaking pretreatment 4%,and tetralin dosage 50%( mass fraction in the total solvent). The sequence of influence factors was NaOH dosage>reaction temperature>tetralin dosage>mass ratio of bagasse to solvent>reaction time. The conversion rate of bagasse was 97. 9% under the optimal conditions. The results also showed that partial substitute for water with tetralin in liquefaction solvents could increase liquefaction efficiency,reduce reaction temperature and pressure,and improve experimental operating condition.

  12. Synthesis and Characterization of Monetite Prepared Using a Sonochemical Method in a Mixed Solvent System of Water/Ethylene Glycol/ N, N-Dimethylformamide

    Science.gov (United States)

    Baradaran, S.; Basirun, W. J.; Mahmoudian, M. R.; Hamdi, M.; Alias, Y.

    2013-05-01

    Bioactive monetite (anhydrous calcium hydrogen phosphate, CaHPO4) has been successfully synthesized using the sonochemical method in the presence of a ternary solvent system of water/ethylene glycol (EG)/ N, N-dimethylformamide (DMF). The morphology and chemical composition of the synthesized powders were characterized using field emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The results indicated that with increasing sonication time, the morphology changed slightly from a plate-like one to a combination of plates (flower-like). The formation of flower-like nanosheets requires an optimum time of 40 minutes, and the nanosheets have an average thickness of 210 ± 87 nm. The concentration of DMF clearly influences the morphology and crystal phase of the products. The ideal product was obtained using a water/EG DMF ratio of 1:2.

  13. Phase behavior of the mixtures of poly(oxyethylene) (10) stearyl ether (Brij-76), 1-butanol, isooctane, and mixed polar solvents II. Water and ethylene glycol (EG) or tetraethylene glycol (TEG).

    Science.gov (United States)

    Nandy, Debdurlav; Mitra, Rajib K; Paul, Bidyut K

    2007-06-01

    The phase diagrams of the pseudo-quaternary systems poly(oxyethylene) (10) stearyl ether (Brij-76)/1-butanol/isooctane/water (with equal amounts of oil and water in the presence of two nonaqueous polar solvents (NPS), ethylene glycol (EG), and tetraethylene glycol (TEG)), have been constructed at 30 degrees C. Regular fish-tail diagrams were obtained up to psi (weight fraction of EG or TEG in the mixture of polar solvents) equal to 0.5, confirming the establishment of hydrophile-lipophile balance (HLB) of the systems. The maximum solubilization capacity passed through a minimum at psi=0.2. No HLB was obtained at higher psi. The usual fish-tail diagrams were also obtained in temperature-induced phase mapping at fixed W(1) (weight fraction of 1-butanol in total amphiphile). Solubilization capacity and HLB temperature (T(HLB)) decreased with increasing psi at a fixed W(1), the effect being more pronounced for TEG than EG. A correlation between HLB temperature (T(HLB)) and HLB number (N(HLB)) of mixed amphiphiles (Brij-76+Bu) in pseudo-quaternary systems (in the presence of water and partial substitution of water with both NPS) has been established. The novelty of the work with respect to possible applications has been discussed.

  14. 混合溶剂中硅烷偶联剂KH570对纳米ZnO的接枝改性%Graft modification of ZnO nanoparticles with silane coupling agent KH570 in mixed solvent

    Institute of Scientific and Technical Information of China (English)

    马书蕊; 施利毅; 冯欣; 虞伟钧; 鲁波

    2008-01-01

    The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification such as Soxhlet extraction, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and zeta potential (ζ). The results of FT-IR and TG-DSC show that the desired reaction chains have been covalently bonded on the surface of ZnO nanoparticles. Zetasizer results reveal that the maximal absolute value of ζ of the modified ZnO particles in acetone medium was 67.0mV, which was much higher than that of the unmodified ZnO particles. So the surface of nanosized ZnO changed from hydrophilicity to hydrophobicity and the dispersity of ZnO nanoparticles were improved simultaneously. Finally, the mechanism of graft modification was discussed.

  15. 复合溶剂提取沙棘籽油的工艺条件研究%Extraction of seabuckthorn seed oil with mixed solvent from Hippophae rhamnoides seed

    Institute of Scientific and Technical Information of China (English)

    张丽霞; 康健; 吴桐

    2011-01-01

    采用响应面优化了正己烷-丙酮复合溶剂浸提沙棘籽油的提取条件,并对沙棘籽油的理化性质进行分析.结果表明:最优条件为料液比1∶14、粉碎度35.00目、正己烷:丙酮为6∶4、浸提温度44.00℃、浸提时间1.84h,在该条件下沙棘籽油提取率为13.788%.沙棘籽油的碘价为156.30mg/100g,酸价为8.80mg KOH/g,皂化值为186.30mg KOH/g,水分及挥发物0.22%,过氧化值为9.21meq/kg,不皂化物含量为1.89%.%Extraction conditions of seabuckthom seed oil with mixed solvents were optimized with response surface methods (RSM) and physiochemical properties of crude oil were analysed. The optimum conditions were as follows: ratios of solid to liquid 1:14, grinding size 35.00 mesh,mixed solvent as nhexane to acetone 6:4, extraction temperature 44.00℃ and extraction time 1.84h. The extraction rate of seabuckthorn seed oil was 13.788% under the optimum conditions. The iodine value, acid value ( AV ) and saponification value of seabuckthorn seed oil were 156. 30mg/100g, 8.80g KOH/g and 186. 30mg KOH/g, respectively. And the water volatiles, peroxide value and unsaponifiable value were 0.22%, 9.21meq/kg, and 1.89%, respectively.

  16. Phase behavior of mixtures of polyoxyethylene(10) stearyl ether (Brij-76), 1-butanol, isooctane, and mixed polar solvents I. Water and formamide (or N,N-dimethyl formamide).

    Science.gov (United States)

    Nandy, Debdurlav; Mitra, Rajib K; Paul, Bidyut K

    2006-08-01

    The isothermal phase diagram of the quaternary system polyoxyethylene(10) stearyl ether (Brij-76)/1-butanol/isooctane/water has been constructed at 30 degrees C with equal amounts of oil and water. A regular fishtail diagram was obtained, confirming the establishment of hydrophile-lipophile balance (HLB) in the system. Mixing of formamide (FA) [or N,N-dimethyl formamide (DMF)] with water as a cosolvent altered the HLB and decreased the solubilization capacity of the quaternary system. No three-phase body appeared at high FA or DMF content. Similar observations were noted for temperature-induced phase diagrams. The effect of DMF was more pronounced than that of FA in reducing the maximum solubilization capacity. The results have been summarized on the basis of HLB and mutual solubility of the components.

  17. Polymorphism and thermodynamic of azihromycin in mixed water-ethanol solvent%水/乙醇溶剂中阿奇霉素的热力学及多晶型研究

    Institute of Scientific and Technical Information of China (English)

    陈晓春; 黄小权; 陈长保; 付天松

    2014-01-01

    在278�2~308�2 K温度范围内,测定阿奇霉素在水/乙醇混合溶剂中的溶解度,根据固液平衡理论建立了该体系的溶解度修正模型。采用X线粉末衍射法和差示扫描量热法,对阿奇霉素在不同温度、不同体积比的水/乙醇混合溶剂中得到的晶体进行鉴别。同时利用溶解度数据估算了阿奇霉素在水/乙醇体系中的溶解热(-25�26~-16�11 kJ/mol)、混合热(9�94~3�25 kJ/mol)。通过溶液化学理论推导了阿奇霉素溶剂化平衡常数K与活度系数γ2的方程:γ2=1/(1+ K),建立了溶剂化焓与温度、水/乙醇两者体积比(φ)之间的关系式,为ΔH =RTln(17�86exp(3�4φ)-1)。采用溶析结晶方法得到的6种阿奇霉素晶体,均属单斜晶系,但具有不同的晶胞参数且其密度和熔点也不同。同时发现温度越高,水/乙醇体积比越大,得到的晶体稳定性越差(晶体的熔点和密度降低)。在水/乙醇混合溶剂的溶析结晶体系中,产生阿齐霉素多晶型的现象与溶剂化作用的强弱有关。%The solubility of azithromycin in water⁃ethanol solvent was measured by the static method between 278�2 and 308�2 K�A modified general solubility model was established based on the solid⁃liquid equilibrium theory�The polymorphs of azithromycin prepared in the mixed solvent with different ratio of water to ethanol under different temperatures were identified by X⁃ray diffraction ( XRD ) and differential scanning calorimetry( DSC)�The dissolution heat (-25�26⁃-16�11 kJ/mol) and the mixing heat (-9�94⁃-3�25 kJ/mol ) of azithromycin were estimated from the solubility experimental data�The relationship between the activity coefficientγ2 and the solvation constant K of azithromycin was deduced as follows:γ2 =1/(1 +K) . An expression correlating the solvation enthalpy with the temperature and the volume

  18. 均三甲苯/二异丁基甲醇混合溶剂黏度测定及关联%Measurement and correlation of viscosities of mixed solvents 1,3,5-trimethylbenzene and diisobutylcarbinol

    Institute of Scientific and Technical Information of China (English)

    张蓉蓉; 窦茂斌; 袁恩先; 李海静; 王莅

    2015-01-01

    采用乌氏黏度仪,在常压和 293.15~323.15 K 温度范围内测定了均三甲苯与二异丁基甲醇混合溶剂以及两种纯溶剂的黏度,计算了不同温度和组成下混合溶剂的超额黏度.用 Redlich-Kister 方程对超额黏度进行了关联;用 Andrade 方程、UNIFA-VISCO 模型以及 Grunberg-Nissan 模型对黏度进行了关联与预测.结果表明,混合溶剂的黏度随温度升高和均三甲苯含量增加而减小.超额黏度均为负值,且随均三甲苯含量增加呈 U 形变化,约在均三甲苯摩尔分数为 0.3 时达到最低.Grunberg-Nissan 模型对黏度数据的关联和预测性最好,预测值与实测值的最大和平均相对偏差分别为 12.96%和 5.74%.%The viscosities of mixed solvents consisted of 1,3,5-trimethylbenzene (TMB) and diisobutylcarbinol (DIBC) were determined at temperature ranging from 293.15 to 323.15 K and atmospheric pressure for the whole range of compositions by using viscometer. The excess molar viscosities of the mixed solvents were calculated and correlated by Redlich-Kister equation. The viscosities of the mixtures were correlated and predicted by Andrade equation, UNIFA-VISCO model, and Grunberg-Nissan model. The viscosities of the mixtures decreased with the increase of temperature and molar fraction of TMB. The excess viscosities showed negative deviations from ideal behavior, gave U-shaped curves as the molar fraction of TMB (x1) increased, and reached the minimum values at ca x1=0.3. The Grunberg-Nissan model was quite reasonable with the maximum and average relative errors between predicted and experimental data of 12.96% and 5.74%.

  19. Microwave -assisted Synthesis Calcium Carbonate in Water/Ethylene Glycol Mixed Solvents%水/乙二醇混合溶剂中微波辅助合成碳酸钙

    Institute of Scientific and Technical Information of China (English)

    孙新园; 张群; 陈敏; 潘玉锁

    2012-01-01

    在水/乙二醇混合溶剂中,通过微波辅助加热的方法,研究溶液过饱和度对碳酸钙成核生长的影响。分别采用扫描电子显微镜(SEM)、X-射线粉末衍射(XRD)对所得的样品进行了表征。结果表明,过饱和度的改变对碳酸钙形貌和晶型具有非常明显的影响,分别获得了菱面体状方解石、纤维捆扎状文石、松树枝状球霰石为主体的碳酸钙晶体。%In this paper, the influence of diffident supersaturations of the bulk solution on the nucleation and crystal growth of calcium carbonate is studied through the method of microwave - assisted beating in water/ethylene glycol mixed solvents. The ob- tained crystals are characterized by scanning electron microscopy (SEM) and X -ray diffraction (XRD). The resuh shows that the morphologies and polymorphs are obvious varied from rhombohedron calcite, fiber strapping aragonite to pine - dendritic vater- ite with the changes of supersaturations.

  20. Distribution of multi-component solvents in solvent vapor extraction chamber

    Energy Technology Data Exchange (ETDEWEB)

    Das, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Marathon Oil Corp., Houston, TX (United States)

    2008-10-15

    Vapex process performance is sensitive to operating pressures, temperatures and the types of solvent used. The hydrocarbon solvents used in Vapex processes typically have between 5 and 10 per cent hydrocarbon impurities, and the accumulation of dense phases inside the vapor chamber reduces gravity drainage potential. This study investigated the partitioning of solvent compounds inside the vapor chamber during in situ Vapex processes.The aim of the study was to examine how the different components of the mixed solvent partitioned inside the extracted chamber during the oil and vapor phase. A 2-D homogenous reservoir model was used to simulate the Vapex process with a solvent mixture comprised of propane and methane at various percentages. The effect of injecting a hot solvent vapor was also investigated. The study showed that injected methane accumulated at both the top and the extraction interface. Accumulations near the top had a positive impact on solvent confinement in thin reservoirs. Diffusion of the solvent component was controlled by gas phase molecular diffusion, and was much faster than the diffusion of solvent molecules in the liquid phase. The use of hot solvent mixtures slowed the extraction process due to lower solvent solubility in the oil phase. It was concluded that the negative impact on viscosity reduction by dilution was not compensated by rises in temperature. 6 refs., 11 figs.

  1. Miscellaneous hydrocarbon solvents.

    Science.gov (United States)

    Bebarta, Vikhyat; DeWitt, Christopher

    2004-08-01

    The solvents discussed in this article are common solvents not categorized as halogenated, aromatic, or botanical. The solvents discussed are categorized into two groups: hydrocarbon mixtures and single agents. The hydrocarbon mixtures discussed are Stoddard solvent, naphtha, and kerosene. The remaining solvents described are n-hexane, methyl n-butyl ketone, dimethylformamide, dimethyl sulfoxide, and butyl mercaptans. Effects common to this group of agents and their unique effects are characterized. Treatment of exposures and toxic effects of these solvents is described, and physiochemical properties and occupational exposure levels are listed.

  2. Solvent resistant nanofiltration membranes

    OpenAIRE

    Dutczak, S.M.

    2011-01-01

    This thesis describes preparation and characterization of membranes for organic solvent filtration (OSF). The main aim was developing membranes for solvent resistant nanofiltration (SRNF) with molecular weight cut-off below 500 g mol-1.

  3. Solvents in novolak synthesis

    Science.gov (United States)

    Sobodacha, Chet J.; Lynch, Thomas J.; Durham, Dana L.; Paradis, Valerie R.

    1993-09-01

    Novolac resins may be prepared with or without a solvent present. We have found that solvent power greatly affects the properties of the finished resin and thus gives the resist chemist another variable with which to `fine-tune' resist properties. Using designed experiments, we investigated the effect of solvent power, as measured by Hansen's Solubility Parameters, of a number of solvents and solvent mixtures on the final properties of the novolac resin. We found that the relative molecular weight (RMW) and dissolution rate of a novolac resin can be varied by selection of a solvent or solvent mixture with the appropriate polarity and hydrogen- bonding characteristics. The solvent polarity and hydrogen-bonding characteristics may affect the stability of the cresol/formaldehyde transition state, thus causing the observed changes in RMW and dissolution rate.

  4. EFFECT OF MIXED SOLVENT AND CONCENTRATION ON FLUORESCENCE EMISSION OF SULFONATED POLYSTYRENE%混合溶剂及浓度对磺化聚苯乙烯荧光光谱的影响

    Institute of Scientific and Technical Information of China (English)

    廖正福; 陈旭东; 李新平

    2000-01-01

    Fluorescence of sulfonated polystyrene(SPS) in dichloroethane(DCE) and mixed solvents was measured as a function of polymer concentration. Fluorescence of SPS in the mixture of toluene and methanol showed cosolvent behavior, as a function of methanol composition. It was found that two emission bands in dilute solution appeared at around 285nm and 335nm, corresponding to the monomer and excimer bands, respectively.The excimer emission peaks take a red shift with the increase of concentration. The emission band, except monomer and excimer emission, centered at around 380nm, was assigned to "excimer-like" emission. The "excimer-like" emission of SPS solution was interpreted as a consequence of excitation of dimer formed in the ground states in concentrated solution and migration of excitation energy to the excited dimer sites from the excited chromophore and excimer.%测定了磺化聚苯乙烯(SPS)在二氯乙烷及混合溶剂中的荧光光谱.在甲苯/甲醇混合溶剂中,SPS的荧光光谱随甲醇含量变化显示共溶性行为.在稀溶液中,分别在285nm和335nm附近出现两个发射带,它们分别对应于单体和激基缔合物谱带.随浓度增高,激基缔合物发射峰出现红移现象,除了单体和激基缔合物发射峰外,在380nm处出现一个"类激基缔合物"发射峰.SPS溶液中的"类激基缔合物"荧光发射峰源于在浓溶液中生色团形成的的二缔合物的激发以及激发能从激发的生色团和激基缔合物迁移到激发的生色团二缔合物上的结果.

  5. Solvent abuse: a review.

    Science.gov (United States)

    Barnes, G E

    1979-01-01

    The literature on solvent abuse is reviewed. Methods of use, symptoms of use, and effects of long-term solvent abuse are discussed. Several surveys on solvent use are summarized. The highest prevalence of solvent abuse seems to occur in native peoples undergoing periods of cultural change. Environmental conditions which are postulated as leading to psychological vulnerability and solvent abuse include: low social assets, parental drug use, peer and sibling influence, and acculturative stress. Solvent abuse seems to provide a pharmacological way out of a stressful environment for people who feel helpless to improve their situation in other ways. Methods of intervention that have been proposed for dealing with solvent abuse are discussed. Methods of intervention thus far employed generally have not been evaluated in any systematic fashion. Suggestions for future research are provided.

  6. PREDISPERSED SOLVENT EXTRACTION──THE STATE-OF-THE-ART REVIEW

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    IntroductionPredispersed solvent extraction (PDSE) differsfrom conventional solvent extraction in three ways:the organic phase is processed into a polyaphron phase,the mixing-settling stage is avoided, and the volumeratio of extracting solvent to the solution to beseparated can be as small as one to a thousandth oreven loweL In liquid-liquid solvent extraction, one ofthe methods to intensify the interfacial mass transfer isto increase the interfacial area. This can be achievedby converting the solvent into ...

  7. Solvent-Free Synthesis of Chalcones

    Science.gov (United States)

    Palleros, Daniel R.

    2004-01-01

    The synthesis of twenty different chalcones in the absence of solvent is presented. The results indicated that out of the twenty different chalcones investigated seventeen can be obtained in a matter of minutes by mixing the corresponding benzaldehyde and acetophenone in the presence of solid NaOH in a mortar with pestle.

  8. Reactivity trends of hydroxide ion attack on high spin Fe(II complexes including bromosalicylidene amino acid ligands in some mixed aqueous solvents: Gibb’s Free Energy of Transfer and initial-transition state analysis

    Directory of Open Access Journals (Sweden)

    Laila H. Abdel-Rahman

    2017-05-01

    Full Text Available The kinetics of hydroxide ion attack on bis(bromosalicylidene alanateiron (II (bsali, bis(bromosalicylidene phenylalanateiron(II (bsphali, bis(bromosalicylidene aspartateiron(II (bsasi, (bromosalicylidene histidinateiron(II (bshi, bis(bromosalicylidene arginateiron(II (bsari have been reported in different binary aqueous solvent mixtures at 298 K. The observed reactivity trends are discussed in terms of the hydrophilic and hydrophobic forms of the complexes investigated, as well as the transfer chemical potentials of hydroxide ion and the complex. Both the solvent–solute and solvent–solvent interactions have been considered. The hydrophobic character of the complexes studied was manifested by decreasing in reactivity. Solvent effect on reactivity trends of the investigated complexes has been analyzed into initial and transition state components by using the transfer chemical potentials of the reactants and the kinetic data of the studied compounds. The decrease in the observed rate constant values (kobs of the base hydrolysis of the investigated complexes with increasing of solvent % is dominated by the initial state (IS.

  9. Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi

    2005-01-01

    A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

  10. Alternative Green Solvents Project

    Science.gov (United States)

    Maloney, Phillip R.

    2012-01-01

    Necessary for safe and proper functioning of equipment. Mainly halogenated solvents. Tetrachloride, Trichloroethylene (TCE), CFC-113. No longer used due to regulatory/safety concerns. Precision Cleaning at KSC: Small % of total parts. Used for liquid oxygen (LOX) systems. Dual solvent process. Vertrel MCA (decafluoropentane (DFP) and trons-dichloroethylene) HFE-7100. DFP has long term environmental concerns. Project Goals: a) Identify potential replacements. b) 22 wet chemical processes. c) 3 alternative processes. d) Develop test procedures. e) Contamination and cleaning. f) Analysis. g) Use results to recommend alternative processes. Conclusions: a) No alternative matched Vertrel in this study. b) No clear second place solvent. c) Hydrocarbons- easy; Fluorinated greases- difficult. d) Fluorinated component may be needed in replacement solvent. e) Process may need to make up for shortcoming of the solvent. f) Plasma and SCC02 warrant further testing.

  11. Factors affecting high-pressure solvent extraction (accelerated solvent extraction) of additives from polymers.

    Science.gov (United States)

    Vandenburg, H J; Clifford, A A; Bartle, K D; Zhu, S A; Carroll, J; Newton, I D; Garden, L M

    1998-05-01

    Irganox 1010 (pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)] propionate) is successfully extracted from polypropylene using solvents at high temperatures and pressures in a homemade accelerated solvent extraction system. For example, using freeze-ground polymer, 90% extraction is possible within 5 min with 2-propanol at 150 °C. Extraction curves for 2-propanol and acetone fit well to the "hot ball" model, previously developed for supercritical fluid extraction. Diffusion coefficients are determined for extractions with 2-propanol, acetone, and cyclohexane over a range of temperatures, and the activation energies for the diffusion are 134, 107, and 61 kJ mol(-)(1), respectively. The lower figure for acetone and cyclohexane indicates that these solvents swell the polymer more than does 2-propanol. The polymer dissolves in the solvent at too high a temperature, which causes blockage of the transfer lines. For maximum extraction rates, the highest temperature for each solvent that avoids dissolution of the polymer should be used. The use of mixed solvents is investigated and shows advantages in some cases, with the aim of producing a solvent that will swell the polymer but not dissolve it.

  12. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ..., Mineral Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic Hydrocarbons...

  13. Supercritical solvent coal extraction

    Science.gov (United States)

    Compton, L. E. (Inventor)

    1984-01-01

    Yields of soluble organic extract are increased up to about 50% by the supercritical extraction of particulate coal at a temperature below the polymerization temperature for coal extract fragments (450 C.) and a pressure from 500 psig to 5,000 psig by the conjoint use of a solvent mixture containing a low volatility, high critical temperature coal dissolution catalyst such as phenanthrene and a high volatility, low critical temperature solvent such as toluene.

  14. Cleaning without chlorinated solvents

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.M.; Simandl, R.F.

    1994-12-31

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

  15. Solvent selection methodology for pharmaceutical processes: Solvent swap

    DEFF Research Database (Denmark)

    Papadakis, Emmanouil; Kumar Tula, Anjan; Gani, Rafiqul

    2016-01-01

    A method for the selection of appropriate solvents for the solvent swap task in pharmaceutical processes has been developed. This solvent swap method is based on the solvent selection method of Gani et al. (2006) and considers additional selection criteria such as boiling point difference, volati...

  16. 异丙醇-环己烷混合溶剂浸出菜籽饼溶剂的分离回收工艺研究%Separation and recovery of mixed solvents from rapeseed cake leached by isopropanol and cyclohexane

    Institute of Scientific and Technical Information of China (English)

    刘大良; 张韩芳; 魏冰; 杨帆; 孟橘

    2013-01-01

    On the basis of oil extraction from rapeseed cake by mixed solvents of isopropanol and cyclohexane, extraction conditions of rapeseed cake, removal of impurities (polysaccharide) from miscella, separation and recovery of mixed solvents and desolventizing of wet meal and miscella were studied. The optimal conditions were obtained as follows:moisture content of rapeseed cake less than 10% ,leaching temperature 62℃,ratio of liquid to solid 3:1,mixed solvents 95% isopropanol and cyclohexane(3:1) , washing temperature of miscella 60℃, dosage of hot water 0.8-1 times of 95% isopropanol,evaporation temperature of isopropanol water solution 100℃, mass fraction of potassium carbonate solution in salting -out extraction 50% , volume ratio of 50% potassium carbonate solution to 95% isopropanol 2:1 and evaporation temperature of potassium carbonate solution 59℃under vacuum of 0.095 MPa.%在异丙醇-环己烷混合溶剂浸出菜籽饼工艺研究的基础上,进一步对浸出菜籽饼的浸出条件、混合油中多糖类杂质的脱除、混合溶剂的分离回收、湿粕的脱溶、混合油的脱溶等进行研究.得出适宜的工艺条件为:菜籽饼水分含量小于10%,浸出温度62℃,液料比3∶1,浸出溶剂95%异丙醇-环己烷(3∶1);混合油水洗温度60℃,热水加入量0.8~1倍95%异丙醇;异丙醇水溶液蒸发温度100℃,盐效萃取中碳酸钾溶液的质量分数50%,50%碳酸钾溶液与95%异丙醇体积比2∶1;碳酸钾溶液的蒸发温度59℃,真空度0.095 MPa.

  17. Purex process solvent: literature review

    Energy Technology Data Exchange (ETDEWEB)

    Geier, R.G.

    1979-10-01

    This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables.

  18. Effects of mixed solvent on the properties of polyurethane dispersion prepared by prepolymer method%混合溶剂对预聚体法聚氨酯分散液性能的影响

    Institute of Scientific and Technical Information of China (English)

    王海花; 何凤; 费贵强; 王成俊

    2014-01-01

    The single solvent and any two solvents among AC ,DMF and NMP were selected as co-solvent in the process of polyurethane preparation .And a series of polyurethane disper-sions were prepared through prepolymer method with toluene diisocyanate (TDI) ,polycapro-lactone glycol (PCL) and dimethylol propionic acid (DMPA) as reaction monomer .Effects of solvent on the particle size of dispersion ,the mechanical properties and water resistance of films were discussed .In addition ,the polyurethane dispersion was utilized as surface sizing a-gent ,and the properties of sized paper were investigated .It was found that the polyurethane dispersion prepared with 67% DMF and 33% AC presented minimum particle size .The polyu-rethane film prepared with 100% AC displayed the highest tensile strength ,and the polyure-thane film prepared with 50% AC and 50% NMP displayed the highest elongation at break . The polyurethane film prepared with 100% NMP showed the lowest water absorption .The paper sized with polyurethane prepared by 50% NMP and 50% DMF was endowed with the highest wet strength .The paper sized with polyurethane prepared by 50% AC and 50% DMF had the highest ring crush index .The paper sized with polyurethane prepared the by 100%NM P displayed the highest folding strength .%将丙酮(AC)、N,N-二甲基甲酰胺(DMF)和N-甲基吡咯烷酮(NMP)中的任意两种按不同比例进行混合,作为有机助溶剂,以甲苯二异氰酸酯(TDI),聚己内酯二元醇(PCL)和二羟甲基丙酸(DMPA)为反应原料,通过预聚体法制备了系列水性聚氨酯分散液。并研究了混合溶剂对分散液粒径、胶膜机械性能和吸水率的影响,又将聚氨酯分散液用作纸张表面施胶剂,分析了其对纸张性能的影响。实验结果表明:由67%DMF和33%AC混合溶剂所制备的分散液平均粒径最小;以100%AC所制胶膜的拉伸强度最大,50%AC和50%NMP混合溶剂所制胶膜

  19. Predicting the Solution Morphology of a Sulfonated Pentablock Copolymer in an Arbitrary Solvent Mixture

    Science.gov (United States)

    Ford, Jamie; Kyei-Manu, William; Winey, Karen

    2013-03-01

    Block copolymers self assemble into a wide array of morphologies in solvents. To predict the solution morphology of the polymer, we assess the interactions between the individual blocks and the solvent or solvents. Here, we use the Hansen solubility parameters to calculate the interactions between a library of solvents and an ABCBA pentablock copolymer with non-polar A and B blocks and a polar, sulfonated C block to predict the expected morphology for a given solvent and compare it to our small-angle X-ray scattering data. In non-polar solvents, we observe micelles with a C core and an A-B corona. We observe inverted micelles in polar solvents - an A-B core with a C corona. We extended our methodology to mixed polar/non-polar solvent systems to predict the solvent ratios corresponding to the transition from micelles to inverted micelles.

  20. Halogenated solvent remediation

    Science.gov (United States)

    Sorenson, Kent S.

    2004-08-31

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. A preferred method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof. Especially preferred compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the composition.

  1. Safe battery solvents

    Science.gov (United States)

    Harrup, Mason K.; Delmastro, Joseph R.; Stewart, Frederick F.; Luther, Thomas A.

    2007-10-23

    An ion transporting solvent maintains very low vapor pressure, contains flame retarding elements, and is nontoxic. The solvent in combination with common battery electrolyte salts can be used to replace the current carbonate electrolyte solution, creating a safer battery. It can also be used in combination with polymer gels or solid polymer electrolytes to produce polymer batteries with enhanced conductivity characteristics. The solvents may comprise a class of cyclic and acyclic low molecular weight phosphazenes compounds, comprising repeating phosphorus and nitrogen units forming a core backbone and ion-carrying pendent groups bound to the phosphorus. In preferred embodiments, the cyclic phosphazene comprises at least 3 phosphorus and nitrogen units, and the pendent groups are polyethers, polythioethers, polyether/polythioethers or any combination thereof, and/or other groups preferably comprising other atoms from Group 6B of the periodic table of elements.

  2. 喜树碱在二甲亚砜和甲醇(或乙醇)混合溶剂中溶解度的测定和关联%Measurement and Correlation of Camptothecine Solubility in Dimethylsulfoxide-Methanol/Ethanol Mixed Solvents

    Institute of Scientific and Technical Information of China (English)

    支娟娟; 徐家阔; 刘琼; 李涛; 任保增

    2016-01-01

    Camptothecine solubility in dimethylsulfoxide-methanol/ethanol mixed solvents was measured over temperature range of 274.50~326.00 K under atmospheric pressure. The experimental results show that the solubility of camptothecine in the mixed solvents increases with the increase of temperature and dimethylsulfoxide mole fraction. The experimental solubility data are well correlated with a modified Apelblat equation, λh equation and ideal equation, respectively. The Akaike’s Information Criterion (AIC) was used to select the best model for correlation. The dissolution enthalpy, entropy and Gibbs free energy change of camptothecine are calculated using the measured solubility.%采用重量法测定了喜树碱(camptothecine,CPT)在二甲亚砜(dimethylsulfoxide, DMSO)+甲醇(或乙醇)混合溶剂中的溶解度,温度范围是274.50~326.00 K。在混合溶剂中CPT的溶解度随温度的升高而增大,随混合溶剂中DMSO摩尔分数含量的增大而增大。分别用修正Apelblat方程、λh方程和理想状态方程进行关联,关联效果令人满意,获得了相关模型参数。相对而言,λh方程关联的效果较好。根据溶解度数据和修正的Apelblat方程计算出溶解焓、溶解熵和吉布斯自由能。

  3. Preparation of membranes using solvent-less vapor deposition followed by in-situ polymerization

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Kevin C [San Ramon, CA; Letts, Stephan A [San Ramon, CA; Spadaccini, Christopher M [Oakland, CA; Morse, Jeffrey C [Pleasant Hill, CA; Buckley, Steven R [Modesto, CA; Fischer, Larry E [Los Gatos, CA; Wilson, Keith B [San Ramon, CA

    2012-01-24

    A system of fabricating a composite membrane from a membrane substrate using solvent-less vapor deposition followed by in-situ polymerization. A first monomer and a second monomer are directed into a mixing chamber in a deposition chamber. The first monomer and the second monomer are mixed in the mixing chamber providing a mixed first monomer and second monomer. The mixed first monomer and second monomer are solvent-less vapor deposited onto the membrane substrate in the deposition chamber. The membrane substrate and the mixed first monomer and second monomer are heated to produce in-situ polymerization and provide the composite membrane.

  4. Preparation of membranes using solvent-less vapor deposition followed by in-situ polymerization

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Kevin C [San Ramon, CA; Letts, Stephan A [San Ramon, CA; Spadaccini, Christopher M [Oakland, CA; Morse, Jeffrey C [Pleasant Hill, CA; Buckley, Steven R [Modesto, CA; Fischer, Larry E [Los Gatos, CA; Wilson, Keith B [San Ramon, CA

    2010-07-13

    A system of fabricating a composite membrane from a membrane substrate using solvent-less vapor deposition followed by in-situ polymerization. A first monomer and a second monomer are directed into a mixing chamber in a deposition chamber. The first monomer and the second monomer are mixed in the mixing chamber providing a mixed first monomer and second monomer. The mixed first monomer and second monomer are solvent-less vapor deposited onto the membrane substrate in the deposition chamber. The membrane substrate and the mixed first monomer and second monomer are heated to produce in-situ polymerization and provide the composite membrane.

  5. Biodiesel production from ethanolysis of palm oil using deep eutectic solvent (DES) as co-solvent

    Science.gov (United States)

    Manurung, R.; Winarta, A.; Taslim; Indra, L.

    2017-06-01

    Biodiesel produced from ethanolysis is more renewable and have better properties (higher oxidation stability, lower cloud and pour point) compared to methanolysis, but it has a disadvantage such as complicated purification. To improve ethanolysis process, deep eutectic solvent (DES) can be prepared from choline chloride and glycerol and used as co-solvent in ethanolysis. The deep eutectic solvent is formed from a quaternary ammonium salt (choline chloride) and a hydrogen bond donor (Glycerol), it is a non-toxic, biodegradable solvent compared to a conventional volatile organic solvent such as hexane. The deep eutectic solvent is prepared by mixing choline chloride and glycerol with molar ratio 1:2 at temperature 80 °C, stirring speed 300 rpm for 1 hour. The DES is characterized by its density and viscosity. The ethanolysis is performed at a reaction temperature of 70 °C, ethanol to oil molar ratio of 9:1, potassium hydroxide as catalyst concentration of 1.2 wt. DES as co-solvent with concentration 0.5 to 3 wt. stirring speed 400 rpm, and a reaction time 1 hour. The obtained biodiesel is then characterized by its density, viscosity, and ester content. The oil - ethanol phase condition is observed in the reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to without DES, showed that oil and ethanol become more slightly miscible, which favors the reaction. Using DES as co-solvent in ethanolysis showed increasing in yield and easier purification. The esters properties meet the international standards ASTM D6751, with the highest yield achieved 83,67 with 99,77 conversion at DES concentration 2 . Increasing DES concentration above 2 in ethanolysis decrease the conversion and yield, because of the excessive glycerol in the systems makes the reaction equilibrium moves to the reactant side.

  6. Antioxidative Polyphenols from Defatted Oilseed Cakes: Effect of Solvents

    OpenAIRE

    Sue-Siang Teh; Alaa El-Din Bekhit; John Birch

    2014-01-01

    Defatted hemp, flax and canola seed cakes were extracted with different solvent systems namely methanol, ethanol, acetone, methanol 80%, acetone 80% and mixed solvent of methanol:acetone:water (MAW, 7:7:6, v/v/v). Each extract was analyzed for antioxidant capacity using ferric reducing/antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. MAW exhibited the highest extraction of phenolic and flavonoid contents in the seed cakes, followed by acetone 80% an...

  7. Luminescence of Au(I)-thiolate complex affected by solvent

    Science.gov (United States)

    Yang, Lina; Cao, Yuanjie; Chen, Juan; Sun, Zhihu; Yao, Tao; Jiang, Yong; Wei, Shiqiang

    2017-08-01

    This work presents a study on the correlation between luminescence property of Au(I)-SR (SR: thiolate) complexes and solvent polarity. Luminescent [Au15(SR)14-16]+ complexes were synthesized in the weakly polar solvent of toluene, while the non-luminescent [Au7(SR)6]+ species were obtained by the same synthesis method in the polar solvent of ethanol. The dependence of luminescence intensity on the mixed solvent with various toluene/ethanol ratios was also explored. It is proposed that the luminescence of Au(I)-SR complexes originates from the aggregation of the bilayer supramolecular structures induced by the weakly polar solvent. This aggregation strengthens the intra and intercomplex aurophilic Au(I)···Au(I) interactions and subsequently enhances the luminescence intensity of the complexes.

  8. GC/MS ANALYSIS OF DATONG RAW AND OXIDIZED COAL EXTRACT USING METHANOL/TETRAHYDROFURAN MIXED SOLVENT%用GC/MS分析研究大同原煤及氧化煤的甲醇/四氢呋喃萃取物

    Institute of Scientific and Technical Information of China (English)

    刘振学; 宗志敏; 魏贤勇

    2003-01-01

    为了研究氧化对煤样萃取性能的影响,先将大同煤破碎到200目并在105℃干燥,然后在温和条件下用双氧水进行氧化.将原煤和氧化煤在超声辐射下用甲醇/四氢呋喃(THF)混合溶剂进行萃取,并用GC/MS进行分析测定.结果发现,在两种甲醇/THF配比下,氧化煤的萃取率均高于原煤;而且随着萃取剂中THF浓度的提高,萃取率增大;从GC/MS测定结果看,四种萃取物的组成各不相同,显示氧化和萃取剂中THF含量的变化均能改变萃取物的化学组成,但四种萃取物中检测出的化合物均以烃类为主.另外,煤粉通过与萃取物和溶剂形成胶体而悬浮于上层清夜中,因此,超声条件下对煤进行萃取时必须过滤.%Datong coal was pulverized to 0.074mm and dried at 105*#℃, then oxidized with hydrogen peroxide under mild condition. Both raw and oxidized coal were extracted with methanol/tetrahydrofuran (THF) mixed solvents under ultrasonic irradiation, then the extracts were analyzed by GC/MS so as to study the difference of extracting between raw and oxidized coal. The result indicates that the extraction yields of oxidized coal were higher than those of raw coal at the test conditions and the extraction yield increased with increasing THF concentration. The components of the four extracts were different from each other, indicating that chemical components of extracts can be changed by both oxidation and THF content in mixed solvent. But the compounds in all the four extracts were mainly hydrocarbons. In addition, coal particles were supernatant through formation of coal powder-extract-solvent colloid, therefore, filtration must be taken in coal extraction under ultrasonic irradiation.

  9. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    1999-05-13

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

  10. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, W.L.

    1998-04-30

    This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel.

  11. Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Vasdekis, Andreas E.; Wilkins, Michael J.; Grate, Jay W.; Kelly, Ryan T.; Konopka, Allan; Xantheas, Sotiris S.; Chang, M. T.

    2014-06-21

    The mechanism of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally brought into contact with a non-modified surface to permanently bond. The underlying polymer-solvent interactions were experimentally and theoretically investigated, and enabled rapid polymer microsystem prototyping. During imprinting, small molecule integration in the molded surfaces was feasible, a principle applied to oxygen sensing. Polystyrene (PS) was employed for microbiological studies at extreme environmental conditions. The thermophile anaerobe Clostridium Thermocellum was grown in PS pore-scale micromodels, revealing a double mean generation lifetime than under ideal culture conditions. Microsystem prototyping through directed polymer dissolution is simple and accessible, while simultaneous patterning, bonding, and surface/volume functionalization are possible in less than one minute.

  12. Role of solvent/non-solvent ratio on microsphere formation using the solvent removal method.

    Science.gov (United States)

    Godbee, J; Scott, E; Pattamunuch, P; Chen, S; Mathiowitz, E

    2004-03-01

    The importance of good solvent concentration in the non-solvent mixture and the non-solvent viscosity on the ability to form microspheres using solvent removal process was investigated. The higher the viscosity of the polymer solutions, the higher the concentration of good solvent needed in the nonsolvent mixture to produce microspheres. This finding was due to faster precipitation of the polymer phase. Also, the addition of a model drug, fluorescein isothiocyanate conjugated-labelled bovine serum albumin, to the polymer solution (10% poly-L-lactic acid:poly(fumaric-co-sebacic) anhydride in methylene chloride) resulted in an overall lower polymer solution viscosity (15.5 cP with fluorescein isothiocyanate conjugated-labelled bovine serum albumin as compared with 18.25 cP for blank polymer at 25 degrees C). Additionally, the effect of good solvent concentration on non-solvent viscosity was evaluated, and the viscosity decreased as the concentration of good solvent increased. The effect of good solvent concentration on the non-solvent mixture on sphere formation was of great importance. Microspheres would not form when the good polymer solvent (methylene chloride) in the non-solvent phase was too low (below 175 ml for poly-L-lactic acid or 150 ml for poly(D,L-lactidco-glycolid)) or was replaced by another good solvent such as ethyl acetate, even though the same viscosity was achieved. It was shown that the concentration of the good solvent in the non-solvent mixture was more of a controlling factor than the viscosity of the non-solvent mixture in microsphere formation and the findings support the conclusion that diffusion is the main controlling parameter in solvent removal.

  13. Diamex solvent regeneration studies

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, C.; Cames, B.; Margot, L.; Ramain, L. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification, DRRV, 30 - Marcoule (France)

    2000-07-01

    The CEA has undertaken the development of the DIAMEX process as the first step in the strategy aiming at recovering minor actinides which could then be transmuted or separately conditioned. The scientific feasibility of this process was demonstrated during counter current hot tests operated in 1993. Then experimental works were conducted, on one hand to optimise the extractant formula, on the other hand to improve the flowsheet. Reference extractant and flowsheet were then chosen, respectively in 1995 and 1996. The next step, still in progress, is the demonstration of the DIAMEX technical feasibility (in 2002); this means that the flowsheet should include solvent regeneration treatments. In this aim, degradation studies were performed to quantify main degradation products, and identify those which could be disturbing in the process. This paper deals with experimental studies performed with intend to propose a regeneration treatment, included in the flowsheet, so that the solvent could be recycled. It comprises: - Quantification of the main degradation products issued from radiolysis or hydrolysis, which are methyl octyl amine (MOA) and carboxylic acids; - Effects of these products on extracting and hydrodynamics performances of the process; - Study of methods able to remove mainly disturbing degradation products. Acidic scrubbing, which are performed in the scrubbing and stripping sections of the DIAMEX process, should allow the quantitative removal of methyl octyl amine. Then basic scrubbings, which were more especially studied, should eliminate at least 80% of carboxylic acids, and part of the cations remaining in the solvent. (authors)

  14. High performance hydrophobic solvent, carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

    Nulwala, Hunaid; Luebke, David

    2017-05-09

    Methods and compositions useful, for example, for physical solvent carbon capture. A method comprising: contacting at least one first composition comprising carbon dioxide with at least one second composition to at least partially dissolve the carbon dioxide of the first composition in the second composition, wherein the second composition comprises at least one siloxane compound which is covalently modified with at least one non-siloxane group comprising at least one heteroatom. Polydimethylsiloxane (PDMS) materials and ethylene-glycol based materials have high carbon dioxide solubility but suffer from various problems. PDMS is hydrophobic but suffers from low selectivity. Ethylene-glycol based systems have good solubility and selectivity, but suffer from high affinity to water. Solvents were developed which keep the desired combinations of properties, and result in a simplified, overall process for carbon dioxide removal from a mixed gas stream.

  15. Occupational solvent exposure and cognition

    Science.gov (United States)

    Sabbath, E.L.; Glymour, M.M.; Berr, C.; Singh-Manoux, A.; Zins, M.; Goldberg, M.

    2012-01-01

    Objective: Chronic occupational solvent exposure is associated with long-term cognitive deficits. Cognitive reserve may protect solvent-exposed workers from cognitive impairment. We tested whether the association between chronic solvent exposure and cognition varied by educational attainment, a proxy for cognitive reserve. Methods: Data were drawn from a prospective cohort of French national gas and electricity (GAZEL) employees (n = 4,134). Lifetime exposure to 4 solvent types (chlorinated solvents, petroleum solvents, benzene, and nonbenzene aromatic solvents) was assessed using a validated job-exposure matrix. Education was dichotomized at less than secondary school or below. Cognitive impairment was defined as scoring below the 25th percentile on the Digit Symbol Substitution Test at mean age 59 (SD 2.8; 88% of participants were retired at testing). Log-binomial regression was used to model risk ratios (RRs) for poor cognition as predicted by solvent exposure, stratified by education and adjusted for sociodemographic and behavioral factors. Results: Solvent exposure rates were higher among less-educated patients. Within this group, there was a dose-response relationship between lifetime exposure to each solvent type and RR for poor cognition (e.g., for high exposure to benzene, RR = 1.24, 95% confidence interval 1.09–1.41), with significant linear trends (p < 0.05) in 3 out of 4 solvent types. Recency of solvent exposure also predicted worse cognition among less-educated patients. Among those with secondary education or higher, there was no significant or near-significant relationship between any quantification of solvent exposure and cognition. Conclusions: Solvent exposure is associated with poor cognition only among less-educated individuals. Higher cognitive reserve in the more-educated group may explain this finding. PMID:22641403

  16. Solvent effects in chemistry

    CERN Document Server

    Buncel, Erwin

    2015-01-01

    This book introduces the concepts, theory and experimental knowledge concerning solvent effects on the rate and equilibrium of chemical reactions of all kinds.  It begins with basic thermodynamics and kinetics, building on this foundation to demonstrate how a more detailed understanding of these effects may be used to aid in determination of reaction mechanisms, and to aid in planning syntheses. Consideration is given to theoretical calculations (quantum chemistry, molecular dynamics, etc.), to statistical methods (chemometrics), and to modern day concerns such as ""green"" chemistry, where ut

  17. Reactivities of Precision Cleaning Solvents with Hypergolic Propellants

    Science.gov (United States)

    Davis, Dennis D.; Delgado, Rafael H.; Williams, James H.

    1999-01-01

    The reactivities of several selected halogenated precision cleaning solvents with hypergolic propellants has been determined by analysis of the rates of formation of halide ion decomposition products. The solvents were Asahiklin AK 225, Asahiklin AK 225 AES, HFE 7100, HFE 7100 DE, Vertrel XF, Vertrel MCA, Vertrel MCA Plus, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and trans-1,2-dichloroethylene (DCE). The propellants were hydrazine (HZ), monomethylhydrazine (MMH), and mixed oxides of nitrogen (MON-3). The Vertrel solvents showed significant reactivity with HZ. All of the solvents except DCE exhibited significant reactivity with MMH, particularly HFE 7100 DE and CFC-113. HFE 7100 DE, Vertrel MCA, and Vertrel MCA Plus also showed significant reactivity with MON-3 oxidizer.

  18. 电位滴定法测定乙醇/水混合体系中松香酸的离解常数%The Determination of the Dissociation Constants of Abietic Acidin Ethanol/Water Mixed Solvent by Potentiometric Titration

    Institute of Scientific and Technical Information of China (English)

    南丹; 蒋丽丹; 王良贵

    2012-01-01

    采用电位滴定法,在乙醇/水混合溶剂体系(I=0.10mol/L,Kcl)测定了松香酸在不同乙醇含量(Ⅳ%)时的离解常数。结果表明,在试验范围内pK同乙醇含量的体积分数有良好线性关系,通过外推求得在试验条件下松香酸水溶液中的离解常数pK为4·937。%The dissociation constants of abietic acid in water- ethanol mixed solvent (I =0.10 mol/L, KC1) were determinded by potentiometric titration. The results showed that the pKa was a good linear function of the volume fraction of ethanol in the concentration range. The dissociation constants of abietic acid in water were determinded by extrapolation to be 4. 937 under the experimental conditions.

  19. 40 CFR Table 6 to Subpart Vvvv of... - Default Organic HAP Contents of Petroleum Solvent Groups

    Science.gov (United States)

    2010-07-01

    ... Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naptha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend.) 3 1% Xylene, 1% Toluene, and 1% Ethylbenzene. Aromatic (Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light...

  20. Effects of the toxicity of mineral oil and solvent emulsifier upon sea fishes

    OpenAIRE

    Mori, Koichiro; Masuda, Nobuto

    1982-01-01

    The solvent emulsifier does not solely exist in the sea water but in a state necessarily mixed with spilt oil. In the present experiment, therefore, we are going to discuse the effects of toxicity, respectively with fish and with mineral oil, through the observations of the fishes bred in the sea water containing mineral oils and solvent emulsifier.

  1. Control of Chemical Equilibrium by Solvent: A Basis for Teaching Physical Chemistry of Solutions

    Science.gov (United States)

    Prezhdo, Oleg V.; Craig, Colleen F.; Fialkov, Yuriy; Prezhdo, Victor V.

    2007-01-01

    The study demonstrates that the solvent present in a system can highly alter and control the chemical equilibrium of a system. The results show that the dipole moment and polarizibility of a system can be highly altered by using different mixed solvents.

  2. Enzymatic Synthesis of Esculin Ester in Ionic Liquids Buffered with Organic Solvents

    DEFF Research Database (Denmark)

    Hu, Yifan; Guo, Zheng; Lue, Bena-Marie

    2009-01-01

    The enzymatic esterification of esculin catalyzed by Candida antarctica lipase B (Novozym 435) was carried out in ionic liquid (IL)-organic solvent mixed systems in comparison with individual systems. The reaction behaviors in IL-organic solvents were systemically evaluated using acetone as a mod...

  3. BIOVENTING OF CHLORINATED SOLVENTS FOR GROUND-WATER CLEANUP THROUGH BIOREMEDIATION

    Science.gov (United States)

    Chlorinated solvents such as tetrachloroethylene, trichloroethylene, carbon tetrachloride, chloroform, 1,2-dichloroethane, and dichloromethane (methylene chloride) can exist in contaminated subsurface material as (1) the neat oil, (2) a component of a mixed oily waste, (3) a solu...

  4. Solubility of C60 in solvent mixtures.

    Science.gov (United States)

    Kulkarni, Pradnya P; Jafvert, Chad T

    2008-02-01

    The potential large-scale production of fullerene C60 and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C60 in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C60 including reactivity and toxicity, particularly when solvates occur in C60 clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C60 was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C60 was measured in mixtures of toluene-acetonitrile, toluene-ethanol, toluene-tetrahydrofuran, and acetonitrile-tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl's equation. The estimated crystal energy term for C60 in tetrahydrofuran was different than that in the other solvents, indicating that the C60 solid phase in equilibrium with tetrahydrofuran solution may be a solvated crystal.

  5. SOLVENT EXTRACTION OF URANIUM VALUES

    Science.gov (United States)

    Feder, H.M.; Ader, M.; Ross, L.E.

    1959-02-01

    A process is presented for extracting uranium salt from aqueous acidic solutions by organic solvent extraction. It consists in contacting the uranium bearing solution with a water immiscible dialkylacetamide having at least 8 carbon atoms in the molecule. Mentioned as a preferred extractant is dibutylacetamide. The organic solvent is usually used with a diluent such as kerosene or CCl/sub 4/.

  6. Supercritical multicomponent solvent coal extraction

    Science.gov (United States)

    Corcoran, W. H.; Fong, W. S.; Pichaichanarong, P.; Chan, P. C. F.; Lawson, D. D. (Inventor)

    1983-01-01

    The yield of organic extract from the supercritical extraction of coal with larger diameter organic solvents such as toluene is increased by use of a minor amount of from 0.1 to 10% by weight of a second solvent such as methanol having a molecular diameter significantly smaller than the average pore diameter of the coal.

  7. Selection and design of solvents

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    . With increasing interest on issues such as waste, sustainability, environmental impact and green chemistry, the selection and design of solvents have become important problems that need to be addressed during chemical product-process design and development. Systematic methods and tools suitable for selection......Solvents are liquid solutions consisting of one or more chemicals. They have a very wide use and their use is not necessarily restricted to the process industries. This lecture will discuss the different roles and uses of solvents in chemical products and processes that manufacture them...... and design of solvents will be presented together with application examples. The selection problem is defined as finding known chemicals that match the desired functions of a solvent for a specified set of applications. The design problem is defined as finding the molecular structure (or mixture of molecules...

  8. Solvent degradation products in nuclear fuel processing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Shook, H.E. Jr.

    1988-06-01

    The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

  9. Switchable Polarity Solvents: Are They Green?

    Science.gov (United States)

    Plaumann, Heinz

    2017-03-01

    Solvents play an incredibly important role in large scale chemical reactions. Switchable polarity solvents may prove to be a class of solvent that offers energy and material efficiencies greater than existing solvents. This paper examines such solvents and their potential in a variety of chemical reactions.

  10. Electrospinning of Polyvinylidene Fluoride and Polyetherimide From Mixed Solvents

    Science.gov (United States)

    Morgret, Leslie D.; Pawlowski, Kristin J.; Hinkley, Jeffrey A.

    2005-01-01

    Polyvinylidene fluoride and Ultem(TradeMark) polyetherimide were dissolved in 50/50 acetone/N,N dimethylformamide (DMF) and 80/20 tetrahydrofuran/DMF, respectively, and electrospun. Polymer solution concentrations and molecular weights were changed while other spinning parameters (voltage, distance, solution feed rate) were held constant. Fiber diameters in the resulting electrospun mats varied from 0.25 to 4.4 microns, increasing with polymer concentration and molecular weight; trends in diameter were compared with trends in viscosities and surface tensions of the spinning solutions.

  11. Synthesis of soluble conducting polymers by acoustic mixing

    Energy Technology Data Exchange (ETDEWEB)

    Kane, Marie C.

    2016-09-13

    A method including combining an aniline monomer, an oxidant, water and an organic solvent; subjecting the combination to acoustic mixing to form an emulsion; and recovering a polyaniliine from the combination. A method including combining a aniline monomer, an oxidant, water and an organic solvent; forming a polyaniline by acoustic mixing the combination; and recovering the polyaniliine from the combination. A method including forming a combination of an aniline monomer, an oxidant, water and an organic solvent in the absence of an emulsifier; acoustic mixing the combination for a time period to form a polyaniline; and recovering a polyaniliine from the combination.

  12. On Separating Molybdenum from Tungsten by Solvent Extraction with Mixed Extractant Using H2O2 as Complex Agent%混合萃取剂双氧水络合萃取分离钨钼的初步研究

    Institute of Scientific and Technical Information of China (English)

    欧惠; 张贵清; 关文娟; 肖连生

    2011-01-01

    This paper studies the separation of molybdenum from tungsten by solvent extraction using the hydrogen peroxide as complex agent from ammonium tungstate solution containing high molybdenum. The effects of equilibrium time, the dosage of H2O2, equilibrium pH value of water phase, temperature on separation of Mo from WO3 are investigated. The extraction isothermal for Mo was plotted and stripping method was explored. The results indicate that, the extraction system has a favorable capability for molybdenum extraction and a good separation efficiency for molybdenum and tungsten. The saturated capacity of organic phase containing 45 % mixed extrantant for molybdenum is 9.2 g/L. The separation coefficient for molybdenum and tungsten can be more than 50. The loaded organic phase can be stripped easily with NaOH solution.%以双氧水为络合剂,采用混合萃取剂进行了高铝钨酸铵工业料液络合萃取分离钨钢的初步试验研究.试验考察了振荡平衡时间、双氧水用量、水相平衡pH值、温度等因素对钨钼萃取分离的影响,绘制了钼的萃取等温线并探索了反萃取方法.研究结果表明,该萃取体系具有良好的萃钼能力和钨钼分离性能,混合萃取剂浓度为45%的有机相对铝的饱和萃取容量达9.2g/L,单级萃取钼钨分离系数可达50以上,NaOH溶液能有效反萃负载有机相.

  13. Sneutrino Mixing

    OpenAIRE

    Grossman, Yuval

    1997-01-01

    In supersymmetric models with nonvanishing Majorana neutrino masses, the sneutrino and antisneutrino mix. The conditions under which this mixing is experimentally observable are studied, and mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are analyzed.

  14. Handbook of organic solvent properties

    CERN Document Server

    Smallwood, Ian

    2012-01-01

    The properties of 72 of the most commonly used solvents are given, tabulated in the most convenient way, making this book a joy for industrial chemists to use as a desk reference. The properties covered are those which answer the basic questions of: Will it do the job? Will it harm the user? Will it pollute the air? Is it easy to handle? Will it pollute the water? Can it be recovered or incinerated? These are all factors that need to be considered at the early stages of choosing a solvent for a new product or process.A collection of the physical properties of most commonly used solvents, their

  15. The Solvent Selection framework: solvents for organic synthesis, separation processes and ionic-organic synthesis

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sansonetti, Sascha; Abildskov, Jens

    2012-01-01

    problems are presented: 1) solvent selection and design for organic synthesis, 2) solvent screening and design of solvent mixtures for pharmaceutical applications and 3) ionic liquids selection and design as solvents. The application of the framework is highlighted successfully through case studies...... focusing on solvent replacement problem in organic synthesis and solvent mixture design for ibuprofen respectively....

  16. Effects of solubility properties of solvents and biomass on biomass pretreatment.

    Science.gov (United States)

    Weerachanchai, Piyarat; Kwak, Sang Kyu; Lee, Jong-Min

    2014-10-01

    Hildebrand solubility parameters of biomasses and pretreatment solvents were examined by a method of intrinsic viscosity. This is to be used as basic information in selecting a suitable solvent for biomass pretreatment processes. The effects of mixing1-ethyl-3-methylimidazolium acetate (EMIM-AC) and different solvents, lignin content in a pretreatment solvent, and biomass type on the Hildebrand solubility parameter and thermodynamic properties were carried out and calculated in this work. The Hildebrand solubility parameters of the mixtures are according to those of organic solvents: δH[EMIM-AC/DMA]=25.07biomass compositions (microcrystalline cellulose, xylan and alkali lignin) and biomasses (cassava pulp residue and rice straw) vary in the ranges of 25.14-26.13. The increases of lignin content in the pretreatment solvents lead to the Hildebrand solubility parameter becoming closer to that of lignin.

  17. Practical Approaches to Green Solvents

    National Research Council Canada - National Science Library

    Joseph M. DeSimone

    2002-01-01

    Solvents are widely used in commercial manufacturing and service industries. Despite abundant precaution, they inevitably contaminate our air, land, and water because they are difficult to contain and recycle...

  18. Hansen Cleaning Solvent Research Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental regulation will force current baseline  precision cleaning solvent (AK-225) to be phased out starting 2015. We plan to develop  a new...

  19. Challenges in subsurface in situ remediation of chlorinated solvents

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Fjordbøge, Annika Sidelmann; Christiansen, Camilla Maymann

    2014-01-01

    Chlorinated solvent source zones in the subsurface pose a continuous threat to groundwater quality at many sites worldwide. In situ remediation of these sites is particularly challenging in heterogeneous fractured media and where the solvents are present as DNAPL. In situ remediation by chemical...... as well as biological degradation of chlorinated solvents is a contact sport and requires direct contact between the contaminant and the reactants and/or degrading microorganisms. In fractured geologic media, where contaminants have spread to the low permeability matrix by diffusion, the contact between......-clay mixing for contact; hydrophobic and/or mobile nano-reactants targeting DNAPL. The complexity of the technologies varies greatly and the current level of implementation ranges from multiple full scale applications to bench scale testing. However, the basic degradation reaction involved is usually well...

  20. Applied biotransformations in green solvents.

    Science.gov (United States)

    Hernáiz, María J; Alcántara, Andrés R; García, José I; Sinisterra, José V

    2010-08-16

    The definite interest in implementing sustainable industrial technologies has impelled the use of biocatalysts (enzymes or cells), leading to high chemo-, regio- and stereoselectivities under mild conditions. As usual substrates are not soluble in water, the employ of organic solvents is mandatory. We will focus on different attempts to combine the valuable properties of green solvents with the advantages of using biocatalysts for developing cleaner synthetic processes.

  1. Excess Volumes of Mixing of Cl– and Br– with Na+ and K+ at 308.15 ...

    African Journals Online (AJOL)

    NJD

    mixing data of electrolyte solutions particularly in mixed solvent systems are lacking. ..... 9 D.J. Turner, Thermodynamics of Aqueous Systems with Industrial Applica- ... 26 R.C. Weast, Handbook of Chemistry and Physics, 68th edn., CRC Press,.

  2. Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

    Science.gov (United States)

    Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

    2011-01-01

    A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

  3. Rare earth element enrichment using membrane based solvent extraction

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.; Zunita, M.; Wenten, I. G.

    2017-01-01

    The chemical, catalytic, electrical, magnetic, and optical properties of rare earth elements are required in broad applications. Rare earth elements have similar physical and chemical properties thus it is difficult to separate one from each other. Rare earth element is relatively abundant in earth's crust but rarely occur in high concentrated deposits. Traditionally, ion-exchange and solvent extraction techniques have been developed to separate and purify single rare earth solutions or compounds. Recently, membrane starts to gain attention for rare earth separation by combining membrane and proven technologies such as solvent extraction. Membrane-based process offers selective, reliable, energy efficient and easy to scale up separation. During membrane-based separation process, one phase passes through membrane pores while the other phase is rejected. There is no direct mixing of two phases thus the solvent loss is very low. Membrane can also lower solvent physical properties requirement (viscosity, density) and backmixing, eliminate flooding phenomenon and provide large interfacial area for mass transfer. This paper will summarize research efforts in developing membrane technology for rare earth element separation. Special attention will be given to solvent extraction related process as the commonly used method for rare earth element separation. Furthermore, membrane configuration and its potentials will also be discussed.

  4. Measurement and correlation of saturated vapor pressure for p -aminophenol- ethanol/water mixed solvent system%对氨基苯酚-乙醇/水复合溶剂体系饱和蒸汽压的测定和关联

    Institute of Scientific and Technical Information of China (English)

    金珊; 孙杰; 金申

    2011-01-01

    Saturated vapor pressures of ethanol -water mixed solvent ( mass fraction of 55% , sample 1) and p - aminophenol - ethanol/water system (mass fraction of 25% .sample 2) were measured by static method at 363 - 423 K, respectively. The non - linear regression of experimental data was conduced by Antoine equation. The results showed that constant terms A,B,C of Antoine equation for sample 1 in turn were 16.042, -3 305.400, -64. 496 , correlation coefficient was 0.999 97.The above values of sample 2 in turn were 10. 525 , -605.260, -269.020,0.999 94. The average deviation of sample 1 between the calculated value and the experimental data was less than 0.60% and the maximum deviation was 1.27% , those of sample 2 were 0. 95% ,2. 30% .respectively.%在363-423 K条件下,采用静态法测定了质量分数为55%的乙醇-水复合溶剂(以下简称试样1)及质量分数为25%的对氨基苯酚-乙醇/水复合溶剂体系(以下简称试样2)的饱和蒸汽压.用Antoine方程对实验数据进行了非线性回归.结果表明,试样1的Antoine方程常数项A,B,C依次为16.042,-3 305.400,- 64.496,相关系数为0.999 97.试样2的上述各值依次为10.525,-605.260,- 269.020,0.999 94.试样1的计算值与实验值的平均偏差为0.60%,最大偏差为1.27%;试样2的分别为0.95%,2.30%.

  5. Handbook of green chemistry, green solvents, supercritical solvents

    CERN Document Server

    Anastas, Paul T; Jessop, Philip G

    2014-01-01

    Green Chemistry is a vitally important subject area in a world where being as green and environmentally sound as possible is no longer a luxury but a necessity. Its applications include the design of chemical products and processes that help to reduce or eliminate the use and generation of hazardous substances. The Handbook of Green Chemistry comprises 12 volumes, split into subject-specific sets as follows: Set I: Green Catalysis Set II: Green Solvents Volume 4: Supercritical Solvents Volume 5: Reactions in Water Volume 6: Ionic Liquids

  6. DOE solvent handbook information sheet

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, A.A.

    1992-01-01

    Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

  7. DOE solvent handbook information sheet

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, A.A.

    1992-05-01

    Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

  8. Computer Aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

    , millions of tons solvents have to be wasted every year [2]. Therefore, it becomes important to minimize and optimize the use of organic solvents as much as possible, to satisfy the “Green Chemistry Principles” [3]. Another challenge is that currently solvent selection relies very much on previous...... is to develop a systematic framework and implement it as software for selection and design of solvents for many applications including organic synthesis, complex reaction systems and solvent-based separations. The solvent selection framework is based on a combination of knowledge from industrial practice...... identification of solvent candidates using special software ProCAMD and ProPred, which are the implementations of computer-aided molecular techniques. The second consists of assigning the RS-indices following the reaction–solvent and then consulting the known solvent database and identifying the set of solvents...

  9. 40 CFR Table 7 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ..., Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c E.g., Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic Hydrocarbons, Aromatic Hydrocarbons...

  10. 40 CFR Table 6 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c E.g., Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic Hydrocarbons...

  11. 40 CFR Table 4 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c e.g., Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic Hydrocarbons...

  12. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ..., Mineral Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c E.g., Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic...

  13. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... aromatic. b Mineral Spirits 135, Mineral Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light...

  14. 40 CFR Table 4 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups 1

    Science.gov (United States)

    2010-07-01

    ... EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. 3 E.g., Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic Hydrocarbons, Aromatic...

  15. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... aliphatic or aromatic. b Mineral Spirits 135, Mineral Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic...

  16. Glycerol based solvents: synthesis, properties and applications

    OpenAIRE

    García, José I.; García-Marín, Héctor; Pires, Elísabet

    2014-01-01

    The most recent advances in the use of glycerol and glycerol derivatives as solvents are reviewed. There are an increasing number of examples of the use of glycerol itself as a reaction medium, solvent-reagent or a dispersive medium for a large variety of applications. In the case of glycerol derivatives, new synthetic methods, physico-chemical properties and application examples as solvents are revised. Recent studies in the field of solvent classification, as well as solvent substitution is...

  17. Multiple sclerosis and organic solvents

    DEFF Research Database (Denmark)

    Mortensen, J T; Brønnum-Hansen, Henrik; Rasmussen, K

    1998-01-01

    We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from......, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless......, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis....

  18. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor;

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection of ...

  19. Solvent based hydrogen bonding: impact on poly(3-hexylthiophene) nanoscale morphology and charge transport characteristics.

    Science.gov (United States)

    Chang, Mincheol; Choi, Dalsu; Fu, Boyi; Reichmanis, Elsa

    2013-06-25

    We demonstrate that supramolecular assembly and subsequent enhancement of charge transport characteristics of conjugated polymers can be facilitated simply by adding small amounts of a more volatile poor solvent, which can hydrogen bond with the majority solvent. Addition of up to 2 vol % acetone to a precursor solution of poly(3-hexylthiophene) (P3HT) in chloroform leads to approximately a 4-fold increase in P3HT field-effect mobility. The improvement is associated with hydrogen bonding interactions between acetone and chloroform which decrease the evaporation rate of the mixed solvent. P3HT is less soluble in the binary solvent than in the more readily vaporized chloroform component, and this characteristic enables the supramolecular assembly of P3HT chains at the nanoscale. Two-dimensional molecular ordering of the polymer film was controlled by varying the quantity of poor solvent added to the precursor solution, and the correlation between field-effect mobility and molecular ordering was investigated. Hansen solubility parameters were used to systematically understand how the solvent mixture enhances the alignment and assembly of polymer chains and influences subsequent thin film properties. The value of the relative energy difference (RED) of the solvent with respect to P3HT increased from less than 1 to more than 1 during film formation, which indicates that the solvent characteristics are initially those of a good solvent but transform into those of a poor dissolution medium. A mechanistic illustration of the molecular ordering process during film formation is postulated.

  20. Which solvent for olfactory testing?

    Science.gov (United States)

    Philpott, C M; Goodenough, P C; Wolstenholme, C R; Murty, G E

    2004-12-01

    The physical properties of any carrier can deteriorate over time and thus alter the results in any olfactory test. The aim of this study was to evaluate clinically potential solvents as a clean odourless carrier for olfactory testing. Sweet almond oil, pure coconut oil, pure peach kernel oil, dipropylene glycol, monopropylene glycol, mineral oil and silicone oil were studied. The experimentation was conducted in two parts. First, an olfactory device was used to conduct air through the solvents on a weekly basis using a cohort of six volunteers to assess the perceived odour of each solvent at weekly intervals. Secondly a cross-reference test was performed using small bottled solutions of phenylethyl-alcohol and 1-butanol in 10-fold dilutions to compare any perceived difference in concentrations over a period of 8 weeks. We concluded that mineral oil is the most suitable carrier for the purpose of olfactory testing, possessing many desirable characteristics of an olfactory solvent, and that silicone oil may provide a suitable alternative for odorants with which it is miscible.

  1. Micellization of alkyl-propoxy-ethoxylate surfactants in water-polar organic solvent mixtures.

    Science.gov (United States)

    Sarkar, Biswajit; Lam, Stephanie; Alexandridis, Paschalis

    2010-07-06

    The effects of cosolvents (glycerol, ethanol, and isopropanol) on the self-assembly of novel alkyl-propoxy-ethoxylate surfactants in aqueous solutions have been investigated with a focus on the (i) quantification of solvent effects on the critical micelle concentration (cmc), (ii) free-energy contributions to micellization, (iii) local environment in the micellar solution, and (iv) structure of the micelles. The introduction of the polar organic solvents considered in this work into water decreases cohesive forces in the solvent mixture, resulting in an increase in the solubility of the surfactant molecules. As a result, micelle formation becomes less favorable and the cmc increases. The contribution of the cosolvent to the free energy of micellization is positive, and the data for different mixed solvents collapse onto a single straight line when plotted versus a function of the solubility parameters of the surfactant alkyl chains and the mixed solvents. The behavior of the poly(propylene oxide) part of the alkyl-propoxy-ethoxylate surfactants is hydrophilic, albeit less so in the ethanol-water mixed solvent than in plain water. Pyrene fluorescence emission I(1)/I(3) data suggest that the microenvironment in micellar solutions is affected mainly by the cosolvent concentration, not the surfactant degree of ethoxylation. Small-angle X-ray scattering data for both water and ethanol-water surfactant solutions are consistent with oblate ellipsoid micelles and reveal that the introduction of 20% ethanol decreases the micelle long axis by 10-15%.

  2. Method for analyzing solvent extracted sponge core

    Energy Technology Data Exchange (ETDEWEB)

    Ellington, W.E.; Calkin, C.L.

    1988-11-22

    For use in solvent extracted sponge core measurements of the oil saturation of earth formations, a method is described for quantifying the volume of oil in the fluids resulting from such extraction. The method consists of: (a) separating the solvent/oil mixture from the water in the extracted fluids, (b) distilling at least a portion of the solvent from the solvent/oil mixture substantially without co-distillation or loss of the light hydrocarbons in the mixture, (c) determining the volume contribution of the solvent remaining in the mixture, and (d) determining the volume of oil removed from the sponge by substracting the determined remaining solvent volume.

  3. Solvent engineering for high-quality perovskite solar cell with an efficiency approaching 20%

    Science.gov (United States)

    Wu, Tongyue; Wu, Jihuai; Tu, Yongguang; He, Xin; Lan, Zhang; Huang, Miaoliang; Lin, Jianming

    2017-10-01

    The perovskite layer is the most crucial factor for the high performance perovskite solar cells. Based on solvent engineering, we develop a ternary-mixed-solvent method for the growth of high-quality [Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3] cation-anion-mixed perovskite films by introducing N-methyl-2-pyrrolidone (NMP) into the precursor mixed solution. By controlling rapid nucleation and retarding crystal growth via intermediate phase PbI2-NMP (Lewis acid-base adduct), a dense, large grain, pinhole-free and long charge carrier lifetime perovskite film is obtained. By optimizing the precursor solvent composition, the perovskite solar cell achieves an impressive power conversion efficiency of 19.61% under one-sun illumination. The research presented here provides a facile, low-cost and highly efficient way for the preparation of perovskite solar cells.

  4. Marketing mix

    OpenAIRE

    Fatrdlová, Adéla

    2016-01-01

    Bachelor thesis is focused on the evaluation of the marketing mix for company HET, analyzing every individual instruments and the subsequently for the improvements. This thesis is composed of two parts,literature reviewed and with personal advice for solution, which falls under subchapter suggestions and recommendations. The first part of thesis are basic concepts associated, included with marketing and marketing mix with a focus on four basic marketing tools. The second part describes the co...

  5. Marketing mix

    OpenAIRE

    Dvořák, Michael

    2016-01-01

    The subject of this thesis, with the official name Marketing mix, is to analyse the actual and future marketing mix in selected company, propose for its improvements and strategy for re-launching traditional footwear company and their products on the Czech market. The theoretical section focuses on the basic concepts of marketing, its history, actual trends and its principles. The theoretical findings are used in the following practical part. The practical section describes the curre...

  6. Solubilities of Isophthalic Acid in Acetic Acid + Water Solvent Mixtures

    Institute of Scientific and Technical Information of China (English)

    CHENG Youwei; HUO Lei; LI Xi

    2013-01-01

    The solubilities of isophthalic acid (1) in binary acetic acid (2) + water (3) solvent mixtures were determined in a pressurized vessel.The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 =0 to 1.A new method to measure the solubility was developed,which solved the problem of sampling at high temperature.The experimental results indicated that within the temperature range studied,the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature.The experimental solubilities were correlated by the Buchowski equation,and the calculate results showed good agreement with the experimental solubilities.Furthermore,the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility,which may be attributed to the intermolecular association between the solute and the solvent mixture.The maximum solubility effect was well modeled by the modified Wilson equation.

  7. New RO TFC Membranes by Interfacial Polymerization in n-Dodecane with Various co-Solvents.

    Science.gov (United States)

    Al-Hobaib, Abdullah Sulaiman; Al-Suhybani, Mohammed Sulaiman; Al-Sheetan, Khalid Mohammed; Mousa, Hasan; Shaik, Mohammed Rafi

    2016-04-29

    The objective of this research is to prepare and characterize a new and highly efficient polyamide TFC RO membrane by interfacial polymerization in dodecane solvent mixed with co-solvents. Three co-solvents were tested namely; acetone, ethyl acetate, and diethyl ether of concentration of 0.5, 1, 2, 3, and 5 wt %. The modified membranes were characterized by SEM, EDX, AFM and contact angle techniques. The results showed that addition of co-solvent results in a decrease in the roughness, pore size and thickness of the produced membranes. However, as the concentration of the co-solvent increases the pore size of the membranes gets larger. Among the three co-solvents tested, acetone was found to result in membranes with the largest pore size and contact angle followed by diethyl ether then ethyl acetate. Measured contact angle increases as the concentration of the co-solvent increases reaching a constant value except for ethyl acetate where it was found to drop. Investigating flux and salt rejection by the formulated membranes showed that higher flux was attained when acetone was used as a co-solvent followed by diethyl ether then ethyl acetate. However, the highest salt rejection was achieved with diethyl ether.

  8. New RO TFC Membranes by Interfacial Polymerization in n-Dodecane with Various co-Solvents

    Directory of Open Access Journals (Sweden)

    Abdullah Sulaiman Al-Hobaib

    2016-04-01

    Full Text Available The objective of this research is to prepare and characterize a new and highly efficient polyamide TFC RO membrane by interfacial polymerization in dodecane solvent mixed with co-solvents. Three co-solvents were tested namely; acetone, ethyl acetate, and diethyl ether of concentration of 0.5, 1, 2, 3, and 5 wt %. The modified membranes were characterized by SEM, EDX, AFM and contact angle techniques. The results showed that addition of co-solvent results in a decrease in the roughness, pore size and thickness of the produced membranes. However, as the concentration of the co-solvent increases the pore size of the membranes gets larger. Among the three co-solvents tested, acetone was found to result in membranes with the largest pore size and contact angle followed by diethyl ether then ethyl acetate. Measured contact angle increases as the concentration of the co-solvent increases reaching a constant value except for ethyl acetate where it was found to drop. Investigating flux and salt rejection by the formulated membranes showed that higher flux was attained when acetone was used as a co-solvent followed by diethyl ether then ethyl acetate. However, the highest salt rejection was achieved with diethyl ether.

  9. Reactions and Separations in Green Solvents

    NARCIS (Netherlands)

    Van Spronsen, J.

    2010-01-01

    Most chemical processes involve solvents in the reaction and the separation step. These solvents give rise to a heavy environmental and economical burden. Moreover, these solvents are based on non-sustainable resources like petroleum. The aim of this thesis has been to develop a number of alternativ

  10. Reactions and Separations in Green Solvents

    NARCIS (Netherlands)

    Van Spronsen, J.

    2010-01-01

    Most chemical processes involve solvents in the reaction and the separation step. These solvents give rise to a heavy environmental and economical burden. Moreover, these solvents are based on non-sustainable resources like petroleum. The aim of this thesis has been to develop a number of

  11. The solvent component of macromolecular crystals

    Energy Technology Data Exchange (ETDEWEB)

    Weichenberger, Christian X. [European Academy of Bozen/Bolzano (EURAC), Viale Druso 1, Bozen/Bolzano, I-39100 Südtirol/Alto Adige (Italy); Afonine, Pavel V. [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Mail Stop 64R0121, Berkeley, CA 94720 (United States); Kantardjieff, Katherine [California State University, San Marcos, CA 92078 (United States); Rupp, Bernhard, E-mail: br@hofkristallamt.org [k.-k. Hofkristallamt, 991 Audrey Place, Vista, CA 92084 (United States); Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck (Austria)

    2015-04-30

    On average, the mother liquor or solvent and its constituents occupy about 50% of a macromolecular crystal. Ordered as well as disordered solvent components need to be accurately accounted for in modelling and refinement, often with considerable complexity. The mother liquor from which a biomolecular crystal is grown will contain water, buffer molecules, native ligands and cofactors, crystallization precipitants and additives, various metal ions, and often small-molecule ligands or inhibitors. On average, about half the volume of a biomolecular crystal consists of this mother liquor, whose components form the disordered bulk solvent. Its scattering contributions can be exploited in initial phasing and must be included in crystal structure refinement as a bulk-solvent model. Concomitantly, distinct electron density originating from ordered solvent components must be correctly identified and represented as part of the atomic crystal structure model. Herein, are reviewed (i) probabilistic bulk-solvent content estimates, (ii) the use of bulk-solvent density modification in phase improvement, (iii) bulk-solvent models and refinement of bulk-solvent contributions and (iv) modelling and validation of ordered solvent constituents. A brief summary is provided of current tools for bulk-solvent analysis and refinement, as well as of modelling, refinement and analysis of ordered solvent components, including small-molecule ligands.

  12. The hype with ionic liquids as solvents

    Science.gov (United States)

    Kunz, Werner; Häckl, Katharina

    2016-09-01

    In this mini review, we give our personal opinion about the present state of the art concerning Ionic Liquids, proposed as alternative solvents. In particular, we consider their different drawbacks and disadvantages and discuss the critical aspects of the research of Ionic Liquids as solvents. Finally, we point out some aspects on potentially promising Ionic Liquid solvents.

  13. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    Mixed Movements is a research project engaged in performance-based architectural drawing. Architectonic implementation questions relations between the human body and a body of architecture by the different ways we handle drawing materials. A drawing may explore architectonic problems at other...... levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear...... as possible operational moves....

  14. Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2009-01-06

    A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

  15. Assessment of Relationship between Spontaneous Abortion and Occupational Exposure to Organic Solvents

    Directory of Open Access Journals (Sweden)

    S Mohammadi

    2011-04-01

    Full Text Available Introduction & Objective: Nowadays, some studies indicate the adverse effects of exposure to chemicals, especially organic solvents on the reproductive system of females. This study aimed to assess the relationship between spontaneous abortion with occupational exposure to organic solvents in pharmaceutical industry. Materials & Methods: This is a cross-sectional and descriptive-analytical study which was carried out in 2010 in one of the pharmaceutical factories located in the suburbs of Tehran. During the study, married women who were working in the factory laboratory units and were exposed to mixed organic solvents were compared with married women who were working in the packing units of the factory without occupational exposure to organic solvents. Frequency of spontaneous abortion and duration of pregnancy were assessed in both two groups. Collected data were analyzed with the SPSS software using t-test, logistic regression, and chi-square test. Results: In the present study, the frequency of spontaneous abortion in employees with exposure to organic solvents mixture was 10.7%. This study showed that even after adjustment for confounding factors, there was a significant correlation between spontaneous abortion and occupational exposure to organic solvents mixture and this correlation increased with increasing levels of exposure to organic solvents. Moreover, a significant correlation was observed between occupational exposure to mixed organic solvents and waiting time to become pregnant (TTP. Furthermore, this study showed that even after adjustment for confounding variables, shift workers were significantly more affected by spontaneous abortion compared to daytime workers (P < 0.001. Conclusion: According to the results of this study, since there is probability of spontaneous abortion resulting from occupational exposure to various chemicals including organic solvents, review of the status of occupational exposure of workers can be helpful

  16. Mixed parentage

    DEFF Research Database (Denmark)

    Bang Appel, Helene; Singla, Rashmi

    2016-01-01

    Despite an increase in cross border intimate relationships and children of mixed parentage, there is little mention or scholarship about them in the area of childhood and migrancy in the Nordic countries. The international literature implies historical pathologisation, contestation and current...

  17. Effect of solvents on the characteristics of rosin walled microcapsules prepared by a solvent evaporation technique.

    Science.gov (United States)

    Sheorey, D S; Dorle, A K

    1991-01-01

    Rosin microcapsules were prepared by a solvent evaporation technique using solvents with different rates of evaporation. Sulphadiazine was used as a model drug. The microcapsules were studied for their size, drug content, wall thickness, surface characteristics and in vitro release. The mean diameter increased and the drug content decreased as the rate of evaporation of the solvent increased. Fast evaporating solvents produced thick walled microcapsules with innumerable surface pores/cracks compared with slow evaporating solvents.

  18. Effect of exposure to a mixture of solvents and noise on hearing and balance in aircraft maintenance workers.

    Science.gov (United States)

    Prasher, Deepak; Al-Hajjaj, Haifa; Aylott, Susan; Aksentijevic, Aleksander

    2005-01-01

    Aircraft maintenance workers are exposed to a mixture of solvents in the presence of intermittent noise. For this study these workers exposed to solvent mix and noise, were compared with mill workers exposed to noise alone, printed circuit board operatives exposed to solvents alone and those exposed to none who acted as controls. Tympanometry, acoustic reflex thresholds, transient and distortion product otoacoustic emissions, auditory brainstem potentials, nystagmography and posturography were examined. There was a significant effect on pure tone thresholds for both noise and solvents+noise. The distortion product otoacoustic emissions declined with frequency and exhibited lower DP amplitude with noise compared to solvents and noise group. The transient emissions showed a similar effect. Over 32% of subjects with solvent and noise exposure had abnormalities of the auditory brainstem responses in terms of interwave interval prolongation. The mean acoustic reflex thresholds showed a pattern of differences which differentiate noise from solvent and noise groups. The contralateral pathway appears to be differentially affected by solvent exposure. 32% of subjects in the solvents and noise group had an abnormal posturographic finding. In the solvents and noise group 74% had abnormalities of saccades, 56% of pursuit and 45% of optokinetic nystagmus.

  19. Deep eutectic solvents for the purification of chloromycetin and thiamphenicol from milk.

    Science.gov (United States)

    Li, Guizhen; Zhu, Tao; Row, Kyung Ho

    2017-02-01

    Deep eutectic solvents were used in both dispersive liquid-liquid microextraction and solid-phase extraction for the purification of chloromycetin and thiamphenicol from milk. In the dispersive liquid-liquid microextraction procedure, deep eutectic solvents mixed with chloroform at different ratios (0:1-5:1, v/v) were used as the extraction agent to optimize the procedure, and the ratio of 2:1 v/v was found to be the best extraction agent with 87.23 and 83.17% recoveries of chloromycetin and thiamphenicol, respectively. Furthermore, deep eutectic solvents were also used to modify molecular imprinted polymers in solid-phase extraction procedure, and the polymers were used to purify chloromycetin and thiamphenicol from milk. Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy were used to characterize the polymers. The solid-phase extraction recoveries with deep eutectic solvents with molecularly imprinted polymers (chloromycetin and thiamphenicol, two templates), molecularly imprinted polymers (without deep eutectic solvents), and nonimprinted polymers (without a template) for chloromycetin were 91.23, 82.64, and 57.3%, respectively, and recoveries for thiamphenicol were 87.02, 79.03, and 52.27%, respectively. The recoveries of chloromycetin and thiamphenicol from milk in the solid-phase extraction procedure were higher than using deep eutectic solvents mixed with chloroform as the extraction agent in the dispersive liquid-liquid microextraction procedure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Efficient removal of naphthalene-2-ol from aqueous solutions by solvent extraction.

    Science.gov (United States)

    Shao, Jingjing; Cheng, Yan; Yang, Chunping; Zeng, Guangming; Liu, Wencan; Jiao, Panpan; He, Huijun

    2016-09-01

    Naphthalene-2-ol is a typical biologically recalcitrant pollutant in dye wastewater. Solvent extraction of naphthalene-2-ol from aqueous solutions using mixed solvents was investigated. Various extractants and diluents were evaluated, and the effects of volume ratio of extractant to diluent, initial pH, initial concentration of naphthalene-2-ol in aqueous solution, extraction time, temperature, volume ratio of organic phase to aqueous phase (O/A), stirring rate and extraction stages, on extraction efficiency were examined separately. Regeneration and reuse of the spent extractant were also investigated. Results showed that tributyl phosphate (TBP) achieved 98% extraction efficiency for naphthalene-2-ol in a single stage extraction, the highest among the 12 extractants evaluated. Extraction efficiency was optimized when cyclohexane and n-octane were used as diluents. The solvent combination of 20% TBP, 20% n-octanol and 60% cyclohexane (V/V) obtained the maximum extraction efficiency for naphthalene-2-ol, 99.3%, within 20min using three cross-current extraction stages under the following extraction conditions: O/A ratio of 1:1, initial pH of 3, 25°C and stirring rate of 150r/min. Recovery of mixed solvents was achieved by using 15% (W/W) NaOH solution at an O:A ratio of 1:1 and a contact time of 15min. The mixed solvents achieved an extraction capacity for naphthalene-2-ol stably higher than 90% during five cycles after regeneration.

  1. Advanced integrated solvent extraction systems

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, E.P.; Dietz, M.L.; Leonard, R.A. [Argonne National Lab., IL (United States)

    1997-10-01

    Advanced integrated solvent extraction systems are a series of novel solvent extraction (SX) processes that will remove and recover all of the major radioisotopes from acidic-dissolved sludge or other acidic high-level wastes. The major focus of this effort during the last 2 years has been the development of a combined cesium-strontium extraction/recovery process, the Combined CSEX-SREX Process. The Combined CSEX-SREX Process relies on a mixture of a strontium-selective macrocyclic polyether and a novel cesium-selective extractant based on dibenzo 18-crown-6. The process offers several potential advantages over possible alternatives in a chemical processing scheme for high-level waste treatment. First, if the process is applied as the first step in chemical pretreatment, the radiation level for all subsequent processing steps (e.g., transuranic extraction/recovery, or TRUEX) will be significantly reduced. Thus, less costly shielding would be required. The second advantage of the Combined CSEX-SREX Process is that the recovered Cs-Sr fraction is non-transuranic, and therefore will decay to low-level waste after only a few hundred years. Finally, combining individual processes into a single process will reduce the amount of equipment required to pretreat the waste and therefore reduce the size and cost of the waste processing facility. In an ongoing collaboration with Lockheed Martin Idaho Technology Company (LMITCO), the authors have successfully tested various segments of the Advanced Integrated Solvent Extraction Systems. Eichrom Industries, Inc. (Darien, IL) synthesizes and markets the Sr extractant and can supply the Cs extractant on a limited basis. Plans are under way to perform a test of the Combined CSEX-SREX Process with real waste at LMITCO in the near future.

  2. Biodiesel production from ethanolysis of DPO using deep eutectic solvent (DES) based choline chloride - ethylene glycol as co-solvent

    Science.gov (United States)

    Taslim, Indra, Leonardo; Manurung, Renita; Winarta, Agus; Ramadhani, Debbie Aditia

    2017-03-01

    Biodiesel is usually produced from transesterification using methanol or ethanol as alcohol. However, biodiesel produced using methanol has several disadvantages because methanol is toxic and not entirely bio-based as it is generally produced from petroleum, natural gas and coal. On the other hand, ethanol also has several disadvantages such as lower reactivity in transesterification process and formation of stable emulsion between ester and glycerol. To improve ethanolysis process, deep eutectic solvent (DES) was prepared from choline chloride and ethylene glycol to be used as co-solvent in ethanolysis. Deep eutectic solvent was prepared by mixing choline chloride and ethylene glycol at molar ratio of 1:2, temperature of 80 °C, and stirring speed of 300 rpm for 1 hour. The DES was characterized by its density and viscosity. The ethanolysis of DPO / Degummed Palm Oil was performed at 70 °C, ethanol to oil molar ratio of 9:1, catalyst (potassium hydroxide) concentration of 0.75 wt.% concentration, co-solvent (DES) concentration of 1, 2, 3, 4, 5 and 6 wt.%, stirring speed of 600 rpm, and reaction time of 1 hour. The obtained biodiesel was then characterized by its density, viscosity and ester content. The oil - ethanol phase condition was observed in reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to that without DES. Which implied that oil and ethanol become more slightly miscible, which favours the reaction. Using DES as co-solvent in ethanolysis resulted in an increase in yield and easier purification. The esters properties met the international standards ASTM D6751, with highest yield achieved at 81.72 % with 99.35 % ethyl ester contents at 4% DES concentration.

  3. Non-polar Solvent Microwave-Assisted Extraction of Volatile Constituents from Dried Zingiber Officinale Rosc.

    Institute of Scientific and Technical Information of China (English)

    YU Yong; WANG Zi-Ming; WANG Yu-Tang; LI Tie-Chun; CHENG Jian-Hua; LIU Zhong-Ying; ZHANG Han-Qi

    2007-01-01

    A new method, non-polar solvent microwave-assisted extraction (NPSMAE), was applied to the extraction of essential oil from Zingiber officinale Rosc. in closed-vessel system. By adding microwave absorption mediumcarbonyl iron powders (CIP) into extraction system, the essential oil was extracted by the non-polar solvent (ether)which can be heated by CIP. The constituents of essential oil obtained by NPSMAE were comparable with those obtained by hydrodistillation (HD) by GC-MS analysis, which indicates that NPSMAE is a feasible way to extract essential oil from dried plant materials. The NPSMAE took much less extraction time (5 min) than HD (180 min),and its extraction efficiency was much higher than that of conventional polar solvent microwave-assisted extraction (PSMAE) and mixed solvent microwave-assisted extraction (MSMAE). It can be a good alternative for the extraction of volatile constituents from dried plant samples.

  4. Comparative study of lipid extraction from microalgae by organic solvent and supercritical CO2.

    Science.gov (United States)

    Cheng, Chen-Hsi; Du, Tz-Bang; Pi, Hsien-Chueh; Jang, Shyue-Ming; Lin, Yun-Huin; Lee, Hom-Ti

    2011-11-01

    Pavlova sp. was employed to evaluate the efficiency of different lipid extraction methods. The microalgal crude lipids content determined using the mixed solvent with ultrasonic method was 44.7 wt.%. The triglyceride content obtained by the mixed solvent method was 15.6 wt.%. The extraction yield was the FAME yield divided by the maximum FAME (15.9 wt.%). The extraction yield was improved by cell disruption prior to extraction, and the highest triglyceride extraction yield of 98.7% was observed using the supercritical fluid extraction (SFE) method with bead-beating. The results indicate that the SFE method is effective and provides higher selectivity for triglyceride extraction though the total lipid extracted was less than that using solvent extraction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Fabrication of fullerene nano-strucutres in mixed films and devices utilizing fullerene nano-structures

    KAUST Repository

    Zhong, Yufei

    2017-04-06

    Embodiments provide methods for controlling crystallization of fullerene compounds in mixed films comprising one or more polymers. Methods can include depositing fullerene mixed films comprising one or more polymers on crystalline fullerene substrates and annealing the deposited mixed films. Methods can further include one or more of exposing the annealed mixed film to UV light, and washing the annealed mixed film with a solvent. Fullerene compounds can include one or more of PCBM, PCBNB, and PCBA.

  6. Effect of Exposure to a Mixture of Organic Solvents on Hearing Thresholds in Petrochemical Industry Workers

    Directory of Open Access Journals (Sweden)

    Ziba Loukzadeh

    2014-10-01

    Full Text Available Introduction: Hearing loss is one of the most common occupational diseases. In most workplaces, workers are exposed to noise and solvents simultaneously, so the potential risk of hearing loss due to solvents may be attributed to noise.  In this study we aimed to assess the effect of exposure to mixed aromatic solvents on hearing in the absence of exposure to hazardous noise.   Materials and Methods: In a cross-sectional study, 99 workers from the petrochemical industry with exposure to a mixture of organic solvents whose noise exposure was lower than 85 dBA were compared with 100 un-exposed controls. After measuring sound pressure level and mean concentration of each solvent in the workplace, pure-tone-audiometry was performed and the two groups were compared in terms of high-frequency and low-frequency hearing loss. T-tests and Chi-square tests were used to compare the two groups.   Results: The mean hearing threshold at all frequencies among petrochemical workers was normal (below 25 dB. We did not observe any significant association between solvent exposure and high-frequency or low-frequency hearing loss.   Conclusion:  This study showed that temporary exposure (less than 4 years to a mixture of organic solvents, without exposure to noise, does not affect workers’ hearing threshold in audiometry tests.

  7. Polylactide microspheres prepared by premix membrane emulsification - Effects of solvent removal rate

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Purwanti, N.; Rinzema, A.; Schroën, C.G.P.H.; Boom, R.M.

    2008-01-01

    Polylactide microspheres were prepared by pre-mix membrane emulsification and subsequent extraction of solvent in a coagulation bath, and ultimately to the gas phase. The polymer was dissolved in dichloromethane and emulsified with water or water¿methanol mixtures by repeated passage through a glass

  8. QM/MM study of the role of the solvent in the formation of the charge separated excited state in 9,9'-bianthryl

    NARCIS (Netherlands)

    Grozema, FC; Swart, M; Zijlstra, RWJ; Piet, JJ; Siebbeles, LDA; van Duijnen, PT

    2005-01-01

    In this paper the role of the solvent in the formation of the charge-separated excited state of 9,9'-bianthryl (BA) is examined by means of mixed molecular mechanical/quantum mechanical (QM/MM) calculations. It is shown that in weakly polar solvents a relaxed excited state is formed with an interuni

  9. Biological Treatment of Solvent-Based Paint

    Science.gov (United States)

    2011-01-01

    solvent. In addition, hydrocarbon mixtures, aromatic hydrocarbon, and Medium Aliphatic Solvent Naphtha are descriptors used by the manufactures to...Enamel Aromatic Hydrocarbon 14 Mineral Spirits 10 Naphtha 10 Ethyl Benzene 0.21 Xylene 1.0 Sherwin Williams Co Enamel Mineral Spirits 49...Solvent Naphtha 31.5 Non-hazardous Ingredients 68 Parker Paints Enamel Mineral Spirits 17 Naphtha 7 Aromatic Hydrocarbons 3 1,2,4

  10. Antioxidative Polyphenols from Defatted Oilseed Cakes: Effect of Solvents

    Directory of Open Access Journals (Sweden)

    Sue-Siang Teh

    2014-02-01

    Full Text Available Defatted hemp, flax and canola seed cakes were extracted with different solvent systems namely methanol, ethanol, acetone, methanol 80%, acetone 80% and mixed solvent of methanol:acetone:water (MAW, 7:7:6, v/v/v. Each extract was analyzed for antioxidant capacity using ferric reducing/antioxidant power (FRAP and 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging assays. MAW exhibited the highest extraction of phenolic and flavonoid contents in the seed cakes, followed by acetone 80% and methanol 80%. The antioxidant capacity was proportional to the polyphenols recovery in the extracts. Canola seed cakes possessed the highest recovery of polyphenols and antioxidant capacity, followed by hemp and flax seed cakes. MAW extract of canola contained total phenolic content, 2104.67 ± 2.52 mg GAE/100 g fresh weight; total flavonoids, 37.79 ± 0.04 mg LUE/100 g fresh weight; percentage inhibition of DPPH•, 33.03 ± 0.38%; FRAP assay, 8.78 ± 0.07 μmol Fe (II/g fresh weight. Identification of individual polyphenol compounds were performed HPLC. MAW extract of canola had the highest (P < 0.05 concentration of all individual polyphenols except gallic acid and catechin. Highest concentration of quercetin and luteolin in MAW extract of hemp was obtained among all solvent systems.

  11. Mixed segmentation

    DEFF Research Database (Denmark)

    Bonde, Anders; Aagaard, Morten; Hansen, Allan Grutt

    This book is about using recent developments in the fields of data analytics and data visualization to frame new ways of identifying target groups in media communication. Based on a mixed-methods approach, the authors combine psychophysiological monitoring (galvanic skin response) with textual...... content analysis and audience segmentation in a single-source perspective. The aim is to explain and understand target groups in relation to, on the one hand, emotional response to commercials or other forms of audio-visual communication and, on the other hand, living preferences and personality traits...

  12. A solvent tolerant isolate of Enterobacter aerogenes.

    Science.gov (United States)

    Gupta, Anshu; Singh, Rajni; Khare, S K; Gupta, M N

    2006-01-01

    A solvent tolerant strain of Enterobacter aerogenes was isolated from soil by cyclohexane enrichment. Presence of cyclohexane (20%) in culture media prolonged the lag phase and caused reduction in biomass. Transmission electron micrographs showed convoluted cell membrane and accumulation of solvent in case of the cells grown in cyclohexane. The Enterobacter isolate was able to grow in the range of organic solvents having log P above 3.2 and also in presence of mercury, thus showing potential for treatment of solvent rich wastes.

  13. Organic solvent use in enterprises in Japan.

    Science.gov (United States)

    Nagasawa, Yasuhiro; Ukai, Hirohiko; Okamoto, Satoru; Samoto, Hajime; Itoh, Kenji; Moriguchi, Jiro; Sakuragi, Sonoko; Ohashi, Fumiko; Takada, Shiro; Kawakami, Tetsuya; Ikeda, Masayuki

    2011-01-01

    This study was initiated to elucidate possible changes in types of organic solvents (to be called solvents in short) used in enterprises in Japan through comparison of current solvent types with historical data since 1983. To investigate current situation in solvent use in enterprises, surveys were conducted during one year of 2009 to 2010. In total, workroom air samples in 1,497 unit workplaces with solvent use were analyzed in accordance with regulatory requirements. Typical use pattern of solvents was as mixtures, accounting for >70% of cases. Adhesives spreading (followed by adhesion) was relatively common in small-scale enterprises, whereas printing and painting work was more common in middle-scale ones, and solvent use for testing and research purpose was basically in large-scaled enterprises. Through-out printing, painting, surface coating and adhesive application, toluene was most common (being detected in 49 to 82% of workplaces depending on work types), whereas isopropyl alcohol was most common (49%) in degreasing, cleaning and wiping workplaces. Other commonly used solvents were methyl alcohol, ethyl acetate and acetone (33 to 37%). Comparison with historical data in Japan and literature-retrieved data outside of Japan all agreed with the observation that toluene is the most commonly used solvent. Application of trichloroethylene and 1,1,1-trichloroethane, once common in 1980s, has ceased to exist in recent years.

  14. Extractive Distillation with Salt in Solvent

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Extractive distillation with salt in solvent is a new process for producing anhydrous ethanol by combining the principle of "salt effect" and some traditional extractive distillation methods. Compared with the common extractive distillation the performance of solvent is improved, the recycling amount of solvent is reduced to 1/4-1/5, and the number of theoretical plates is reduced to 1/3. Energy consumption and cost of equipment are also reduced and continuous production is realized. High efficiency and low solvent wastage make this technique feasible.

  15. OCCUPATIONAL SOLVENT EXPOSURE ASSOCIATED WITH DEVELOPMENTAL TOXICITY

    Directory of Open Access Journals (Sweden)

    Alina-Costina LUCA

    2016-05-01

    Full Text Available Organic solvent is a broad term that applies to many classes of chemicals. The solvent (benzene, toluene etc. aspects of occupational exposure are reviewed via the examination of the use, occurrence, and disposition as well as population’s potential of risk. The general public can be exposed to solvent in ambient air as a result of its occurrence in paint process. Solvents are primarily irritants to the skin and mucous membranes and have narcotic properties at high concentrations. Published epidemiological data identified various types of birth defects in certain occupations.

  16. Green Solvents for Precision Cleaning

    Science.gov (United States)

    Grandelli, Heather; Maloney, Phillip; DeVor, Robert; Surma, Jan; Hintze, Paul

    2013-01-01

    Aerospace machinery used in liquid oxygen (LOX) fuel systems must be precision cleaned to achieve a very low level of non-volatile residue (< 1 mg0.1 m2), especially flammable residue. Traditionally chlorofluorocarbons (CFCs) have been used in the precision cleaning of LOX systems, specifically CFC 113 (C2Cl3F3). CFCs have been known to cause the depletion of ozone and in 1987, were banned by the Montreal Protocol due to health, safety and environmental concerns. This has now led to the development of new processes in the precision cleaning of aerospace components. An ideal solvent-replacement is non-flammable, environmentally benign, non-corrosive, inexpensive, effective and evaporates completely, leaving no residue. Highlighted is a green precision cleaning process, which is contaminant removal using supercritical carbon dioxide as the environmentally benign solvent. In this process, the contaminant is dissolved in carbon dioxide, and the parts are recovered at the end of the cleaning process completely dry and ready for use. Typical contaminants of aerospace components include hydrocarbon greases, hydraulic fluids, silicone fluids and greases, fluorocarbon fluids and greases and fingerprint oil. Metallic aerospace components range from small nuts and bolts to much larger parts, such as butterfly valves 18 in diameter. A fluorinated grease, Krytox, is investigated as a model contaminant in these preliminary studies, and aluminum coupons are employed as a model aerospace component. Preliminary studies are presented in which the experimental parameters are optimized for removal of Krytox from aluminum coupons in a stirred-batch process. The experimental conditions investigated are temperature, pressure, exposure time and impeller speed. Temperatures of 308 - 423 K, pressures in the range of 8.3 - 41.4 MPa, exposure times between 5 - 60 min and impeller speeds of 0 - 1000 rpm were investigated. Preliminary results showed up to 86 cleaning efficiency with the

  17. Separation of the Mixed Solvent Including Methanol,Acetone and Ethyl acetate in Cefotaxime sodium Production%头孢噻肟钠生产中甲醇、丙酮与乙酸乙酯混合溶媒的分离

    Institute of Scientific and Technical Information of China (English)

    王亚其; 李科

    2012-01-01

    通过萃取精馏、精馏对甲醇、丙酮与乙酸乙酯的混合溶媒加以分离,通过对生产数据的调整,确定了萃取精馏过程中混合溶媒与萃取水加入比例为1∶1,此条件下,萃取效果最好。萃取塔顶可以得到丙酮与乙酸乙酯和水的共沸物,塔底可以得到纯度为99.5%的甲醇。%To separate the mixture solvent including methanol,acetone and ethyl acetate by extractive distillation and distillation.Through adjusting production data,to determine the ratio of the mixture solvent to water was 1∶1 in the the extractive distillation process,and under the conditions,the extraction results were the best.To obtain the azeotrope including acetone ethyl acetate and water in the top of the tower,99.5% methanol in the bottom.

  18. A facile one-step solution deposition via non-solvent/solvent mixture for efficient organometal halide perovskite light-emitting diodes.

    Science.gov (United States)

    Jiao, Bo; Zhu, Xiaobo; Wu, Wen; Dong, Hua; Xia, Bin; Xi, Jun; Lei, Ting; Hou, Xun; Wu, Zhaoxin

    2016-06-01

    Although organometal halide perovskite materials have shown great potential in light-emitting diodes, their performance is greatly restricted by the poor morphology of the perovskite layer. In this work, we demonstrate a facile one-step solution method to improve the perovskite film morphology via a non-solvent/solvent mixture. An efficient CH3NH3PbBr3-based light-emitting diode was prepared with a chlorobenzene/N,N-dimethylformamide mixed solvent. A high efficiency of 0.54 cd A(-1) is demonstrated, which is 22 times higher than that of a device fabricated by a traditional one-step solution process. Furthermore, the uniformity of the emission region and the device stability are strongly improved by this facile one-step solution process. Our work paves a new way for the morphological control of perovskite films for application in light-emitting diodes.

  19. Additive diffusion from LDPE slabs into contacting solvents as a function of solvent absorption

    NARCIS (Netherlands)

    Helmroth, I.E.; Dekker, M.; Hankemeier, Th.

    2003-01-01

    This article describes the simultaneous diffusion of a migrant and a solvent in low density polyethylene (LDPE). The migrant (Irganox 1076) moves out of the slab, while the solvent (isooctane, n-heptane or cyclohexane) moves inwards. Solvent absorption was measured separately by following the increa

  20. Additive Diffusion from LDPE Slabs into Contacting Solvents as a Function of Solvent Absorption

    NARCIS (Netherlands)

    Helmroth, I.E.; Dekker, M.; Hankemeier, T.

    2003-01-01

    This article describes the simultaneous diffusion of a migrant and a solvent in low density polyethylene (LDPE). The migrant (Irganox 1076) moves out of the slab, while the solvent (isooctane, n-heptane or cyclohexane) moves inwards. Solvent absorption was measured separately by following the increa

  1. Solvent effect in the Walden inversion reactions

    Science.gov (United States)

    Jaume, J.; Lluch, J. M.; Oliva, A.; Bertrán, J.

    1984-04-01

    The solvent effect on the fluoride exchange reaction has been studied by means of ab initio calculations using the 3-21G basis set. It is shown that the motion of the solvent molecules is an important part of the reaction coordinate.

  2. Solvation of rhodamine575 in some solvents

    Science.gov (United States)

    Sharma, Amit

    2016-05-01

    FTIR spectra of Rhodamine575 dye in powder form and in different solvents are reported. Positions of some of the observed FTIR bands show noticeable change in solvents. The bands, which shift, have contributions from the vibrational motion of nitrogen atoms of the ethylamine groups, oxygen atom of the carboxylic group attached to the phenyl ring and oxygen atom of the Xanthene ring.

  3. Composite capillary membrane for solvent resistant nanofiltration

    NARCIS (Netherlands)

    Dutczak, S.M.; Luiten-Olieman, Maria W.J.; Zwijnenberg, Harmen Jan; Bolhuis-Versteeg, Lydia A.M.; Winnubst, Aloysius J.A.; Hempenius, Mark A.; Benes, Nieck Edwin; Wessling, Matthias; Stamatialis, Dimitrios

    2011-01-01

    Solvent resistant nanofiltration (SRNF) is a membrane separation process allowing for an efficient separation of small molecules of 200–1000 g mol−1 from organic solvents. The application of SRNF in industry applications is currently hindered by a limited choice of SRNF membranes and configurations.

  4. Supercritical-Multiple-Solvent Extraction From Coal

    Science.gov (United States)

    Corcoran, W.; Fong, W.; Pichaichanarong, P.; Chan, P.; Lawson, D.

    1983-01-01

    Large and small molecules dissolve different constituents. Experimental apparatus used to test supercritical extraction of hydrogen rich compounds from coal in various organic solvents. In decreasing order of importance, relevant process parameters were found to be temperature, solvent type, pressure, and residence time.

  5. Improved Supercritical-Solvent Extraction of Coal

    Science.gov (United States)

    Compton, L.

    1982-01-01

    Raw coal upgraded by supercritical-solvent extraction system that uses two materials instead of one. System achieved extraction yields of 20 to 49 weight percent. Single-solvent yields are about 25 weight percent. Experimental results show extraction yields may be timedependent. Observed decreases in weight of coal agreed well with increases in ash content of residue.

  6. Solvent-vapor-assisted imprint lithography

    NARCIS (Netherlands)

    Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

    2007-01-01

    Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

  7. Relationship between Fermi Resonance and Solvent Effects

    Institute of Scientific and Technical Information of China (English)

    JIANG Xiu-Lan; LI Dong-Fei; SUN Cheng-Lin; LI Zhan-Long; YANG Guang; ZHOU Mi; LI Zuo-Wei; GAO Shu-Qin

    2011-01-01

    We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS2 in C6H6 at different concentrations. Also, we investigate the Fermi resonance of C6H6 and CCl4 in their solution at different pressures. It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio, etc., on the other hand, the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.%@@ We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS2 in C6H6 at different concentrations.Also,we investigate the Fermi resonance of C6H6 and CCl4 in their solution at different pressures.It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio,etc.,on the other hand,the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.

  8. Predicting the solubility of sulfamethoxypyridazine in individual solvents. II: Relationship between solute-solvent interaction terms and partial solubility parameters.

    Science.gov (United States)

    Martin, A; Bustamante, P; Escalera, B; Sellés, E

    1989-08-01

    In the first paper in the series, an expanded system of parameters was devised to account for orientation and induction effects, and the term Wh was introduced to replace delta 1h delta 2h of the extended Hansen solubility approach. In the present report, a new term, Kh = Wh/delta 1h delta 2h is observed to take on values larger or smaller than unity depending on whether the hydrogen bonded solute-solvent interaction is larger or smaller than predicted by the term delta 1h delta 2h. The acidic delta a and basic delta b solubility parameters are used to represent two parameters, sigma and tau, suggested by Small in his study of proton donor-acceptor properties. The Small equation, including a heat of mixing term for hydrogen bonded species, is shown to be capable of semiquantitative evaluation. A partial molar heat delta H2h of hydrogen bonding is calculated using delta h and Wh terms; delta H2h is found to be correlated with the logarithm of the residual activity coefficient, In alpha R, a term representing strong solute-solvent interaction. The terms Wh, delta H2h, and In alpha 2R may be used to test the deviation from the geometric mean assumed in regular solution theory, and to replace the hydrogen bonding terms of the extended Hansen three-parameter model. The solubility of sulfamethoxypyridazine in 30 solvents is used to test the semiempirical solubility equations. The results are interpreted in terms of partial solubility parameters and the proton donor-acceptor properties of the solvents.

  9. Toxic hepatitis in occupational exposure to solvents

    Institute of Scientific and Technical Information of China (English)

    Giulia Malaguarnera; Emanuela Cataudella; Maria Giordano; Giuseppe Nunnari; Giuseppe Chisari; Mariano Malaguarnera

    2012-01-01

    The liver is the main organ responsible for the metabolism of drugs and toxic chemicals,and so is the primary target organ for many organic solvents.Work activities with hepatotoxins exposures are numerous and,moreover,organic solvents are used in various industrial processes.Organic solvents used in different industrial processes may be associated with hepatotoxicity.Several factors contribute to liver toxicity; among these are:species differences,nutritional condition,genetic factors,interaction with medications in use,alcohol abuse and interaction,and age.This review addresses the mechanisms of hepatotoxicity.The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are:inflammation,dysfunction of cytochrome P450,mitochondrial dysfunction and oxidative stress.The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.

  10. Assessment of solvents for cellulose dissolution.

    Science.gov (United States)

    Ghasemi, Mohammad; Tsianou, Marina; Alexandridis, Paschalis

    2017-03-01

    A necessary step in the processing of biomass is the pretreatment and dissolution of cellulose. A good solvent for cellulose involves high diffusivity, aggressiveness in decrystallization, and capability of disassociating the cellulose chains. However, it is not clear which of these factors and under what conditions should be improved in order to obtain a more effective solvent. To this end, a newly-developed phenomenological model has been applied to assess the controlling mechanism of cellulose dissolution. Among the findings, the cellulose fibers remain crystalline almost to the end of the dissolution process for decrystallization-controlled kinetics. In such solvents, decreasing the fiber crystallinity, e.g., via pretreatment, would result in a considerable increase in the dissolution rate. Such insights improve the understanding of cellulose dissolution and facilitate the selection of more efficient solvents and processing conditions for biomass. Specific examples of solvents are provided where dissolution is limited due to decrystallization or disentanglement.

  11. Preparation of coal slurry with organic solvents.

    Science.gov (United States)

    Shin, Yu-Jen; Shen, Yun-Hwei

    2007-06-01

    In this study, various organic solvents were used to prepare coal slurries and the rheological and thermal properties of coal-organic solvent slurries were examined. Solvents with molecules containing unpaired electrons (high basicity) show high extraction power and cause swelling of coal. Therefore, coal-organic solvent slurries usually showed higher viscosities compared to coal-water slurry. In addition, coal slurries prepared by alcohols and cyclohexanone demonstrated lower settling rates but a high specific sedimentation volume presumably because these solvents swelled coal particles well and led to the formation of weak gel structures in the bulk. In addition, ethanol and cyclohexanone are capable of breaking a considerable amount of hydrogen bonds in coal and subsequently opening up the structures. Thus, more surface area is available for combustion and the combustion rate of coal slurries was increased.

  12. Efficient cellulose solvent: quaternary ammonium chlorides.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; El Seoud, Omar A; Heinze, Thomas

    2013-10-01

    Pure quaternary tetraalkylammonium chlorides with one long alkyl chain dissolved in various organic solvents constitute a new class of cellulose solvents. The electrolytes are prepared in high yields and purity by Menshutkin quaternization, an inexpensive and easy synthesis route. The pure molten tetraalkylammonium chlorides dissolve up to 15 wt% of cellulose. Cosolvents, including N,N-dimethylacetamide (DMA), may be added in large excess, leading to a system of decreased viscosity. Contrary to the well-established solvent DMA/LiCl, cellulose dissolves in DMA/quaternary ammonium chlorides without any pretreatment. Thus, the use of the new solvent avoids some disadvantages of DMA/LiCl and ionic liquids, the most extensively employed solvents for homogeneous cellulose chemistry.

  13. Green-solvent-processable organic solar cells

    Directory of Open Access Journals (Sweden)

    Shaoqing Zhang

    2016-11-01

    Full Text Available Solution-processable organic photovoltaics (OPV has emerged as a promising clean energy-generating technology due to its potential for low-cost manufacturing with a high power/weight ratio. The state-of-the-art OPV devices are processed by hazardous halogenated solvents. Fabricating high-efficiency OPV devices using greener solvents is a necessary step toward their eventual commercialization. In this review, recent research efforts and advances in green-solvent-processable OPVs are summarized, and two basic strategies including material design and solvent selection of light-harvesting layers are discussed. In particular, the most recent green-solvent-processable OPVs with high efficiencies in excess of 9% are highlighted.

  14. Investigation of aggregation in solvent extraction of lanthanides by acidic extractants (organophosphorus and naphthenic acid)

    Science.gov (United States)

    Zhou, N.; Wu, J.; Yu, Z.; Neuman, R.D.; Wang, D.; Xu, G.

    1997-01-01

    Three acidic extractants (I) di(2-ethylhexyl) phosphoric acid (HDEHP), (II) 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (HEHPEHE) and (III) naphthenic acid were employed in preparing the samples for the characterization of the coordination structure of lanthanide-extractant complexes and the physicochemical nature of aggregates formed in the organic diluent of the solvent extraction systems. Photo correlation spectroscopy (PCS) results on the aggregates formed by the partially saponified HDEHP in n-heptane showed that the hydrodynamic radius of the aggregates was comparable to the molecular dimensions of HDEHP. The addition of 2-octanol into the diluent, by which the mixed solvent was formed, increased the dimensions of the corresponding aggregates. Aggregates formed from the lanthanide ions and HDEHP in the organic phase of the extraction systems were found very unstable. In the case of naphthenic acid, PCS data showed the formation of w/o microemulsion from the saponified naphthenic acid in the mixed solvent. The extraction of lanthanides by the saponified naphthenic acid in the mixed solvent under the given experimental conditions was a process of destruction of the w/o microemulsion. A possible mechanism of the breakdown of the w/o microemulsion droplets is discussed.

  15. [Neurotoxicity of organic solvents--recent findings].

    Science.gov (United States)

    Matsuoka, Masato

    2007-06-01

    In this review, the recent findings of central nervous system (CNS) or peripheral nervous system (PNS) dysfunction induced by occupational exposure to organic solvents are described. While acute, high-level exposure to almost all organic solvents causes the general, nonspecific depression of CNS, it is still not clear whether chronic, low-level occupational exposure causes the chronic neurological dysfunction which has been called "organic solvent syndrome", "painters syndrome", "psycho-organic syndrome" or "chronic solvent encephalopathy". At least at lower than occupational exposure limits, chronic and low-level organic solvent exposure does not appear to cause the "sy mptomatic" neurological dysfunction. The chronic, moderate- to high-level exposure to a few organic solvents (such as carbon disulfide, n-hexane and methyl n-butyl ketone) affects CNS or PNS specifically. The substitutes for chlorofluorocarbons, 2-bromopropane and 1-bromopropane were shown to have the peripheral nerve toxicity in the experimental animals. Shortly after these observations, human cases of 1-bromopropane intoxication with the dysfunction of CNS and PNS were reported in the United States. Neurological abnormalities in workers of a 1-bromopropane factory in China were also reported. Thus, the possible neurotoxicity of newly introduced substitutes for ozone-depleting solvents into the workplace must be considered. Enough evidences indicate that some common solvents (such as toluene and styrene) induce sensorineural hearing loss and acquired color vision disturbances in workers. In some studies using magnetic resonance imaging (MRI), cerebral atrophy, patchy periventricular hyperintensities and hypointensities in the basal ganglia were found in solvent-exposed workers as have been shown in toluene abusers (toluene leukoencephalopathy). Further studies using the neurobehavioral test batteries, neurophysiological measurements and advanced neuroimaging techniques are required to detect the

  16. The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

    CERN Document Server

    Lagowski, J J

    1976-01-01

    The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

  17. Solvation of Lithium Irons in Mixed Organic Electrolyte Solutions by Electrospray Ionization Mass Spectroscopy

    OpenAIRE

    MATSUDA, Yoshiharu; FUKUSHIMA, Tsuyoshi; Hashimoto, Hiroyuki; ARAKAWA, Ryuichi

    2002-01-01

    Solvation of lithium ions in mixed organic electrolyte solutions for secondary lithium batteries was investigated by electrospray ionization mass spectroscopy. The electrolyte solutions were mixed binary solutions of diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylene carbonate (EC),γ-butyrolactone (GBL), and propylene carbonate (PC) containing LiClO4. Lithium ions solvated mainly to two solvent molecules. The order of the inclination of the solvent molecules solvating to lithium ions...

  18. PARIS II: Computer Aided Solvent Design for Pollution Prevention

    Science.gov (United States)

    This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

  19. Thermal decomposition of organic solvent with nitric acid in nuclear fuel reprocessing plants

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Tadao; Nishio, Gunji; Takada, Junichi; Tukamoto, Michio; Watanabe, Kouji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Miyata, Sadaichirou

    1995-02-01

    Since a thermal decomposition of organic solvent containing TBP (tributyl phosphate) with nitric acid and heavy metal nitrates is an exothermic reaction, it is possible to cause an explosive decomposition of TBP-complex materials formed by a nitration between the solvent and nitric acid, if the solvent involving TBP-complex is heated upto a thermal limit in an evaporator to concentrate a fuel liquid solution from the extraction process in the reprocessing plant. In JAERI, the demonstration test for explosive decomposition of TBP-complex by the nitration was performed to elucidate the safety margin of the evaporator in the event of hypothetical explosion under auspices of the Science and Technology Agency. The demonstration test was carried out by heating TBP/n-dodecane solvent mixed with nitric acid and uranium nitrate. In the test, the thermal decomposition behavior of the solvent was examined, and also a kinematic reaction constant and a heat formation of the TBP-complex decomposition were measured by the test. In the paper, a safety analysis of a model evaporator was conducted during accidental conditions under the explosive decomposition of the solvent. (author).

  20. Mixed cryoglobulinemia

    Directory of Open Access Journals (Sweden)

    Ferri Clodoveo

    2008-09-01

    Full Text Available Abstract Mixed cryoglobulinemia (MC, type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1, but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers, chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome

  1. Microwave-Assisted Solvent-Free Synthesis of Zeolitic Imidazolate Framework-67

    Directory of Open Access Journals (Sweden)

    Heng Zhang

    2016-01-01

    Full Text Available A microporous metal-organic framework (MOF, cobalt-based zeolitic imidazolate framework-67 (ZIF-67, was synthesized by the combination of solvent-free hand-mill and microwave irradiation, without any organic solvent and within 30 minutes. The hand-milling process can mix the reactants well by the virtue of high moisture/water absorption capacity of reactants. In addition, the outstanding electromagnetic wave absorption capability of cobalt leads to efficient conversion to MOF structures before carbonization. The obtained ZIF-67 possesses high surface area and micropore volume.

  2. THE INFLUENCE OF THE SOLVENT ON THE THERMODYNAMICS OF ION ASSOCIATION

    Directory of Open Access Journals (Sweden)

    Vitalii Chumak

    2011-03-01

    Full Text Available Abstract. Some approaches which allow to divide thermodynamic functions of the ion associationprocess in two components have been developed. The first component belongs to the process, the second oneis caused by the temperature dependence of the dielectric permittivity of the solvent. The theory is confirmedby numerous examples of the ion association process of different electrolytes in the binary mixed solvents.Keywords: covalent part of the constant of ionic association, electrostatic part of the constant of ionicassociation, enthalpy of the chemical equilibria in solution, enthropy of the chemical equilibria in solution,ionic association, ionic equilibrias, the equilibrium constant.

  3. Predicting the Solubility of Pharmaceutical Cocrystals in Solvent/Anti-Solvent Mixtures

    Directory of Open Access Journals (Sweden)

    Linda Lange

    2016-05-01

    Full Text Available In this work, the solubilities of pharmaceutical cocrystals in solvent/anti-solvent systems were predicted using PC-SAFT in order to increase the efficiency of cocrystal formation processes. Modeling results and experimental data were compared for the cocrystal system nicotinamide/succinic acid (2:1 in the solvent/anti-solvent mixtures ethanol/water, ethanol/acetonitrile and ethanol/ethyl acetate at 298.15 K and in the ethanol/ethyl acetate mixture also at 310.15 K. The solubility of the investigated cocrystal slightly increased when adding small amounts of anti-solvent to the solvent, but drastically decreased for high anti-solvent amounts. Furthermore, the solubilities of nicotinamide, succinic acid and the cocrystal in the considered solvent/anti-solvent mixtures showed strong deviations from ideal-solution behavior. However, by accounting for the thermodynamic non-ideality of the components, PC-SAFT is able to predict the solubilities in all above-mentioned solvent/anti-solvent systems in good agreement with the experimental data.

  4. Organic Solvent Tolerant Lipases and Applications

    Directory of Open Access Journals (Sweden)

    Shivika Sharma

    2014-01-01

    Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

  5. Polar Solvents Trigger Formation of Reverse Micelles.

    Science.gov (United States)

    Khoshnood, Atefeh; Firoozabadi, Abbas

    2015-06-09

    We use molecular dynamics simulations and molecular thermodynamics to investigate the formation of reverse micelles in a system of surfactants and nonpolar solvents. Since the early observation of reverse micelles, the question has been whether the existence of polar solvent molecules such as water is the driving force for the formation of reverse micelles in nonpolar solvents. In this work, we use a simple coarse-grained model of surfactants and solvents to show that a small number of polar solvent molecules triggers the formation of large permanent aggregates. In the absence of polar molecules, both the thermodynamic model and molecular simulations show that small aggregates are more populated in the solution and larger ones are less frequent as the system evolves over time. The size and shape of reverse micelles depend on the size of the polar core: the shape is spherical for a large core and ellipsoidal for a smaller one. Using the coarse-grained model, we also investigate the effect of temperature and surfactant tail length. Our results reveal that the number of surfactant molecules in the micelle decreases as the temperature increases, but the average diameter does not change because the size of the polar core remains invariant. A reverse micelle with small polar core attracts fewer surfactants when the tail is long. The uptake of solvent particles by a micelle of longer surfactant tail is less than shorter ones when the polar solvent particles are initially distributed randomly.

  6. Auditory dysfunction associated with solvent exposure

    Directory of Open Access Journals (Sweden)

    Fuente Adrian

    2013-01-01

    Full Text Available Abstract Background A number of studies have demonstrated that solvents may induce auditory dysfunction. However, there is still little knowledge regarding the main signs and symptoms of solvent-induced hearing loss (SIHL. The aim of this research was to investigate the association between solvent exposure and adverse effects on peripheral and central auditory functioning with a comprehensive audiological test battery. Methods Seventy-two solvent-exposed workers and 72 non-exposed workers were selected to participate in the study. The test battery comprised pure-tone audiometry (PTA, transient evoked otoacoustic emissions (TEOAE, Random Gap Detection (RGD and Hearing-in-Noise test (HINT. Results Solvent-exposed subjects presented with poorer mean test results than non-exposed subjects. A bivariate and multivariate linear regression model analysis was performed. One model for each auditory outcome (PTA, TEOAE, RGD and HINT was independently constructed. For all of the models solvent exposure was significantly associated with the auditory outcome. Age also appeared significantly associated with some auditory outcomes. Conclusions This study provides further evidence of the possible adverse effect of solvents on the peripheral and central auditory functioning. A discussion of these effects and the utility of selected hearing tests to assess SIHL is addressed.

  7. Solvent Effect on the Photolysis of Riboflavin.

    Science.gov (United States)

    Ahmad, Iqbal; Anwar, Zubair; Ahmed, Sofia; Sheraz, Muhammad Ali; Bano, Raheela; Hafeez, Ambreen

    2015-10-01

    The kinetics of photolysis of riboflavin (RF) in water (pH 7.0) and in organic solvents (acetonitrile, methanol, ethanol, 1-propanol, 1-butanol, ethyl acetate) has been studied using a multicomponent spectrometric method for the assay of RF and its major photoproducts, formylmethylflavin and lumichrome. The apparent first-order rate constants (k obs) for the reaction range from 3.19 (ethyl acetate) to 4.61 × 10(-3) min(-1) (water). The values of k obs have been found to be a linear function of solvent dielectric constant implying the participation of a dipolar intermediate along the reaction pathway. The degradation of this intermediate is promoted by the polarity of the medium. This indicates a greater stabilization of the excited-triplet states of RF with an increase in solvent polarity to facilitate its reduction. The rate constants for the reaction show a linear relation with the solvent acceptor number indicating the degree of solute-solvent interaction in different solvents. It would depend on the electron-donating capacity of RF molecule in organic solvents. The values of k obs are inversely proportional to the viscosity of the medium as a result of diffusion-controlled processes.

  8. Chemical reactions in solvents and melts

    CERN Document Server

    Charlot, G

    1969-01-01

    Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

  9. a Molecular Approach to Electrolyte Solutions: Predicting Phase Behavior and Thermodynamic Properties of Single and Binary-Solvent Systems

    Science.gov (United States)

    Gering, Kevin Leslie

    A molecular formulation based on modern liquid state theory is applied to the properties and phase behavior of electrolyte systems containing volatile species. An electrolyte model based on the exponential modification of the Mean Spherical Approximation (EXP-MSA) is used to describe the cation-cation, cation-anion, and anion-anion distributions of the ionic species. This theory represents an improvement over the nonmodified MSA approach, and goes beyond the usual Debye-Huckel theory and Pitzer correlation for treating concentrated solutions. Electrolyte solutions such as water-salt, ammonia-salt, mixed salts, and mixed -solvent systems are investigated over a wide range of temperatures, pressures, and compositions. The usual salt properties, such as osmotic and mean activity coefficients and other thermodynamic properties (enthalpies), are calculated. The predictions are accurate to saturation limits. In addition, an iterative method is presented that is used to predict vapor-liquid equilibria (VLE) and thermodynamic properties of single-salt multisolvent electrolytes of the form solvent-cosolvent-salt. In this method, a local composition model (LCM) and EXP-MSA theory are combined with traditional phase equilibria relations to estimate the pressures and compositions of a vapor phase in equilibrium with a binary-solvent electrolyte. Also, a pseudo-solvent model is proposed as a means of obtaining a variety of averaged liquid phase electrolyte properties. To predict preferential solvation in mixed solvents, a general framework is developed that is based on predicted solvation numbers of each solvent. Preferential solvation will be shown to influence VLE. Results show that phase equilibria is accurately predicted by the above iterative method. Three mixed-solvent electrolyte systems are investigated: water -ethylene glycol-LiBr, ammonia-water-LiBr, and methanol -water-LiCl. Finally, the above electrolyte model is utilized in predicting design criteria for a single

  10. Solvent-Free Synthesis of New Coumarins

    Directory of Open Access Journals (Sweden)

    Redah I. Al-Bayati

    2012-01-01

    Full Text Available A solvent-free synthesis of five series of coumarin derivatives using microwave assistant is presented herein. The synthesized compounds are fully characterized by UV-VIS, FT-IR, and NMR spectroscopy.

  11. "Solvent Effects" in 1H NMR Spectroscopy.

    Science.gov (United States)

    Cavaleiro, Jose A. S.

    1987-01-01

    Describes a simple undergraduate experiment in chemistry dealing with the "solvent effects" in nuclear magnetic resonance (NMR) spectroscopy. Stresses the importance of having students learn NMR spectroscopy as a tool in analytical chemistry. (TW)

  12. Solvent Extraction Developments in Southern Africa

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The largest solvent-extraction plant in the world at the time, the Nchanga Copper Operation, was in Zambia. The first commercial process using solvent extraction for the refining of the platinum-group metals was in South Africa. More recently, the Southern African region has seen the implementation of solvent extraction for other base metals, precious metals, and specialty metals. These include the world firsts of primary production of zinc at Skorpion Zinc in Namibia and the large-scale refining of gold by Harmony Gold in South Africa. Several other flowsheets that use solvent-extraction technology are currently under commissioning, development, or feasibility study for implementation in this part of the world, including those for the recovery of copper, cobalt, nickel, tantalum, and niobium.

  13. Natural deep eutectic solvents as new potential media for green technology

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yuntao [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Spronsen, Jaap van; Witkamp, Geert-Jan [Laboratory for Process Equipment, Delft University of Technology, Delft (Netherlands); Verpoorte, Robert [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Choi, Young Hae, E-mail: y.choi@chem.leidenuniv.nl [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands)

    2013-03-05

    Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the

  14. Effects of organic solvent and solution temperature on electrospun polyvinylidene fluoride nanofibers.

    Science.gov (United States)

    Wei, Kai; Kim, Han-Ki; Kimura, Naotaka; Suzuki, Hiroaki; Satou, Hidekazu; Lee, Ki-Hoon; Park, Young-Hwan; Kim, Ick-Soo

    2013-04-01

    In this study, the Poly(vinylidene fluoride-trifluoethylene) (PVDF) electrospun fibers were successfully prepared by electrospinning. Processing parameters, such as solvents and solution temperature were varied to study their influence on fiber dimensions. Electrospun PVDF fibers were characterized by scanning electron microscope (SEM), Fourier transform infrared spectrophotometer (FT-IR), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). The result indicated that the solvent component and temperature have great influence on fiber dimensions. 19% PVDF dissolved in DMF/MEK mixed solvents with the ratio of 8:2 was considered to be most suitable in this study. Furthermore, the increasing of solution temperature can probably induce the formation of beta-phases in electrospun PVDF Fibers.

  15. Water as a Solvent for Life

    Science.gov (United States)

    Pohorille, Andrew; Pratt, Lawrence R.

    2015-01-01

    "Follow the water" is our basic strategy in searching for life in the universe. The universality of water as the solvent for living systems is usually justified by arguing that water supports the rich organic chemistry that seeds life, but alternative chemistries are possible in other organic solvents. Here, other, essential criteria for life that have not been sufficiently considered so far, will be discussed.

  16. Biofiltration of solvent vapors from air

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Young-sook.

    1993-01-01

    For various industrial solvent vapors, biofiltration promises to offer a cost-effective emission control technology. Exploiting the full potential of this technology will help attain the goals of the Clean Air Act Amendments of 1990. Concentrating on large volumes of volatile industrial solvents, stable multicomponent microbial enrichments capable of growing a mineral medium with solvent vapors as their only source of carbon and energy were obtained from soil and sewage sludge. These consortia were immobilized on an optimized porous solid support (ground peat moss and perlite). The biofilter material was packed in glass columns connected to an array of pumps and flow meters that allowed the independent variation of superficial velocity and solvent vapor concentrations. In various experiments, single solvents, such as methanol, butanol, acetonitrile, hexane and nitrobenzene, and solvent mixtures, such as benzene-toluene-xylene (BTX) and chlorobenzene-o-dichlorobenzene (CB/DCB) were biofiltered with rates ranging from 15 to334 g solvent removed per m[sup 3] filter volume /h. Pressure drops were low to moderate (0-10 mmHg/m) and with periodic replacement of moisture, the biofiltration activity could be maintained for a period of several months. The experimental data on methanol biofiltration were subjected to mathematical analysis and modeling by the group of Dr. Baltzis at NJIT for a better understanding and a possible scale up of solvent vapor biofilters. In the case of chlorobenzenes and nitrobenzene, the biofilter columns had to be operated with water recirculation in a trickling filter mode. To prevent inactivation of the trickling filter by acidity during CB/DCB removal, pH control was necessary, and the removal rate of CB/DCB was strongly influenced by the flow rate of the recyling water. Nitrobenzene removal in a trickling filter did not require pH control, since the nitro group was reduced and volatilized as ammonia.

  17. Competitive solvent-molecule interactions govern primary processes of diphenylcarbene in solvent mixtures

    Science.gov (United States)

    Knorr, Johannes; Sokkar, Pandian; Schott, Sebastian; Costa, Paolo; Thiel, Walter; Sander, Wolfram; Sanchez-Garcia, Elsa; Nuernberger, Patrick

    2016-10-01

    Photochemical reactions in solution often proceed via competing reaction pathways comprising intermediates that capture a solvent molecule. A disclosure of the underlying reaction mechanisms is challenging due to the rapid nature of these processes and the intricate identification of how many solvent molecules are involved. Here combining broadband femtosecond transient absorption and quantum mechanics/molecular mechanics simulations, we show for one of the most reactive species, diphenylcarbene, that the decision-maker is not the nearest solvent molecule but its neighbour. The hydrogen bonding dynamics determine which reaction channels are accessible in binary solvent mixtures at room temperature. In-depth analysis of the amount of nascent intermediates corroborates the importance of a hydrogen-bonded complex with a protic solvent molecule, in striking analogy to complexes found at cryogenic temperatures. Our results show that adjacent solvent molecules take the role of key abettors rather than bystanders for the fate of the reactive intermediate.

  18. Solvent dependent photophysical properties of dimethoxy curcumin

    Science.gov (United States)

    Barik, Atanu; Indira Priyadarsini, K.

    2013-03-01

    Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Δf), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (ϕf) and fluorescence lifetime (τf) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, ϕf increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes.

  19. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Computer-aided tool for solvent selection in pharmaceutical processes: Solvent swap

    DEFF Research Database (Denmark)

    Papadakis, Emmanouil; K. Tula, Anjan; Gernaey, Krist V.

    In the pharmaceutical processes, solvents have a multipurpose role since different solvents can be used in different stages (such as chemical reactions, separations and purification) in the multistage active pharmaceutical ingredients (APIs) production process. The solvent swap and selection task......-aided framework with the objective to assist the pharmaceutical industry in gaining better process understanding. A software interface to improve the usability of the tool has been created also....

  1. Influence of solvent polarity on preferential solvation of molecular recognition probes in solvent mixtures.

    Science.gov (United States)

    Amenta, Valeria; Cook, Joanne L; Hunter, Christopher A; Low, Caroline M R; Vinter, Jeremy G

    2012-12-13

    The association constants for formation of 1:1 complexes between a H-bond acceptor, tri-n-butylphosphine oxide, and a H-bond donor, 4-phenylazophenol, have been measured in a range of different solvent mixtures. Binary mixtures of n-octane and a more polar solvent (ether, ester, ketone, nitrile, sulfoxide, tertiary amide, and halogenated and aromatic solvents) have been investigated. Similar behavior was observed in all cases. When the concentration of the more polar solvent is low, the association constant is identical to that observed in pure n-octane. Once a threshold concentration of the more polar solvent in reached, the logarithm of the association constant decreases in direct proportion to the logarithm of the concentration of the more polar solvent. This indicates that one of the two solutes is preferentially solvated by the more polar solvent, and it is competition with this solvation equilibrium that determines the observed association constant. The concentration of the more polar solvent at which the onset of preferential solvation takes place depends on solvent polarity: 700 mM for toluene, 60 mM for 1,1,2,2-tetrachloroethane, 20 mM for the ether, ester, ketone, and nitrile, 0.2 mM for the tertiary amide, and 0.1 mM for the sulfoxide solvents. The results can be explained by a simple model that considers only pairwise interactions between specific sites on the surfaces of the solutes and solvents, which implies that the bulk properties of the solvent have little impact on solvation thermodynamics.

  2. An Organic Mixed Ion–Electron Conductor for Power Electronics

    DEFF Research Database (Denmark)

    Malti, Abdellah; Edberg, Jesper; Granberg, Hjalmar

    2016-01-01

    A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting...

  3. An Organic Mixed Ion-Electron Conductor for Power Electronics

    DEFF Research Database (Denmark)

    Malti, Abdellah; Edberg, Jesper; Granberg, Hjalmar

    2016-01-01

    A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting...

  4. Enthalpy and entropy contributions to the solubility of sulphamethoxypyridazine in solvent mixtures showing two solubility maxima.

    Science.gov (United States)

    Bustamante, P; Escalera, B

    1995-07-01

    The solubility of sulphamethoxypyridazine was measured at several temperatures in mixtures of water:ethanol and ethanol:ethyl acetate. Sulphamethoxypyridazine was chosen as a model drug to compare the solvation effects of proton donor-proton acceptor (water and ethanol) and proton acceptor (ethyl acetate) solvents and mixtures of these solvents because this drug contains functional groups capable of Lewis acid-base interaction. A plot of the mole fraction solubility against the solubility parameter (delta 1 = 30.87 MPa1/2 (20:80 v/v water:ethanol) and another at delta 1 = 20.88 MPa1/2 (30:70 v/v ethanol:ethyl acetate) at all the temperatures under study. The enthalpies and entropies of mixing as well as the enthalpies and entropies of transfer of sulphamethoxypyridazine from ethanol of mixing as well as the enthalpies and entropies of transfer of sulphamethoxypyridazine from ethanol to water:ethanol and ethanol:ethyl acetate mixtures were calculated to compare solvation characteristics of the solvent mixtures toward the drug. As ethanol is added to water, the entropy increases and the structure of the solvent mixture became less ordered, favouring the interaction of the drug with the solvent mixture. On the other hand, in the case of the ethanol:ethyl acetate mixture, solubility is favoured by the more negative enthalpy values. This way, the same result, i.e. a solubility maximum, is obtained by different routes. In the ethanol:water mixtures, the dissolution process if entropy-controlled while enthalpy is the driving force in the case of ethanol:ethyl acetate mixtures. The two solvent systems show enthalpy-entropy compensation. Water deviates from the linear relationship due possibly to its hydrophobic effect.

  5. CHEMICAL STABILITY OF POLYPHENYLENE SULFIDE IN THE NEXT GENERATION SOLVENT FOR CAUSTIC-SIDE SOLVENT EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Fink, S.

    2011-12-08

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. For simplicity, this solvent is referred to as the Next Generation Solvent (NGS). The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The initial deployment target envisioned for the technology was within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with polyphenylene sulfide (PPS), the polymer used in the coalescers within MCU. This report provides the data from exposing PPS polymer to NGS. The test was conducted over a three month period. PPS is remarkably stable in the presence of the next generation solvent. Testing showed no indication of swelling or significant leaching. Preferential sorption of the Modifier on PPS was observed but the same behavior occurs with the baseline solvent. Therefore, PPS coalescers exposed to the NGS are expected to perform comparably to those in contact with the baseline solvent.

  6. The use of environmentally sustainable bio-derived solvents in solvent extraction applications-A review

    Institute of Scientific and Technical Information of China (English)

    Zheng Li; Kathryn H. Smith; Geoffrey W. Stevens

    2016-01-01

    Replacement of volatile organic compounds (VOCs) by greener or more environmental y sustainable solvents is becoming increasingly important due to the increasing health and environmental concerns as wel as economic pressures associated with VOCs. Solvents that are derived from biomass, namely bio-derived solvents, are a type of green solvent that have attracted intensive investigations in recent years because of their advantages over con-ventional VOCs, such as low toxicity, biodegradability and renewability. This review aims to summarize the use of bio-derived solvents in solvent extraction applications, with special emphasis given to utilization of biodiesels and terpenes. Compared with the conventional VOCs, the overall performance of these bio-derived solvents is comparable in terms of extraction yields and selectivity for natural product extraction and no difference was found for metal extraction. To date most researchers have focused on laboratory scale thermodynamics studies. Future work is required to develop and test new bio-derived solvents and understand the kinetic performance as well as solvent extraction pilot plant studies.

  7. CHEMICAL STABILITY OF POLYPHENYLENE SULFIDE IN THE NEXT GENERATION SOLVENT FOR CAUSTIC-SIDE SOLVENT EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Fink, S.

    2011-12-08

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. For simplicity, this solvent is referred to as the Next Generation Solvent (NGS). The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The initial deployment target envisioned for the technology was within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with polyphenylene sulfide (PPS), the polymer used in the coalescers within MCU. This report provides the data from exposing PPS polymer to NGS. The test was conducted over a three month period. PPS is remarkably stable in the presence of the next generation solvent. Testing showed no indication of swelling or significant leaching. Preferential sorption of the Modifier on PPS was observed but the same behavior occurs with the baseline solvent. Therefore, PPS coalescers exposed to the NGS are expected to perform comparably to those in contact with the baseline solvent.

  8. Influence of Energy on Solvent Diffusion in Polymer/Solvent Systems

    Institute of Scientific and Technical Information of China (English)

    HUHuijun; JIANGWenhua; 等

    2002-01-01

    The Vrentas-Duda free-volume theory has been extensively used to correlate or predict the solvent diffusion coefficient of a polymer/solvent system.The energy term in the free volume diffusion equation is difficult to estimate,so the energy term was usually neglected in previous predictive versions of the free volume diffusion coefficient equation.Recent studies show that the energy effect is very important even above the glass transition temperature of the system. In this paper, a new evaluation method of the energy term is proposed,that is the diffusion energy at different solvent concentrations is assumed to be a linear function of the solvent diffusion energy in pure solvents and that in polymers under the condition that the solvent in infinite dilution.By taking consideration of the influence of energy on the solvent diffustion,the prediction of solvent diffusion coefficient was preformed for three polymer/solvent systems over a wide range of concentrations and temperatures.The results show an improvement on the predictive capability of the free volume diffusion theory.

  9. Conductivity of LiBF4/mixed ether electrolytes for secondary lithium cells

    Science.gov (United States)

    Matsuda, Y.; Morita, M.; Yamashita, T.

    1984-12-01

    Electrolytic conductivity of LiBF4 has been studied in the mixed system of 1,3-dioxolane with 1,2-dimethoxyethane or with tetrahydrofuran. Relative permittivity (dielectric constant) of the solvents suggested the formation of associated ion pairs in the systems, but the conductivity measured was higher than that expected from the viewpoint of ionic association. Conductivity maxima were observed in the solutions containing about 1:1 (by volume) mixed solvents. Viscosities of the solvent and the solution were also measured, and their contribution to the conductivity change with the solvent composition was discussed. Solute concentration dependence of the molar conductivity was specific for the ether solutions. Apparent activation energy for conduction, which was determined by the temperature dependence of the conductivity, varied with LiBF4 concentration. Structural specificity of the mixed ether solutions was discussed with these parameters and H-1 NMR spectra of the solutions.

  10. Phase transition of carbonate solvent mixture solutions at low temperatures

    Science.gov (United States)

    Okumura, Takefumi; Horiba, Tatsuo

    2016-01-01

    The phase transition of carbonate solvent mixture solutions consisting of ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and LiPF6 salt have been studied for improving the low temperature performance of lithium-ion batteries. The Li ion conductivity at 25 °C was maximum at x = 0.3 in a series of 1 M LiPF6 mixed carbonate solvents compositions consisting of ECxDMC0.5-0.5xEMC0.5-0.5x (x = 0 to 0.6), while the maximum tended to shift to x = 0.2 as the temperature lowered. The differential scanning calorimetry results showed that the freezing temperature depressions of EC in the 1 M LiPF6 solution were larger than those of the DMC or EMC. The chemical shift of 7Li nuclear magnetic resonance changed from a constant to increasing at around x = 0.3, which could be reasonably understood by focusing on the change in solvation energy calculated using Born equation. However, in the region of a high EC concentration of over x = 0.3 (EC/LiPF6 > 4) in the 1 M LiPF6 solution, the free EC from the solvation to the lithium ions seems to reduce the freezing temperature depression of the EC, and thus, decreases the ionic conductivity of the solution at low temperatures, due to the EC freezing.

  11. Mixed Stroke

    Institute of Scientific and Technical Information of China (English)

    HuangRuxun(黄如训); Zeng Jinsheng(曾进胜)

    2000-01-01

    Purpose To summarize the chnical, autoptic and animal experimental dala of stroke, propose the concept of mixed stroke (MS) and demonstrate the enoiogy, pathogenesis, clinical mainfestations, prophylaxis and treatment of MS Background At present. stroke still is classified in the national and international academic fields as two main groups: hemorrhage and ischema In fact, thc cerebral vascular disease with hemorrhage forus and ischema focus at the same time is not rare moreover, this type of stroke has special etiology, pathogenesis and clinical manifestations. But it is always made a main dagnosis and neglected the other nature of coexistent focus on either clinical or pathological diagnosis according to traditional classification of stroke Data sources and methods Mort of pablished originsl articles about MS in our department and laboralory wcre reviewed. Resulta The clinical autoptic and animal experimental dats all prcved that hemorrhage and infarction could occur in the course of a stroke simultaneously or in suecession during a short time, which demonstrated the existence of MS It was found clinically that MS patients all had the hustory of hypcrtension and in the autoptic data the MS patients dying of stroke all had typical hypertensive changes in the heart and kidney. and had hypertensive arteriosclerosis in the cerebral arteriole and small artery. MS was cas lily thdueed in stroke-prone renovascular hypertensivc rats This kind of rats are free from genetic deficiency and arc not affected by senile factor, so their cerebral vascular foci are mainly induced by the single factor -hypertension. TThese indicate definitely that hypertensive cerebral vascular lesion is the basis inducing MS. The main lesions of hypertensive cerebral arteriole and small artery were hyalinosis and fibrinoid of the walls, and the formation of microaneurysms or hyperplasla of iniernal and external layers The math lcsions of hypertensive cerebral capillaries were increasing vascular

  12. EFFECT OF SOLVENT COMPOSITION ON THE SULFONATION DEGREE OF OLY(PHENYLENE OXIDE) (PPO)

    Institute of Scientific and Technical Information of China (English)

    Tong-wen Xu; Wei-hua Yang; Bing-lin He

    2002-01-01

    This paper investigates the possibility of attaining sulphonated poly(phenylene oxide) (SPPO) with a relatively higher sulfonation degree. To achieve this aim, the approach we adopt is to improve the solubility of the final product in the mixed solvent so that the sulfonation may take place between the bulk solutions and PPO powders even at higher sulfonation degree. It is shown that the addition of a proper amount of dimethyl formide (DMF) to the conventional PPO-chloroform system can actually enhance the sulfonation effect. The solvent composition is then correlated with the sulfonation degree based on the solubility parameters. It is interesting to find that solubility parameters between the mixed solvent and the precipitated products keep an approximately unchanged value at about 4.9, which is just equal to that when pure chloroform is used, though the solubility parameters of both solvents increase with the content of DMF in solution. This may be the main reason why the addition of DMF can reduce the precipitation and improve the ion exchange capacity (IEC) of SPPO polymer.

  13. Effect of Solvents on Oxidation of 1,1′-Bi-2-naphthol

    Institute of Scientific and Technical Information of China (English)

    SONG Ji-guo; SHEN Pei-kang

    2005-01-01

    A novel biomimetic catalyst of complex Cu(p-OTs)2/ethanolamine(1∶1) was used to oxidize 1,1′-bi-2-naphthol into xanthene derivatives with a relative high yield in a mixed solvents of dimethyl sulfoxide(DMSO) and CH3OH. The studies on the effect of some solvents on the yield of xanthene derivatives indicates that the yield reduces dramatically with the increase of the content of H2O in the mixed solvents of H2O and DMSO. No product can be obtained when the content of H2O is up to 70%. The cyclic voltammetric study demonstrated that the copper ion in complex Cu(p-OTs)2/ethanolamine(1∶1) is reduced via a two-step one-electron reduction process from Cu(Ⅱ) to Cu in the mixture of DMSO and H2O. Water as a poor solvent in respect to the reactants probably hampered the coordination of 1,1′-bi-2-naphthol to copper/amine complex and led to the insufficient catalytic efficiency of complex Cu(p-OTs)2/ethanolamine(1∶1).

  14. Aggregation behavior modulation of 1-dodecyl-3-methylimidazolium bromide by organic solvents in aqueous solution.

    Science.gov (United States)

    Wang, Jianji; Zhang, Lamei; Wang, Huiyong; Wu, Changzeng

    2011-05-05

    Material preparation in ionic liquids and environmental pollution control by ionic liquids are often closely dependent on the aggregation behavior of ionic liquids in solution. In the present work, conductivity, fluorescence probe, and dynamic light scattering techniques have been used to study the effect of organic solvents on the aggregation behavior of 1-dodecyl-3-methylimidazolium bromide in water. It was shown that the critical aggregation concentration (CAC), the ionization degree of the aggregates (α), and the standard Gibbs energy of aggregation (ΔG(m)°) of the ionic liquid increase, while its aggregation number (N(agg)) and aggregates' size decrease with increasing concentration of organic additives in water. These results have been discussed from the favorable interactions of alkyl chain of the ionic liquid with the mixed solvents. It is suggested that the solvophobic parameter, characterized quantitatively by Gibbs energy of transfer of hydrocarbon from gas into a given solvent, can be used to account for the effect of organic additives on the formation and growth of the ionic liquid aggregates in water. Aggregation behavior of ionic liquids in aqueous organic solutions can be modulated simply by the solvophobic parameters of hydrocarbon in the mixed solvents.

  15. Investigation of Nanoparticles Dispersion in Sodium Hydroxide (NaOH Solvent

    Directory of Open Access Journals (Sweden)

    Wee Sia Chee

    2017-01-01

    Full Text Available Recently, the study on nanoparticles application in enhanced oil recovery (EOR starts to growth. Nanoparticles have given better indication for EOR development such as in foam stability as its nano size particles can be feasibly dispersed in aqueous solution and easily flow through porous media. Aggregation of nanoparticles are said to be a major contributor for paralyzing nanoparticles dispersion deep into the formation. Hence, in this research sodium hydroxide (NaOH is used as stabilizing solvents or carrier fluids in enhancing nanoparticles properties to prevent coagulation of nanoparticles when mixed to create a nanofluid. The dispersion of various concentration of silica oxide (SiO2 and aluminium oxide (Al2O3 are examined by using turbidity test. Results from this research show that the silicon dioxide nanoparticles are at best to be mixed in NaOH solvent to retain longer retention time.

  16. Stability of the Caustic-Side Solvent Extraction (CSSX) Process Solvent: Effect of High Nitrite on Solvent Nitration

    Energy Technology Data Exchange (ETDEWEB)

    Bonnesen, P.V.

    2002-06-26

    The purpose of this investigation was to determine whether nitrated organic compounds could be formed during operation of the Caustic-Side Solvent Extraction (CSSX) process, and whether such compounds would present a safety concern. The CSSX process was developed to remove cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site (SRS). The solvent is composed of the cesium extractant calix[4]arene-bis-(4-tert-octylbenzo-crown-6) (BOBCalixC6), a fluorinated alcohol phase modifier, tri-n-octylamine (TOA), and an isoparaffinic diluent (Iospar{reg_sign}). During the CSSX process, the solvent is expected to be exposed to high concentrations of nitrate and nitrite dissolved in the alkaline waste feed. The solvent will also be exposed to dilute (50 mM) nitric acid solutions containing low concentrations of nitrite during scrubbing, followed by stripping with 1 mM nitric acid. The solvent is expected to last for one year of plant operation, and the temperatures the solvent may experience during the process could range from as low as 15 C to as high as 35 C. Excursions from standard process conditions could result in the solvent experiencing higher temperatures, as well as concentrations of nitrate, nitrite, and most importantly nitric acid, that exceed normal operating conditions. Accordingly, conditions may exist where nitration reactions involving the solvent components, possibly leading to other chemical reactions stemming from nitration reactions, could occur. To model such nitration reactions, the solvent was exposed to the types of nitrate- and nitrite-containing solutions that might be expected to be encountered during the process (even under off-normal conditions), as a function of time, temperature, and concentration of nitrate, nitrite, and nitric acid. The experiments conducted as part of this report were designed to examine the more specific effect that high nitrite concentrations could have on forming nitrated

  17. Ions in a binary asymmetric dipolar mixture: mole fraction dependent Born energy of solvation and partial solvent polarization structure.

    Science.gov (United States)

    Kashyap, Hemant K; Biswas, Ranjit

    2007-11-14

    Mean spherical approximation (MSA) for electrolyte solution has been extended to investigate the role of partial solvent polarization densities around an ion in a completely asymmetric binary dipolar mixture. The differences in solvent diameters, dipole moments, and ionic size are incorporated systematically within the MSA framework in the present theory for the first time. In addition to the contributions due to difference in dipole moments, the solvent-solvent and ion-solvent size ratios are found to significantly affect the nonideality in binary dipolar mixtures. Subsequently, the theory is used to investigate the role of ion-solvent and solvent-solvent size ratios in determining the nonideality in Born free energy of solvation of a unipositive rigid ion in alcohol-water and dimethyl sulfoxide-acetonitrile mixtures, where the solvent components are represented only by their molecular diameters and dipole moments. Nonideality in Born free energy of solvation in such simplified mixtures is found to be stronger for smaller ions. The slope of the nonideality for smaller alkali metal ions in methanol-water mixture is found to be opposite to that for larger ion, such as quaternary tertiary butyl ammonium ion. For ethanol-water mixtures, the slopes are in the same direction for all the ions studied here. These results are in qualitative agreement with experiments, which is surprising as the present MSA approach does not include the hydrogen bonding and hydrophobic interactions present in the real mixtures. The calculated partial polarization densities around a unipositive ion also show the characteristic deviation from ideality and reveal the microscopic origin of the ion and solvent size dependent preferential solvation. Also, the excess free energy of mixing (in the absence of any ion) for these binary mixtures has been calculated and a good agreement between theory and experiment has been found.

  18. Solvent-dependent fluorescence enhancement and piezochromism of a carbazole-substituted naphthopyran

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lihui; Wang, Aixia [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Wang, Guang, E-mail: wangg923@nenu.edu.cn [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Munyentwari, Alexis [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Zhou, Yihan, E-mail: yhzhou@ciac.ac.cn [National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2015-09-15

    A novel carbazole-substituted naphthopyran, 3,3-bis-(4-carbazolylphenyl)-[3H]-naphtho[2,1-b]pyran (CzNP) was designed and synthesized. The new compound exhibited normal photochromism in dichloromethane solution and the UV irradiation did not influence its fluorescence. On the contrary, the fluorescence of CzNP in N,N-dimethylformamide (DMF) was intensively enhanced to 29 times after 60 min of the UV irradiation and this enhanced fluorescence can be quenched by addition of triethylamine (TEA). The study of enhanced extent of fluorescence of CzNP in solvents with different polarities and in mixed solvents demonstrated that the enhanced fluorescence is dependent on the polarity of solvents. The larger the polarity of solvent was, the stronger was the fluorescence of CzNP. CzNP also exhibited piezochromic performance and the pressure led to the cleavage of the C–O bond of pyran ring. - Highlights: • A carbazole-substituted photochromic naphthopyran was designed and synthesized. • The fluorescence was enhanced under the existence of DMF and UV irradiation. • The polarity of solvent was the dominating factor to affect the fluorescence. • The new compound also displayed piezochromic performance.

  19. Effective Improvement of the Photovoltaic Performance of Carbon-Based Perovskite Solar Cells by Additional Solvents

    Institute of Scientific and Technical Information of China (English)

    Chenxi Zhang; Yudan Luo; Xiaohong Chen; Yiwei Chen; Zhuo Sun; Sumei Huang

    2016-01-01

    A solvent-assisted methodology has been developed to synthesize CH3NH3PbI3 perovskite absorber layers. It involved the use of a mixed solvent of CH3NH3I, PbI2,γ-butyrolactone, and dimethyl sulfoxide (DMSO) followed by the addition of chlorobenzene (CB). The method produced ultra-flat and dense perovskite capping layers atop mesoporous TiO2 films, enabling a remarkable improvement in the performance of free hole transport material (HTM) carbon elec-trode-based perovskite solar cells (PSCs). Toluene (TO) was also studied as an additional solvent for comparison. At the annealing temperature of 100 °C, the fabricated HTM-free PSCs based on drop-casting CB demonstrated power conversion efficiency (PCE) of 9.73%, which is 36 and 71% higher than those fabricated from the perovskite films using TO or without adding an extra solvent, respectively. The interaction between the PbI2–DMSO–CH3NH3I intermediate phase and the additional solvent was discussed. Furthermore, the influence of the annealing temperature on the absorber film formation, morphology, and crystalline structure was investigated and correlated with the photovoltaic performance. Highly efficient, simple, and stable HTM-free solar cells with a PCE of 11.44% were prepared utilizing the optimum perovskite absorbers annealed at 120 °C.

  20. Natural deep eutectic solvents as new potential media for green technology.

    Science.gov (United States)

    Dai, Yuntao; van Spronsen, Jaap; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-03-05

    Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the results the novel NADES may be expected as potential green solvents at room temperature in diverse fields of chemistry. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Lipase catalyzed esterification of glycidol in nonaqueous solvents: solvent effects on enzymatic activity.

    Science.gov (United States)

    Martins, J F; de Sampaio, T C; de Carvalho, I B; Barreiros, S

    1994-06-05

    We studied the effect of organic solvents on the kinetics of porcine pancreatic lipase (pp) for the resolution of racemic glycidol through esterification with butyric acid. We quantified ppl hydration by measuring water sorption isotherms for the enzyme in the solvents/mixtures tested. The determination of initial rates as a function of enzyme hydration revealed that the enzyme exhibits maximum apparent activity in the solvents/mixtures at the same water content (9% to 11% w/w) within the associated experimental error. The maximum initial rates are different in all the media and correlate well with the logarithm of the molar solubility of water in the media, higher initial rates being observed in the solvents/mixtures with lower water solubilities. The data for the mixtures indicate that ppl apparent activity responds to bulk property of the solvent. Measurements of enzyme particle sizes in five of the solvents, as function of enzyme hydration, revealed that mean particle sizes increased with enzyme hydration in all the solvents, differences between solvents being more pronounced at enzyme hydration levels close to 10%. At this hydration level, solvents having a higher water content lead to lower reaction rates; these are the solvents where the mean enzyme particle sizes are greater. Calculation of the observable modulus indicates there are no internal diffusion limitations. The observed correlation between changes in initial rates and changes in external surface area of the enzyme particles suggests that interfacial activation of ppl is only effective at the external surface of the particles. Data obtained for the mixtures indicate that ppl enantioselectivity depends on specific solvent-enzyme interactions. We make reference to ppl hydration and activity in supercritical carbon dioxide.

  2. Solvent additive to achieve highly ordered nanostructural semicrystalline DPP copolymers: toward a high charge carrier mobility.

    Science.gov (United States)

    An, Tae Kyu; Kang, Il; Yun, Hui-jun; Cha, Hyojung; Hwang, Jihun; Park, Seonuk; Kim, Jiye; Kim, Yu Jin; Chung, Dae Sung; Kwon, Soon-Ki; Kim, Yun-Hi; Park, Chan Eon

    2013-12-23

    A facile spin-coating method in which a small percentage of the solvent additive, 1-chloronaphthalene (CN), is found to increase the drying time during film deposition, is reported. The field-effect mobility of a PDPPDBTE film cast from a chloroform-CN mixed solution is 0.46 cm(2) V(-1) s(-1). The addition of CN to the chloroform solution facilitates the formation of highly crystalline polymer structures.

  3. On the Integration Role of Solvents in Process Synthesis-Design-Intensification: Application to DMC/MeOH separation

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Babi, Deenesh Kavi

    2015-01-01

    Solvents (mass separating agents) play an important role in separation-based processes. For example, consider the separation of an azeotropic mixture. If the azeotrope is not pressure dependent, then a feasible separation technique that can be employed for separation of the azeotrope is usually...... separating agent, find the best (optimal or near-optimal) solvent candidate (or mixture) that can perform the separation subject to economic, environmental and thermo-physical property constraints. This design problem inherently is a mixed integer non-linear programming problem because the property-process...... design problem into manageable sub-problems. In the first stage, a number of solvent candidates are generated based on pre-defined structural constraints, for example, acyclic, cyclic and/or aromatic compounds, etc. In the second stage, the solvent candidates are screened using property constraints...

  4. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  5. Asymmetric Diketopyrrolopyrrole Conjugated Polymers for Field-Effect Transistors and Polymer Solar Cells Processed from a Nonchlorinated Solvent.

    Science.gov (United States)

    Ji, Yunjing; Xiao, Chengyi; Wang, Qiang; Zhang, Jianqi; Li, Cheng; Wu, Yonggang; Wei, Zhixiang; Zhan, Xiaowei; Hu, Wenping; Wang, Zhaohui; Janssen, René A J; Li, Weiwei

    2016-02-01

    Newly designed asymmetric diketopyrrolopyrrole conjugated polymers with two different aromatic substituents possess a hole mobility of 12.5 cm(2) V(-1) s(-1) in field-effect transistors and a power conversion efficiency of 6.5% in polymer solar cells, when solution processed from a nonchlorinated toluene/diphenyl ether mixed solvent.

  6. Reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride under solvent-free conditions

    Institute of Scientific and Technical Information of China (English)

    Heshmatollah; Alinezhad; Mahmood; Tajbakhsh; Neda; Hamidi

    2010-01-01

    A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH_4/silica chloride at room temperature,afforded excellent yield of the corresponding amines.

  7. Application of natural deep eutectic solvents to the extraction of anthocyanins from Catharanthus roseus with high extractability and stability replacing conventional organic solvents.

    Science.gov (United States)

    Dai, Yuntao; Rozema, Evelien; Verpoorte, Robert; Choi, Young Hae

    2016-02-19

    Natural deep eutectic solvents (NADES) have attracted a great deal of attention in recent times as promising green media. They are generally composed of neutral, acidic or basic compounds that form liquids of high viscosity when mixed in certain molar ratio. Despite their potential, viscosity and acid or basic nature of some ingredients may affect the extraction capacity and stabilizing ability of the target compounds. To investigate these effects, extraction with a series of NADES was employed for the analysis of anthocyanins in flower petals of Catharanthus roseus in combination with HPLC-DAD-based metabolic profiling. Along with the extraction yields of anthocyanins their stability in NADES was also studied. Multivariate data analysis indicates that the lactic acid-glucose (LGH), and 1,2-propanediol-choline chloride (PCH) NADES present a similar extraction power for anthocyanins as conventional organic solvents. Furthermore, among the NADES employed, LGH exhibits an at least three times higher stabilizing capacity for cyanidins than acidified ethanol, which facilitates their extraction and analysis process. Comparing NADES to the conventional organic solvents, in addition to their reduced environmental impact, they proved to provide higher stability for anthocyanins, and therefore have a great potential as possible alternatives to those organic solvents in health related areas such as food, pharmaceuticals and cosmetics.

  8. New Polymeric Membranes for Organic Solvent Nanofiltration

    KAUST Repository

    Aburabie, Jamaliah

    2017-05-01

    The focus of this dissertation was the development, synthesis and modification of polymers for the preparation of membranes for organic solvent nanofiltration. High chemical stability in a wide range of solvents was a key requirement. Membranes prepared from synthesized polymers as well as from commercial polymers were designed and chemically modified to reach OSN requirements. A solvent stable thin-film composite (TFC) membrane is reported, which is fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate. The membranes exhibited high fluxes towards solvents like THF, DMF and DMSO ranging around 20 L/m2 h at 5 bar with a MWCO of around 1000 g/mol. Ultrafiltration PTSC membranes were prepared by non-solvent induced phase separation and crosslinked with GPTMS. The crosslinking reaction was responsible for the formation of an inorganic-type-network that tuned the membrane pore size. The crosslinked membranes acquired high solvent stability in DMSO, DMF and THF with a MWCO above 1300 g/mol. Reaction Induced Phase Separation (RIPS) was introduced as a new method for the preparation of skinned asymmetric membranes. These membranes have two distinctive layers with different morphologies both from the same polymer. The top dense layer is composed of chemically crosslinked polymer chains while the bottom layer is a porous structure formed by non-crosslinked polymer chains. Such membranes were tested for vitamin B12 in solvents after either crosslinking the support or dissolving the support and fixing the freestanding membrane on alumina. Pebax® 1657 was utilized for the preparation of composite membranes by simple coating. Porous PAN membranes were coated with Pebax® 1657 which was then crosslinked using TDI. Crosslinked Pebax® membranes show high stability towards ethanol, propanol and acetone. The membranes were also stable in DMF once crosslinked PAN supports were used. Sodium alginate polymer was investigated for the preparation of thin film composite

  9. The orientation of solvent-dipoles at the surface of the pure solvent

    NARCIS (Netherlands)

    Nedermeijer-Denessen, H.J.M.; Ligny, C.L. de

    1975-01-01

    A method is described for the assessment of the preferential orientation of solvent-dipoles at the surface of the solvent from the surface potential χ and its temperature coefficient, dχ/dT. The method is based on the model of Levine et al. of the Stern inner region at the mercury-water interface in

  10. The orientation of solvent-dipoles at the surface of the pure solvent

    NARCIS (Netherlands)

    Nedermeijer-Denessen, H.J.M.; Ligny, C.L. de

    1975-01-01

    A method is described for the assessment of the preferential orientation of solvent-dipoles at the surface of the solvent from the surface potential χ and its temperature coefficient, dχ/dT. The method is based on the model of Levine et al. of the Stern inner region at the mercury-water interface in

  11. PSE For Solvent Applications: A Generic Computer-aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sin, Gürkan; Gani, Rafiqul

    Solvents are widely used across a number of industries in many applications such as separation agents, reaction mediums, cleaning agents and product carriers. Selection of optimal solvents in these applications is mostly based on previous experiences and experimental trial and error. A process sy...

  12. Solvent System Selection Strategies in Countercurrent Separation

    Science.gov (United States)

    Liu, Yang; Friesen, J. Brent; McAlpine, James B.; Pauli, Guido F.

    2015-01-01

    The majority of applications in countercurrent and centrifugal partition chromatography, collectively known as countercurrent separation, are dedicated to medicinal plant and natural product research. In countercurrent separation, the selection of the appropriate solvent system is of utmost importance as it is the equivalent to the simultaneous choice of column and eluent in liquid chromatography. However, solvent system selection is often laborious, involving extensive partition and/or analytical trials. Therefore, simplified solvent system selection strategies that predict the partition coefficients and, thus, analyte behavior are in high demand and may advance both the science of countercurrent separation and its applications. The last decade of solvent system selection theory and applications are critically reviewed, and strategies are classified according to their data input requirements. This offers the practitioner an up-to-date overview of rationales and methods for choosing an efficient solvent system, provides a perspective regarding their accuracy, reliability, and practicality, and discusses the possibility of combining multiple methods for enhanced prediction power. PMID:26393937

  13. Otoneurologic disturbances caused by solvent pollution.

    Science.gov (United States)

    Odkvist, L M; Möller, C; Thuomas, K A

    1992-06-01

    Subjects exposed to industrial solvents may experience vertigo and nausea. Solvents are usually volatile hydrocarbon compounds, which are important parts of everyday life in a modern society. They may also cause neurastenia, personality changes, and reduced intellectual capacity. The syndrome that may develop was formerly named psycho-organic syndrome (POS), but in modern terminology it is called chronic toxic encephalopathy (CTE). The syndrome develops slowly, and during the first years no pathological findings will be found using various test batteries. Somewhat later, when the syndrome still might be reversible, psychometric, auditory, and otoneurologic testing may well unveil disturbances within the posterior fossa structures. Animal experiments suggest one site of effect for solvents to be within the cerebellum and brainstem regions with close relationship to the gamma-amino-butyric acid (GABA) transmission. In the otoneurologic test battery, visual suppression and smooth pursuit are of extreme value, as are some auditory tests such as discrimination of interrupted speech and cortical response audiometry using frequency glides as stimuli. Dynamic posturography and magnetic resonance imaging (MRI) have recently proved valuable in the diagnosis. Research is needed concerning the most efficient test battery for early detection of solvent-induced lesions. During further research it is important to unveil other toxic agents, like heavy metals and alcohol, and their damage to the central nervous system and to make comparisons between these substances and the lesions caused by hydrocarbon solvents.

  14. Chlorinated solvent replacements recycle/recovery review report

    Energy Technology Data Exchange (ETDEWEB)

    Beal, M.; Hsu, D.; McAtee, R.E.; Weidner, J.R. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Berg, L.; McCandless, F.P.; Waltari, S.; Peterson, C. (Montana State Univ., Bozeman, MT (United States). Dept. of Chemical Engineering)

    1992-08-01

    This report is a literature review of waste solvents recycle/recovery methods and shows the results of solvent separations using membrane and distillation technologies. The experimental solvent recovery methods were conducted on solvent replacements for chlorinated solvents at Montana State University. The literature review covers waste solvents separation using distillation, membranes decantation, filtration, carbon adsorption, solvent extraction, and other vapor-phase separation techniques. The results of this study identify solvent distillation methods as the most common separation technique. The alternative separation methods typically supplement distillation. The study shows the need for industries to identify waste solvent disposal methods and investigate the economics of waste solvent recycling as a possible waste reduction method.

  15. Development of deep eutectic solvents applied in extraction and separation.

    Science.gov (United States)

    Li, Xiaoxia; Row, Kyung Ho

    2016-09-01

    Deep eutectic solvents, as an alternative to ionic liquids, have greener credentials than ionic liquids, and have attracted considerable attention in related chemical research. Deep eutectic solvents have attracted increasing attention in chemistry for the extraction and separation of various target compounds from natural products. This review highlights the preparation of deep eutectic solvents, unique properties of deep eutectic solvents, and synthesis of deep-eutectic-solvent-based materials. On the other hand, application in the extraction and separation of deep eutectic solvents is also included in this report. In this paper, the available data and references in this field are reviewed to summarize the applications and developments of deep eutectic solvents. Based on the development of deep eutectic solvents, an exploitation of new deep eutectic solvents and deep eutectic solvents-based materials is expected to diversify into extraction and separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Recommended methods for purification of solvents and tests for impurities

    CERN Document Server

    Coetzee, J F

    1982-01-01

    Recommended Methods for Purification of Solvents and Tests for Impurities is a compilation of recommended procedures for purification of solvents and tests for solvent impurities. Ten solvents are covered: acetonitrile, sulfolane, propylene carbonate, dimethyl sulfoxide, dimethylformamide, hexamethylphosphoramide, pyridine, ethylenediamine, N-methylacetamide, and N-methylpropionamide. This book is comprised of 12 chapters and opens with an introduction to general aspects of impurity effects. The rationale for the selection of solvent is explained, and the relative reactivities of solutes in di

  17. Alternative Solvents through Green Chemistry Project

    Science.gov (United States)

    Hintze, Paul E.; Quinn, Jacqueline

    2014-01-01

    Components in the aerospace industry must perform with accuracy and precision under extreme conditions, and surface contamination can be detrimental to the desired performance, especially in cases when the components come into contact with strong oxidizers such as liquid oxygen. Therefore, precision cleaning is an important part of a components preparation prior to utilization in aerospace applications. Current cleaning technologies employ a variety of cleaning agents, many of which are halogenated solvents that are either toxic or cause environmental damage. Thus, this project seeks to identify alternative precision cleaning solvents and technologies, including use of less harmful cleaning solvents, ultrasonic and megasonic agitation, low-pressure plasma cleaning techniques, and supercritical carbon dioxide extraction. Please review all data content found in the Public Data tab located at: https:techport.nasa.govview11697public

  18. Nanoscale Mixing of Soft Solids

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Soo-Hyung; Lee, Sangwoo; Soto, Haidy E.; Lodge, Timothy P.; Bates, Frank S. (UMM); (Texas)

    2013-03-07

    Assessing the state of mixing on the molecular scale in soft solids is challenging. Concentrated solutions of micelles formed by self-assembly of polystyrene-block-poly(ethylene-alt-propylene) (PS-PEP) diblock copolymers in squalane (C{sub 30}H{sub 62}) adopt a body-centered cubic (bcc) lattice, with glassy PS cores. Utilizing small-angle neutron scattering (SANS) and isotopic labeling ({sup 1}H and {sup 2}H (D) polystyrene blocks) in a contrast-matching solvent (a mixture of squalane and perdeuterated squalane), we demonstrate quantitatively the remarkable fact that a commercial mixer can create completely random mixtures of micelles with either normal, PS(H), or deuterium-labeled, PS(D), cores on a well-defined bcc lattice. The resulting SANS intensity is quantitatively modeled by the form factor of a single spherical core. These results demonstrate both the possibility of achieving complete nanoscale mixing in a soft solid and the use of SANS to quantify the randomness.

  19. Bioprocessing of a stored mixed liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Wolfram, J.H.; Rogers, R.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Finney, R. [Mound Applied Technologies, Miamisburg, OH (United States)] [and others

    1995-12-31

    This paper describes the development and results of a demonstration for a continuous bioprocess for mixed waste treatment. A key element of the process is an unique microbial strain which tolerates high levels of aromatic solvents and surfactants. This microorganism is the biocatalysis of the continuous flow system designed for the processing of stored liquid scintillation wastes. During the past year a process demonstration has been conducted on commercial formulation of liquid scintillation cocktails (LSC). Based on data obtained from this demonstration, the Ohio EPA granted the Mound Applied Technologies Lab a treatability permit allowing the limited processing of actual mixed waste. Since August 1994, the system has been successfully processing stored, {open_quotes}hot{close_quotes} LSC waste. The initial LSC waste fed into the system contained 11% pseudocumene and detectable quantities of plutonium. Another treated waste stream contained pseudocumene and tritium. Data from this initial work shows that the hazardous organic solvent, and pseudocumene have been removed due to processing, leaving the aqueous low level radioactive waste. Results to date have shown that living cells are not affected by the dissolved plutonium and that 95% of the plutonium was sorbed to the biomass. This paper discusses the bioprocess, rates of processing, effluent, and the implications of bioprocessing for mixed waste management.

  20. Solvent-free fluidic organic dye lasers.

    Science.gov (United States)

    Choi, Eun Young; Mager, Loic; Cham, Tran Thi; Dorkenoo, Kokou D; Fort, Alain; Wu, Jeong Weon; Barsella, Alberto; Ribierre, Jean-Charles

    2013-05-06

    We report on the demonstration of liquid organic dye lasers based on 9-(2-ethylhexyl)carbazole (EHCz), so-called liquid carbazole, doped with green- and red-emitting laser dyes. Both waveguide and Fabry-Perot type microcavity fluidic organic dye lasers were prepared by capillary action under solvent-free conditions. Cascade Förster-type energy transfer processes from liquid carbazole to laser dyes were employed to achieve color-variable amplified spontaneous emission and lasing. Overall, this study provides the first step towards the development of solvent-free fluidic organic semiconducting lasers and demonstrates a new kind of optoelectronic applications for liquid organic semiconductors.

  1. NMR spectroscopy using liquid crystal solvents

    CERN Document Server

    Emsley, JW

    2013-01-01

    NMR Spectroscopy using Liquid Crystal Solvents covers the importance of using a liquid crystal solvent in NMR to derive nuclear dipolar spin-spin coupling constants. This book is composed of ten chapters, and begins with a brief description of the features and benefits of liquid crystal in NMR spectroscopic analysis. The succeeding chapters deal with the mode of operation of nuclear spin Hamiltonian for partially oriented molecules and the analysis of NMR spectra of partially oriented molecules, as well as the determination of rigid molecule structure. These topics are followed by discussions

  2. Solvent-resistant microporous polymide membranes

    Science.gov (United States)

    Miller, Warren K.; McCray, Scott B.; Friesen, Dwayne T.

    1998-01-01

    An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

  3. Occupational exposure to solvents and bladder cancer

    DEFF Research Database (Denmark)

    Hadkhale, Kishor; Martinsen, Jan Ivar; Weiderpass, Elisabete;

    2017-01-01

    logistic regression model was used to estimate hazard ratios (HR) and their 95% confidence intervals (95% CI). Increased risks were observed for trichloroethylene (HR 1.23, 95% 95% CI 1.12-1.40), toluene (HR 1.20, 95% CI 1.00-1.38), benzene (HR 1.16, 95% CI 1.04-1.31), aromatic hydrocarbon solvents (HR 1...... of occupational exposure to trichloroethylene, perchloroethylene, aromatic hydrocarbon solvents, benzene and toluene and the risk of bladder cancer. This article is protected by copyright. All rights reserved....

  4. European mixed forests

    DEFF Research Database (Denmark)

    Bravo-Oviedo, Andres; Pretzsch, Hans; Ammer, Christian;

    2014-01-01

    Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material...... and Methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any...... density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields...

  5. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    and then the second part is solved to determine the optimal mixture. The decomposition of the CAMD MINLP model into relatively easy to solve subproblems is essentially a partitioning of the constraints from the original set. This approach is illustrated through two case studies. The first case study involves...... the design of an optimal extractant for the separation of acetic acid from water by liquid-liquid extraction. The results suggest that the new extractant would be able to perform better than the extractant being widely used for this separation. The second case study is an industrial problem involving......This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...

  6. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...... is to be optimized subject to structural, property, and process constraints. The general molecular/mixture design problem is divided into two parts. For optimal single-compound design, the first part is solved. For mixture design, the single-compound design is first carried out to identify candidates...... the design of an optimal extractant for the separation of acetic acid from water by liquid-liquid extraction. The results suggest that the new extractant would be able to perform better than the extractant being widely used for this separation. The second case study is an industrial problem involving...

  7. TODGA Process Development: an Improved Solvent Formulation

    Energy Technology Data Exchange (ETDEWEB)

    Geist, Andreas [Forschungszentrum Karlsruhe, Institut fuer Nukleare Entsorgung, 76021 Karlsruhe (Germany); Modolo, Giuseppe [Forschungszentrum Juelich, Institute for Energy Research, Safety Research and Reactor Technology, 52425 Juelich (Germany)

    2009-06-15

    Introduction: TODGA (N,N,N',N'-tetra-n-octyl diglycolamide) is studied in the European ACSEPT project as a promising extractant for actinide separations. A mixture of TODGA and TBP in TPH (a kerosene) [1] was successfully used for spiked and hot continuous counter-current tests for the separation of actinides(III) and lanthanides(III) from PUREX raffinate [2, 3]. Furthermore this solvent composition is used for GANEX (group actinide extraction) process development, i.e., co-extraction of Np, Pu, Am, Cm, and Ln from PUREX raffinate with selective stripping of the actinides [4, 5]. We address two of this solvent's drawbacks by replacing TBP (which acts as phase modifier to prevent third phase formation) with 1-octanol: (1) The presence of a non-CHON compound (TBP); (2) The pronounced co-extraction of nitric acid (e.g., 0.2 M TODGA + 0.5 M TBP in TPH extracts approx. 0.6 M HNO{sub 3} from 4 M HNO{sub 3}). Results: When contacting 0.2 M TODGA in TPH with 0.1 M Nd(NO{sub 3}){sub 3} in 5 M HNO{sub 3}, as little as 3 % vol. 1-octanol suppresses the formation of a third phase. Thus, the following solvent composition is used for further studies: 0.2 M TODGA + 5 % vol. 1-octanol in TPH. Due to the absence of TBP, the amount of HNO{sub 3} extraction is reduced to approx. 50 % as compared to the solvent consisting of 0.2 M TODGA + 0.5 M TBP in TPH. Am(III) and Eu(III) distribution ratios are similar to those with the TODGA + TBP solvent [1]. Loading the solvent by extracting from solutions of up to 0.2 M Nd(NO{sub 3}){sub 3} in 3 M or 4 M HNO{sub 3} confirms a 1:3 stoichiometry of the extracted complex. Further investigations are under way. Conclusion: The improved solvent formulation reduces the HNO{sub 3} co-extraction which may be advantageous especially for GANEX process development. Furthermore, the solvent complies with the CHON principle. 1) G. Modolo, H. Asp, C. Schreinemachers, H. Vijgen, Development of a TODGA based process for partitioning of

  8. Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tara E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scherman, Carl [Savannah River Remediation, LLC., Aiken, SC (United States); Martin, David [Savannah River Remediation, LLC., Aiken, SC (United States); Suggs, Patricia [Savannah River Site (SRS), Aiken, SC (United States)

    2015-01-14

    Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

  9. Centrifugal contactor with liquid mixing and flow control vanes and method of mixing liquids of different phases

    Science.gov (United States)

    Jubin, Robert T.; Randolph, John D.

    1991-01-01

    The invention is directed to a centrifugal contactor for solvent extraction systems. The centrifugal contactor is provided with an annular vertically oriented mixing chamber between the rotor housing and the rotor for mixing process liquids such as the aqueous and organic phases of the solvent extraction process used for nuclear fuel reprocessing. A set of stationary helically disposed vanes carried by the housing is in the lower region of the mixing chamber at a location below the process-liquid inlets for the purpose of urging the liquids in an upward direction toward the inlets and enhancing the mixing of the liquids and mass transfer between the liquids. The upper region of the mixing vessel above the inlets for the process liquids is also provided with a set helically disposed vanes carried by the housing for urging the process liquids in a downward direction when the liquid flow rates through the inlets are relatively high and the liquids contact the vane set in the upper region. The use of these opposing vane sets in the mixing zone maintains the liquid in the mixing zone at suitable levels.

  10. Used Solvent Testing and Reclamation. Volume 2. Vapor Degreasing and Precision Cleaning Solvents

    Science.gov (United States)

    1988-12-01

    Dependence of the 1,3-Dioxolane/AlCI 3 Reaction Using Arrhenius’ Law 88 36 Effect of 1,4-Dioxane on Reactor Pressure 91 67 Effect of 1,4-Dioxane on HCI...and spent solvent. This process was performed for all of the three solvents. Inhibitor Kinetic Studies Batch Reactions. Batch reactor kinetic studies...acceptor in chlorinated solvents. It is an 4 80. Levenspiel , Chemical Reaction Engineering, 2nd ed. (John Wiley and Sons, 1972), pp 41-86. 490

  11. Solvent tuned single molecule dual emission in protic solvents: effect of polarity and H-bonding.

    Science.gov (United States)

    Chevreux, S; Allain, C; Wilbraham, L; Nakatani, K; Jacques, P; Ciofini, I; Lemercier, G

    2015-01-01

    Phen-PENMe2 has recently been proposed as a promising new molecule displaying solvent-tuned dual emission, highlighting an original and newly-described charge transfer model. The study of the photophysical behaviour of this molecule was extended to include protic solvents. The effects of polarity and hydrogen bonding lead to an even more evident dual emission associated with a large multi-emission band in some solvents like methanol, highlighting Phen-PENMe2 as a promising candidate for white light emission.

  12. Computer-Aided Solvent Screening for Biocatalysis

    DEFF Research Database (Denmark)

    Abildskov, Jens; Leeuwen, M.B. van; Boeriu, C.G.;

    2013-01-01

    . Esterification of acrylic acid with octanol is also addressed. Solvents are screened and candidates identified, confirming existing experimental results. Although the examples involve lipases, the method is quite general, so there seems to be no preclusion against application to other biocatalysts....

  13. Selective solvent absorption in coal conversion

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, J.W.; Lapucha, A.; Lazarov, L.; Amui, J.

    1992-04-01

    The objectives of this project are: (1) to determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; and (2) to determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  14. Spherical polymer brushes under good solvent conditions

    DEFF Research Database (Denmark)

    Lo Verso, Federica; Egorov, Sergei A.; Milchev, Andrey

    2010-01-01

    A coarse grained model for flexible polymers end-grafted to repulsive spherical nanoparticles is studied for various chain lengths and grafting densities under good solvent conditions by molecular dynamics methods and density functional theory. With increasing chain length, the monomer density...

  15. Organic solvents in electromembrane extraction: recent insights

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-01-01

    Electromembrane extraction (EME) was invented in 2006 as a miniaturized sample preparation technique for the separation of ionized species from aqueous samples. This concept has been investigated in different areas of analytical chemistry by different research groups worldwide since the introduct......Electromembrane extraction (EME) was invented in 2006 as a miniaturized sample preparation technique for the separation of ionized species from aqueous samples. This concept has been investigated in different areas of analytical chemistry by different research groups worldwide since...... the introduction. Under the influence of an electrical field, EME is based on electrokinetic migration of the analytes through a supported liquid membrane (SLM), which is an organic solvent immobilized in the pores of the polymeric membrane, and into the acceptor solution. Up to date, close to 150 research...... articles with focus on EME have been published. The current review summarizes the performance of EME with different organic solvents and discusses several criteria for efficient solvents in EME. In addition, the authors highlight their personal perspective about the most promising organic solvents for EME...

  16. THE TRAVELLING SOLVENT METHOD OF CRYSTAL GROWTH

    Science.gov (United States)

    dicumene Electron beam melting of Cr on SiC Wetting studies of Cr on SiC in different ambients Etching studies in molten salts Zone movement studies Ga-GaAs System P-N junction formation by solvent doping

  17. Organic solvent nanofiltration: prospects and application

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, A V; Korneeva, G A; Tereshchenko, Gennadii F [A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow (Russian Federation)

    2008-11-30

    The key lines of research in a new field of the membrane science and technology, viz., organic solvent nanofiltration, are considered. The prospects for its use in chemical, petrochemical and food industries are discussed. Attention is focused on membranes developed for this method.

  18. ESES: Software for Eulerian solvent excluded surface.

    Science.gov (United States)

    Liu, Beibei; Wang, Bao; Zhao, Rundong; Tong, Yiying; Wei, Guo-Wei

    2017-03-15

    Solvent excluded surface (SES) is one of the most popular surface definitions in biophysics and molecular biology. In addition to its usage in biomolecular visualization, it has been widely used in implicit solvent models, in which SES is usually immersed in a Cartesian mesh. Therefore, it is important to construct SESs in the Eulerian representation for biophysical modeling and computation. This work describes a software package called Eulerian solvent excluded surface (ESES) for the generation of accurate SESs in Cartesian grids. ESES offers the description of the solvent and solute domains by specifying all the intersection points between the SES and the Cartesian grid lines. Additionally, the interface normal at each intersection point is evaluated. Furthermore, for a given biomolecule, the ESES software not only provides the whole surface area, but also partitions the surface area according to atomic types. Homology theory is utilized to detect topological features, such as loops and cavities, on the complex formed by the SES. The sizes of loops and cavities are measured based on persistent homology with an evolutionary partial differential equation-based filtration. ESES is extensively validated by surface visualization, electrostatic solvation free energy computation, surface area and volume calculations, and loop and cavity detection and their size estimation. We used the Amber PBSA test set in our electrostatic solvation energy, area, and volume validations. Our results are either calibrated by analytical values or compared with those from the MSMS software. © 2017 Wiley Periodicals, Inc.

  19. Expanding solvent SAGD in heavy oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Govind, P.A. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Das, S.; Wheeler, T.J. [Society of Petroleum Engineers, Richardson, TX (United States)]|[ConocoPhillips Co., Houston, TX (United States); Srinivasan, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Texas Univ., Austin, TX (United States)

    2008-10-15

    Steam assisted gravity drainage (SAGD) projects have proven effective for the recovery of oil and bitumen. Expanding solvent (ES) SAGD pilot projects have also demonstrated positive results of improved performance. This paper presented the results of a simulation study that investigated several important factors of the ES-SAGD process, including solvent types; concentration; operating pressure; and injection strategy. The objectives of the study were to examine the effectiveness of the ES-SAGD process in terms of production acceleration and energy requirements; to optimize solvent selection; to understand the effect of dilation in unconsolidated oil sands and the directional impact on reservoir parameters and oil production rate in ES-SAGD; and to understand the impact of operating conditions such as pressure, solvent concentration, circulation preheating period and the role of conduction heating and grid size in this process. The advantages of ES-SAGD over SAGD were also outlined. The paper presented results of sensitivity studies that were conducted on these four factors. Conclusions and recommendations for operating strategy were also offered. It was concluded that dilation is an important factor for SAGD performance at high operating pressure. 8 refs., 15 figs.

  20. Solvent and Temperature Effects on Spectral Properties of Two Poly(3-alkyl)thiophene Derivatives

    Institute of Scientific and Technical Information of China (English)

    GAO Chao; WU Hong-cai; YI Wen-hui; ZHANG Qing-xue; DONG Fa-xin

    2005-01-01

    Two alkyl substituted polythiophene derivatives:poly(3-hexylthiophene)(P3HT) and poly(3-decylthiophene)(P3DT), have synthesized by oxidation coupling polymerization of 3-alkylthiophene using iron(III) chloride as catalyst in chloroform. While both polymers in pure chloroform solution have maximum absorption at approximately same wavelength of 440 nm, they behave differently with respect to changes observed on their UV-visible and photoluminescence spectra when the quality of the poor solvent is changed in good solvent (chloroform)/poor solvent (methanol) mixtures. With increasing volume fraction of methanol in mixtures, the absorption spectra of P3HT and P3DT red-shift, peaking at maximum wavelength of 495nm (P3HT)and 510nm(P3DT). Furthermore, the absorption spectra of the two polymers in chloroform blue-shift as the temperature rises. P3HT shows 4.73nm blue-shifts at 50℃ in contrast to the case at 20℃, while P3DT blue-shifts about 5.04nm. The photoluminescence spectra of the two polymers in mixed solution are also investigated, which show that the luminescence spectra shift to longer wavelength with an accompanying drop in the PL intensity as methanol is increased. The absorption and emission spectra of the two polymers in a poor solvent and a thin film are similar, which indicate that a similar longer conjugation length in the two cases. It could conclude that the polymers exist almost the same conformations and aggregations in both a poor solvent and a thin film. P3DT exhibits more sensitive spectra properties (big red-shifts in both absorption and luminescence spectra in poor solvents and large blue-shifts at high temperature) with contrast to P3HT, which imply that long side alkyl may improve the chromic properties of the polymer.

  1. Carbon nanotube embedded PVDF membranes: Effect of solvent composition on the structural morphology for membrane distillation

    Science.gov (United States)

    Mapunda, Edgar C.; Mamba, Bhekie B.; Msagati, Titus A. M.

    2017-08-01

    Rapid population increase, growth in industrial and agricultural sectors and global climate change have added significant pressure on conventional freshwater resources. Tapping freshwater from non-conventional water sources such as desalination and wastewater recycling is considered as sustainable alternative to the fundamental challenges of water scarcity. However, affordable and sustainable technologies need to be applied for the communities to benefit from the treatment of non-conventional water source. Membrane distillation is a potential desalination technology which can be used sustainably for this purpose. In this work multi-walled carbon nanotube embedded polyvinylidene fluoride membranes for application in membrane distillation desalination were prepared via non-solvent induced phase separation method. The casting solution was prepared using mixed solvents (N, N-dimethylacetamide and triethyl phosphate) at varying ratios to study the effect of solvent composition on membrane morphological structures. Membrane morphological features were studied using a number of techniques including scanning electron microscope, atomic force microscope, SAXSpace tensile strength analysis, membrane thickness, porosity and contact angle measurements. It was revealed that membrane hydrophobicity, thickness, tensile strength and surface roughness were increasing as the composition of N, N-dimethylacetamide in the solvent was increasing with maximum values obtained between 40 and 60% N, N-dimethylacetamide. Internal morphological structures were changing from cellular structures to short finger-like and sponge-like pores and finally to large macro void type of pores when the amount of N, N-dimethylacetamide in the solvent was changed from low to high respectively. Multi-walled carbon nanotube embedded polyvinylidene fluoride membranes of desired morphological structures and physical properties can be synthesized by regulating the composition of solvents used to prepare the

  2. A Visual Demonstration of Solvent Effect in Chemical Kinetics through Blue Bottle Experiment

    Directory of Open Access Journals (Sweden)

    *R. Azmat

    2013-03-01

    Full Text Available In the study of chemical kinetics, usually solvent effect was explained to show the consequences on rate of reaction theoretically which is difficult to understand for under graduate students. The blue bottle experiment as a “one day activity” can be used to explain well visually the solvent effect through demonstration of color change. Kinetics of reduction of methylene green by sucrose and mannose in pure and aqueous methanol medium in presence of NaOH has been investigated for demonstration of solvent effect. The two sugars sucrose and mannose were selected for the experiment those acts as a reducing agents in a basic solution and reduces the methylene green into colorless form. The progress of this reduction reaction was followed by the color changes that the methylene green goes through in variable percentage of alcohol. When the bottle is shaken the oxygen in the air mixes with the solution and oxidizes the methylene green back to its intermediate state (purple. The color of the solution will gradually change and become purple (intermediate and then colorless in 5-10% methanol but in pure methanol color transition were Blue-> purple-> pink indicate the color due to the alcoholic medium. It was observed that increase in percentage in the solvent composition decrease the rate of reduction. The pink color continues due to alcoholic medium which may be attributed with the solvent effect. The observed variation in reading with solvent compositions has been interpreted in terms of interactions of media with the reacting species and the transitions state involved in this reaction.

  3. Fermi resonance and solvent dependence of the vC=O frequency shifts of Raman spectra: cyclohexanone and 2-cyclohexene-1-one

    CERN Document Server

    Nam, S I; Lee, M S; Jung, Y M

    2001-01-01

    The carbonyl stretching vibration, vC=O of 2-cyclohexene-1-one , is in Fermi resonance with a combination tone. The amount of Fermi resonance interaction between these two modes is dependent upon the amount of solute/solvent interaction due to hydrogen bonding between the carbonyl oxygen and the solvent proton. The corrected vC=O frequency of 2-cyclohexene-1-one occurs at a lower frequency than the observed vC=O mode of cyclohexanone, possibly caused by expanded conjugation effects. The carbonyl stretching modes of cyclic ketones were also affected by interaction with the ROH/CCl sub 4 mixed solvent system.

  4. Solvent density mode instability in non-polar solutions

    Indian Academy of Sciences (India)

    Susmita Kar; Ranjit Biswas; J Chakrabarti

    2008-08-01

    We analyse the origin of the multiple long time scales associated with the long time decay observed in non-polar solvation dynamics by linear stability analysis of solvent density modes where the effects of compressibility and solvent structure are systematically incorporated. The coupling of the solute–solvent interactions at both ground and excited states of the solute with the compressibility and solvent structure is found to have important effects on the time scales. The present theory suggests that the relatively longer time constant is controlled by the solvent compressibility, while the solvent structure at the nearest-neighbour length scale dominates the shorter time constant.

  5. The Effect of Solvents on the Performance of CH3NH3PbI3 Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Pao-Hsun Huang

    2017-04-01

    Full Text Available The properties of perovskite solar cells (PSCs fabricated using various solvents was studied. The devices had an indium tin oxide (ITO/poly(3,4-ethylenedioxythiophene: poly(styrenesulfonate (PEDOT:PSS/CH3NH3PbI3 (fabricated by using various solvents/fullerene (C60/bathocuproine (BCP/silver (Ag structure. The solvents used were dimethylformamide (DMF, γ-butyrolactone (GBL, dimethyl sulfoxide (DMSO, a mixture of DMSO and DMF (1:1 v/v, and a mixture of DMSO and GBL (DMSO: GBL, 1:1 v/v, respectively. The power conversion efficiency (PCE of the device fabricated using DMF is zero, which is attributed to the poor coverage of CH3NH3PbI3 film on the substrate. In addition, the PCE of the device made using GBL is only 1.74% due to the low solubility of PbI2 and CH3NH3I. In contrast, the PCE of the device fabricated using the solvents containing DMSO showed better performance. This is ascribed to the high solubilization properties and strong coordination of DMSO. As a result, a PCE of 9.77% was obtained using a mixed DMSO:GBL solvent due to the smooth surface, uniform film coverage on the substrate and the high crystallization of the perovskite structure. Finally, a mixed DMSO: DMF:GBL (5:2:3 v/v/v solvent that combined the advantages of each solvent was used to fabricate a device, leading to a further improvement of the PCE of the resulting PSC to 10.84%.

  6. Ionic liquids and deep eutectic solvents in natural products research: mixtures of solids as extraction solvents.

    Science.gov (United States)

    Dai, Yuntao; van Spronsen, Jaap; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-11-22

    Mixtures of solid chemicals may become liquid under certain conditions. These liquids are characterized by the formation of strong ionic (ionic liquids) or hydrogen bonds (deep eutectic solvents). Due to their extremely low vapor pressure, they are now widely used in polymer chemistry and synthetic organic chemistry, yet little attention has been paid to their use as extraction solvents of natural products. This review summarizes the preparation of ionic liquids and deep eutectic solvents with natural product components and recent progress in their applications to the extraction and analysis of natural products as well as the recovery of extracted compounds from their extracts. Additionally, various factors affecting extraction features of ionic liquids and deep eutectic solvents, as well as potential useful technologies including microwave and ultrasound to increase the extraction efficiency, are discussed.

  7. Comparison of solvent mixtures for pressurized solvent extraction of soil fatty acid biomarkers.

    Science.gov (United States)

    Jeannotte, Richard; Hamel, Chantal; Jabaji, Suha; Whalen, Joann K

    2008-10-19

    The extraction and transesterification of soil lipids into fatty acid methyl esters (FAMEs) is a useful technique for studying soil microbial communities. The objective of this study was to find the best solvent mixture to extract soil lipids with a pressurized solvent extractor system. Four solvent mixtures were selected for testing: chloroform:methanol:phosphate buffer (1:2:0.8, v/v/v), chloroform:methanol (1:2, v/v), hexane:2-propanol (3:2, v/v) and acetone. Soils were from agricultural fields and had a wide range of clay, organic matter and microbial biomass contents. Total lipid fatty acid methyl esters (TL-FAMEs) were the extractable soil lipids identified and quantified with gas chromatography and flame ionization detection. Concentrations of TL-FAMEs ranged from 57.3 to 542.2 nmole g(-1) soil (dry weight basis). The highest concentrations of TL-FAMEs were extracted with chloroform:methanol:buffer or chloroform:methanol mixtures than with the hexane:2-propanol or acetone solvents. The concentrations of TL-FAMEs in chemical groups, including saturated, branched, mono- and poly-unsaturated and hydroxy fatty acids were assessed, and biological groups (soil bacteria, mycorrhizal fungi, saprophytic fungi and higher plants) was distinguished. The extraction efficiency for the chemical and biological groups followed the general trend of: chloroform:methanol:buffer> or =chloroform:methanol>hexane:2-propanol=acetone. Discriminant analysis revealed differences in TL-FAME profiles based on the solvent mixture and the soil type. Although solvent mixtures containing chloroform and methanol were the most efficient for extracting lipids from the agricultural soils in this study, soil properties and the lipid groups to be studied should be considered when selecting a solvent mixture. According to our knowledge, this is the first report of soil lipid extraction with hexane:2-propanol or acetone in a pressurized solvent extraction system.

  8. Theoretical analysis of co-solvent effect on the proton transfer reaction of glycine in a water-acetonitrile mixture.

    Science.gov (United States)

    Kasai, Yukako; Yoshida, Norio; Nakano, Haruyuki

    2015-05-28

    The co-solvent effect on the proton transfer reaction of glycine in a water-acetonitrile mixture was examined using the reference interaction-site model self-consistent field theory. The free energy profiles of the proton transfer reaction of glycine between the carboxyl oxygen and amino nitrogen were computed in a water-acetonitrile mixture solvent at various molar fractions. Two types of reactions, the intramolecular proton transfer and water-mediated proton transfer, were considered. In both types of the reactions, a similar tendency was observed. In the pure water solvent, the zwitterionic form, where the carboxyl oxygen is deprotonated while the amino nitrogen is protonated, is more stable than the neutral form. The reaction free energy is -10.6 kcal mol(-1). On the other hand, in the pure acetonitrile solvent, glycine takes only the neutral form. The reaction free energy from the neutral to zwitterionic form gradually increases with increasing acetonitrile concentration, and in an equally mixed solvent, the zwitterionic and neutral forms are almost isoenergetic, with a difference of only 0.3 kcal mol(-1). The free energy component analysis based on the thermodynamic cycle of the reaction also revealed that the free energy change of the neutral form is insensitive to the change of solvent environment but the zwitterionic form shows drastic changes. In particular, the excess chemical potential, one of the components of the solvation free energy, is dominant and contributes to the stabilization of the zwitterionic form.

  9. Fluoroester Co-Solvents for Low-Temperature Li+ Cells

    Science.gov (United States)

    Smart, Marshall; Bugga, Ratnakumar; Prakash, G. K. Surya; Smith, Kiah; Bhalla, Pooja

    2009-01-01

    Electrolytes comprising LiPF6 dissolved in alkyl carbonate/fluoroester mixtures have been found to afford improved low-temperature performance and greater high-temperature resilience in rechargeable lithium-ion electrochemical cells. These and other electrolytes comprising lithium salts dissolved mixtures of esters have been studied in continuing research directed toward extending the lower limit of operating temperatures of such cells. This research at earlier stages, and the underlying physical and chemical principles, were reported in numerous previous NASA Tech Briefs articles. The purpose of the present focus on high-temperature resilience in addition to low-temperature performance is to address issues posed by the flammability of the esters and, at temperatures near the upper end (about 55 C) of their intended operating temperature range, by their high chemical reactivity. As used here, high-temperature resilience signifies, loosely, a desired combination of low flammability of an electrolyte mixture and the ability of a cell that contains the mixture to sustain a relatively small loss of reversible charge/discharge capacity during storage in the fully charged condition at high temperature. The selection of fluoroesters for study as candidate electrolyte solvent components to increase high-temperature resilience was prompted in part by the observation that like other halogenated compounds, fluoroesters have low flammability. The fluoroesters investigated in this study include trifluoroethyl butyrate (TFEB), ethyl trifluoroacetate (ETFA), trifluoroethyl acetate (TFEA), and methyl pentafluoropropionate (MPFP). Solvent mixtures were prepared by mixing these fluoroesters with two other esters: ethylene carbonate (EC) and ethyl methyl carbonate (EMC).

  10. Relative ototoxicity of 21 aromatic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Gagnaire, Francois; Langlais, Cristina [Institut National de Recherche et de Securite, Departement Polluants et Sante, Vandoeuvre (France)

    2005-06-01

    Some aromatic solvents (e.g. toluene, p-xylene, styrene, and ethylbenzene) show, in the rat, striking ototoxicity characterized by an irreversible hearing loss, as measured by behavioural or electrophysiological methods, associated with damage to outer hair cells in the cochlea of the exposed animals. To broaden the range of aromatic solvents studied concerning their potential ototoxicity and to compare their ototoxicity quantitatively, 21 aromatic solvents were administered orally by gastric intubation to Sprague-Dawley rats for 5 days/week for a 2-week period. The dose used was 8.47 mmol kg{sup -1} body weight day{sup -1}. The possible ototoxicity of the aromatic solvents was evaluated by morphological investigation of the cochlea. Whole-mount surface preparations of the organ of Corti were made to quantify the number of missing hair cells (cytocochleogram). Among the 21 solvents studied, eight (toluene, p-xylene, ethylbenzene, n-propylbenzene, styrene, {alpha}-methylstyrene, trans-{beta}-methylstyrene, and allylbenzene) caused histological lesions of the organ of Corti. They differed widely in their potency. The least ototoxic solvents caused outer hair cell (OHC) loss in the middle turn of the organ of Corti. The OHC loss was slight in the first row, and greater in the second and third rows. The most ototoxic solvents caused high losses in the three rows of the outer hair cells along the entire length of the basilar membrane. There were also occasional inner hair cell (ICH) losses in the most affected animals. Although no measurements were made of the chemical concentrations reached in the blood or the brain, tentative ranking of an increasing ototoxicity of the eight aromatic solvents could be proposed on the basis of the histological losses observed - {alpha}-methylstyrene

  11. Mixing in explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A.L.

    1993-12-01

    Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.

  12. Wet in situ transesterification of microalgae using ethyl acetate as a co-solvent and reactant.

    Science.gov (United States)

    Park, Jeongseok; Kim, Bora; Chang, Yong Keun; Lee, Jae W

    2017-04-01

    This study addresses wet in situ transesterification of microalgae for the production of biodiesel by introducing ethyl acetate as both reactant and co-solvent. Ethyl acetate and acid catalyst are mixed with wet microalgae in one pot and the mixture is heated for simultaneous lipid extraction and transesterification. As a single reactant and co-solvent, ethyl acetate can provide higher FAEE yield and more saccharification of carbohydrates than the case of binary ethanol and chloroform as a reactant and a co-solvent. The optimal yield was 97.8wt% at 114°C and 4.06M catalyst with 6.67mlEtOAC/g dried algae based on experimental results and response surface methodology (RSM). This wet in situ transesterification of microalgae using ethyl acetate doesn't require an additional co-solvent and it also promises more economic benefit as combining extraction and transesterification in a single process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. THE MARKETING MIX OPTIMIZATION

    OpenAIRE

    SABOU FELICIA

    2014-01-01

    The paper presents the marketing mix and the necessity of the marketing mix optimization. In the marketing mix a particularly important issue is to choose the best combination of its variables, this lead to the achievement objectives, in time. Choosing the right marketing mix is possible only by reporting information to some clear benchmarks, these criteria a related to the objective of the company at the time of analyze. The study shows that the companies must give a great importance to opti...

  14. SPORT MARKETING MIX STRATEGIES

    OpenAIRE

    Alexandru Lucian MIHAI

    2013-01-01

    This paper presents a brief overview of a significant element of the sport marketing management model called the marketing mix. The marketing mix is crucial because it defines the sport business, and much of the sport marketer’s time is spent on various functions within the marketing mix. The marketing mix is the strategic combination of the product, price, place and promotion elements. These elements are typically called the four Ps of marketing. Decisions and strategies for each are importa...

  15. 29 CFR 1915.32 - Toxic cleaning solvents.

    Science.gov (United States)

    2010-07-01

    ... Preservation § 1915.32 Toxic cleaning solvents. (a) When toxic solvents are used, the employer shall employ one... space. (2) Either natural ventilation or mechanical exhaust ventilation shall be used to remove the...

  16. Organic Solvent Tropical Report [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    2000-06-21

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines.

  17. Selection and evaluation of alternative solvents for caprolactam extraction

    NARCIS (Netherlands)

    Delden, van Mathijs L.; Kuipers, Norbert J.M.; Haan, de André B.

    2006-01-01

    Because of the strict legislation for currently applied solvents in the industrial extraction of caprolactam, being benzene, toluene and chlorinated hydrocarbons, a need exists for alternative, environmentally benign solvents. An experimental screening procedure consisting of several steps was used

  18. Occupational exposure to chlorinated and petroleum solvents and mycosis fungoides

    DEFF Research Database (Denmark)

    Morales-Suárez-Varela, Maria M; Olsen, Jørn; Villeneuve, Sara

    2013-01-01

    To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF).......To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF)....

  19. The Ideal Solvent for Paper Chromatography of Food Dyes.

    Science.gov (United States)

    Markow, Peter G.

    1988-01-01

    Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  2. Optimal Mixing Evolutionary Algorithms

    NARCIS (Netherlands)

    Thierens, D.; Bosman, P.A.N.; Krasnogor, N.

    2011-01-01

    A key search mechanism in Evolutionary Algorithms is the mixing or juxtaposing of partial solutions present in the parent solutions. In this paper we look at the efficiency of mixing in genetic algorithms (GAs) and estimation-of-distribution algorithms (EDAs). We compute the mixing probabilities of

  3. Neutrino Mixing and Cosmology

    OpenAIRE

    Bell, Nicole F.

    2003-01-01

    We review the consequences of neutrino mixing in the early universe. For both active-sterile mixing or mixing between three active neutrinos only, the consequences of oscillations depend crucially upon the size of the universe's lepton number (relic neutrino asymmetry.)

  4. European mixed forests

    DEFF Research Database (Denmark)

    Bravo-Oviedo, Andres; Pretzsch, Hans; Ammer, Christian

    2014-01-01

    Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material and Met...

  5. A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

    2015-08-31

    We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

  6. Direct Electrospinning of Ultrafine Fibers with Interconnected Macropores Enabled by in Situ Mixing Microfluidics.

    Science.gov (United States)

    Liu, Wanjun; Zhu, Lei; Huang, Chen; Jin, Xiangyu

    2016-12-21

    Porous ultrafine fibers are of great importance to various applications. Herein, we report a method to directly fabricate macro-porous ultrafine fibers by an in situ mixing microfluidics which allows for the simultaneous electrospinning of solution immediately after mixing. The formation mechanism of macro-pores should be attributed to the incomplete mixing coupled with nonsolvent-induced phase separation, which was elucidated by systematical investigation of various solvent systems and mixing solvents. The diameter of the macro-porous fibers can be tuned from 1.80 ± 0.40 to 6.75 ± 0.48 μm by adjusting the solution concentration and the feeding rate of mixing solvent. The results indicated that macro-porous fibers exhibited higher specific surface area (48.66 ± 8.30 m(2) g(-1)), larger pore size (116.73 nm) and pore volume (0.169 ± 0.007 cm(3) g(-1)) than conventional electrospun porous fibers, enabling the high oil absorption capacities of 95.68, 57.98, and 34.82 g g(-1) for silicon oil, motor oil, and peanut oil, respectively. Our method has greatly expanded the solution scope for electrospinning from stable solution systems to unstable or substable solution systems, thus providing intriguing opportunities for the investigation and fabrication of heterogeneous fibers by in situ mixing of various immiscible solvents/solutions. Our findings can serve as guidelines for the electrospinning of ultrafine fibers with interconnected macro-pores (>50 nm).

  7. Functionalization of graphene using deep eutectic solvents

    Science.gov (United States)

    Hayyan, Maan; Abo-Hamad, Ali; AlSaadi, Mohammed AbdulHakim; Hashim, Mohd Ali

    2015-08-01

    Deep eutectic solvents (DESs) have received attention in various applications because of their distinctive properties. In this work, DESs were used as functionalizing agents for graphene due to their potential to introduce new functional groups and cause other surface modifications. Eighteen different types of ammonium- and phosphonium-salt-based DESs were prepared and characterized by FTIR. The graphene was characterized by FTIR, STA, Raman spectroscopy, XRD, SEM, and TEM. Additional experiments were performed to study the dispersion behavior of the functionalized graphene in different solvents. The DESs exhibited both reduction and functionalization effects on DES-treated graphene. Dispersion stability was investigated and then characterized by UV-vis spectroscopy and zeta potential. DES-modified graphene can be used in many applications, such as drug delivery, wastewater treatment, catalysts, composite materials, nanofluids, and biosensors. To the best of our knowledge, this is the first investigation on the use of DESs for graphene functionalization.

  8. Alternative solvents for post combustion carbon capture

    Directory of Open Access Journals (Sweden)

    Udara S. P. R. Arachchige, Morten C. Melaaen

    2013-01-01

    Full Text Available The process model of post combustion chemical absorption is developed in Aspen Plus for both coal and gas fired power plant flue gas treating. The re-boiler energy requirement is considered as the most important factor to be optimized. Two types of solvents, mono-ethylamine (MEA and di-ethylamine (DEA, are used to implement the model for three different efficiencies. The re-boiler energy requirement for regeneration process is calculated. Temperature and concentration profiles in absorption column are analyzed to understand the model behavior. Re-boiler energy requirement is considerably lower for DEA than MEA as well as impact of corrosion also less in DEA. Therefore, DEA can be recommended as a better solvent for post combustion process for carbon capture plants in fossil fuel fired power industries.

  9. Myoglobin solvent structure at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, B.V.; Korszun, Z.R. [Brookhaven National Laboratory, Upton, NY (United States); Schoenborn, B.P. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    The structure of the solvent surrounding myoglobin crystals has been analyzed using neutron diffraction data, and the results indicate that the water around the protein is not disordered, but rather lies in well-defined hydration shells. We have analyzed the structure of the solvent surrounding the protein by collecting neutron diffraction data at four different temperatures, namely, 80, 130, 180, and 240K. Relative Wilson Statistics applied to low resolution data showed evidence of a phase transition in the region of 180K. A plot of the liquidity factor, B{sub sn}, versus distance from the protein surface begins with a high plateau near the surface of the protein and drops to two minima at distances from the protein surface of about 2.35{Angstrom} and 3.85{Angstrom}. Two distinct hydration shells are observed. Both hydration shells are observed to expand as the temperature is increased.

  10. Critical bubble radius in solvent sublation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The complex compound of dithizone-Co(Ⅱ) was separated and concentrated from the aqueous phase to n-octanol by solvent sublation. From the analysis of the coalescence behavior of bubbles on water-organic interface, the conception of critical bubble radius was proposed, and the value of the critical bubble radius in the water-octanol system was obtained: 1.196 × 10-3 m. The simulation of the mathematical model using CBR and experimental data is completed with perfect results, and the simulation of the mathematical model using CBR is very different with the classic one. The analytical results proved that the critical bubble radius should be adequately considered in mathematical model of solvent sublation.

  11. Alternative solvents for post combustion carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Arachchige, Udara S.P.R. [Telemark University College, Porsgrunn (Norway); Melaaen, Morten C. [Telemark University College, Porsgrunn (Norway); Tel-Tek, Porsgrunn (Norway)

    2013-07-01

    The process model of post combustion chemical absorption is developed in Aspen Plus for both coal and gas fired power plant flue gas treating. The re-boiler energy requirement is considered as the most important factor to be optimized. Two types of solvents, mono-ethylamine (MEA) and di-ethylamine (DEA), are used to implement the model for three different efficiencies. The re-boiler energy requirement for regeneration process is calculated. Temperature and concentration profiles in absorption column are analyzed to understand the model behavior. Re-boiler energy requirement is considerably lower for DEA than MEA as well as impact of corrosion also less in DEA. Therefore, DEA can be recommended as a better solvent for post combustion process for carbon capture plants in fossil fuel fired power industries.

  12. Effect of water droplet in solvent sublation

    Institute of Scientific and Technical Information of China (English)

    Peng Yu Bi; Hui Ru Dong; Nan Nan Wang

    2008-01-01

    Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation. In the dynamic processof mass transfer, they are always neglected, but they are very important in the investigation of thermodynamic equilibrium. In thispaper, the effect of water droplet in solvent sublation was discussed in detail, and the previous mathematical model of solventsubaltion was improved. Matlab 6.5 was used to simulate the process of water droplets, and the comparison between the previoushypothesis and the improvement in this paper showed the superiority, especially in the investigation of thermodynamic equilibrium.Moreover, the separation and concentration of the complex compound dithizone-Co(Ⅱ) from aqueous phase to n-octanol by solventsublation also proved the improved mathematical model was reasonable.2008 Hui Ru Dong. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  13. Development of a solvent processed insensitive propellant

    Science.gov (United States)

    Trask, R.; Costa, E.; Beardell, A. J.

    1980-01-01

    Two types of low vulnerability propellants are studied which are distinguished by whether the binder is a rubber, such as polyurethane or CTBN, or a plasticizable polymer such as ethyl cellulose or cellulose acetate. The former propellants are made by a partial cure extrusion process while the latter are made by the conventional solvent process. Emphasis is given to a cellulose binder (plasticizer) RDX composition. The type of binder used, the particle size of the RDX and the presence of small quantities of nitrocellulose in the solvent processed compositions have important influences on the mechanical and combustion characteristics of the propellant. The low temperature combustion is of particular concern because of potential breakup of the grains that can lead to instability.

  14. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  15. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  16. Solvent Retention Capacities of Oat Flour

    Directory of Open Access Journals (Sweden)

    Qianwen Niu

    2017-03-01

    Full Text Available This study measured the solvent retention capacities (SRCs of flours from eight oat varieties and one wheat variety against different solvents to explore the swelling volume of oat flour with different solvents, and thus provide a theoretical basis for quick β-glucan analysis. The SRC profile consists of water SRC (WSRC, 50% sucrose SRC (SSRC, 5% lactic acid SRC (LASRC, 5% Na2CO3 SRC (SCASRC, NaCl SRC (SCSRC, CaCl2 SRC (CCSRC, FeCl3 SRC (FCSRC, sodium cholate SRC (SCHSRC, NaOH (pH 10 SRC (SHSRC, Na2CO3 (pH 10 SRC (SCABSRC and SDS (pH 10 SRC (SDSSRC values, and a Chopin SRC kit was used to measure the SRC value. SRCs of the oat flours increased when the solvents turned from neutral (water and NaCl to acidic (5% lactic acid or alkaline (5% Na2CO3, CaCl2, FeCl3, NaOH and pH 10 Na2CO3, and rose as the metal ion valencies of the metal salts (NaCl, CaCl2 and FeCl3 increased. The β-glucan contents were significantly positively correlated with the SCSRC (0.83**, CCSRC (0.82**, SCHSRC (0.80** and FCSRC (0.78*. SRC measurements of β-glucan in oat flours revealed that the CCSRC values were related with β-glucan (0.64* but not related with protein and starch. CaCl2 could therefore potentially be exploited as a reagent for β-glucan assay.

  17. Indentation of polydimethylsiloxane submerged in organic solvents

    OpenAIRE

    Hu, Yuhang; Chen, Xin; Whitesides, George McClelland; Vlassak, Joost J.; Suo, Zhigang

    2011-01-01

    This work uses a method based on indentation to characterize a polydimethylsiloxane (PDMS) elastomer submerged in an organic solvent (decane, heptane, pentane, or cyclohexane). An indenter is pressed into a disk of a swollen elastomer to a fixed depth, and the force on the indenter is recorded as a function of time. By examining how the relaxation time scales with the radius of contact, one can differentiate the poroelastic behavior from the viscoelastic behavior. By matching the relaxation c...

  18. Coupling of protein dynamics with the solvent

    Science.gov (United States)

    Caliskan, Gokhan; Sauzan, Azzam; Mehtani, Disha; Sokolov, Alexei

    2003-03-01

    Glycerol and trehalose are among the many viscous solvents that are widely used for biostabilization and controlling the dynamics of proteins. It is believed that the suppression of the structural relaxations by high viscosity of solvent is responsible for improved stability in proteins. However, results of [1] and [2] demonstrate stronger suppression of biochemical activity and dynamics of proteins by liquid glycerol than by solid trehalose in a wide temperature range. The authors tried to explain the counterintuitive observations by a possible decoupling of the dynamics of the protein from trehalose. In order to test the validity of this assumption and to investigate the influence of the fast dynamics in proteins, the low frequency Raman scattering spectroscopy technique is used. Both relaxational and vibrational dynamics of glycerol, trehalose, and lysozyme in glycerol and in trehalose are studied in a wide temperature range. Dynamics of lysozyme in glycerol follows the strong temperature dependence of relaxational and vibrational dynamics of the bulk glycerol. On the other hand, the weak temperature dependence of dynamics of lysozyme in trehalose follows exactly the behavior of pure trehalose. This proves that there is a strong dynamic coupling between the protein and the solvents used. Interestingly, stronger relaxations in solid trehalose as compared to liquid glycerol are observed in the GHz region at low temperatures. This could be the reason for the enhanced protein activity observed in trehalose, compared to that in glycerol in this temperature range. Suppression of these fast relaxations should be the key for providing long-term stability to proteins. 1. Sastry, G.M. and N. Agmon, Trehalose prevents myoglobin collapse and preserves its internal mobility. BIOCHEMISTRY, 1997, 36(23): p. 7097-108. 2. Caliskan, G., et al., Influence of solvent on dynamics and stability of a protein. Journal of Non-Crystalline Solids, 2002, 307-310: p. 887-893.

  19. Solvent Retention Capacities of Oat Flour

    Science.gov (United States)

    Niu, Qianwen; Pu, Yu; Li, Xiaoping; Ma, Zhen; Hu, Xinzhong

    2017-01-01

    This study measured the solvent retention capacities (SRCs) of flours from eight oat varieties and one wheat variety against different solvents to explore the swelling volume of oat flour with different solvents, and thus provide a theoretical basis for quick β-glucan analysis. The SRC profile consists of water SRC (WSRC), 50% sucrose SRC (SSRC), 5% lactic acid SRC (LASRC), 5% Na2CO3 SRC (SCASRC), NaCl SRC (SCSRC), CaCl2 SRC (CCSRC), FeCl3 SRC (FCSRC), sodium cholate SRC (SCHSRC), NaOH (pH 10) SRC (SHSRC), Na2CO3 (pH 10) SRC (SCABSRC) and SDS (pH 10) SRC (SDSSRC) values, and a Chopin SRC kit was used to measure the SRC value. SRCs of the oat flours increased when the solvents turned from neutral (water and NaCl) to acidic (5% lactic acid) or alkaline (5% Na2CO3, CaCl2, FeCl3, NaOH and pH 10 Na2CO3), and rose as the metal ion valencies of the metal salts (NaCl, CaCl2 and FeCl3) increased. The β-glucan contents were significantly positively correlated with the SCSRC (0.83**), CCSRC (0.82**), SCHSRC (0.80**) and FCSRC (0.78*). SRC measurements of β-glucan in oat flours revealed that the CCSRC values were related with β-glucan (0.64*) but not related with protein and starch. CaCl2 could therefore potentially be exploited as a reagent for β-glucan assay. PMID:28335393

  20. Bioremediation of a Large Chlorinated Solvent Plume, Dover AFB, DE

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Aleisa C [ORNL

    2015-01-01

    Bioremediation of a Large Chlorinated Solvent Plume, Dover AFB, DE Aleisa Bloom, (Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA) Robert Lyon (bob.lyon@aecom.com), Laurie Stenberg, and Holly Brown (AECOM, Germantown, Maryland, USA) ABSTRACT: Past disposal practices at Dover Air Force Base (AFB), Delaware, created a large solvent plume called Area 6 (about 1 mile long, 2,000 feet wide, and 345 acres). The main contaminants are PCE, TCE, and their degradation products. The remedy is in-situ accelerated anaerobic bioremediation (AAB). AAB started in 2006 and is focusing on source areas and downgradient plume cores. Direct-push injections occurred in source areas where contamination is typically between 5 and 20 feet below ground surface. Lower concentration dissolved-phased contamination is present downgradient at 35 and 50 feet below ground surface. Here, permanent injection/extraction wells installed in transects perpendicular to the flow of groundwater are used to apply AAB. The AAB substrate is a mix of sodium lactate, emulsified vegetable oil, and nutrients. After eight years, dissolved contaminant mass within the main 80-acre treatment area has been reduced by over 98 percent. This successful application of AAB has stopped the flux of contaminants to the more distal portions of the plume. While more time is needed for effects to be seen in the distal plume, AAB injections will soon cease, and the remedy will transition to natural attenuation. INTRODUCTION Oak Ridge National Laboratory Environmental Science Division (ORNL) and AECOM (formerly URS Corporation) have successfully implemented in situ accelerated anaerobic bioremediation (AAB) to remediate chlorinated solvent contamination in a large, multi-sourced groundwater plume at Dover Air Force Base (AFB). AAB has resulted in significant reductions of dissolved phase chlorinated solvent concentrations. This plume, called Area 6, was originally over 1 mile in length and over 2,000 feet wide (Figure 1

  1. Green solvents and technologies for oil extraction from oilseeds.

    Science.gov (United States)

    Kumar, S P Jeevan; Prasad, S Rajendra; Banerjee, Rintu; Agarwal, Dinesh K; Kulkarni, Kalyani S; Ramesh, K V

    2017-01-01

    Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330 kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to look for alternative options. To circumvent the problem, green solvents could be a promising approach to replace solvent extraction. In this review, green solvents and technology like aqueous assisted enzyme extraction are better solution for oil extraction from oilseeds. Enzyme mediated extraction is eco-friendly, can obtain higher yields, cost-effective and aids in obtaining co-products without any damage. Enzyme technology has great potential for oil extraction in oilseed industry. Similarly, green solvents such as terpenes and ionic liquids have tremendous solvent properties that enable to extract the oil in eco-friendly manner. These green solvents and technologies are considered green owing to the attributes of energy reduction, eco-friendliness, non-toxicity and non-harmfulness. Hence, the review is mainly focussed on the prospects and challenges of green solvents and technology as the best option to replace the conventional methods without compromising the quality of the extracted products.

  2. 27 CFR 21.125 - Rubber hydrocarbon solvent.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative....

  3. Dynamics of solvent-free grafted nanoparticles

    KAUST Repository

    Chremos, Alexandros

    2012-01-01

    The diffusivity and structural relaxation characteristics of oligomer-grafted nanoparticles have been investigated with simulations of a previously proposed coarse-grained model at atmospheric pressure. Solvent-free, polymer-grafted nanoparticles as well as grafted nanoparticles in a melt were compared to a reference system of bare (ungrafted) particles in a melt. Whereas longer chains lead to a larger hydrodynamic radius and lower relative diffusivity for grafted particles in a melt, bulk solvent-free nanoparticles with longer chains have higher relative diffusivities than their short chain counterparts. Solvent-free nanoparticles with short chains undergo a glass transition as indicated by a vanishing diffusivity, diverging structural relaxation time and the formation of body-centered-cubic-like order. Nanoparticles with longer chains exhibit a more gradual increase in the structural relaxation time with decreasing temperature and concomitantly increasing particle volume fraction. The diffusivity of the long chain nanoparticles exhibits a minimum at an intermediate temperature and volume fraction where the polymer brushes of neighboring particles overlap, but must stretch to fill the interparticle space. © 2012 American Institute of Physics.

  4. Flash pyrolysis of coal-solvent slurry prepared from the oxidized coal and the coal dissolved in solvent; Ichibu yokaishita sanka kaishitsutan slurry no jinsoku netsubunkai

    Energy Technology Data Exchange (ETDEWEB)

    Maki, T.; Mae, K.; Okutsu, H.; Miura, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1996-10-28

    In order to develop a high-efficiency coal pyrolysis method, flash pyrolysis was experimented on slurry prepared by using liquid-phase oxidation reformed coal and a methanol-based solvent mixture. Australian Morwell coal was used for the experiment. The oxidized coal, into which carboxyl groups have been introduced, has the condensation structure relaxed largely, and becomes highly fluid slurry by means of the solvent. Char production can be suppressed by making the oxidation-pretreated coal into slurry, resulting in drastically improved pyrolytic conversion. The slurry was divided into dissolved solution, dried substance, extracted residue, and residual slurry, which were pyrolized independently. The dissolved solution showed very high conversion. Improvement in the conversion is contributed by separating the dissolved substances (coal macromolecules) at molecular levels, coagulating the molecules, suppressing cross-link formation, and reducing molecular weight of the dissolved substances. Oxidized coal can be dissolved to 80% or higher by using several kinds of mixed solvents. As a result of the dissolution, a possibility was suggested on pyrolysis which is easy in handling and high in conversion. 7 refs., 6 figs., 2 tabs.

  5. Foundations of chaotic mixing.

    Science.gov (United States)

    Wiggins, Stephen; Ottino, Julio M

    2004-05-15

    The simplest mixing problem corresponds to the mixing of a fluid with itself; this case provides a foundation on which the subject rests. The objective here is to study mixing independently of the mechanisms used to create the motion and review elements of theory focusing mostly on mathematical foundations and minimal models. The flows under consideration will be of two types: two-dimensional (2D) 'blinking flows', or three-dimensional (3D) duct flows. Given that mixing in continuous 3D duct flows depends critically on cross-sectional mixing, and that many microfluidic applications involve continuous flows, we focus on the essential aspects of mixing in 2D flows, as they provide a foundation from which to base our understanding of more complex cases. The baker's transformation is taken as the centrepiece for describing the dynamical systems framework. In particular, a hierarchy of characterizations of mixing exist, Bernoulli --> mixing --> ergodic, ordered according to the quality of mixing (the strongest first). Most importantly for the design process, we show how the so-called linked twist maps function as a minimal picture of mixing, provide a mathematical structure for understanding the type of 2D flows that arise in many micromixers already built, and give conditions guaranteeing the best quality mixing. Extensions of these concepts lead to first-principle-based designs without resorting to lengthy computations.

  6. Evolution of a degradative bacterial consortium during the enrichment of naphtha solvent.

    Science.gov (United States)

    Cavalca, L; Confalonieri, A; Larcher, S; Andreoni, V

    2000-06-01

    A microbial mixed culture able to degrade naphtha solvent, a model of hydrocarbon aromatic mixture, was isolated from a hydrocarbon-polluted soil. Composition of the population was monitored by phenotypic and molecular methods applied on soil DNA, on whole enrichment culture DNA, and on 85 isolated strains. Strains were characterized for their 16S rDNA restriction profiles and for their random amplified polymorphic DNA profiles. Catabolic capabilities were monitored by phenotypic traits and by PCR assays for the presence of the catabolic genes methyl mono-oxygenase ( xylA, M), catechol 2,3 dioxygenase (xylE) and toluene dioxygenase (todC1) of TOL and TOD pathways. Different haplotypes belonging to Pseudomonas putida, Ps. aureofaciens and Ps. aeruginosa were found to degrade aromatic compounds and naphtha solvent. The intrinsic catabolic activity of the microbial population of the polluted site was detected by PCR amplification of the xylE gene directly from soil DNA.

  7. Influence of solvents on properties of solar selective coatings obtained by spray pyrolysis

    Indian Academy of Sciences (India)

    Mihaela Dudita; Luminita Isac; Anca Duta

    2012-11-01

    Solar selective coatings for solar thermal flat-plate collectors consisting of crystalline copper oxides and amorphous nickel oxide composites were obtained by robotic spray pyrolyzed deposition. The parameters were optimized for increased spectral selectivity (): high solar absorptance and low thermal emittance. The coatings were deposited using nickel and copper acetate, dissolved in mixed solvents with various water: ethanol ratios. The coatings’ properties were characterized in terms of crystalline composition (XRD), surface morphology (AFM, contact angle) and optical properties (solar absorptance, thermal emittance and spectral selectivity). Considering the precursor solutions composition (solvent, wetting behaviour), the growth processes were modelled for two different systems: predominant hydrophilic and predominant hydrophobic. The high selectivity values ( > 30) of the optimized composite coatings were explained based on two parallel mechanisms: intrinsic absorption and multiple reflections generated when absorbers with controlled roughness are deposited.

  8. Enhancement of third-order nonlinear optical susceptibility of Alqsub>3sub> in polar aprotic solvents.

    Science.gov (United States)

    Derkowska-Zielinska, Beata

    2017-02-01

    The influence of solvent polarity on nonlinear optical properties of tris-(8-hydroxyquinoline)-aluminum (Alqsub>3sub>) was investigated by the degenerate four-wave mixing method at the 532 nm. It was obtained that the effective values of the third-order nonlinear optical susceptibility (χeff⟨3⟩) and the second-order hyperpolarizability (γsub>effsub>) of Alqsub>3sub> depend on the solvent polarity. Additionally, it was found that Alqsub>3sub> dissolved in dimethyl sulfoxide has the highest values of χeff⟨3⟩ and γsub>effsub>. Furthermore, two Stegeman's figures of merit were also calculated. The obtained results suggest that Alqsub>3sub> is also promising material for application in all-optical signal processing devices.

  9. An evaluation of the applicability of the EPA Organic Leachate Model to leaching of solvent and non-solvent wastes

    OpenAIRE

    Bosserman, Carolyn Whitney

    1989-01-01

    The author evaluated the applicability of the Environmental Protection Agency's Organic Leachate Model to wastes containing organic solvents and other organic compounds ("non-solvents"), and determined that the model tends to overestimate the leaching of organic solvents and other organic compounds. Furthermore, when evaluated for its ability to predict leaching of organic compounds, the model was found to predict the leaching of organic solvent compounds with some accuracy, with a correlatio...

  10. Solvent-mediated gel formation, hierarchical structures, and rheological properties of organogels.

    Science.gov (United States)

    Su, Ming-Ming; Yang, Hai-Kuan; Ren, Li-Jun; Zheng, Ping; Wang, Wei

    2015-01-28

    We report the formation of solvent-mediated gels as well as their hierarchical structures and rheological properties. The gelator used is a hybrid with a molecular structure of cholesterol-polyoxometalate-cholesterol, in which the cholesterol dissolves well in toluene and N,N-dimethylformamide (DMF), whereas the polyoxometalate cluster dissolves only in DMF. These solubility differences enable the gelator to form thermally reversible supramolecular organogels by mixing solvents of toluene and DMF when the volume fraction, ftol, of toluene is larger than 85.7 v/v%. We found a V-shaped correlation between the gelation times, tgel and ftol: tgel decreases from 1300 min to 2 min when ftol increases from 85.7 v/v% to 90.0 v/v%. It then increases from 2 min to 5800 min when ftol further increases from 90.0 v/v% to 100.0 v/v%. We observed ribbon-like self-assembled structures in the gels as well as a structural evolution from rigid and straight ribbons to twistable ones from ftol=85.7 v/v% to ftol=100.0 v/v%. These ribbons constitute two three-dimensional (3D) gel networks: one is constructed via physical connection of the rigid and straight ribbon, and the other is built up from ribbons splitting and intertwining. The latter has a better 3D gel network that offers improved rheological properties. Fundamentally, this solvent-mediated approach regulates the balance between solubility and insolubility of this gelator in the mixing solvents. It also provides a new method for the preparation of organogels.

  11. Measurement of oxygen transfer from air into organic solvents

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Mayr, Torsten; Hobisch, Mathias

    2016-01-01

    applications). Subsequently, we measured the oxygen transfer rates from air into these organic solvents. Conclusion The measurement of oxygen transfer rates from air into organic solvents using the dynamic method was established using the solvent resistant optical sensor. The feasibility of online oxygen...... biological reactions require the supply of oxygen, most normally from air. However, reliable on-line measurements of oxygen concentration in organic solvents (and hence oxygen transfer rates from air to the solvent) has to date proven impossible due limitations in the current analytical methods. Results...

  12. The Development of a Microscale Continuous Hot Solvent Extractor

    Science.gov (United States)

    Wesolowski, Steve S.; Mulcahy, Thomas; Zafoni, Christina M.; Wesolowski, Wayne E.

    1999-08-01

    The extraction of soluble materials from organic samples plays an important role in many industries. For example, extraction of oils and grease from soil samples using traditional Soxhlet extractors is an essential procedure in waste management laboratories. These extractors use from 25 to 1000 mL of solvent per sample and the waste solvent is typically distilled or simply disposed of upon completion of the extraction. To minimize the waste solvent produced, we have developed a microscale continuous hot solvent extractor that effectively extracts 100-500-mg samples using about 4 mL of solvent.

  13. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands.

    Science.gov (United States)

    Emara, Adel A A; Abu-Hussein, Azza A A; Taha, Ahmed A; Mahmoud, Nelly H

    2010-10-15

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules.

  14. Computing the Absorption and Emission Spectra of 5-Methylcytidine in Different Solvents: A Test-Case for Different Solvation Models.

    Science.gov (United States)

    Martínez-Fernández, L; Pepino, A J; Segarra-Martí, J; Banyasz, A; Garavelli, M; Improta, R

    2016-09-13

    The optical spectra of 5-methylcytidine in three different solvents (tetrahydrofuran, acetonitrile, and water) is measured, showing that both the absorption and the emission maximum in water are significantly blue-shifted (0.08 eV). The absorption spectra are simulated based on CAM-B3LYP/TD-DFT calculations but including solvent effects with three different approaches: (i) a hybrid implicit/explicit full quantum mechanical approach, (ii) a mixed QM/MM static approach, and (iii) a QM/MM method exploiting the structures issuing from molecular dynamics classical simulations. Ab-initio Molecular dynamics simulations based on CAM-B3LYP functionals have also been performed. The adopted approaches all reproduce the main features of the experimental spectra, giving insights on the chemical-physical effects responsible for the solvent shifts in the spectra of 5-methylcytidine and providing the basis for discussing advantages and limitations of the adopted solvation models.

  15. Mixing of solids in different mixing devices

    Indian Academy of Sciences (India)

    Ingrid Bauman; Duška Ćurić; Matija Boban

    2008-12-01

    Mixing of powders is a common operation in any industry. Most powders are known to be cohesive, many agglomerate spontaneously when exposed to humid atmosphere or elevated storage temperature. Agitation of the powder (especially powders with different bulk densities) may result in migration of smaller particles downwards and of larger ones upwards. Another problem is segregation whose main cause is the difference in particle size, density shape and resilience. There are standard mixing devices, such as drum tumblers or Turbula mixers. Alternate device type used is the static mixer of Kenics type. Static mixers save energy, disable segregation and effect particle migration. In this paper, static mixers, as devices for powder mixing, are tested as well as Turbula and V-shaped drum mixer, since those devices are commonly used for powder blending in industry. Mixtures that were blended by means of those three devices were made out of the model material, quartz sand, in different component ratios (20:80 and 30:70). The results were statistically calculated and graphically presented. Cohesion indexes were measured with Powder Flow Analyser to see the effect of material flow on the mixture quality. The results obtained by those three devices, the particle size effect and cohesion indexes, bring us to the conclusion that static mixers could be used for mixing of powders, but their shape, number of mixing elements and the mixer length should be adapted for each mixture separately, experimentally and mathematically, through modelling of the system.

  16. An Organic Mixed Ion-Electron Conductor for Power Electronics.

    Science.gov (United States)

    Malti, Abdellah; Edberg, Jesper; Granberg, Hjalmar; Khan, Zia Ullah; Andreasen, Jens W; Liu, Xianjie; Zhao, Dan; Zhang, Hao; Yao, Yulong; Brill, Joseph W; Engquist, Isak; Fahlman, Mats; Wågberg, Lars; Crispin, Xavier; Berggren, Magnus

    2016-02-01

    A mixed ionic-electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio-phene):-poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting nanopaper are exploited in devices which exhibit record values for the charge storage capacitance (1F) in supercapacitors and transconductance (1S) in electrochemical transistors.

  17. Enhanced removal of lead from contaminated soil by polyol-based deep eutectic solvents and saponin

    Science.gov (United States)

    Mukhopadhyay, Soumyadeep; Mukherjee, Sumona; Hayyan, Adeeb; Hayyan, Maan; Hashim, Mohd Ali; Sen Gupta, Bhaskar

    2016-11-01

    Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.g. glycerol and ethylene glycol. A natural surfactant saponin obtained from soapnut fruit pericarp, was mixed with DESs to boost their efficiency. The DESs on their own did not perform satisfactory due to higher pH; however, they improved the performance of soapnut by up to 100%. Pb removal from contaminated soil using mixture of 40% DES-Gly and 1% saponin and mixture of 10% DES-Gly and 2% saponin were above 72% XRD and SEM studies did not detect any major corrosion in the soil texture. The environmental friendliness of both DESs and saponin and their affordable costs merit thorough investigation of their potential as soil washing agents.

  18. Investigation of the dispersion behavior of fluorinated MWCNTs in various solvents.

    Science.gov (United States)

    Liu, Yang; Zhang, Yichun; Wang, Zaoming; Lai, Wenchuan; Zhang, Xiaojiao; Wang, Xu; Liu, Xiangyang

    2017-08-16

    The investigation of the dispersion behavior of fluorinated MWCNTs (F-MWCNTs) is very important to understand their structure and take full advantage of their good properties. In this present paper, the dispersion behavior of F-MWCNTs with a low content and a high content of fluorine (denoted as lF-MWCNTs and hF-MWCNTs) was explored in 18 kinds of common solvents. The surface of hF-MWCNTs is considered to be a heterostructure consisting of fluorinated regions and aromatic regions, while lF-MWCNTs are inclined to be a homogeneous structure on the basis of their dispersion behavior. According to dispersion theory based on surface energy and Hansen solubility parameters (HSPs), it was indicated that the corresponding preferable solvents are different for different regions. As a result, good solvents of hF-MWCNTs are distributed in a quite wide scope while lF-MWCNTs can be dispersed only in a significantly narrow range of solvents. The HSPs of lF-MWCNTs and hF-MWCNTs are determined to be δD = 17.6 MPa(1/2), δP = 11.8 MPa(1/2), δH = 8.8 MPa(1/2) and δD = 16.9 MPa(1/2), δP = 9.3 MPa(1/2), δH = 13.5 MPa(1/2), respectively. As a result, mixed solvents of acetone and water were carefully tuned to be compatible with hF-MWCNTs. The dispersion behaviors of lF-MWCNTs and hF-MWCNTs in epoxy were also predicted according to HSPs. It was found that hF-MWCNTs maintain a stable dispersion in epoxy due to their heterogeneous structure at elevated temperatures.

  19. Depleting depletion: Polymer swelling in poor solvent mixtures

    Science.gov (United States)

    Mukherji, Debashish; Marques, Carlos; Stuehn, Torsten; Kremer, Kurt

    A polymer collapses in a solvent when the solvent particles dislike monomers more than the repulsion between monomers. This leads to an effective attraction between monomers, also referred to as depletion induced attraction. This attraction is the key factor behind standard polymer collapse in poor solvents. Strikingly, even if a polymer exhibits poor solvent condition in two different solvents, it can also swell in mixtures of these two poor solvents. This collapse-swelling-collapse scenario is displayed by poly(methyl methacrylate) (PMMA) in aqueous alcohol. Using molecular dynamics simulations of a thermodynamically consistent generic model and theoretical arguments, we unveil the microscopic origin of this phenomenon. Our analysis suggests that a subtle interplay of the bulk solution properties and the local depletion forces reduces depletion effects, thus dictating polymer swelling in poor solvent mixtures.

  20. MIXED AND MIXING SYSTEMS WORLDWIDE: A PREFACE

    Directory of Open Access Journals (Sweden)

    Seán Patrick Donlan

    2012-09-01

    Full Text Available This issue of the Potchefstroom Electronic Law Journal (South Africa sees thepublication of a selection of articles derived from the Third International Congress ofthe World Society of Mixed Jurisdiction Jurists (WSMJJ. That Congress was held atthe Hebrew University of Jerusalem, Israel in the summer of 2011. It reflected athriving Society consolidating its core scholarship on classical mixed jurisdictions(Israel, Louisiana, the Philippines, Puerto Rico, Quebec, Scotland, and South Africawhile reaching to new horizons (including Cyprus, Hong Kong and Macau, Malta,Nepal, etc. This publication reflects in microcosm the complexity of contemporaryscholarship on mixed and plural legal systems. This complexity is, of course, wellunderstoodby South African jurists whose system is derived both from the dominantEuropean traditions as well as from African customary systems, including both thosethat make up part of the official law of the state as well as those non-state norms thatcontinue to be important in the daily lives of many South Africans.

  1. Operando Solid-State NMR Observation of Solvent-Mediated Adsorption-Reaction of Carbohydrates in Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Long; Alamillo, Ricardo; Elliott, William A.; Andersen, Amity; Hoyt, David W.; Walter, Eric D.; Han, Kee Sung; Washton, Nancy M.; Rioux, Robert M.; Dumesic, James A.; Scott, Susannah L.

    2017-03-31

    In the liquid-phase catalytic processing of molecules using heterogeneous catalysts - an important strategy for obtaining renewable chemicals from biomass - many of the key reactions occur at solid-liquid interfaces. In particular, glucose isomerization occurs when the glucose is adsorbed in the micropores of a zeolite catalyst. Since solvent molecules are coadsorbed, the catalytic activity depends strongly and often nonmonotonically on the solvent composition. For glucose isomerization catalyzed by NaX and NaY zeolites, there is an initial steep decline when water is mixed with a small amount of the organic cosolvent γ-valerolactone (GVL), followed by a dramatic and surprising recovery as the GVL content in the mixed solvent increases. Here we elucidate the origin of this complex solvent effect using operando solid-state NMR spectroscopy. The glucopyranose tautomers immobilized in the zeolite pores were observed and their transformations into fructose and mannose followed in real time. The microheterogeneity of the solvent system, manifested by a nonmonotonic trend in the mixing enthalpy, influences the mobility and adsorption behavior of the carbohydrates, water, and GVL, which were studied using pulsed-field gradient (PFG) NMR diffusivity measurements. At low GVL concentrations, glucose is depleted in the zeolite pores relative to the solution phase and changes in the local structure of coadsorbed water serve to further suppress the isomerization rate. At higher GVL concentrations, this lower intrinsic reactivity is largely compensated by strong glucose partitioning into the pores, resulting in dramatic (up to 32×) enhancements in the local sugar concentration at the solid-liquid interface.

  2. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  3. Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Birdwell, Joseph F. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2014-03-01

    This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter laboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

  4. Next Generation Solvent (NGS): Development for Caustic-Side Solvent Extraction of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Birdwell, Jr, Joseph F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duncan, Nathan C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ensor, Dale [Tennessee Technological Univ., Cookeville, TN (United States); Hill, Talon G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Denise L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rajbanshi, Arbin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roach, Benjamin D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Szczygiel, Patricia L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sloop, Jr., Frederick V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stoner, Erica L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Neil J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-03-01

    This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Interlaboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

  5. Co-non-solvency: Mean-field polymer theory does not describe polymer collapse transition in a mixture of two competing good solvents

    Energy Technology Data Exchange (ETDEWEB)

    Mukherji, Debashish; Stuehn, Torsten; Kremer, Kurt [Max-Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany); Marques, Carlos M. [Max-Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany); Institut Charles Sadron, Université de Strasbourg, CNRS, Strasbourg (France)

    2015-03-21

    Smart polymers are a modern class of polymeric materials that often exhibit unpredictable behavior in mixtures of solvents. One such phenomenon is co-non-solvency. Co-non-solvency occurs when two (perfectly) miscible and competing good solvents, for a given polymer, are mixed together. As a result, the same polymer collapses into a compact globule within intermediate mixing ratios. More interestingly, polymer collapses when the solvent quality remains good and even gets increasingly better by the addition of the better cosolvent. This is a puzzling phenomenon that is driven by strong local concentration fluctuations. Because of the discrete particle based nature of the interactions, Flory-Huggins type mean field arguments become unsuitable. In this work, we extend the analysis of the co-non-solvency effect presented earlier [D. Mukherji et al., Nat. Commun. 5, 4882 (2014)]. We explain why co-non-solvency is a generic phenomenon, which can only be understood by the thermodynamic treatment of the competitive displacement of (co)solvent components. This competition can result in a polymer collapse upon improvement of the solvent quality. Specific chemical details are not required to understand these complex conformational transitions. Therefore, a broad range of polymers are expected to exhibit similar reentrant coil-globule-coil transitions in competing good solvents.

  6. Going beyond the classical amphiphilicity paradigm: the self-assembly of completely hydrophobic polymers into free-standing sheets and hollow nanostructures in solvents of variable quality.

    Science.gov (United States)

    Huang, Huanting; Liao, Yin; Bu, Weifeng; Wang, Wenjie; Sun, Jing Zhi

    2016-06-14

    Self-assembly is well-known to occur in amphiphiles, and the totally hydrophobic ones are never reported to self-assemble. In this work we report for the first time that the latter can self-assemble into free-standing sheets and hollow spheres in toluene/methanol mixed solvents by modulating the solvent quality. The homopolymers studied in this work are polystyrene (PS), polyphenylacetylene (PPA), and poly(3-hexyl thiophene) (P3HT), representing polymers with different rigidity. All the three form a homogenous solution in toluene, but self-assembly occurs in the toluene/methanol mixed solvents. Micrometer sized free-standing sheets were formed for PS, PPA, and P3HT at methanol volume fractions being 43%, 50%, and 67%, respectively, and hollow spheres were observed for PPA at higher methanol fractions of 75 and 90%. Under the latter solvent conditions, PS forms solid spheres, yet ill-defined aggregates and free-standing sheets coexist in the case of P3HT. This non-solvent induced self-assembly was explained by a delicate balance of two "opposing forces": van der Waals attractive and entropic repulsive forces generated between the segments of these homopolymers within a single chain, between two chains, and among more chains in the solvents of worsened quality.

  7. Co-non-solvency: Mean-field polymer theory does not describe polymer collapse transition in a mixture of two competing good solvents

    Science.gov (United States)

    Mukherji, Debashish; Marques, Carlos M.; Stuehn, Torsten; Kremer, Kurt

    2015-03-01

    Smart polymers are a modern class of polymeric materials that often exhibit unpredictable behavior in mixtures of solvents. One such phenomenon is co-non-solvency. Co-non-solvency occurs when two (perfectly) miscible and competing good solvents, for a given polymer, are mixed together. As a result, the same polymer collapses into a compact globule within intermediate mixing ratios. More interestingly, polymer collapses when the solvent quality remains good and even gets increasingly better by the addition of the better cosolvent. This is a puzzling phenomenon that is driven by strong local concentration fluctuations. Because of the discrete particle based nature of the interactions, Flory-Huggins type mean field arguments become unsuitable. In this work, we extend the analysis of the co-non-solvency effect presented earlier [D. Mukherji et al., Nat. Commun. 5, 4882 (2014)]. We explain why co-non-solvency is a generic phenomenon, which can only be understood by the thermodynamic treatment of the competitive displacement of (co)solvent components. This competition can result in a polymer collapse upon improvement of the solvent quality. Specific chemical details are not required to understand these complex conformational transitions. Therefore, a broad range of polymers are expected to exhibit similar reentrant coil-globule-coil transitions in competing good solvents.

  8. Compound forming extractants, solvating solvents and inert solvents IUPAC chemical data series

    CERN Document Server

    Marcus, Y; Kertes, A S

    2013-01-01

    Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part III: Compound Forming Extractants, Solvating Solvents, and Inert Solvents focuses on the compilation of equilibrium constants of various compounds, such as acids, ions, salts, and aqueous solutions. The manuscript presents tables that show the distribution reactions of carboxylic and sulfonic acid extractants and their dimerization and other reactions in the organic phase and extraction reactions of metal ions from aqueous solutions. The book also states that the inorganic anions in these solutions are irrelevant, since they d

  9. MARKETING MIX THEORETICAL ASPECTS

    OpenAIRE

    Margarita Išoraitė

    2016-01-01

    Aim of article is to analyze marketing mix theoretical aspects. The article discusses that marketing mix is one of the main objectives of the marketing mix elements for setting objectives and marketing budget measures. The importance of each element depends not only on the company and its activities, but also on the competition and time. All marketing elements are interrelated and should be seen in the whole of their actions. Some items may have greater importance than others; it depends main...

  10. Marketingový mix

    OpenAIRE

    Kosová, Michaela

    2016-01-01

    Bachelor thesis, entitled The marketing mix, is engaged in the marketing mix of a company which offers services, and its seven components, which are product, price, distribution, promotion, physical environment, people and processes. In the first, theoretical part, they are based on the study of scientific literature discussed in more detail the concepts of marketing and marketing mix. The second part represents the company Podbaba Fitness Centre, which is under investigation. This sect...

  11. Scenarios Evaluation Tool for Chlorinated Solvent MNA

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, Karen; Michael J. Truex; Charles J. Newell; Brian Looney

    2007-02-28

    Over the past three decades, much progress has been made in the remediation of chlorinated solvents from the subsurface. Yet these pervasive contaminants continue to present a significant challenge to the U.S. Department of Energy (DOE), other federal agencies, and other public and private organizations. The physical and chemical properties of chlorinated solvents make it difficult to rapidly reach the low concentrations typically set as regulatory limits. These technical challenges often result in high costs and long remediation time frames. In 2003, the DOE through the Office of Environmental Management funded a science-based technical project that uses the U.S. Environmental Protection Agency's technical protocol (EPA, 1998) and directives (EPA, 1999) on Monitored Natural Attenuation (MNA) as the foundation on which to introduce supporting concepts and new scientific developments that will support remediation of chlorinated solvents based on natural attenuation processes. This project supports the direction in which many site owners want to move to complete the remediation of their site(s), that being to complete the active treatment portion of the remedial effort and transition into MNA. The overarching objective of the effort was to examine environmental remedies that are based on natural processes--remedies such as Monitored Natural Attenuation (MNA) or Enhanced Attenuation (EA). The research program did identify several specific opportunities for advances based on: (1) mass balance as the central framework for attenuation based remedies, (2) scientific advancements and achievements during the past ten years, (3) regulatory and policy development and real-world experience using MNA, and (4) exploration of various ideas for integrating attenuation remedies into a systematic set of ''combined remedies'' for contaminated sites. These opportunities are summarized herein and are addressed in more detail in referenced project documents and

  12. Summary of findings on evaluation of aqueous degreasers versus chlorinated solvents at the Paducah Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Gunn, D.

    1988-01-01

    Spent trichloroethylene (TCE), 1,1,1-trichloroethane (TC-ane), and sludge are generated mainly as a result of vapor degreasing operations at the Paducah Gaseous Diffusion Plant (PGDP). Additionally, small quantities of spent chlorinated solvents are generated as a result of small parts cleanup. Additionally, some of the solvents become contaminated with uranium which classifies them as mixed waste for which no disposal method is currently available. Due to health and environmental concerns and the desire to minimize mixed and hazardous waste generation, a study was initiated to identify nonchlorinated, less toxic degreasers, perform laboratory testing of the most promising alternatives, and initiate field testing to determine if alternate degreasers present operational problems. The degreaser that cleaned and protected metal surfaces best was an all-purpose, water-based, hard surface cleaner consisting of biodegradable synthetic detergents, inorganic builders, and glycol either solvent. Additionally, this product was free-rinsing and did not leave any contaminants that would react with commonly used process gases. This product is recommended as a replacement for chlorinated solvents for many degreasing operations at PGDP.

  13. Synthesis of Aluminium Nanoparticles in A Water/Polyethylene Glycol Mixed Solvent using μ-EDM

    Science.gov (United States)

    Sahu, R. K.; Hiremath, Somashekhar S.

    2017-08-01

    Nanoparticles present a practical way of retaining the results of the property at the atomic or molecular level. Due to the recent use of nanoparticles in scientific, industrial and medical applications, synthesis of nanoparticles and their characterization have become considerably important. Currently, aluminium nanoparticles have attracted significant research attention because of their reasonable cost, unique properties and interdisciplinary emerging applications. The present paper reports the synthesis of aluminium nanoparticles in the mixture of Deionized water (DI water) and Polyethylene Glycol (PEG) using a developed micro-Electrical Discharge Machining (μ-EDM) method. PEG was used as a stabilizer to prevent nanoparticles from agglomeration produced during the μ -EDM process. The synthesized aluminium nanoparticles were examined by Transmission Electron Microscopy (TEM), Energy Dispersive Analysis by X-rays (EDAX) and Selected Area Electron Diffraction (SAED) pattern to determine their size, shape, chemical nature and crystal structure. The average size of the polyhedral aluminium nanoparticles is found to be 196 nm.

  14. Systematical shape evolution of hexagonal NiSe crystals caused by mixed solvents and ammonium chloride

    Science.gov (United States)

    Chen, Shuguang; Zeng, Kai; Song, Yande; Li, Haibin; Liu, Peng; Li, Fujin

    2012-11-01

    Systematic shape evolution of hexagonal NiSe crystals is realized via a simple solvothermal route in a mixture of NiCl2·6H2O, elemental selenium, hydrazine hydrate and ethylenediamine. By introducing ammonium chloride as electrolyte and varying the volume ratios of hydrazine hydrate to ethylenediamine, shape evolution of hexagonal NiSe crystals from small hexagonal microdisks to hexagonal microdisks in larger width, microspheres, hexagonal prisms and hexagonal bitowers is successfully achieved. X-ray powder diffraction, field emission scanning electron microscopy, energy dispersion spectrometer, transmission electron microscopy and selected area electron diffraction are performed for the analyses of the products. The ionization and hydrolysis of ammonium chloride decrease the nucleation rate of hexagonal NiSe and the diffusion rate of growth resources, while the adsorption of ethylenediamine at {001} facets of hexagonal NiSe crystals inhibits the crystal growth in directions, thus leading to various novel architectures.

  15. Sonochemical synthesis of monodispersed magnetite nanoparticles by using an ethanol-water mixed solvent.

    Science.gov (United States)

    Dang, Feng; Enomoto, Naoya; Hojo, Junichi; Enpuku, Keiji

    2009-06-01

    The magnetite nanoparticles were synthesized in an ethanol-water solution under ultrasonic irradiation from a Fe(OH)(2) precipitate. XRD, TEM, TG, IR, VSM and UV/vis absorption spectrum were used to characterize the magnetite nanoparticles. It was found that the formation of magnetite was accelerated in ethanol-water solution in the presence of ultrasonic irradiation, whereas, it was limited in ethanol-water solution under mechanical stirring. The monodispersibility of magnetite particles was improved significantly through the sonochemical synthesis in ethanol-water solution. The magnetic properties were improved for the samples synthesized under ultrasonic irradiation. This would be attributed to high Fe(2+) concentration in the magnetite cubic structure.

  16. Cycloadditions in mixed aqueous solvents : the role of the water concentration

    NARCIS (Netherlands)

    Rispens, T; Engberts, JBFN

    2005-01-01

    We examined the kinetics of a series of cycloaddition reactions in mixtures of water with methanol, acetonitrile and poly(ethylene glycol) (MW 1000). The reactions include the Diels-Alder (DA) reaction between cyclopentadiene and N-n-butylmaleimide or acridizinium bromide, the retro-Diels-Alder (RDA

  17. Molecular Dynamics Analysis of Lysozyme Protein in Ethanol- Water Mixed Solvent

    Science.gov (United States)

    2012-01-01

    Hermans , 1981; Levitt & Warshel, 1975). The idea for molecular dynamic simulation was born out of the quest to solve and understand the following  To...GROMACS is the MD analysis code employed in the present work. Groningen machine for chemical simulations( GROMACS)(Lindahl, Hess , & Van Der Spoel...Physical Chemistry B, 106(14), 3668-3672. Berendsen, H., Postma, J., Van Gunsteren, W., & Hermans , J. (1981). Interaction models for water in

  18. Mixing through shear instabilities

    CERN Document Server

    Brüggen, M

    2000-01-01

    In this paper we present the results of numerical simulations of the Kelvin-Helmholtz instability in a stratified shear layer. This shear instability is believed to be responsible for extra mixing in differentially rotating stellar interiors and is the prime candidate to explain the abundance anomalies observed in many rotating stars. All mixing prescriptions currently in use are based on phenomenological and heuristic estimates whose validity is often unclear. Using three-dimensional numerical simulations, we study the mixing efficiency as a function of the Richardson number and compare our results with some semi-analytical formalisms of mixing.

  19. Cleaning with solvents methods and machinery

    CERN Document Server

    Durkee, John

    2014-01-01

    High-precision cleaning is required across many sectors, including aerospace, defense, medical device manufacturing, pharmaceutical processing, semiconductor/electronics, and more. In this comprehensive reference work, solvent cleaning equipment is thoroughly covered with a focus on the engineering details of its operation and selection. Key data is provided alongside practical guidance, giving scientists and engineers in multiple sectors the information they need not only to choose the correct machine in the first place, but also how to operate it effectively and efficiently. Low emission

  20. Water as a solvent for life

    Science.gov (United States)

    Pohorille, Andrew

    2015-08-01

    “Follow the water” is our basic strategy in searching for life in the universe. The universality of water as the solvent for living systems is usually justified by arguing that water supports the rich organic chemistry that seeds life, but alternative chemistries are possible in other organic solvents. Here, other, essential criteria for life that have not been sufficiently considered so far, will be discussed.Life is based on non-covalent interactions. They might be either specific (enzyme-substrate interactions, selective ion transport) or nonspecific (lipid-lipid or lipid-protein interactions). Their strength needs to be properly tuned, and this is mediated by the solvent. If interactions are too weak, there might be undesired response to natural fluctuations of physical and chemical parameters. If they are too strong it could impede kinetics and energetics of cellular processes. Thus, the solvent must allow for balancing these interactions, which provides strong constraints for life.Water exhibits a remarkable trait that it promotes both solvophobic and solvophilic interactions. Solvophobic (hydrophobic in the case of water) interactions are necessary for self-organization of matter. They are responsible, among others, for the formation of membranes and protein folding. The diversity of structures supported by hydrophobic interactions is the hallmark of terrestrial life responsible for its diversity, evolution and the ability to survive environmental changes. Solvophilic interactions, in turn, are needed to ensure solubility of polar species. Water offers a large temperature domain of stable liquid and the characteristic hydrophobic effects are a consequence of the temperature insensitivity of essential properties of its liquid state. Water, however, might not be the only liquid with these properties. Properties of water and other pure liquids or their mixtures that have a high dielectric constant and simultaneously support self-organization will be

  1. PULSED MIXER-SETTLER SOLVENT EXTRACTION CONTACTORS

    Science.gov (United States)

    Figg, W.S.

    1958-08-12

    A mixer-settler extractor is described for contacting immiscible liquids having different specific gravities in order to withdraw one or more components from one liquid with the aid of the other liquid. The extractor consists of a hollow column, a rotary drive shafi extending : through the column with a number of impellers spaced thereon, an equal nunnber of separator plate sets each consisting of one fluorothene and one stainless steel plate with peripheral recesses and flow slots mounted on the column, and a pulse generator. This apparatus is particularly useful in solvent extraction processes for recovering plutonium from aqueous acidic solutions of irradiated uranium.

  2. Solvent extraction of metals with hydroxamic acids.

    Science.gov (United States)

    Vernon, F; Khorassani, J H

    1978-07-01

    Solvent extraction with hydroxamic acids has been investigated. with comparison of aliphatic and aromatic reagents for the extraction of iron, copper, cobalt and nickel. Caprylohydroxamic acid has been evaluated for use in extraction systems for titanium, vanadium, chromium, molybdenum and uranium, both in terms of acidity of aqueous phase and oxidation state of the metal. It has been established that caprylohydroxamic acid in 1-hexanol is a suitable extractant for the removal of titanium(IV), vanadium(V), chromium(VI), molybdenum(VI) and uranium(VI) from 6M hydrochloric acid.

  3. Diffusion Coefficient of Tin(II) Methanesulfonate in Ionic Liquid and Methane Sulfonic Acid (MSA) Solvent

    Science.gov (United States)

    Yang, Kok Kee; Mahmoudian, M. R.; Ebadi, Mehdi; Koay, Hun Lee; Basirun, Wan Jeffrey

    2011-12-01

    Voltammetry and chronoamperometry for the electrodeposition of tin from Tin(II) methane sulfonate mixed with ionic liquid and methane sulfonate acid at room temperature was studied. Cyclic voltammetry shows redox waves of Tin(II), which proves that the electrodeposition of tin from Tin(II) methane sulfonate is a diffusion-controlled process. The diffusion coefficient of Tin(II) ions in the solvent mixture showed good agreement from both voltammetry and chronoamperometry results. The diffusion coefficient of Tin(II) in the mixture was much smaller than in aqueous solution, and it depends on the anion of the ionic liquid.

  4. The Effect of Solvent Environment on Molecular Electronic Transition Moment Directions

    DEFF Research Database (Denmark)

    Langkilde, F. W.; Thulstrup, E. W.; Michl, J.

    1983-01-01

    Measurements of polarized fluorescence and phosphorescence of pyrene, 2‐fluoropyrene, and 2‐methylpyrene in 3‐methylpentane glass at 77 K reveal significant differences among the three molecules. These are interpreted in terms of solvent‐induced mixing of the Lb and La states. It is proposed that...... that such symmetry‐lowering effects of the solvent environment may well be important contributors to the often observed discrepancies between the theoretical limiting values of polarization ratios and the values actually observed....

  5. Enthalpies of glycylglycinate ion transfer from water to a water-ethanol solvent

    Science.gov (United States)

    Isaeva, V. A.; Naumov, V. V.; Sharnin, V. A.

    2016-05-01

    The heat effects of mixing a sodium glycylglycinate water solution with a solvent containing from 0.0 to 0.8 mole fraction of ethanol are measured by means of calorimetry at 298.15 K. The enthalpies of sodium glycylglycinate and glycylglycinate ion transfer from water to water-ethanol solutions of different compositions are calculated. The increase of the concentration of nonaqueous component in solution leads to higher endothermicity of glycylglycinate ion transfer, resulting in weaker solvation. The contribution from the enthalpy of glycylglycinate ion resolvation to the heat effects of its complexation reactions with transition metal ions is assessed.

  6. Silk fibroin membranes from solvent-crystallized silk fibroin/gelatin blends: Effects of blend and solvent composition

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Eun S. [Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695 (United States); Frankowski, David J. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Hudson, Samuel M. [Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695 (United States); Spontak, Richard J. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 (United States) and Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)]. E-mail: Rich_Spontak@ncsu.edu

    2007-04-15

    Protein membranes have been prepared by mixing gelatin (G) with Bombyx mori silk fibroin (SF) and using aqueous methanol (MeOH) to induce SF crystallization. Amorphous blends of these polymers appear quasi-homogeneous, as discerned from visual observation, electron microscopy and Fourier-transform infrared (FTIR) spectroscopy. Upon subsequent exposure to aqueous MeOH, SF undergoes a conformational change from random-coil to {beta}-sheet. This transformation occurs in pure SF, as well as in each of the G/SF blends, as discerned from FTIR spectroscopy and thermal calorimetry. The influence of MeOH-induced SF crystallization on structure and property development has been measured as functions of blend and solvent composition. By preserving a support scaffold above the G helix-to-coil transition temperature, the formation of crystalline SF networks in G/SF blends can be used to stabilize G-based hydrogels or generate SF membranes for biomaterial, pharmaceutical and gas-separation purposes. The present study not only examines the properties of G/SF blends before and after SF crystallization, but also establishes the foundation for future research into thermally-responsive G/SF bioconjugates.

  7. Effect of Solvents on Microalbuminuria Among Automobile Painters

    Directory of Open Access Journals (Sweden)

    T Shushtarizadeh

    2008-06-01

    Full Text Available Background: The health risk associated with chronic exposure to organic solvents investigated in several epidemiologic studies indicates a significant relationship between solvent exposure and glomerulonephritis. Solvents are the most commonly used chemicals in industry. According to European statistics 43% of all solvent consumption takes place in the painting industry, 10% in metal cleansing, 6.7% in adhesives and 3.9 percent in the laundry (dry cleaning industries. Although BUN and creatinine indicate massive loss of glomerular function, microalbumin is a sensitive urinary marker for nephrotoxins in the early detection of solvent-induced effects on the glomerulus. The purpose of our study was to use microalbumin, serum BUN and serum creatinine levels to identify occupational solvent-induced effects on the glomerulus.Methods: Renal dysfunction was monitored by microalbumin, BUN and creatinine serum levels in a cohort study of 92 workers currently exposed to solvents (solvent group. A control group of 92 individuals were selected from parts of the same factory not exposed to solvents. All individuals in the study were men, without diabetes or hypertension. The percentage of smokers was equal between the two groups. The solvent group was selected using environmental monitoring of organic solvents in different parts of the painting room. The individuals were chosen by simple random selection. Exclusion factors included less than one year of work in the painting room, use analgesic or aminoglycoside one month before the study and medically diagnosed renal disease, such as glomerulonephritis or renal failure. Data was gathered using a questionnaire requesting demographic information, history of present and past diseases, present and past occupational history, drug history, history of illness in their colleagues and safety conditions at work (use of safety gloves, masks, clothing, goggles and general and local ventilation. The results analyzed with

  8. A real-time study of the benefits of co-solvents in polymer solar cell processing.

    Science.gov (United States)

    van Franeker, Jacobus J; Turbiez, Mathieu; Li, Weiwei; Wienk, Martijn M; Janssen, René A J

    2015-02-06

    The photoactive layer of organic solar cells consists of a nanoscale blend of electron-donating and electron-accepting organic semiconductors. Controlling the degree of phase separation between these components is crucial to reach efficient solar cells. In solution-processed polymer-fullerene solar cells, small amounts of co-solvents are commonly used to avoid the formation of undesired large fullerene domains that reduce performance. There is an ongoing discussion about the origin of this effect. To clarify the role of co-solvents, we combine three optical measurements to investigate layer thickness, phase separation and polymer aggregation in real time during solvent evaporation under realistic processing conditions. Without co-solvent, large fullerene-rich domains form via liquid-liquid phase separation at ~20 vol% solid content. Under such supersaturated conditions, co-solvents induce polymer aggregation below 20 vol% solids and prevent the formation of large domains. This rationalizes the formation of intimately mixed films that give high-efficient solar cells for the materials studied.

  9. Pyrolysates of raw vitrinites and their residues after CS2-NMP solvent extraction and its significance for petroleum geology

    Institute of Scientific and Technical Information of China (English)

    LIU Dayong; PENG Ping'an

    2006-01-01

    Binary solvent (CS2-NMP) has extreme high extraction ability to coals, and it can extract most bitumens out of coals and vitrinites. And large amount of messages on side chains and their distribution character in vitrinites should be acquired through flash pyrolysis before and after binary solvent (CS2-NMP) extraction. A few low maturated coals have been selected and vitrinites are handpicked from coals. Then vitrinites have been extracted using different solvents in the order of polarity. Flash pyrolysis-Gas Chromatography/Mass spectrum has been applied to samples. The result shows that CS2-NMP is efficient for the extraction of vitirnites, giving much higher extraction yield than common solvents. Production ratio of liquid hydrocarbons in pyrolysates of vitrinites extracted with CS2-NMP is lower than that of raw vitrinites. And relative ratio of each component in pyrolysates has changed apparently. Production ratio of aliphatic hydrocarbons, especially those long chain aliphatics have decreased much after mixed solvent extraction. It shows that bitumens extracted with CS2-NMP have largely contributed to pyrolysates, especially those aliphatics in pyrolysates.

  10. Enhancing detection sensitivity in gradient liquid chromatography via post-column refocusing and strong-solvent remobilization.

    Science.gov (United States)

    De Vos, Jelle; Desmet, Gert; Eeltink, Sebastiaan

    2016-07-15

    We developed earlier the post-column refocusing strategy for isocratic separations, which employs trapping target analytes after an analytical separation and additionally focusing them using a strong remobilization solvent prior to detection, and have now extended it to high-speed gradient LC. A gradient separation of antibiotics and its metabolites, applying a linear aqueous acetonitrile gradient from 2 to 65% (v/v) ACN containing 0.1% FA in 10min, performed on an analytical column was selected as an application. Eluted heart-cut fractions were directed from the analytical silica C18 column to a trap column packed with Hypercarb particles. The remobilization of the target analytes was performed in back-flush mode using solvent mixtures tuned to maximize the solvent strength by mixing isopropanol into the remobilization solvent containing acetonitrile. Additionally, a viscosity-calibration experiment showed that the viscosity difference between trapping and remobilization solvents should be smaller than 0.15mPa·s to prevent viscous fingering. To keep the viscosity difference below this limit, during the gradient separation performed on the analytical column, the composition of the remobilization solvent was changed in time. An empirical equation is provided that allows for the selection of the optimal remobilization-solvent composition. To maximize the signal enhancement, the loading time of target analytes on the trap column should be optimized. Peak dispersion was further minimized by applying a flow rate that corresponded to the optimal van-Deemter flow rate of the trap column (20μL/min). Finally, decreasing the diameter of the trap column from 1mm to 0.3mm led to a significant enhancement of the detection sensitivity with more than one order of magnitude. Using an optimized trap configuration and elution/remobilization conditions, a signal enhancement of a factor of 14 was achieved for sulfaguanidine (early-eluting compound in the gradient separation) and 7

  11. Modeling the structure and absorption spectra of stilbazolium merocyanine in polar and nonpolar solvents using hybrid QM/MM techniques.

    Science.gov (United States)

    Murugan, N Arul; Kongsted, Jacob; Rinkevicius, Zilvinas; Aidas, Kestutis; Ågren, Hans

    2010-10-28

    We have performed Car-Parrinello mixed quantum mechanics/molecular mechanics (CP-QM/MM) calculations for stilbazolium merocyanine (SM) in polar and nonpolar solvents in order to explore the role of solute molecular geometry, solvation shell structure, and different interaction mechanisms on the absorption spectra and its dependence on solvent polarity. On the basis of the average bond length values and group charge distributions, we find that the SM molecule remains in a neutral quinonoid form in chloroform (a nonpolar solvent) while it transforms to a charge-separated benzenoid form in water (a polar solvent). Based on a quantum mechanical/molecular mechanical response technique, with different MM descriptions for the water environment, absorption spectra were obtained as averages over configurations derived from the CP-QM/MM simulations. We show that for SM in water the solute polarization plays a major role in predictions of the λ(max) and solvatochromic shift and that once this effect is included the contributions from solvent polarization and intermolecular charge transfer become less important. For SM in chloroform and water solvents, we have also performed absorption spectra calculations using a polarizable continuum model in order to address its relative performance compared to the QM/MM response technique. In the case of SM in water, our study supports the notion that, in order to predict accurate absorption spectra and solvatochromic shifts, it is important to use a discrete description of the solvent when it, as in water, is involved in site-specific interaction with the solute molecule. The technique is thus shown to outperform the more conventional polarizable continuum model in predicting the solvatochromic shift.

  12. Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: comparison between hard-sphere solvent and water.

    Science.gov (United States)

    Oshima, Hiraku; Kinoshita, Masahiro

    2015-04-14

    In earlier works, we showed that the entropic effect originating from the translational displacement of water molecules plays the pivotal role in protein folding and denaturation. The two different solvent models, hard-sphere solvent and model water, were employed in theoretical methods wherein the entropic effect was treated as an essential factor. However, there were similarities and differences in the results obtained from the two solvent models. In the present work, to unveil the physical origins of the similarities and differences, we simultaneously consider structural transition, cold denaturation, and pressure denaturation for the same protein by employing the two solvent models and considering three different thermodynamic states for each solvent model. The solvent-entropy change upon protein folding/unfolding is decomposed into the protein-solvent pair (PA) and many-body (MB) correlation components using the integral equation theories. Each component is further decomposed into the excluded-volume (EV) and solvent-accessible surface (SAS) terms by applying the morphometric approach. The four physically insightful constituents, (PA, EV), (PA, SAS), (MB, EV), and (MB, SAS), are thus obtained. Moreover, (MB, SAS) is discussed by dividing it into two factors. This all-inclusive investigation leads to the following results: (1) the protein-water many-body correlation always plays critical roles in a variety of folding/unfolding processes; (2) the hard-sphere solvent model fails when it does not correctly reproduce the protein-water many-body correlation; (3) the hard-sphere solvent model becomes problematic when the dependence of the many-body correlation on the solvent number density and temperature is essential: it is not quite suited to studies on cold and pressure denaturating of a protein; (4) when the temperature and solvent number density are limited to the ambient values, the hard-sphere solvent model is usually successful; and (5) even at the ambient

  13. Solvent viscosity dependence for enzymatic reactions

    CERN Document Server

    Sitnitsky, A E

    2008-01-01

    A mechanism for relationship of solvent viscosity with reaction rate constant at enzyme action is suggested. It is based on fluctuations of electric field in enzyme active site produced by thermally equilibrium rocking (cranckshaft motion) of the rigid plane (in which the dipole moment $\\approx 3.6 D$ lies) of a favourably located and oriented peptide group (or may be a few of them). Thus the rocking of the plane leads to fluctuations of the electric field of the dipole moment. These fluctuations can interact with the reaction coordinate because the latter in its turn has transition dipole moment due to separation of charges at movement of the reacting system along it. The rocking of the plane of the peptide group is sensitive to the microviscosity of its environment in protein interior and the latter is a function of the solvent viscosity. Thus we obtain an additional factor of interrelationship for these characteristics with the reaction rate constant. We argue that due to the properties of the cranckshaft ...

  14. Conformation of repaglinide: A solvent dependent structure

    Science.gov (United States)

    Chashmniam, Saeed; Tafazzoli, Mohsen

    2017-09-01

    Experimental and theoretical conformational study of repaglinide in chloroform and dimethyl sulfoxide was investigated. By applying potential energy scanning (PES) at B3LYP/6-311++g** and B3LYP-D3/6-311++g** level of theory on rotatable single bonds, four stable conformers (R1-R4) were identified. Spin-spin coupling constant values were obtained from a set of 2D NMR spectra (Hsbnd H COSY, Hsbnd C HMQC and Hsbnd C HMBC) and compared to its calculated values. Interestingly, from 1HNMR and 2D-NOESY NMR, it has been found that repaglinide structure is folded in CDCl3 and cause all single bonds to rotate at an extremely slow rate. On the other hand, in DMSO-d6, with strong solvent-solute intermolecular interactions, the single bonds rotate freely. Also, energy barrier and thermodynamic parameters for chair to chair interconversion was measured (13.04 kcal mol-1) in CDCl3 solvent by using temperature dynamic NMR.

  15. Non-Ideal Behavior in Solvent Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Peter Zalupski

    2011-09-01

    This report presents a summary of the work performed to meet FCR&D level 3 milestone M31SW050801, 'Complete the year-end report summarizing FY11 experimental and modeling activities.' This work was carried out under the auspices of the Non-Ideality in Solvent Extraction Systems FCR&D work package. The report summarizes our initial considerations of potential influences that non-ideal chemistry may impose on computational prediction of outcomes in solvent extraction systems. The report is packaged into three separate test cases where a robustness of the prediction by SXFIT program is under scrutiny. The computational exercises presented here emphasize the importance of accurate representation of both an aqueous and organic mixtures when modeling liquid-liquid distribution systems. Case No.1 demonstrates that non-ideal behavior of HDEHP in aliphatic diluents, such as n-dodecane, interferes with the computation. Cases No.2 and No.3 focus on the chemical complexity of aqueous electrolyte mixtures. Both exercises stress the need for an improved thermodynamic model of an aqueous environment present in the europium distribution experiments. Our efforts for year 2 of this project will focus on the improvements of aqueous and non-aqueous solution models using fundamental physical properties of mixtures acquired experimentally in our laboratories.

  16. Solvents, Ethanol, Car Crashes and Tolerance: How Risky is Inhalation of Organic Solvents?

    Science.gov (United States)

    A research program in the National Health and Environmental Effects Research Laboratory of the U.S. EPA has led to some surprising considerations regarding the potential hazard of exposure to low concentrations of solvent vapors. This program involved conducting experiments to ch...

  17. Solvent effects on a Diels-Alder reaction involving a cationic diene: Consequences of the absence of hydrogen-bond interactions for accelerations in aqueous media

    NARCIS (Netherlands)

    van der Wel, Gerben K.; Wijnen, Jan W.; Engberts, Jan B.F.N.

    1996-01-01

    In order to study the influence of hydrogen-bond interactions on the accelerations of Diels-Alder reactions in water and highly aqueous mixed solvent systems, second-order rate constants for the Diels-Alder reaction of acridizinium bromide (1a) with cyclopentadiene (CP) have been measured in aqueous

  18. Solvent effects on a Diels-Alder reaction involving a cationic diene : Consequences of the absence of hydrogen-bond interactions for accelerations in aqueous media

    NARCIS (Netherlands)

    Wel, Gerben K. van der; Wijnen, Jan W.; Engberts, Jan B.F.N.

    1996-01-01

    In order to study the influence of hydrogen-bond interactions on the accelerations of Diels-Alder reactions in water and highly aqueous mixed solvent systems, second-order rate constants for the Diels-Alder reaction of acridizinium bromide (1a) with cyclopentadiene (CP) have been measured in aqueous

  19. The Mixed language Debate

    DEFF Research Database (Denmark)

    A range of views on mixed languages and their connections to phenomena such as secret languages, massive borrowing, codeswitching and codemixing, and thier origin.......A range of views on mixed languages and their connections to phenomena such as secret languages, massive borrowing, codeswitching and codemixing, and thier origin....

  20. Mixed Ability Teaching.

    Science.gov (United States)

    Skov, Poul

    1986-01-01

    As a basis for taking a position on the future school structure in grades 8-10 in Denmark, an extensive study was carried out on mixed ability teaching (teaching in heterogeneous classes) on these grade levels. Results showed that mixed ability teaching gave at least as good results as teaching in differentiated classes. (Author/LMO)

  1. Theory for Neutrino Mixing

    Science.gov (United States)

    He, Xiao-Gang

    2016-07-01

    Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, θ23 is close to π/4 and the CP violating phase is close to - π/2. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on A4 family symmetry are given.

  2. High-mix insulins

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2015-01-01

    Full Text Available Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use.

  3. Stochastic level-set variational implicit-solvent approach to solute-solvent interfacial fluctuations.

    Science.gov (United States)

    Zhou, Shenggao; Sun, Hui; Cheng, Li-Tien; Dzubiella, Joachim; Li, Bo; McCammon, J Andrew

    2016-08-01

    Recent years have seen the initial success of a variational implicit-solvent model (VISM), implemented with a robust level-set method, in capturing efficiently different hydration states and providing quantitatively good estimation of solvation free energies of biomolecules. The level-set minimization of the VISM solvation free-energy functional of all possible solute-solvent interfaces or dielectric boundaries predicts an equilibrium biomolecular conformation that is often close to an initial guess. In this work, we develop a theory in the form of Langevin geometrical flow to incorporate solute-solvent interfacial fluctuations into the VISM. Such fluctuations are crucial to biomolecular conformational changes and binding process. We also develop a stochastic level-set method to numerically implement such a theory. We describe the interfacial fluctuation through the "normal velocity" that is the solute-solvent interfacial force, derive the corresponding stochastic level-set equation in the sense of Stratonovich so that the surface representation is independent of the choice of implicit function, and develop numerical techniques for solving such an equation and processing the numerical data. We apply our computational method to study the dewetting transition in the system of two hydrophobic plates and a hydrophobic cavity of a synthetic host molecule cucurbit[7]uril. Numerical simulations demonstrate that our approach can describe an underlying system jumping out of a local minimum of the free-energy functional and can capture dewetting transitions of hydrophobic systems. In the case of two hydrophobic plates, we find that the wavelength of interfacial fluctuations has a strong influence to the dewetting transition. In addition, we find that the estimated energy barrier of the dewetting transition scales quadratically with the inter-plate distance, agreeing well with existing studies of molecular dynamics simulations. Our work is a first step toward the inclusion of

  4. Effect of some organic solvents on oxidative phosphorylation in rat liver mitochondria: Choice of organic solvents.

    Science.gov (United States)

    Syed, Muzeeb; Skonberg, Christian; Hansen, Steen Honoré

    2013-12-01

    The effect of acetone, acetonitrile, dimethyl sulfoxide (DMSO), ethanol and methanol on oxidative phosphorylation (ATP synthesis) in rat liver mitochondria has been studied. All the organic solvents inhibited the oxidative phosphorylation in a concentration dependent manner, but with differences in potencies. Among the tested organic solvents, acetonitrile and acetone were more potent than ethanol, methanol, and DMSO. There was no significant difference in oxidative phosphorylation, compared to controls, when the concentrations of acetone was below 1% (v/v), of acetonitrile below 2% (v/v), of DMSO below 10% (v/v), of ethanol below 5% or of methanol below 2%, respectively. There was complete inhibition of oxidative phosphorylation at 50% (v/v) of acetone, acetonitrile and ethanol. But in the case of DMSO and methanol there were some residual activities observed at the 50% concentration level. DMSO showed least effect on oxidative phosphorylation with an IC50 value of 13.3±1.1% (v/v), followed by methanol (IC50 value 8.3±1.0), ethanol (IC50 value 4.6±1.1), acetone (IC50 value 4.3±1.0) and finally acetonitrile (IC50 value 2.1±1.0). All the organic solvents showed modulatory effects on 2,4-dinitrophenol (DNP) mediated inhibition of oxidative phosphorylation with potentiation of the action of DNP. Acetonitrile showed the highest potentiation effect followed by acetone, ethanol, methanol, and DMSO in presence of DNP. The use of organic solvents for investigation of the effects of compounds on oxidative phosphorylation in mitochondria should therefore include the use of relevant concentrations of the organic solvent in order to validate the contribution.

  5. UV-Vis spectroscopic study and DFT calculation on the solvent effect of trimethoprim in neat solvents and aqueous mixtures.

    Science.gov (United States)

    Almandoz, M C; Sancho, M I; Duchowicz, P R; Blanco, S E

    2014-08-14

    The solvatochromic behavior of trimethoprim (TMP) was analyzed using UV-Vis spectroscopy and DFT methods in neat and binary aqueous solvent mixtures. The effects of solvent dipolarity/polarizability and solvent-solute hydrogen bonding interactions on the absorption maxima were evaluated by means of the linear solvation energy relationship concept of Kamlet and Taft. This analysis indicated that both interactions play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra of TMP and TMP:(solvent)n complexes in ACN and H2O using TD-DFT methods were in agreement with the experimental ones. Binary aqueous mixtures containing as co-solvents DMSO, ACN and EtOH were studied. Preferential solvation was detected as a nonideal behavior of the wavenumber curve respective to the analytical mole fraction of co-solvent in all binary systems. TMP molecules were preferentially solvated by the organic solvent over the whole composition range. Index of preferential solvation, as well as the influence of solvent parameters were calculated as a function of solvent composition.

  6. A new solvent suppression method via radiation damping effect

    Institute of Scientific and Technical Information of China (English)

    Cui Xiao-Hong; Peng Ling; Zhang Zhen-Min; Cai Shu-Hui; Chen Zhong

    2011-01-01

    Radiation damping effects induced by the dominated solvent in a solution sample can be applied to suppress the solvent signal.The precession pathway and rate back to equilibrium state between solute and solvent spins are different under radiation damping.In this paper,a series of pulse sequences using radiation damping were designed for the solvent suppression in nuclear magnetic resonance (NMR) spectroscopy.Compared to the WATERGATE method,the solute signals adjacent to the solvent would not be influenced by using the radiation damping method.The one-dimensional (1D) 1H NMR,two-dimensional (2D) gCOSY,and J-resolved experimental results show the practicability of solvent suppression via radiation damping effects in 1D and 2D NMR spectroscopy.

  7. GREEN TECHNIQUE-SOLVENT FREE SYNTHESIS AND ITS ADVANTAGES

    Directory of Open Access Journals (Sweden)

    M.Himaja

    2011-04-01

    Full Text Available Green Chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances is an overarching approach that is applicable to all aspects of chemistry. All synthetic processes involve the use of different solvents. Unfortunately many of the solvents are used in industry and retail are volatile organic compounds (VOCs which lead to environmental damage, through pollution, risks to human health and to resource depletion, we need to develop and apply more environmentally friendly approaches. So, all traditional and old synthetic routes obviously give adverse effects to the mankind and all living beings. Green chemistry provides “Green” paths for different synthetic routes using non-hazardous solvents and environmental- friendly chemicals. Solvent free synthesis has several advantages over the classical method of synthesis. Due to enormous advantages of solvent free reactions, new solvent-free approaches are being discovered for eco-friendly synthesis of many compounds.

  8. ADVANCED MIXING MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-11-13

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. If shorter mixing times can be shown to support Defense Waste Processing Facility (DWPF) or other feed requirements, longer pump lifetimes can be achieved with associated operational cost and

  9. Terpenes as Green Solvents for Extraction of Oil from Microalgae

    OpenAIRE

    Celine Dejoye Tanzi; Maryline Abert Vian; Christian Ginies; Mohamed Elmaataoui; Farid Chemat

    2012-01-01

    Herein is described a green and original alternative procedure for the extraction of oil from microalgae. Extractions were carried out using terpenes obtained from renewable feedstocks as alternative solvents instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using Soxhlet extraction followed by the elimination of the solvent from the medium using Clevenger distillation in the second step. Oils extracted from microalgae...

  10. Modeling post-combustion CO2 capture with amine solvents

    OpenAIRE

    Léonard, Grégoire; Heyen, Georges

    2010-01-01

    In order to avoid the emission of large amounts of greenhouse gas, CO2 capture in fossil fuel power plants and subsequent underground CO2 sequestration is studied. The capture occurs by reactive CO2 absorption into chemical solvent systems at moderate temperature (~50°C) followed by solvent regeneration at higher temperature (~120°C). So far, the most employed solvent for acid gas capture is monoethanolamine (MEA). One main drawback of this technology is the high energy consumption necessary ...

  11. Alcohols as hydrogen-donor solvents for treatment of coal

    Science.gov (United States)

    Ross, David S.; Blessing, James E.

    1981-01-01

    A method for the hydroconversion of coal by solvent treatment at elevated temperatures and pressure wherein an alcohol having an .alpha.-hydrogen atom, particularly a secondary alcohol such as isopropanol, is utilized as a hydrogen donor solvent. In a particular embodiment, a base capable of providing a catalytically effective amount of the corresponding alcoholate anion under the solvent treatment conditions is added to catalyze the alcohol-coal reaction.

  12. Solvent effects on enzymes - Implications for extraterrestrial life.

    Science.gov (United States)

    Heinrich, M. R.

    1972-01-01

    Review of several studies on the alterations taking place in the structure, catalytic activity, specificity, and stability of an enzyme when some or all of the water in the medium is replaced by another solvent. These studies show the utility of solvents as a tool for probing enzyme function. They also suggest that solvents other than water should be investigated as media for controlling and directing enzyme reactions.

  13. Solvent effect modelling of isocyanuric products synthesis by chemometric methods

    OpenAIRE

    Havet, Jean-Louis; Billiau-Loreau, Myriam; Porte, Catherine; Delacroix, Alain

    2002-01-01

    Chemometric tools were used to generate the modelling of solvent e¡ects on the N-alkylation of an isocyanuric acid salt. The method proceeded from a central composite design applied on the Carlson solvent classification using principal components analysis. The selectivity of the reaction was studied from the production of different substituted isocyanuric derivatives. Response graphs were obtained for each compound and used to devise a strategy for solvent selection. The prediction models wer...

  14. Solvent-free, molecular-level modeling of self-assembling amphiphiles in water

    Science.gov (United States)

    Dey, Somajit; Saha, Jayashree

    2017-02-01

    Aggregation mesophases of self-assembling amphiphiles in water are highly important in the context of biology (biomembranes), therapy (liposomes), industry (polymer surfactants), and condensed-matter physics (lyotropic liquid crystals). Besides helping to increase fundamental understanding of collective molecular behavior, simulations of these lyotropic phases are pivotal to technological and medical developments such as smart drug carriers for gene therapy. Implicit-solvent, coarse-grained, low resolution modeling with a simple pair potential is the key to realizing the larger length and time scales associated with such mesoscopic phenomena during a computer simulation. Modeling amphiphiles by directed, soft, ellipsoidal cores interacting via a computationally simple yet tunable anisotropic pair potential, we have come to such a single-site model amphiphile that can rapidly self-assemble to give diverse lyotropic phases (such as fluid bilayers, micelles, etc.) without requiring the explicit incorporation of solvent particles. The model directly represents a tunable packing parameter that manifests in the spontaneous curvature of the amphiphile aggregates. Besides the all-important hydrophobic interaction, the hydration force is also treated implicitly. Thanks to the efficient solvent-free molecular-level coarse graining, this model is suitable for generic mesoscale studies of phenomena such as self-assembly, amphiphile mixing, domain formation, fusion, elasticity, etc., in amphiphile aggregates.

  15. Solvent-Free Manufacturing of Electrodes for Lithium-ion Batteries

    Science.gov (United States)

    Ludwig, Brandon; Zheng, Zhangfeng; Shou, Wan; Wang, Yan; Pan, Heng

    2016-03-01

    Lithium ion battery electrodes were manufactured using a new, completely dry powder painting process. The solvents used for conventional slurry-cast electrodes have been completely removed. Thermal activation time has been greatly reduced due to the time and resource demanding solvent evaporation process needed with slurry-cast electrode manufacturing being replaced by a hot rolling process. It has been found that thermal activation time to induce mechanical bonding of the thermoplastic polymer to the remaining active electrode particles is only a few seconds. Removing the solvent and drying process allows large-scale Li-ion battery production to be more economically viable in markets such as automotive energy storage systems. By understanding the surface energies of various powders which govern the powder mixing and binder distribution, bonding tests of the dry-deposited particles onto the current collector show that the bonding strength is greater than slurry-cast electrodes, 148.8 kPa as compared to 84.3 kPa. Electrochemical tests show that the new electrodes outperform conventional slurry processed electrodes, which is due to different binder distribution.

  16. Experimental investigation on the minimum ignition temperature of hybrid mixtures of dusts and gases or solvents.

    Science.gov (United States)

    Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

    2016-01-15

    Investigations on the minimum ignition temperatures (MIT) of hybrid mixtures of dusts with gases or solvents were performed in the modified Godbert-Greenwald (GG) furnace. Five combustible dusts and six flammable gases (three ideal and three real) were used. The test protocol was according to EN 50281-2-1 for dust-air mixtures whereas in the case of gases, solvents and hybrid mixtures this standard was used with slight modification. The experimental results demonstrated a significant decrease of the MIT of gas, solvent or dust and an increase in the likelihood of explosion when a small amount of dust, which was either below the minimum explosion concentration or not ignitable by itself, was mixed with gas and vice versa. For example, the MIT of toluene decreased from 540°C to 455°C when small amount of lycopodium was added. It was also confirmed that a hybrid mixture explosion is possible even when both dust and vapour or gas concentrations are respectively lower than their minimum explosion concentration (MEC) and lower explosion limit (LEL). Another example is CN4, the MEC of which of 304 g/m(3) decreased to 37 g/m(3) when propane was added, even though the concentrations of the gas was below its LEL. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Retention modeling in combined pH/organic solvent gradient reversed-phase HPLC.

    Science.gov (United States)

    Zisi, Ch; Fasoula, S; Nikitas, P; Pappa-Louisi, A

    2013-07-07

    An approach for retention modeling of double pH/organic solvent gradient data easily generated by automatically mixing two mobile phases with different pH and organic content according to a linear pump program is proposed. This approach is based on retention models arising from the evaluation of the retention data of a set of 17 OPA derivatives of amino acids obtained in 27 combined pH/organic solvent gradient runs performed between fixed initial pH/organic modifier values but different final ones and for different gradient duration. The derived general model is a ninth parameter equation easily manageable through a linear least-squares fitting but it requires eighteen initial pH/organic modifier gradient experiments for a satisfactory retention prediction in various double gradients of the same kind with those used in the fitting procedure. Two simplified versions of the general model, which were parameterized based on six only initial pH/organic modifier gradients, were also proposed, when one of the final double gradient conditions, pH or organic content was kept constant. The full and the simplified models allowed us to predict the experimental retention data in simultaneous pH/organic solvent double gradient mode very satisfactorily without the solution of the fundamental equation of gradient elution.

  18. An efficient phase-selective gelator for aromatic solvents recovery based on a cyanostilbene amide derivative.

    Science.gov (United States)

    Zhang, Yuping; Ma, Yao; Deng, Mengyu; Shang, Hongxing; Liang, Chunshuang; Jiang, Shimei

    2015-07-07

    Two novel low molecular weight organogelators (LMOGs) 1 and 2 composed of a cholesteryl group, an amide group and various terminal cyanostilbene moieties were synthesized. They could form stable gels in p-xylene. In particular, 2 with more extended π-conjugation length showed remarkable gelation ability in many aromatic solvents, chloroform and chloroform-containing mixed solvents at a relatively low concentration. FT-IR and XRD spectra indicated that the difference between 1 and 2 in the gelation properties may result from the deviation of the intermolecular hydrogen bonding and π–π stacking as driving forces for the formation of the gels. Significantly, 2 can function as an efficient room-temperature phase-selective gelator (PSG) for potential application in the separation and recovery of various aromatic solvents from its mixture with water. Meanwhile, the gelator can be easily recovered and reused several times. Furthermore, the phase-selective gelation properties of 2 can provide a simple and feasible approach for the removal of the rhodamine B (RhB) dye from water.

  19. Coacervate Core Micelles for the Dispersion and Stabilization of Organophosphate Hydrolase in Organic Solvents

    Science.gov (United States)

    Mills, Carolyn; Obermeyer, Allie; Dong, Xuehui; Olsen, Bradley D.

    Bulk organophosphate (OP) nerve agents are difficult to decontaminate on site and dangerous to transport. The organophosphate hydrolase (OPH) enzyme is an efficient catalyst for hydrolyzing, and thus decontaminating, these compounds, but suffers from poor stability in the hydrophobic bulk OP environment. Here, we exploit the complex coacervation phase separation phenomenon to form complex coacervate core micelles (C3Ms) that can protect this OPH enzyme under these conditions. Stable C3Ms form when mixing a charged-neutral block copolymer methyl-quaternized poly(4-vinylpyridine)-block-poly(oligo(ethylene glycol) methacrylate) (Qp4vp- b-POEGMA), a homopolymer poly(acrylic acid) (PAA), and OPH under a certain conditions. The C3Ms are then transferred into two organic solvents, ethanol and dimethyl methylphosphonate (DMMP), which is a good simulant for the physical properties of the OP compounds. The C3Ms retain their nanostructures in the organic solvents. The activity test of OPH indicates that the C3Ms successfully protect OPH activity in organic solvents.

  20. Solvent-Free Manufacturing of Electrodes for Lithium-ion Batteries.

    Science.gov (United States)

    Ludwig, Brandon; Zheng, Zhangfeng; Shou, Wan; Wang, Yan; Pan, Heng

    2016-03-17

    Lithium ion battery electrodes were manufactured using a new, completely dry powder painting process. The solvents used for conventional slurry-cast electrodes have been completely removed. Thermal activation time has been greatly reduced due to the time and resource demanding solvent evaporation process needed with slurry-cast electrode manufacturing being replaced by a hot rolling process. It has been found that thermal activation time to induce mechanical bonding of the thermoplastic polymer to the remaining active electrode particles is only a few seconds. Removing the solvent and drying process allows large-scale Li-ion battery production to be more economically viable in markets such as automotive energy storage systems. By understanding the surface energies of various powders which govern the powder mixing and binder distribution, bonding tests of the dry-deposited particles onto the current collector show that the bonding strength is greater than slurry-cast electrodes, 148.8 kPa as compared to 84.3 kPa. Electrochemical tests show that the new electrodes outperform conventional slurry processed electrodes, which is due to different binder distribution.

  1. ADVANCED MIXING MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    The process of recovering and processing High Level Waste (HLW) the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four mixers (pumps) located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are typically set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The focus of the present work is to establish mixing criteria applicable to miscible fluids, with an ultimate goal of addressing waste processing in HLW tanks at SRS and quantifying the mixing time required to suspend sludge particles with the submersible jet pump. A single-phase computational fluid dynamics (CFD) approach was taken for the analysis of jet flow patterns with an emphasis on the velocity decay and the turbulent flow evolution for the farfield region from the pump. Literature results for a turbulent jet flow are reviewed, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. The work described in this report suggests a basis for further development of the theory leading to the identified mixing indicators, with benchmark analyses demonstrating their consistency with widely accepted correlations. Although the indicators are somewhat generic in nature, they are applied to Savannah River Site (SRS) waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in

  2. Electrospinning of Grooved Polystyrene Fibers: Effect of Solvent Systems

    Science.gov (United States)

    Liu, Wanjun; Huang, Chen; Jin, Xiangyu

    2015-05-01

    Secondary surface texture is of great significance to morphological variety and further expands the application areas of electrospun nanofibers. This paper presents the possibility of directly electrospinning grooved polystyrene (PS) fibers using both single and binary solvent systems. Solvents were classified as low boiling point solvent (LBPS): dichloromethane (DCM), acetone (ACE), and tetrahydrofuran (THF); high boiling point solvent (HBPS): N, N-dimethylformamide (DMF) and cyclohexanone (CYCo); and non-solvent (NS): 1-butanol (BuOH). By the systematic selection and combination of these solvents at given parameters, we found that single solvent systems produced non-grooved fibers. LBPS/DMF solvent systems resulted in fibers with different grooved textures, while LBPS/CYCo led to fibers with double grooved texture. Grooved fibers can also be fabricated from LBPS/LBPS, NS/LBPS, and NS/HBPS systems under specific conditions. The results indicated that the difference of evaporation rate (DER) between the two solvents played a key role in the formation of grooved texture. The formation of this unique texture should be attributed to three separate mechanisms, namely void-based elongation, wrinkle-based elongation, and collapsed jet-based elongation. Our findings can serve as guidelines for the preparation of ultrafine fibers with grooved secondary texture.

  3. Discrete solvent effects on the effective interaction between charged colloids

    CERN Document Server

    Allahyarov, E

    2000-01-01

    Using computer simulations of two charged colloidal spheres with their counterions in a hard sphere solvent, we show that the granular nature of the solvent significantly influences the effective colloidal interaction. For divalent counterions, the total effective force can become attractive generated by counterion hydration, while for monovalent counterions the forces are repulsive and well-described by a solvent-induced colloidal charge renormalization. Both effects are not contained in the traditional "primitive" approaches but can be accounted for in a solvent-averaged primitive model.

  4. The development of Gallstone solvent temperature adaptive PID control system

    Institute of Scientific and Technical Information of China (English)

    MA; BING; QIAO; BO; YAN

    2012-01-01

    The paper expatiated the work principle,general project,and the control part of the corresponding program of the temperature system in the gallstone dissolving instrument.Gallstone dissolving instrument adopts automatic control solvent cycle of direct solution stone treatment,replacing the traditional external shock wave rock row stone and gallblad-der surgery method.PID control system to realize the gall stone solvent temperature intelligent control,the basic principle of work is as solvent temperature below the set temperature,the relay control heater to solvent to be heated,conversely,no heating,achieve better able to dissolve the the rapeutic effect of gallstones.

  5. Efficiency of bulky protic solvent for SN2 reaction.

    Science.gov (United States)

    Lee, Sung-Sik; Kim, Ho-Sung; Hwang, Tae-Kyu; Oh, Young-Ho; Park, Sung-Woo; Lee, Sungyul; Lee, Byoung Se; Chi, Dae Yoon

    2008-01-03

    We calculate and compare the effects of aprotic vs protic solvent on the rate of SN2 reaction [F- + C3H7OMs--> C3H7F + OMs-]. We find that aprotic solvent acetonitrile is more efficient than a small protic solvent such as methanol. Bulky protic solvent (tert-butyl alcohol) is predicted to be quite efficient, giving the rate constant that is similar to that in CH3CN. Our calculated relative activation barriers of the SN2 reaction in methanol, tert-butyl alcohol, and CH3CN are in good agreement with experimental observations.

  6. THE MARKETING MIX OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    SABOU FELICIA

    2014-02-01

    Full Text Available ing mix a particularly important issue is to choose the best combination of its variables, this lead to the achievement objectives, in time. Choosing the right marketing mix is possible only by reporting information to some clear benchmarks, these criteria a related to the objective of the company at the time of analyze. The study shows that the companies must give a great importance to optimize the marketing mix, because of how its combines and integrates company policies relating to the product, price, distribution and promotion, depends the success or the failure on its market. The practice has shown that if an element of the marketing mix is wrong implemented, marketing strategies and programs do not achieve their objectives, and the company can not generate the expected profit. To optimize the marketing mix, companies should consider the following issues: the resources (materials, financial and human, which will be properly allocated to all the elements of the marketing mix, the specific marketing tools and the relationship of interdependence of all the methods and tools used to optimize the marketing mix.

  7. Enzyme catalysis in organic solvents: influence of water content, solvent composition and temperature on Candida rugosa lipase catalyzed transesterification.

    Science.gov (United States)

    Herbst, Daniela; Peper, Stephanie; Niemeyer, Bernd

    2012-12-31

    In the present study the influence of water content, solvent composition and reaction temperature on the transesterification of 1-phenylpropan-2-ol catalyzed by Candida rugosa lipase was examined. Reactions were carried out in different mixtures of hexane and tetrahydrofurane. The studies showed that an increasing water content of the organic solvent results in an increasing enzyme activity and a decreasing enantiomeric excess. Furthermore, a significant influence of the solvent hydrophilicity both on the enzyme activity and on the enantiomeric excess was found. An increase in solvent hydrophilicity leads to a decrease of enzyme activity and an increase of the enantiomeric excess. This indicates that the enzyme becomes more selective with decreasing flexibility. Similar effects were found by variation of the reaction temperature. Taken together, the decrease in conversion and the increase in selectivity with increasing solvent hydrophilicity are induced by the different water contents on the enzyme surface and not by the solvent itself.

  8. Organogels thermodynamics, structure, solvent role, and properties

    CERN Document Server

    Guenet, Jean-Michel

    2016-01-01

    This book provides a physics-oriented introduction to organogels with a comparison to polymer thermoreversible gels whenever relevant. The past decade has seen the development of a wide variety of newly-synthesized molecules that can spontaneously self-assemble or crystallize from their organic or aqueous solutions to produce fibrillar networks, namely organogels, with potential applications in organic electronics, light harvesting, bio-imaging, non-linear optics, and the like. This compact volume presents a detailed outlook of these novel molecular systems with special emphasis upon their thermodynamics, morphology, molecular structure, and rheology. The definition of these complex systems is also tackled, as well as the role of the solvent. The text features numerous temperature-phase diagrams for a variety of organogels as well as illustrations of their structures at the microscopic, mesoscopic and macroscopic level. A review of some potential applications is provided including hybrid functional materials ...

  9. Solvent control of intramolecular proton transfer

    DEFF Research Database (Denmark)

    Manolova, Y.; Marciniak, Heinz; Tschierlei, S.

    2017-01-01

    The solvent dependent excited state dynamics of 4-hydroxy-3-(piperidin-1-ylmethyl)-1-naphthaldehyde (compound 2), a candidate for a molecular switch based on intramolecular proton transfer, was investigated by ultrafast spectroscopy and quantum-chemical calculations. In acetonitrile a mixture...... of molecules in the enol and zwitterionic proton transfer (PT) form exists in the ground state. However, the zwitterion is the energetically favored one in the electronically excited state. Optical excitation of the enol form results in intramolecular proton transfer and formation of the PT form within 1.4 ps....... In addition we observe the appearance of a long living species with a rate of 1/(330 ps) which returns to the original ground state on time scales beyond 2 ns and which is attributed to the triplet state. In toluene the enol form is the only observed ground state tautomer, but no light induced proton transfer...

  10. Is Water a Universal Solvent for Life?

    Science.gov (United States)

    Pohorill, Andrew

    2012-01-01

    There are strong reasons to believe that the laws, principles and constraints of physics and chemistry are universal. It is much less clear how this universality translates into our understanding of the origins of life. Conventionally, discussions of this topic focus on chemistry that must be sufficiently rich to seed life. Although this is clearly a prerequisite for the emergence of living systems, I propose to focus instead on self-organization of matter into functional structures capable of reproduction, evolution and responding to environmental changes. In biology, most essential functions are largely mediated by noncovalent interactions (interactions that do not involve making or breaking chemical bonds). Forming chemical bonds is only a small part of what living systems do. There are specific implications of this point of view for universality. I will concentrate on one of these implications. Strength of non-covalent interactions must be properly tuned. If they were too weak, the system would exhibit undesired, uncontrolled response to natural fluctuations of physical and chemical parameters. If they were too strong kinetics of biological processes would be slow and energetics costly. This balance, however, is not a natural property of complex chemical systems. Instead, it has to be achieved with the aid of an appropriate solvent for life. In particular, potential solvents for life must be characterized by a high dielectric constant to ensure solubility of polar species and sufficient flexibility of biological structures stabilized by electrostatic interactions. Among these solvents, water exhibits a remarkable trait that it also promotes solvophobic (hydrophobic) interactions between non-polar species, typically manifested by a tendency of these species to aggregate and minimize their contacts with the aqueous solvent. Hydrophobic interactions are responsible, at least in part, for many self-organization phenomena in biological systems, such as the formation

  11. Solvent Extraction in Hydrometallurgy: Present and Future

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During the past 10 years, there have been incremental advances in the application of solvent extraction to process hydrometallurgy. The most cited areas in the literature include chemistry, chemical engineering, pilot plants, and plant operation. Within these areas, there were considerable interest in synergism,diluents, degradation, contactors, surfactants, hydrometallurgical applications, environmental and secondary applications, and health and safety. The summary to the present is followed by a prediction for the future in the above areas of interest. These include the use of speciation; improved understanding of the role of surfactants on the system; optimization through modelling, pilot plants, and contactor selection; improvements in plant operation; further new applications; and plant safety. The review has indicated that considerable knowledge is now available to optimize and improve on process design and plant applications.

  12. RH Mixing observable?

    CERN Document Server

    Achiman, Yoav

    1999-01-01

    Asymmetric mass matrices can induce large RH mixings. Those are non -measurable in the SM but are there and play an important role in its extensions. The RH rotations are in particular relevant for the proton decay, neutrino properties and baryon asymmetry. E.g. large RH mixings lead to kaon dominated proton decay even without SUSY and could be the reason for a large neutrino mixing. By studying those phenomena one can learn about the RH rotation matrices and this can reduce considerably the arbitrariness in the present fermionic mass study.

  13. Device Scale Modeling of Solvent Absorption using MFIX-TFM

    Energy Technology Data Exchange (ETDEWEB)

    Carney, Janine E. [National Energy Technology Lab. (NETL), Albany, OR (United States); Finn, Justin R. [National Energy Technology Lab. (NETL), Albany, OR (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

    2016-10-01

    Recent climate change is largely attributed to greenhouse gases (e.g., carbon dioxide, methane) and fossil fuels account for a large majority of global CO2 emissions. That said, fossil fuels will continue to play a significant role in the generation of power for the foreseeable future. The extent to which CO2 is emitted needs to be reduced, however, carbon capture and sequestration are also necessary actions to tackle climate change. Different approaches exist for CO2 capture including both post-combustion and pre-combustion technologies, oxy-fuel combustion and/or chemical looping combustion. The focus of this effort is on post-combustion solvent-absorption technology. To apply CO2 technologies at commercial scale, the availability and maturity and the potential for scalability of that technology need to be considered. Solvent absorption is a proven technology but not at the scale needed by typical power plant. The scale up and down and design of laboratory and commercial packed bed reactors depends heavily on the specific knowledge of two-phase pressure drop, liquid holdup, the wetting efficiency and mass transfer efficiency as a function of operating conditions. Simple scaling rules often fail to provide proper design. Conventional reactor design modeling approaches will generally characterize complex non-ideal flow and mixing patterns using simplified and/or mechanistic flow assumptions. While there are varying levels of complexity used within these approaches, none of these models resolve the local velocity fields. Consequently, they are unable to account for important design factors such as flow maldistribution and channeling from a fundamental perspective. Ideally design would be aided by development of predictive models based on truer representation of the physical and chemical processes that occur at different scales. Computational fluid dynamic (CFD) models are based on multidimensional flow equations with first

  14. Guidelines for mixed waste minimization

    Energy Technology Data Exchange (ETDEWEB)

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization.

  15. Use of Organic Solvents to Extract Organochlorine Pesticides (OCPs) from Aged Contaminated Soils

    Institute of Scientific and Technical Information of China (English)

    YE Mao; JIN Xin; JIANG Xin; YANG Xing-Lun; SUN Ming-Ming; BIAN Yong-Rong; WANG Fang; GU Cheng-Gang; WEI Hai-Jiang; SONG Yang; WANG Lei

    2013-01-01

    Problems associated with organochlorine pesticide (OCP)-contaminated sites in China have received wide attention.To solve such problems,innovative ex-situ methods of site remediation are urgently needed.We investigated the feasibility of the extraction method with different organic solvents,ethanol,1-propanol,and three fractions of petroleum ether,using a soil collected from Wujiang (WJ),China,a region with long-term contamination of dichlorodiphenyltrichloroethanes (DDTs).We evaluated different influential factors,including organic solvent concentration,washing time,mixing speed,solution-to-soil ratio,and washing temperature,on the removal of DDTs from the WJ soil.A set of relatively better parameters were selected for extraction with 100 mL L-1 petroleum ether (60-90 ℃):washing time of 180 min,mixing speed of 100 r min-1,solution-to-soil ratio of 10:1,and washing temperature of 50 ℃.These selected parameters were also applied on three other seriously OCP-polluted soils.Results demonstrated their broad-spectrum effectiveness and excellent OCP extraction performance on the contaminated soils with different characteristics.

  16. Gels and lyotropic liquid crystals: using an imidazolium-based catanionic surfactant in binary solvents.

    Science.gov (United States)

    Cheng, Ni; Hu, Qiongzheng; Bi, Yanhui; Xu, Wenwen; Gong, Yanjun; Yu, Li

    2014-08-01

    The self-assembly behavior of an imidazolium-based catanionic surfactant, 1-butyl-3-methylimidazolium dodecylsulfate ([C4mim][C12H25SO4]), was investigated in water-ethylammonium nitrate (EAN) mixed solvents with different volume ratios. It is particular interesting that this simple surfactant could not only form lyotropic liquid crystals (LLC) with multimesophases, i.e., normal hexagonal (H1), lamellar liquid crystal (Lα), and reverse bicontinuous cubic phase (V2), in the water-rich environment but also act as an efficient low-molecular-weight gelator (LMWG) which gelated EAN-abundant binary media in a broad concentration range. The peculiar nanodisk cluster morphology of gels composed of similar bilayer units was first observed. FT-IR spectra and density functional theory (DFT) calculations reveal that strong H bonding and electrostatic interactions between EAN and the headgroups of [C4mim][C12H25SO4] are primarily responsible for gelation. The self-assembled gels displayed excellent mechanical strength and a thermoreversible sol-gel transition. It is for the first time that a rich variety of controllable ordered aggregates could be observed only by simply modulating the concentration of a single imidazolium-based catanionic surfactant or the ratio of mixed solvents. This environmentally friendly system is expected to have broad applications in various fields, such as materials science, drug delivery systems, and supramolecular chemistry.

  17. First title: Ionic liquids-useful reaction green solvents for the future Second title: ionic liquids are the replacements for environmentally damaging solvents in a wide range of chemical processes.

    Directory of Open Access Journals (Sweden)

    K.Vijaya Bhaskar

    2012-09-01

    "designer solvents”. This means that their properties can be adjusted to suit the requirements of a particular process. Properties such as melting point, viscosity, density, and hydrophobicity can be varied by simple changes to the structure of the ions. For example, the melting points of 1-alkyl-3-methylimidazolium tetrafluoroborates and hexafluorophosphates are a function of the length of the 1-alkyl group, and form liquid crystalline phases for alkyl chain lengths over 12 carbon atoms. Another important property that changes with structure is the miscibility of water in these ionic liquids. For example, 1-alkyl-3-methylimidazolium tetrafluoroborate salts are miscible with water at 25 °C where the alkyl chain length is less than 6, but at or above 6 carbon atoms, they form a separate phase when mixed with water. This behaviour can be of substantial benefit when carrying out solvent extractions or product separations, as the relative solubility’s of the ionic and extraction phase can be adjusted to make the separation as easy as possible. In addition, ionic liquids have practically no vapour pressure which facilitates product separation by distillation. There are also indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity. This opens up a wide field for future investigations into this new class of solvents in catalytic applications. Research into ionic liquids is booming. The first industrial process involving ionic liquids was announced in March 2003, and the potential of ionic liquids for new chemical technologies is beginning to be recognized. One of the primary driving forces behind research into ionic liquids is the perceived benefit of substituting traditional industrial solvents, most of which are volatile organic compounds (VOCs, with non-volatile ionic liquids. Replacement of conventional solvents by ionic liquids would prevent the emission of VOCs, a major source of environmental

  18. Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

    Institute of Scientific and Technical Information of China (English)

    Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

    2012-01-01

    Palm-based dihydroxystearic acid of 69.55% purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69% when carried out with 70-80% isopropyl alcohol at 20 ℃.

  19. STABILITY OF A CYLINDRICAL SOLUTE-SOLVENT INTERFACE: EFFECT OF GEOMETRY, ELECTROSTATICS, AND HYDRODYNAMICS*

    OpenAIRE

    Li, Bo; Sun, Hui; Zhou, Shenggao

    2015-01-01

    The solute-solvent interface that separates biological molecules from their surrounding aqueous solvent characterizes the conformation and dynamics of such molecules. In this work, we construct a solvent fluid dielectric boundary model for the solvation of charged molecules and apply it to study the stability of a model cylindrical solute-solvent interface. The motion of the solute-solvent interface is defined to be the same as that of solvent fluid at the interface. The solvent fluid is assu...

  20. Mixed-Media Owls

    Science.gov (United States)

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.