Solvent effects in the synergistic solvent extraction of Co2+

International Nuclear Information System (INIS)

Kandil, A.T.; Ramadan, A.

1979-01-01

The extraction of Co 2+ from a 0.1M ionic strength aqueous phase (Na + , CH 3 COOH) of pH = 5.1 was studied using thenoyltrifluoroacetone, HTTA, in eight different solvents and HTTA + trioctylphosphine oxide, TOPO, in the same solvents. A comparison of the effect of solvent dielectric constant on the equilibrium constant shows a synergism as a result of the increased hydrophobic character imparted to the metal complex due to the formation of the TOPO adduct. (author)

SOLVENT FIRE BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

Walker, D; Samuel Fink, S

2006-05-22

Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

An overview of industrial solvent use or is there life after chlorinated solvents?

International Nuclear Information System (INIS)

Green, B.

1991-01-01

Everyone using industrial chemicals has been affected by the fire- storm of new regulations governing solvent use. How will companies currently using hazardous solvents prepare for the changes ahead? What will the impact be on commonly used industrial solvents? What effect are environmental pressures having on solvent use and disposal? Are the responsible individuals in your company up-to-date on phase-out schedules? This paper is written for an audience of compliance coordinators, consultants, production engineers and corporate management. In it, the either addresses the above questions and discusses the specific products affected. The author reviews currently available alternatives to chlorinated and hazardous solvents and introduces a simple system for rating alternatives. The program also includes a discussion of solvent minimization programs and worker reeducation

Solvent - solute interaction

International Nuclear Information System (INIS)

Urbanczyk, A.; Kalinowski, M.K.

1983-01-01

The electronic absorption spectrum of vanadyl acetylacetonate has been studied in 15 organic solvents. It has been found that wavenumbers and molar absorptivities of the long-wavelength bands (d-d transitions) can be well described by a complementary Lewis acid-base model including Gutmann's donor number [Gutmann V., Wychera E., Inorg. Nucl. Chem. Letters 2, 257 (1966)] and acceptor number [Mayer U., Gutmann V., Gerger W., Monatsh. Chem. 106, 1235 (1975)] of a solvent. This model describes also the solvent effect of the hyperfine splitting constant, Asub(iso)( 51 V), from e.s.r. spectra of VOacac 2 . These observations are discussed in terms of the donor-acceptor concept for solvent-solute interactions. (Author)

Deasphalting solvents

International Nuclear Information System (INIS)

Carrillo, J. A; Caceres, J; Vela, G; Bueno, H

1996-01-01

This paper describes how the deasphalted oil (DMO) or demetalized oil (DMO) quality (CCR, Ni, V end asphaltenes contents) changes with: DAO or DMO yield, solvent/feed ratio, type of vacuum reside (from paraffinic to blends with vis breaking bottoms), extraction temperature and extraction solvent (propane, propylene, n-butane and I butane)

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

Science.gov (United States)

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

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.

Porous fiber formation in polymer-solvent system undergoing solvent evaporation

Science.gov (United States)

Dayal, Pratyush; Kyu, Thein

2006-08-01

Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys. 28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solvent evaporation rate. To guide the solvent evaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for the nonconserved nature of the concentration field caused by the solvent loss. The process of solvent evaporation across the fiber skin-air interface was treated in accordance with the classical Fick's law [R. B. Bird et al., Transport Phenomena (J. Wiley, New York, 1960), p. 780]. The simulated morphologies include gradient type, hollow fiber type, bicontinuous type, and host-guest type. The development of these diverse fiber morphologies is explicable in terms of the phase diagram of the polymer solution in a manner dependent on the competition between the phase separation dynamics and rate of solvent evaporation.

Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: Comparison between hard-sphere solvent and water

International Nuclear Information System (INIS)

Oshima, Hiraku; Kinoshita, Masahiro

2015-01-01

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

Restoring solvent for nuclear separation processes

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

Solvent extraction separation processes are used to recover usable nuclear materials from spent fuels. These processes involve the use of an extractant/diluent (solvent) for separation of the reusable actinides from unwanted fission products. The most widely used processes employ tributyl phosphate as an extractant diluted with a normal-paraffin hydrocarbon. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. In most processes, the solvent is recycled after cleaning. Solvent cleaning generally involves scrubbing with a sodium carbonate solution. Studies at the Savannah River Laboratory have shown that carbonate washing, although removing residual solvent activity, does not remove more solvent-soluble binding ligands (formed by solvent degradation), which hold fission products in the solvent. Treatment of the solvent with a solid adsorbent after carbonate washing removes binding ligands and significantly improves recycled solvent performance. Laboratory work to establish the advantage of adsorbent cleaning and the development of a full-scale adsorption process is described. The application of this process for cleaning the first cycle solvent of a Savannah River Plant production process is discussed

Selective solvent extraction of oils

Energy Technology Data Exchange (ETDEWEB)

1938-04-09

In the selective solvent extraction of naphthenic base oils, the solvent used consists of the extract obtained by treating a paraffinic base oil with a selective solvent. The extract, or partially spent solvent is less selective than the solvent itself. Selective solvents specified for the extraction of the paraffinic base oil are phenol, sulphur dioxide, cresylic acid, nitrobenzene, B:B/sup 1/-dichlorethyl ether, furfural, nitroaniline and benzaldehyde. Oils treated are Coastal lubricating oils, or naphthenic oils from the cracking, or destructive hydrogenation of coal, tar, lignite, peat, shale, bitumen, or petroleum. The extraction may be effected by a batch or counter-current method, and in the presence of (1) liquefied propane, or butane, or naphtha, or (2) agents which modify the solvent power such as, water, ammonia, acetonitrile, glycerine, glycol, caustic soda or potash. Treatment (2) may form a post-treatment effected on the extract phase. In counter-current treatment in a tower some pure selective solvent may be introduced near the raffinate outlet to wash out any extract therefrom.

Solvent substitutes

International Nuclear Information System (INIS)

Evanoff, S.P.

1995-01-01

The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

Canyon solvent cleaning with solid adsorbents

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

The HM Process at the Savannah River Plant (SRP) uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands that hold fission products in the solvent. Treatment of solvent with a solid adsorbent removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale adsorption process and the use of the process to clean HM Process first cycle solvent are presented

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.

Purex process solvent: literature review

International Nuclear Information System (INIS)

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

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.

Hazardous Solvent Substitution Data System reference manual

International Nuclear Information System (INIS)

Branham-Haar, K.A.; Twitchell, K.E.

1993-07-01

Concern for the environment, in addition to Federal regulation, mandate the replacement of hazardous solvents with safer cleaning agents. Manufacturers are working to produce these replacement solvents. As these products are developed, potential users need to be informed of their availability. To promote the use of these new products instead of traditional solvents, the Idaho National Engineering Laboratory (INEL) has developed the Hazardous Solvent Substitution Data System (HSSDS). The HSSDS provides a comprehensive system of information on alternatives to hazardous solvents and related subjects, and it makes that information available to solvent users, industrial hygienists, and process engineers. The HSSDS uses TOPIC reg-sign, a text retrieval system produced by Verity, Inc., to allow a user to search for information on a particular subject. TOPIC reg-sign produces a listing of the retrieved documents and allows the use to examine the documents individually and to use the information contained in them. This reference manual does not replace the comprehensive TOPIC reg-sign user documentation (available from Verity, Inc.), or the HSSDS Tutorial (available from the INEL). The purpose of this reference manual is to provide enough instruction on TOPIC reg-sign so the user may begin accessing the data contained in the HSSDS

Solvent/non-solvent sintering: a novel route to create porous microsphere scaffolds for tissue regeneration.

Science.gov (United States)

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

2008-08-01

Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter, and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from -8 to 41 degrees C and poly (lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1 mum, respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3 MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. (c) 2007 Wiley Periodicals, Inc.

Measurement and correlation of solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures

International Nuclear Information System (INIS)

Wang, Jinxiu; Xie, Chuang; Yin, Qiuxiang; Tao, Linggang; Lv, Jun; Wang, Yongli; He, Fang; Hao, Hongxun

2016-01-01

Highlights: • Solubility of cefmenoxime hydrochloride in pure and binary solvents was determined. • The experimental solubility data were correlated by thermodynamic models. • A model was employed to calculate the melting temperature of cefmenoxime hydrochloride. • Mixing thermodynamic properties of cefmenoxime hydrochloride were calculated. - Abstract: The solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures was measured at temperatures from (283.15 to 313.15) K by using the UV spectroscopic method. The results reveal that the solubility of cefmenoxime hydrochloride increases with increasing temperature in all solvent selected. The solubility of cefmenoxime hydrochloride reaches its maximum value when the mole fraction of isopropanol is 0.2 in the binary solvent mixtures of (isopropanol + water). The modified Apelblat equation and the NRTL model were successfully used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. In addition, the mixing thermodynamic properties of cefmenoxime hydrochloride in different solvents were also calculated based on the NRTL model and experimental solubility data.

Measurement and prediction of dabigatran etexilate mesylate Form II solubility in mono-solvents and mixed solvents

International Nuclear Information System (INIS)

Xiao, Yan; Wang, Jingkang; Wang, Ting; Ouyang, Jinbo; Huang, Xin; Hao, Hongxun; Bao, Ying; Fang, Wen; Yin, Qiuxiang

2016-01-01

Highlights: • Solubility of DEM Form II in mono-solvents and binary solvent mixtures was measured. • Regressed UNIFAC model was used to predict the solubility in solvent mixtures. • The experimental solubility data were correlated by different models. - Abstract: UV spectrometer method was used to measure the solubility data of dabigatran etexilate mesylate (DEM) Form II in five mono-solvents (methanol, ethanol, ethane-1,2-diol, DMF, DMAC) and binary solvent mixtures of methanol and ethanol in the temperature range from 287.37 K to 323.39 K. The experimental solubility data in mono-solvents were correlated with modified Apelblat equation, van’t Hoff equation and λh equation. GSM model and Modified Jouyban-Acree model were employed to correlate the solubility data in mixed solvent systems. And Regressed UNIFAC model was used to predict the solubility of DEM Form II in the binary solvent mixtures. Results showed that the predicted data were consistent with the experimental data.

Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

KAUST Repository

Wadsworth, Andrew; Ashraf, Raja; Abdelsamie, Maged; Pont, Sebastian; Little, Mark; Moser, Maximilian; Hamid, Zeinab; Neophytou, Marios; Zhang, Weimin; Amassian, Aram; Durrant, James R.; Baran, Derya; McCulloch, Iain

2017-01-01

With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

KAUST Repository

Wadsworth, Andrew

2017-06-01

With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

Cesium Concentration in MCU Solvent

International Nuclear Information System (INIS)

Walker, D

2006-01-01

During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

Iodine removing method in organic solvent

International Nuclear Information System (INIS)

Suzuki, Takeo; Sakurai, Manabu

1988-01-01

Purpose: To effectively remove iodine in an organic solvent to thereby remove iodine in the solvent that can be re-used or put to purning treatment. Method: Organic solvent formed from wastes of nuclear facilities is mixed with basic lead acetate, or silica gel or activated carbon incorporated with such a compound to adsorb iodine in the organic solvent to the basic lead acetate. Then, iodine in the organic solvent is removed by separating to eliminate the basic lead acetate adsorbing iodine from the organic solvent or by passing the organic solvent through a tower or column charged or pre-coated with silica gel or activated carbon incorporated with lead acetate. By using basic lead acetate as the adsorbents, iodine can effective by adsorbed and eliminated. Thus, the possibility of circumstantial release of iodine can be reduced upon reusing or burning treatment of the organic solvent. (Kamimura, M.)

Sensibilidade do carrapato Boophilus microplus a solventes Sensibility of Boophilus microplus tick to solvents

Directory of Open Access Journals (Sweden)

Ana Carolina de Souza Chagas

2003-02-01

Full Text Available Os experimentos envolvendo o uso de acaricidas sintéticos ou naturais, geralmente necessitam da utilização de um solvente. Com a finalidade de verificar a sensibilidade do carrapato bovino Boophilus microplus a diferentes solventes, larvas e fêmeas ingurgitadas deste ectoparasito foram expostas a sete solventes em cinco diferentes concentrações, na ausência e presença de azeite de oliva. Os resultados mostraram que a utilização do azeite de oliva não produz resultados diferentes estatisticamente em testes de larvas com papel impregnado, fato não verificado em testes de imersão de adultos com compostos hidrofílicos. A mortalidade média causada pelos solventes foi menor nos testes com papel impregnado, aumentando nos testes de imersão de larvas e de adultos. Solventes de baixo peso molecular e pouca viscosidade como o álcool metílico e o álcool etílico, não interferiram na mortalidade média em testes biológicos de B. microplus, principalmente em concentrações inferiores a 76%.Experiments carried out with synthetic or natural acaricides usually use a solvent. To investigate the sensitivity of Boophilus microplus cattle tick to different solvents, larvae and engorged female were subjected to seven solvents in five different concentrations. It was done in the presence and absence of olive oil. The results showed that the utilization of olive oil doesn't produce different statistical results in impregnated paper larvae test. It did not happen in adults immersion test with hydrophilic compounds. The mean mortality caused by solvents was small in impregnated paper larvae test, increasing in immersion tests of larvae and adults. Solvents with low molecular weight and viscosity like ethyl alcohol and methyl alcohol did not cause interference in the mortality of B. microplus in biological tests, mainly in concentrations below 76%.

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.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

This article is an overview of efforts at INEL to reduce the generation of hazardous wastes through the elimination of hazardous solvents. To aid in their efforts, a number of databases have been developed and will become a part of an Integrated Solvent Substitution Data System. This latter data system will be accessible through Internet

Selection and Evaluation of Alternative Solvents for Caprolactam Extraction

NARCIS (Netherlands)

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

Selection and evaluation of alternative solvents for caprolactam extraction

NARCIS (Netherlands)

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

Organic Solvent Tropical Report

International Nuclear Information System (INIS)

COWLEY, W.L.

2000-01-01

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

Next Generation Solvent - Materials Compatibility With Polymer Components Within Modular Caustic-Side Solvent Extraction Unit (Final Report)

International Nuclear Information System (INIS)

Fondeur, F.; Peters, T.; Fink, S.

2012-01-01

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. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is 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 organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX(reg s ign)79 and MaxCalix was varied systematically) showed that LIX(reg s ign)79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX(reg s ign)79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX(reg s ign)79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX(reg s ign)79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT)

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F.; Peters, T.; Fink, S.

2012-01-17

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. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is 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 organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX{reg_sign}79 and MaxCalix was varied systematically) showed that LIX{reg_sign}79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX{reg_sign}79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX{reg_sign}79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX{reg_sign}79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

Insecticide solvents: interference with insecticidal action.

Science.gov (United States)

Brattsten, L B; Wilkinson, C F

1977-06-10

Several commercial solvent mixtures commonly used as insecticide carriers in spray formulations increase by more than threefold the microsomal N-demethylation of p-chloro N-methylaniline in midgut preparations of southern army-worm (Spodoptera eridania) larvae exposed orally to the test solvents. Under laboratory conditions, the same solvent mixtures exhibit a protective action against the in vivo toxicity of the insecticide carbaryl to the larvae. The data are discussed with respect to possible solvent-insecticide interactions occurring under field conditions and, more broadly, to potential toxicological hazards of these solvents to humans.

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.

Computer Aided Solvent Selection and Design Framework

DEFF Research Database (Denmark)

Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

and computer-aided tools and methods for property prediction and computer-aided molecular design (CAMD) principles. This framework is applicable for solvent selection and design in product design as well as process design. The first module of the framework is dedicated to the solvent selection and design...... in terms of: physical and chemical properties (solvent-pure properties); Environment, Health and Safety (EHS) characteristic (solvent-EHS properties); operational properties (solvent–solute properties). 3. Performing the search. The search step consists of two stages. The first is a generation and property...... 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...

Improvements in solvent extraction columns

International Nuclear Information System (INIS)

Aughwane, K.R.

1987-01-01

Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

Gas separation by composite solvent-swollen membranes

Science.gov (United States)

Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

1989-01-01

There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

Gas separation by composite solvent-swollen membranes

Science.gov (United States)

Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

1989-04-25

There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

SERDP/ESTCP Expert Panel Workshop on Research and Development Needs for Cleanup of Chlorinated Solvent Sites

National Research Council Canada - National Science Library

2001-01-01

...) perform its mission. These programs together conducted an expert panel workshop on August 6-7, 2001 to evaluate the needs for research and development in the general area of chlorinated solvent site cleanup...

Processing of polymers using reactive solvents

NARCIS (Netherlands)

Lemstra, P.J.; Kurja, J.; Meijer, H.E.H.; Meijer, H.E.H.

1997-01-01

A review with many refs. on processing of polymers using reactive solvents including classification of synthetic polymers, guidelines for the selection of reactive solvents, basic aspects of processing, examples of intractable and tractable polymer/reactive solvent system

40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction... formulation data. Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent...

Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

Directory of Open Access Journals (Sweden)

BRATISLAV Ž. JOVANOVIĆ

2009-12-01

Full Text Available The rate constants for the reactions of diazodiphenylmethane (DDM with 6-substituted nicotinic acids in aprotic solvents at 30 °C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship – LSER in the form: log k = log k0 + s* + a + b. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent p parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute–solvent interaction on the acid reactivity.

40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent by mass 1...

40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the.... Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1...

Can green solvents be alternatives for thermal stabilization of collagen?

Science.gov (United States)

Mehta, Ami; Rao, J Raghava; Fathima, Nishter Nishad

2014-08-01

"Go Green" campaign is gaining light for various industrial applications where water consumption needs to be reduced. To resolve this, industries have adopted usage of green, organic solvents, as an alternative to water. For leather making, tanning industry consumes gallons of water. Therefore, for adopting green solvents in leather making, it is necessary to evaluate its influence on type I collagen, the major protein present in the skin matrix. The thermal stability of collagen from rat tail tendon fiber (RTT) treated with seven green solvents namely, ethanol, ethyl lactate, ethyl acetate, propylene carbonate, propylene glycol, polyethylene glycol-200 and heptane was determined using differential scanning calorimetry (DSC). Crosslinking efficiency of basic chromium sulfate and wattle on RTT in green solvents was determined. DSC thermograms show increase in thermal stability of RTT collagen against heat with green solvents (>78°C) compared to water (63°C). In the presence of crosslinkers, RTT demonstrated thermal stability >100°C in some green solvents, resulting in increased intermolecular forces between collagen, solvent and crosslinkers. The significant improvement in thermal stability of collagen potentiates the capability of green solvents as an alternative for water. Copyright © 2014 Elsevier B.V. All rights reserved.

Solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

International Nuclear Information System (INIS)

Fan, Jie-Ping; Yang, Dan; Xu, Xiao-Kang; Guo, Xiao-Jie; Zhang, Xue-Hong

2015-01-01

Highlights: • The solubilities of daidzin were measured in various solvents. • The solubility data were correlated by three models. • The thermodynamic properties of the dissolution process were also determined. - Abstract: The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven

Adaptive Resolution Simulation of MARTINI Solvents

NARCIS (Netherlands)

Zavadlav, Julija; Melo, Manuel N.; Cunha, Ana V.; de Vries, Alex H.; Marrink, Siewert J.; Praprotnik, Matej

We present adaptive resolution dynamics simulations of aqueous and apolar solvents coarse-grained molecular models that are compatible with the MARTINI force field. As representatives of both classes solvents we have chosen liquid water and butane, respectively, at ambient temperature. The solvent

Green and Bio-Based Solvents.

Science.gov (United States)

Calvo-Flores, Francisco G; Monteagudo-Arrebola, María José; Dobado, José A; Isac-García, Joaquín

2018-04-24

Chemical reactions and many of the procedures of separation and purification employed in industry, research or chemistry teaching utilize solvents massively. In the last decades, with the birth of Green Chemistry, concerns about the employment of solvents and the effects on human health, as well as its environmental impacts and its dependence on non-renewable raw materials for manufacturing most of them, has drawn the attention of the scientific community. In this work, we review the concept of green solvent and the properties and characteristics to be considered green. Additionally, we discuss the different possible routes to prepare many solvents from biomass, as an alternative way to those methods currently applied in the petrochemical industry.

Solvent Extraction of Furfural From Biomass

Science.gov (United States)

Humphrey, M. F.

1984-01-01

Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

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.

Organic solvent topical report

International Nuclear Information System (INIS)

Cowley, W.L.

1998-01-01

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

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.

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.

Acetone-based cellulose solvent.

Science.gov (United States)

Kostag, Marc; Liebert, Tim; Heinze, Thomas

2014-08-01

Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

DEFF Research Database (Denmark)

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

-liquid equilibria). The application of the developed model-based framework is highlighted through several cases studies published in the literature. In the current state, the framework is suitable for problems where the original solvent is exchanged by distillation. A solvent selection guide for fast of suitable......-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....

Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

Science.gov (United States)

Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

On linear correlation between interfacial tension of water-solvent interface solubility of water in organic solvents and parameters of diluent effect scale

International Nuclear Information System (INIS)

Mezhov, Eh.A.; Khananashvili, N.L.; Shmidt, V.S.

1988-01-01

Presence of linear correlation between water solubility in nonmiscible with it organic solvents, interfacial tension of water-solvent interface, on the one hand, and solvent effect scale parameters and these solvents π* - on the other hand, is established. It allows, using certain tabular parameters of solvent effect or each solvent π*, to predict values of interfacial tension and water solubility for corresponding systems. It is shown, that solvent effect scale allows to predict values more accurately, than other known solvent scales, as it in contrast to other scales characterizes solvents, which are in equilibrium with water

Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

Energy Technology Data Exchange (ETDEWEB)

Saini, R.K.; Das, K., E-mail: kaustuv@rrcat.gov.in

2014-01-15

Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step.

Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

International Nuclear Information System (INIS)

Saini, R.K.; Das, K.

2014-01-01

Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step

Linear correlation of interfacial tension at water-solvent interface, solubility of water in organic solvents, and SE* scale parameters

International Nuclear Information System (INIS)

Mezhov, E.A.; Khananashvili, N.L.; Shmidt, V.S.

1988-01-01

A linear correlation has been established between the solubility of water in water-immiscible organic solvents and the interfacial tension at the water-solvent interface on the one hand and the parameters of the SE* and π* scales for these solvents on the other hand. This allows us, using the known tabulated SE* or π* parameters for each solvent, to predict the values of the interfacial tension and the solubility of water for the corresponding systems. We have shown that the SE* scale allows us to predict these values more accurately than other known solvent scales, since in contrast to other scales it characterizes solvents found in equilibrium with water

Solvents and Parkinson disease: A systematic review of toxicological and epidemiological evidence

Energy Technology Data Exchange (ETDEWEB)

Lock, Edward A., E-mail: e.lock@ljmu.ac.uk [Liverpool John Moores University, School of Pharmacy and Biomolecular Sciences, Byrom Street, Liverpool (United Kingdom); Zhang, Jing [University of Washington, Department of Pathology, School of Medicine, Seattle, WA (United States); Checkoway, Harvey [University of Washington, Department of Environmental and Occupational Health Sciences, Seattle, WA (United States)

2013-02-01

Parkinson disease (PD) is a debilitating neurodegenerative motor disorder, with its motor symptoms largely attributable to loss of dopaminergic neurons in the substantia nigra. The causes of PD remain poorly understood, although environmental toxicants may play etiologic roles. Solvents are widespread neurotoxicants present in the workplace and ambient environment. Case reports of parkinsonism, including PD, have been associated with exposures to various solvents, most notably trichloroethylene (TCE). Animal toxicology studies have been conducted on various organic solvents, with some, including TCE, demonstrating potential for inducing nigral system damage. However, a confirmed animal model of solvent-induced PD has not been developed. Numerous epidemiologic studies have investigated potential links between solvents and PD, yielding mostly null or weak associations. An exception is a recent study of twins indicating possible etiologic relations with TCE and other chlorinated solvents, although findings were based on small numbers, and dose–response gradients were not observed. At present, there is no consistent evidence from either the toxicological or epidemiologic perspective that any specific solvent or class of solvents is a cause of PD. Future toxicological research that addresses mechanisms of nigral damage from TCE and its metabolites, with exposure routes and doses relevant to human exposures, is recommended. Improvements in epidemiologic research, especially with regard to quantitative characterization of long-term exposures to specific solvents, are needed to advance scientific knowledge on this topic. -- Highlights: ► The potential for organic solvents to cause Parkinson's disease has been reviewed. ► Twins study suggests etiologic relations with chlorinated solvents and Parkinson's. ► Animal studies with TCE showed potential to cause damage to dopaminergic neurons. ► Need to determine if effects in animals are relevant to human

Solvents and Parkinson disease: A systematic review of toxicological and epidemiological evidence

International Nuclear Information System (INIS)

Lock, Edward A.; Zhang, Jing; Checkoway, Harvey

2013-01-01

Parkinson disease (PD) is a debilitating neurodegenerative motor disorder, with its motor symptoms largely attributable to loss of dopaminergic neurons in the substantia nigra. The causes of PD remain poorly understood, although environmental toxicants may play etiologic roles. Solvents are widespread neurotoxicants present in the workplace and ambient environment. Case reports of parkinsonism, including PD, have been associated with exposures to various solvents, most notably trichloroethylene (TCE). Animal toxicology studies have been conducted on various organic solvents, with some, including TCE, demonstrating potential for inducing nigral system damage. However, a confirmed animal model of solvent-induced PD has not been developed. Numerous epidemiologic studies have investigated potential links between solvents and PD, yielding mostly null or weak associations. An exception is a recent study of twins indicating possible etiologic relations with TCE and other chlorinated solvents, although findings were based on small numbers, and dose–response gradients were not observed. At present, there is no consistent evidence from either the toxicological or epidemiologic perspective that any specific solvent or class of solvents is a cause of PD. Future toxicological research that addresses mechanisms of nigral damage from TCE and its metabolites, with exposure routes and doses relevant to human exposures, is recommended. Improvements in epidemiologic research, especially with regard to quantitative characterization of long-term exposures to specific solvents, are needed to advance scientific knowledge on this topic. -- Highlights: ► The potential for organic solvents to cause Parkinson's disease has been reviewed. ► Twins study suggests etiologic relations with chlorinated solvents and Parkinson's. ► Animal studies with TCE showed potential to cause damage to dopaminergic neurons. ► Need to determine if effects in animals are relevant to human exposure

29 CFR 1915.32 - Toxic cleaning solvents.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Toxic cleaning solvents. 1915.32 Section 1915.32 Labor... Preservation § 1915.32 Toxic cleaning solvents. (a) When toxic solvents are used, the employer shall employ one or more of the following measures to safeguard the health of employees exposed to these solvents. (1...

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Li, W.Y.; Feng, J.; Xie, K.C.; Kandiyoti, R. [Taiyuan University of Technology, Taiyuan (China)

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350 {sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Wen-Ying Li; Jie Feng; Ke-Chang Xie; R. Kandiyoti [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology for Ministry of Education and Shanxi Province

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350{sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Organic solvent topical report

International Nuclear Information System (INIS)

COWLEY, W.L.

1999-01-01

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

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.

Oak Ridge K-25 Site chlorinated solvent pollution prevention opportunity assessment

Energy Technology Data Exchange (ETDEWEB)

1994-08-01

A pollution prevention opportunity assessment (PPOA) was conducted at the Oak Ridge K-25 Site to identify opportunities to reduce and better manage the use of chlorinated solvents. At the K-25 Site, 67 control areas were examined for their potential use of chlorinated solvents. Of these areas, 27 were found to be using (1) chlorinated solvents for cleaning, degreasing, and lubricating; (2) laboratory standards and solvents; and (3) test medium. Current management practices encourage the identification and use of nonhazardous chemicals, including the use of chlorinated solvents. The main pollution prevention principles are source reduction and recycling, and a number of pollution prevention options based on these principles were identified and evaluated as part of this chlorinated solvent PPOA. Source reduction options evaluated for the K-25 Site include the substitution of chlorinated solvents with nonchlorinated solvents. Recycling was identified for those areas that would benefit most from the reuse of the chlorinated solvents in use. The pollution prevention options that offer the greatest opportunity for success at the K-25 Site are the implementation of substitutes at the 10 control areas using chlorinated solvents for cleaning, degreasing, and lubrication. A change in the process may be all that is needed to eliminate the use of a chlorinated solvent. Once a decision is made to implement a substitution, the information should be communicated to all shops and laboratories. Another option to consider is the installation of recycling units to recycle the large amounts of methylene chloride used in the analytical sampling procedure.

Oak Ridge K-25 Site chlorinated solvent pollution prevention opportunity assessment

International Nuclear Information System (INIS)

1994-08-01

A pollution prevention opportunity assessment (PPOA) was conducted at the Oak Ridge K-25 Site to identify opportunities to reduce and better manage the use of chlorinated solvents. At the K-25 Site, 67 control areas were examined for their potential use of chlorinated solvents. Of these areas, 27 were found to be using (1) chlorinated solvents for cleaning, degreasing, and lubricating; (2) laboratory standards and solvents; and (3) test medium. Current management practices encourage the identification and use of nonhazardous chemicals, including the use of chlorinated solvents. The main pollution prevention principles are source reduction and recycling, and a number of pollution prevention options based on these principles were identified and evaluated as part of this chlorinated solvent PPOA. Source reduction options evaluated for the K-25 Site include the substitution of chlorinated solvents with nonchlorinated solvents. Recycling was identified for those areas that would benefit most from the reuse of the chlorinated solvents in use. The pollution prevention options that offer the greatest opportunity for success at the K-25 Site are the implementation of substitutes at the 10 control areas using chlorinated solvents for cleaning, degreasing, and lubrication. A change in the process may be all that is needed to eliminate the use of a chlorinated solvent. Once a decision is made to implement a substitution, the information should be communicated to all shops and laboratories. Another option to consider is the installation of recycling units to recycle the large amounts of methylene chloride used in the analytical sampling procedure

Implicit solvent simulations of DNA and DNA-protein complexes: Agreement with explicit solvent vs experiment

Czech Academy of Sciences Publication Activity Database

Chocholoušová, Jana; Feig, M.

2006-01-01

Roč. 110, č. 34 (2006), s. 17240-17251 ISSN 1520-6106 Keywords : implicit solvent * explicit solvent * protein DNA complex Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.115, year: 2006

Biomolecular-solvent stereodynamic coupling probed by deuteration

International Nuclear Information System (INIS)

Fornili, S.L.; Leone, M.; Madonia, F.; Migliore, M.; Palma-Vittorelli, M.B.; Palma, M.U.; San Biagio, P.L.

1983-01-01

Thermodynamic interpretation of experiments with isotopically perturbed solvent supports the view that solvent stereodynamics is directly relevant to thermodynamic stability of biomolecules. According with the current understanding of the structure of the aqueous solvent, in any stereodynamic configuration of the latter, connectivity pathways are identifiable for their topologic and order properties. Perturbing the solvent by isotopic substitution or, e.g., by addition of co-solvents, can therefore be viewed as reinforcing or otherwise perturbing these topologic structures. This microscopic model readily visualizes thermodynamic interpretation. In conclusion, the topologic stereodynamic structures of connectivity pathways in the solvent, as modified by interaction with solutes, acquire a specific thermodynamic and biological significance, and the problem of thermodynamic and functional stability of biomolecules is seen in its full pertinent phase space

Quantification of residual solvents in antibody drug conjugates using gas chromatography

Energy Technology Data Exchange (ETDEWEB)

Medley, Colin D., E-mail: medley.colin@gene.com [Genentech Inc., Small Molecule Pharmaceutical Sciences, 1 DNA Way, South San Francisco, CA 94080 (United States); Kay, Jacob [Research Pharmaceutical Services, 520 Virginia Dr. Fort, Washington, PA (United States); Li, Yi; Gruenhagen, Jason; Yehl, Peter; Chetwyn, Nik P. [Genentech Inc., Small Molecule Pharmaceutical Sciences, 1 DNA Way, South San Francisco, CA 94080 (United States)

2014-11-19

Highlights: • Sensitive residual solvents detection in ADCs. • 125 ppm QL for common conjugation solvents. • Generic and validatable method. - Abstract: The detection and quantification of residual solvents present in clinical and commercial pharmaceutical products is necessary from both patient safety and regulatory perspectives. Head-space gas chromatography is routinely used for quantitation of residual solvents for small molecule APIs produced through synthetic processes; however residual solvent analysis is generally not needed for protein based pharmaceuticals produced through cultured cell lines where solvents are not introduced. In contrast, antibody drug conjugates and other protein conjugates where a drug or other molecule is covalently bound to a protein typically use solvents such as N,N-dimethylacetamide (DMA), N,N‑dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or propylene glycol (PG) to dissolve the hydrophobic small molecule drug for conjugation to the protein. The levels of the solvent remaining following the conjugation step are therefore important to patient safety as these parental drug products are introduced directly into the patients bloodstream. We have developed a rapid sample preparation followed by a gas chromatography separation for the detection and quantification of several solvents typically used in these conjugation reactions. This generic method has been validated and can be easily implemented for use in quality control testing for clinical or commercial bioconjugated products.

Structural transition of a homopolymer in solvents mixture

International Nuclear Information System (INIS)

Guettari, Moez; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh

2008-01-01

The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M w = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X A is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X A = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture

Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

International Nuclear Information System (INIS)

Asim, Sadia; Mansha, Asim; Grampp, Günter; Landgraf, Stephan; Zahid, Muhammad; Bhatti, Ijaz Ahmad

2014-01-01

Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε s ≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv 0 / ), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν ν ) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G ET = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair or solvent separated

Aminosilicone solvent recovery methods and systems

Science.gov (United States)

Spiry, Irina Pavlovna; Perry, Robert James; Wood, Benjamin Rue; Singh, Surinder Prabhjot; Farnum, Rachel Lizabeth; Genovese, Sarah Elizabeth

2018-02-13

The present invention is directed to aminosilicone solvent recovery methods and systems. The methods and systems disclosed herein may be used to recover aminosilicone solvent from a carbon dioxide containing vapor stream, for example, a vapor stream that leaves an aminosilicone solvent desorber apparatus. The methods and systems of the invention utilize a first condensation process at a temperature from about 80.degree. C. to about 150.degree. C. and a second condensation process at a temperature from about 5.degree. C. to about 75.degree. C. The first condensation process yields recovered aminosilicone solvent. The second condensation process yields water.

Work ability score of solvent-exposed workers.

Science.gov (United States)

Furu, Heidi; Sainio, Markku; Hyvärinen, Hanna-Kaisa; Kaukiainen, Ari

2018-03-28

Occupational chronic solvent encephalopathy (CSE), characterized by neurocognitive dysfunction, often leads to early retirement. However, only the more severe cases are diagnosed with CSE, and little is known about the work ability of solvent-exposed workers in general. The aim was to study memory and concentration symptoms, work ability and the effect of both solvent-related and non-occupational factors on work ability, in an actively working solvent-exposed population. A questionnaire on exposure and health was sent to 3640 workers in four solvent-exposed fields, i.e. painters and floor-layers, boat builders, printers, and metal workers. The total number of responses was 1730. We determined the work ability score (WAS), a single question item of the Work Ability Index, and studied solvent exposure, demographic factors, Euroquest memory and concentration symptoms, chronic diseases, and employment status using univariate and multivariate analyses. The findings were compared to those of a corresponding national blue-collar reference population (n = 221), and a small cohort of workers with CSE (n = 18). The proportion of workers with memory and concentration symptoms was significantly associated with solvent exposure. The WAS of solvent-exposed workers was lower than that of the national blue-collar reference group, and the difference was significant in the oldest age group (those aged over 60). Solvent-exposed worker's WAS were higher than those of workers diagnosed with CSE. The WAS were lowest among painters and floor-layers, followed by metal workers and printers, and highest among boat builders. The strongest explanatory factors for poor work ability were the number of chronic diseases, age and employment status. Solvent exposure was a weak independent risk factor for reduced WAS, comparable to a level of high alcohol consumption. Even if memory and concentration symptoms were associated with higher solvent exposure, the effect of solvents on self

Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

International Nuclear Information System (INIS)

Park, Youngjune; Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa; Petit, Camille

2015-01-01

CO 2 capture by amine scrubbing, which has a high CO 2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO 2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO 2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO 2 capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO 2 capture solvents, which are often anhydrous, have been developed as the third-generation CO 2 capture solvents. These novel classes of liquid materials include ionic liquids, CO 2 -triggered switchable solvents (i.e., CO 2 -binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO 2 capture. Particular attention is given to the mechanisms of CO 2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO 2 capture media.

Structural transition of a homopolymer in solvents mixture

Energy Technology Data Exchange (ETDEWEB)

Guettari, Moez [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)], E-mail: gtarimoez@yahoo.fr; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)

2008-07-01

The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M{sub w} = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X{sub A} is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X{sub A} = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture.

Quantitation of buried contamination by use of solvents. [degradation of silicone polymers by amine solvents

Science.gov (United States)

Pappas, S. P.; Hsiao, Y. C.; Hill, L. W.

1973-01-01

Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided.

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

Diluent effects in solvent extraction. The Effects of Diluents in Solvent Extraction - a literature study

International Nuclear Information System (INIS)

Loefstroem-Engdahl, Elin; Aneheim, Emma; Ekberg, Christian; Foreman, Mark; Skarnemark, Gunnar

2010-01-01

The fact that the choice of organic diluent is important for a solvent extraction process goes without saying. Several factors, such as e.g. price, flash point, viscosity, polarity etc. each have their place in the planning of a solvent extraction system. This high number of variables makes the lack of compilations concerning diluent effects to an interesting topic. Often the interest for the research concerning a specific extraction system focuses on the extractant used and the complexes built up during an extraction. The diluents used are often classical ones, even if it has been shown that choice of diluent can affect extraction as well as separation in an extraction system. An attempt to point out important steps in the understanding of diluent effects in solvent extraction is here presented. This large field is, of course, not summarized in this article, but an attempt is made to present important steps in the understanding of diluents effects in solvent extraction. Trying to make the information concerning diluent effects and applications more easily accessible this review offers a selected summarizing of literature concerning diluents effects in solvent extraction. (authors)

Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

Energy Technology Data Exchange (ETDEWEB)

Asim, Sadia [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Mansha, Asim [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry, Government College University, Faisalabad (Pakistan); Grampp, Günter, E-mail: grampp@tugraz.at [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Landgraf, Stephan [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Zahid, Muhammad [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Bhatti, Ijaz Ahmad [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan)

2014-09-15

Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε{sub s}≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv{sub 0}{sup /}), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν{sub ν}) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G{sub ET} = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair

Solvent extraction studies of RERTR silicide fuels

International Nuclear Information System (INIS)

Gouge, Anthony P.

1983-01-01

Uranium silicide fuels, which are candidate RERTR fuel compositions, may require special considerations in solvent extraction reprocessing. Since Savannah River Plant may be reprocessing RERTR fuels as early as 1985, studies have been conducted at Savannah River Laboratory to demonstrate the solvent extraction behavior of this fuel. Results of solvent extraction studies with both unirradiated and irradiated fuel are presented along with the preliminary RERTR solvent extraction reprocessing flow sheet for Savannah River Plant. (author)

Canyon solvent cleaning with activated alumina

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

This paper presents recent work at SRL concerning the cleaning of solvent extraction solvent used at SRP. The paper explains why we undertook the work, and some laboratory studies on two approaches to solvent cleaning, namely extended carbonate washing and use of solid adsorbents. The paper then discusses scale-up of the preferred method and the results of the full-scale cleaning. 19 figs

Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-01

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.

Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

Directory of Open Access Journals (Sweden)

YOUNGJUNE ePARK

2015-10-01

Full Text Available CO2 capture by amine scrubbing, which has a high CO2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO2 capture solvents including high volatility and corrosiveness of the amine solutions, as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO2 capture solvents, which are often anhydrous, have been developed as the third-generation CO2 capture solvents. These novel classes of liquid materials include: Ionic Liquids (ILs, CO2-triggered switchable solvents (i.e., CO2 Binding Organic Liquids (CO2BOLs, Reversible Ionic Liquids (RevILs, and Nanoparticle Organic Hybrid Materials (NOHMs. This paper provides a review of these various anhydrous solvents and their potential for CO2 capture. Particular attention is given to the mechanisms of CO2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO2 capture media.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

Recent solvent extraction experience at Savannah River

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.

1986-01-01

Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

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 ℃.

Solvents interactions with thermochromic print

Directory of Open Access Journals (Sweden)

Mirela Rožić

2017-12-01

Full Text Available In this study, the interactions between different solvents (benzene, acetone, cyclohexanone, various alcohols and water and thermochromic printing ink were investigated. Thermochromic printing ink was printed on metal surface. Components of thermochromic printing inks are polymeric microcapsules and classic yellow offset printing ink. Below its activation temperature, dye and developer within the microcapsules form a blue coloured complex. Therefore, thermochromic print is green. By heating above the activation temperature, blue colour of the complex turns into the leuco dye colourless state and the green colour of the prints turns into the yellow colour of the classic offset pigment. The results of the interaction with various solvents show that the thermochromic print is stable in all tested solvents except in ethanol, acetone and cyclohexanone. In ethanol, the green colour of the print becomes yellow. SEM analysis shows that microcapsules are dissolved. In acetone and cyclohexanone, the green colour of the print turns into blue, and the microcapsules become significantly more visible. Thus, the yellow pigment interacts with examined ketones. Based on the obtained interactions it can be concluded that the microcapsules have more polar nature than the classical pigment particles. Solvent-thermocromic print interactions were analysed using Hansen solubility parameters that rank the solvents based on their estimated interaction capabilities.

Density Changes in the Optimized CSSX Solvent System

Energy Technology Data Exchange (ETDEWEB)

Lee, D.D.

2002-11-25

Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separate experimental programs performed by different groups of researchers. Such changes indicate a change in chemical composition. Increased density adversely affects separation of solvent from denser aqueous solutions present in the CSSX process. Identification and control of factors affecting solvent density are essential for design and operation of the centrifugal contactors. The goals of this research were to identify the factors affecting solvent density (composition) and to develop correlations between easily measured solvent properties (density and viscosity) and the chemical composition of the solvent, which will permit real-time determination and adjustment of the solvent composition. In evaporation experiments, virgin solvent was subjected to evaporation under quiescent conditions at 25, 35, and 45 C with continuously flowing dry air passing over the surface of the solvent. Density and viscosity were measured periodically, and chemical analysis was performed on the solvent samples. Chemical interaction tests were completed to determine if any chemical reaction takes place over extended contact time that changes the composition and/or physical properties. Solvent and simulant, solvent and strip solution, and solvent and wash solution were contacted continuously in agitated flasks. They were periodically sampled and the density measured (viscosity was also measured on some samples) and then submitted to the Chemical Sciences Division of Oak Ridge National Laboratory for analysis by nuclear magnetic resonance (NMR) spectrometry and high-performance liquid chromatography (HPLC) using the virgin solvent as the baseline. Chemical interaction tests showed that solvent densities and viscosities did not change appreciably during contact with simulant, strip, or wash solution. No effects on density and viscosity and no chemical changes in the solvent were noted within

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...

Organic solvents in electromembrane extraction: recent insights

DEFF Research Database (Denmark)

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

2016-01-01

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...... and have indicated that more fundamental work is required to investigate and discover new organic solvents for EME....

Dendritic brushes under theta and poor solvent conditions

Science.gov (United States)

Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

2013-07-01

The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

Development of a Complex Geometry Standard Fixture and Solvent Evaluation Method fo Assessing Replacement Solvents for AK-225G

Data.gov (United States)

National Aeronautics and Space Administration — Environmental regulatory requirements dictate the need for NASA Stennis, and NASA as a whole to identify new solvents that conform to changing environmental impact...

40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass fraction...

40 CFR 52.254 - Organic solvent usage.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Organic solvent usage. 52.254 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.254 Organic solvent usage. (a) This... (d) of this section and the architectural coatings and solvent disposal emission limitations...

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. (b...

The spectral properties of (--epigallocatechin 3-O-gallate (EGCG fluorescence in different solvents: dependence on solvent polarity.

Directory of Open Access Journals (Sweden)

Vladislav Snitsarev

Full Text Available (--Epigallocatechin 3-O-gallate (EGCG a molecule found in green tea and known for a plethora of bioactive properties is an inhibitor of heat shock protein 90 (HSP90, a protein of interest as a target for cancer and neuroprotection. Determination of the spectral properties of EGCG fluorescence in environments similar to those of binding sites found in proteins provides an important tool to directly study protein-EGCG interactions. The goal of this study is to examine the spectral properties of EGCG fluorescence in an aqueous buffer (AB at pH=7.0, acetonitrile (AN (a polar aprotic solvent, dimethylsulfoxide (DMSO (a polar aprotic solvent, and ethanol (EtOH (a polar protic solvent. We demonstrate that EGCG is a highly fluorescent molecule when excited at approximately 275 nm with emission maxima between 350 and 400 nm depending on solvent. Another smaller excitation peak was found when EGCG is excited at approximately 235 nm with maximum emission between 340 and 400 nm. We found that the fluorescence intensity (FI of EGCG in AB at pH=7.0 is significantly quenched, and that it is about 85 times higher in an aprotic solvent DMSO. The Stokes shifts of EGCG fluorescence were determined by solvent polarity. In addition, while the emission maxima of EGCG fluorescence in AB, DMSO, and EtOH follow the Lippert-Mataga equation, its fluorescence in AN points to non-specific solvent effects on EGCG fluorescence. We conclude that significant solvent-dependent changes in both fluorescence intensity and fluorescence emission shifts can be effectively used to distinguish EGCG in aqueous solutions from EGCG in environments of different polarity, and, thus, can be used to study specific EGCG binding to protein binding sites where the environment is often different from aqueous in terms of polarity.

40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction.... If a solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass...

Separation by solvent extraction

International Nuclear Information System (INIS)

Holt, C.H. Jr.

1976-01-01

In a process for separating fission product values from U and Pu values contained in an aqueous solution, an oxidizing agent is added to the solution to secure U and Pu in their hexavalent state. The aqueous solution is contacted with a substantially water-immiscible organic solvent with agitation while the temperature is maintained at from -1 to -2 0 C until the major part of the water present is frozen. The solid ice phase is continuously separated as it is formed and a remaining aqueous liquid phase containing fission product values and a solvent phase containing Pu and U values are separated from each other. The last obtained part of the ice phase is melted and added to the separated liquid phase. The resulting liquid is treated with a new supply of solvent whereby it is practically depleted of U and Pu

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...

Solvent distillations studies for a reprocessing plant

International Nuclear Information System (INIS)

Ginisty, C.; Guillaume, B.

1989-01-01

The substantial amounts of solvent used in large reprocessing plants are such that considerable care must be paid to solvent management to limit the production of organic wastes. The installation of intensive treatment by chemical regeneration serves to increase the service life of the solvent. General solvent management, combined with a distillation unit under reduced pressure also helps to recycle the two components of the solvent at a low activity level. Distillation also serves to remove the heavy degradation products that are generally responsible for poor hydraulic behavior and for the holdup of radioactive products such as plutonium, zirconium and ruthenium. From the safety standpoint, the flashpoint of the distilled diluent tends to rise. It can therefore be recycled without risk

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....

Accumulation of solvent-soluble and solvent-insoluble antioxidant phenolics in edible bean sprouts: implication of germination

Directory of Open Access Journals (Sweden)

Ren-You Gan

2016-08-01

Full Text Available Background: Edible bean sprouts are popular fresh vegetables widely recognized for their nutritional quality. However, while their antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble extracts has not been systematically evaluated. Methods: The antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble fractions of 12 cultivars of edible bean sprouts were evaluated, and relationships of antioxidant capacity and total phenolic content were also analyzed. Results: Sprouts demonstrated a wide range of antioxidant capacity and total phenolic content, with lower but substantial antioxidant capacity and total phenolic content in the solvent-insoluble fractions. Highest levels were found in the green mung bean sprout. Phenolic compounds, such as catechin, ellagic acid, ferulic acid, gallic acid and p-coumaric acid were widely detected in these sprouts. Additionally, a positive correlation was discovered between antioxidant capacity and total phenolic content in these edible bean sprouts. Conclusions: Germination generally resulted in the accumulation of antioxidant phenolics in the most edible bean sprouts. Edible bean sprouts with high antioxidant phenolics can be valuable natural sources of dietary antioxidants for the prevention of oxidative stress-related chronic diseases.

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.

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

Batch extracting process using magnetic particle held solvents

Science.gov (United States)

Nunez, L.; Vandergrift, G.F.

1995-11-21

A process is described for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents. 5 figs.

Recent Advances in Anhydrous Solvents for CO{sub 2} Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

Energy Technology Data Exchange (ETDEWEB)

Park, Youngjune [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju (Korea, Republic of); Lin, Kun-Yi Andrew [Department of Environmental Engineering, National Chung Hsing University, Taichung City (China); Park, Ah-Hyung Alissa, E-mail: ap2622@columbia.edu [Department of Earth and Environmental Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Petit, Camille, E-mail: ap2622@columbia.edu [Department of Chemical Engineering, Imperial College London, London (United Kingdom)

2015-10-01

CO{sub 2} capture by amine scrubbing, which has a high CO{sub 2} capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO{sub 2} capture from flue gases. The findings from these demonstrations will significantly advance the field of CO{sub 2} capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO{sub 2} capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO{sub 2} capture solvents, which are often anhydrous, have been developed as the third-generation CO{sub 2} capture solvents. These novel classes of liquid materials include ionic liquids, CO{sub 2}-triggered switchable solvents (i.e., CO{sub 2}-binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO{sub 2} capture. Particular attention is given to the mechanisms of CO{sub 2} absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO{sub 2} capture media.

Fluoro-Carbonate Solvents for Li-Ion Cells

International Nuclear Information System (INIS)

NAGASUBRAMANIAN, GANESAN

1999-01-01

A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conductivity of single and mixed fluoro carbonate electrolytes containing 1 M LiPF(sub 6) was measured at different temperatures. These electrolytes did not freeze at -40 C. We are evaluating currently, the irreversible 1st cycle capacity loss in carbon anode in these electrolytes and the capacity loss will be compared to that in the conventional electrolytes. Voltage stability windows of the electrolytes were measured at room temperature and compared with that of the conventional electrolytes. The fluoro-carbon electrolytes appear to be more stable than the conventional electrolytes near Li voltage. Few preliminary electrochemical data of the fluoro-carbonate solvents in full cells are reported in the literature. For example, some of the fluorocarbonate solvents appear to have a wider voltage window than the conventional electrolyte solvents. For example, methyl 2,2,2 trifluoro ethyl carbonate containing 1 M LiPF(sub 6) electrolyte has a decomposition voltage exceeding 6 V vs. Li compared to and lt;5 V for conventional electrolytes. The solvent also appears to be stable in contact with lithium at room temperature

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

International Nuclear Information System (INIS)

Clark, Sue B.

2016-01-01

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.

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.

Method of decomposing radioactive organic solvent wastes

International Nuclear Information System (INIS)

Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

1986-01-01

Purpose: To decompose radioactive organic solvent wastes or radioactive hydrocarbon solvents separated therefrom into organic materials under moderate conditions, as well as greatly decrease the amount of secondary wastes generated. Method: Radioactive organic solvent wastes comprising an organic phosphoric acid ester ingredient and a hydrocarbon ingredient as a diluent therefor, or radioactive hydrocarbon solvents separated therefrom are oxidatively decomposed by hydrogen peroxide in an aqueous phosphoric acid solution of phosphoric acid metal salts finally into organic materials to perform decomposing treatment for the radioactive organic solvent wastes. The decomposing reaction is carried out under relatively moderate conditions and cause less burden to facilities or the likes. Further, since the decomposed liquid after the treatment can be reused for the decomposing reaction as a catalyst solution secondary wastes can significantly be decreased. (Yoshihara, H.)

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

Ursin, C; Hansen, C M; Van Dyk, J W

1995-01-01

A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... of DMSO and octyl acetate were measured. No octyl acetate was detected and the permeability of DMSO was proportional to its mole fraction in the mixture. The effect of two hours of solvent exposure on the viability of skin (based on DNA synthesis) was measured and found to be very dependent on the solvent....

Chlorinated solvents in groundwater of the United States

Science.gov (United States)

Moran, M.J.; Zogorski, J.S.; Squillace, P.J.

2007-01-01

Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents were among the most frequently detected. Mixtures of solvents in groundwater were common and may be the result of common usage of solvents or degradation of one solvent to another. Relative to other VOCs with Maximum Contaminant Levels (MCLs), PCE and TCE ranked high in terms of the frequencies of concentrations greater than or near MCLs. The probability of occurrence of solvents in groundwater was associated with dissolved oxygen content of groundwater, sources such as urban land use and population density, and hydraulic properties of the aquifer. The results reinforce the importance of understanding the redox conditions of aquifers and the hydraulic properties of the saturated and vadose zones in determining the intrinsic susceptibility of groundwater to contamination by solvents. The results also reinforce the importance of controlling sources of solvents to groundwater. ?? 2007 American Chemical Society.

Solvent purification with high-porosity (macroreticular) ion-exchange resin

International Nuclear Information System (INIS)

McKibben, J.M.

Numerous solvent degradation products exist in all of our process solvents that are not efficiently removed in the routine solvent washing operation. Tests indicate that a relatively new type of resin - variously called high-porosity, macroreticular, or macroporous resin - removes at least some of these persistent chemicals and substantially improves the quality of any TBP process solvent. A plant test is proposed for the purification of the first cycle solvent of the HM process, in which a loop will be installed to draw a small side stream of solvent from the washed solvent hold tank (904), pass it through a 2.7 ft 3 resin column, and return it to the same tank

Development of Effective Solvent Modifiers for the Solvent Extraction of Cesium from Alkaline High-Level Tank Waste

International Nuclear Information System (INIS)

Bonnesen, Peter V.; Delmau, Laetitia H.; Moyer, Bruce A.; Lumetta, Gregg J.

2003-01-01

A series of novel alkylphenoxy fluorinated alcohols were prepared and investigated for their effectiveness as modifiers in solvents containing calix(4)arene-bis-(tert-octylbenzo)-crown-6 for extracting cesium from alkaline nitrate media. A modifier that contained a terminal 1,1,2,2-tetrafluoroethoxy group was found to decompose following long-term exposure to warm alkaline solutions. However, replacement of the tetrafluoroethoxy group with a 2,2,3,3-tetrafluoropropoxy group led to a series of modifiers that possessed the alkaline stability required for a solvent extraction process. Within this series of modifiers, the structure of the alkyl substituent (tert-octyl, tert-butyl, tert-amyl, and sec-butyl) of the alkylphenoxy moiety was found to have a profound impact on the phase behavior of the solvent in liquid-liquid contacting experiments, and hence on the overall suitability of the modifier for a solvent extraction process. The sec-butyl derivative(1-(2,2,3,3-tetrafluoropropoxy)-3- (4-sec-butylphenoxy)-2-propanol) (Cs-7SB) was found to possess the best overall balance of properties with respect to third phase and coalescence behavior, cleanup following degradation, resistance to solids formation, and cesium distribution behavior. Accordingly, this modifier was selected for use as a component of the solvent employed in the Caustic-Side Solvent Extraction (CSSX) process for removing cesium from high level nuclear waste (HLW) at the U.S. Department of Energy's (DOE) Savannah River Site. In batch equilibrium experiments, this solvent has also been successfully shown to extract cesium from both simulated and actual solutions generated from caustic leaching of HLW tank sludge stored in tank B-110 at the DOE's Hanford Site.

Stochastic level-set variational implicit-solvent approach to solute-solvent interfacial fluctuations

Energy Technology Data Exchange (ETDEWEB)

Zhou, Shenggao, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Mathematical Center for Interdiscipline Research, Soochow University, 1 Shizi Street, Jiangsu, Suzhou 215006 (China); Sun, Hui; Cheng, Li-Tien [Department of Mathematics, University of California, San Diego, La Jolla, California 92093-0112 (United States); Dzubiella, Joachim [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin, Germany and Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Li, Bo, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Quantitative Biology Graduate Program, University of California, San Diego, La Jolla, California 92093-0112 (United States); McCammon, J. Andrew [Department of Chemistry and Biochemistry, Department of Pharmacology, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093-0365 (United States)

2016-08-07

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

Process for hydrogenating coal and coal solvents

Science.gov (United States)

Tarrer, Arthur R.; Shridharani, Ketan G.

1983-01-01

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

COMPUTER-AIDED SOLVENT DESIGN FOR POLLUTION PREVENTION: PARIS II

Science.gov (United States)

Solvent substitution is an attractive way of elijminating the use of regulated solvents because it usually does not require major chanages in existing processes, equipment or operations. Successful solvent substitution is dependent on finding solvents that are as effective or be...

Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-10-06

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(_Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(_Cs) measured 12.5, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges. This revision was created to correct an error. The previous revision used an incorrect set of temperature correction coefficients which resulted in slight deviations from the correct D(_Cs) results.

Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

Science.gov (United States)

Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

2014-01-01

The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

Solvent sorting in (mixed solvent electrolyte) systems: Time-resolved ...

Indian Academy of Sciences (India)

lar solvents as an effective single component dipo- lar liquid that is characterized ... and time (t) dependent solvation energy of mobile dipo- lar solute with density ..... Even though this way for modification of C is purely ad- hoc, the observation ...

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

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......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...... 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...

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

Molecular accessibility in solvent swelled coals. Final report

Energy Technology Data Exchange (ETDEWEB)

Kispert, L.D.

1994-04-01

The conversion of coal by an economically feasible catalytic method requires the catalyst to diffuse into the coal sample so that hydrogenation catalysis can occur from within as well as the normal surface catalysis. Thus an estimate of the size, shape, and reactivity, of the pores in the coal before and after the swelling with different solvents is needed so that an optimum sized catalyst will be used. This study characterizes the accessible area found in Argonne Premium Coal Samples (APCS) using a EPR spin probe technique. The properties deduced in this manner correlate well with the findings deduced from SANS, NMR, SEM, SAXS and light scattering measurements. The use of nitroxide spin probes with swelling solvents is a simple way in which to gain an understanding of the pore structure of coals, how it changes in the presence of swelling solvents and the chemistry that occurs at the pore wall. Hydrogen bonding sites occur primarily in low-rank coals and vary in reactive strength as rank is varied. Unswelled coals contain small, spherical pores which disappear when coal is swelled in the presence of polar solvents. Swelling studies of polystyrene-divinyl benzene copolymers implied that coal is polymeric, contains significant quantities of covalent cross-links and the covalent cross-link density increases with rank.

40 CFR 148.10 - Waste specific prohibitions-solvent wastes.

Science.gov (United States)

2010-07-01

... injection unless the solvent waste is a solvent-water mixture or solvent-containing sludge containing less... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Waste specific prohibitions-solvent wastes. 148.10 Section 148.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER...

Compressed air-assisted solvent extraction (CASX) for metal removal.

Science.gov (United States)

Li, Chi-Wang; Chen, Yi-Ming; Hsiao, Shin-Tien

2008-03-01

A novel process, compressed air-assisted solvent extraction (CASX), was developed to generate micro-sized solvent-coated air bubbles (MSAB) for metal extraction. Through pressurization of solvent with compressed air followed by releasing air-oversaturated solvent into metal-containing wastewater, MSAB were generated instantaneously. The enormous surface area of MSAB makes extraction process extremely fast and achieves very high aqueous/solvent weight ratio (A/S ratio). CASX process completely removed Cr(VI) from acidic electroplating wastewater under A/S ratio of 115 and extraction time of less than 10s. When synthetic wastewater containing Cd(II) of 50mgl(-1) was treated, A/S ratios of higher than 714 and 1190 could be achieved using solvent with extractant/diluent weight ratio of 1:1 and 5:1, respectively. Also, MSAB have very different physical properties, such as size and density, compared to the emulsified solvent droplets, making separation and recovery of solvent from treated effluent very easy.

Process for hydrogenating coal and coal solvents

Energy Technology Data Exchange (ETDEWEB)

Shridharani, K.G.; Tarrer, A.R.

1983-02-15

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260/sup 0/ C to 315/sup 0/ C in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275/sup 0/ C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350/sup 0/ C.

A computer-aided molecular design framework for crystallization solvent design

DEFF Research Database (Denmark)

Karunanithi, Arunprakash T.; Achenie, Luke E.K.; Gani, Rafiqul

2006-01-01

One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem is formu......One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem...... solvent molecules. Solvent design and selection for two types of solution crystallization processes namely cooling crystallization and drowning out crystallization are presented. In the first case study, the design of single compound solvent for crystallization of ibuprofen, which is an important...

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

Ursin, C; Hansen, C M; Van Dyk, J W

1995-01-01

A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... was characterized by calculation of the "percent error of the slope." The following permeability rates (g/m2h) of single solvents were measured: dimethyl sulfoxide (DMSO), 176; N-methyl-2-pyrrolidone, 171; dimethyl acetamide, 107; methyl ethyl ketone, 53; methylene chloride, 24; [3H]water, 14.8; ethanol, 11...

Radiation destruction of vitamin A in lipid solvents

International Nuclear Information System (INIS)

Snauwaert, F.; Maes, E.; Tobback, P.; Bhushan, B.

1978-01-01

The radiation response of vitamin A alcohol and its acetate derivative was compared in different lipid solvents. In all the solvents vitamin A alcohol exhibited a much higher radiation sensitivity than its ester counterpart. The nature of the solvent and the initial concentration was found to have a great influence on the extent of radiation degradation of vitamin A alcohol. In contrast to a high radiolability in non-polar solvents, vitamin A alcohol exhibited a remarkable stability in isopropanol. In addition, in isopropanol the G(-) relationship with radiation dose showed a reverse trend to that observed for other solvents. A thin-layer chromatographic procedure was developed for separation of the radiation degradation products. (author)

Solvent extraction studies in miniature centrifugal contactors

International Nuclear Information System (INIS)

Siczek, A.A.; Meisenhelder, J.H.; Bernstein, G.J.; Steindler, M.J.

1980-01-01

A miniature short-residence-time centrifugal solvent extraction contactor and an eight-stage laboratory minibank of centrifugal contactors were used for testing the possibility of utilizing kinetic effects for improving the separation of uranium from ruthenium and zirconium in the Purex process. Results of these tests showed that a small improvement found in ruthenium and zirconium decontamination in single-stage solvent extraction tests was lost in the multistage extraction tests- in fact, the extent of saturation of the solvent by uranium, rather than the stage residence time, controlled the extent of ruthenium and zirconium extraction. In applying the centrifugal contactor to the Purex process, the primary advantages would be less radiolytic damage to the solvent, high troughput, reduced solvent inventory, and rapid attainment of steady-state operating conditions. The multistage mini contactor was also tested to determine the suitability of short-residence-time contactors for use with the Civex and Thorex processes and was found to be compatible with the requirements of these processes. (orig.) [de

Green solvents and technologies for oil extraction from oilseeds

OpenAIRE

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...

A comparative study on the effect of solvent on nucleophilic fluorination with [18F]fluoride. Protic solvents as co-solvents in SN2 and SNAr reactions

International Nuclear Information System (INIS)

Koivula, T.; Simecek, J.; Jalomaeki, J.; Helariutta, K.; Airaksinen, A.J.

2011-01-01

The effect of solvent on nucleophilic substitution with cyclotron-produced [ 18 F]fluoride was studied in polar aprotic (CH 3 CN and DMF) and protic solvent (t-BuOH and t-amyl alcohol) mixtures (CH 3 CN/co-solvent, 2:8) in a series of model compounds, 4-(R 1 -methyl)benzyl R 2 -benzoates, using a K2.2.2/[ 18 F]KF phase transfer system (R 1 = -Cl, -OMs or -OH; R 2 = -Cl, -I or -NO 2 ). 18 F-fluorination of compounds 1-3, with chloride or mesylate as a leaving group in the benzylic position (R 1 ), afforded the desired 4-([ 18 F]fluoromethyl)benzyl analogues in all solvents during 15 min reaction time. The highest radiochemical yields (RCY) in all the studied reaction temperatures (80, 120 and 160 C) were achieved in CH 3 CN. Radiochemical yields in protic solvents were comparable to RCY in CH 3 CN only with the sulfonate ester 3 as a starting material. 18 F-Fluorination of the benzylic halides 1 and 2 was not promoted in the same extent; in addition, labelled side-products were detected at higher reaction temperatures. Radiofluorination in tert-alcohols was also studied using [ 18 F]CsF with and without added phase transfer catalyst, resulting in both conditions lower RCY when compared to K2.2.2/[ 18 F]KF system. Protic solvents were not able to promote aromatic 18 F-fluorination. 18 F-Fluorination of compound 5, having para-activated nitro group in the aromatic position (R 2 ), failed in tert-alcohols even at the highest temperature, but it was labelled successfully in DMF and to some extent in CH 3 CN. (orig.)

Spreadsheet algorithm for stagewise solvent extraction

International Nuclear Information System (INIS)

Leonard, R.A.; Regalbuto, M.C.

1994-01-01

The material balance and equilibrium equations for solvent extraction processes have been combined with computer spreadsheets in a new way so that models for very complex multicomponent multistage operations can be setup and used easily. A part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets. 22 refs., 4 figs., 2 tabs

Method of removing deterioration product in hydrocarbon type solvent

International Nuclear Information System (INIS)

Ito, Yoshifumi; Takashina, Toru; Murasawa, Kenji.

1988-01-01

Purpose: To remarkably reduce radioactive wastes by bringing adsorbents comprising titanium oxide and/or zirconium oxide into contact with hydrocarbon type solvents. Method: In a nuclear fuel re-processing step, an appropriate processing is applied to extraction solvents suffering from radioactive degradation, to separate the hydrocarbon solvents and store them in a solvent tank. Then, titanium oxide and/or zirconium oxide adsorbents are continuously mixed and agitated therewith to adsorb degradation products on the adsorbents. Then, they are introduced with adsorbent separators to recover purified hydrocarbon type solvents. Meanwhile, the separated adsorbents are discharged from pipeways. This enables to regenerate the hydrocarbon type solvents for reuse, as well as remarkably reduce the radioactive wastes. (Takahashi, M.)

Re-Refining of Waste Lubricating Oil by Solvent Extraction

Directory of Open Access Journals (Sweden)

Hassan Ali Durrani

2011-04-01

Full Text Available Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. This work also attempts to study the performance of the composite solvent in the extraction process for recovering waste lubricating oil. The key parameters considered were vacuum pressure, temperature and the weight ratio of solvent to waste lubricating oil. The performance was investigated on the PSR (Percentage Sludge Removal and POL (Percent Oil Loss. The best results were obtained using composite solvent 25% 2-propanol, 37% 1-butanol and 38% butanone by a solvent to oil ratio of 6:1 at vacuum pressure 600mmHg and distillation temperature 250oC. The vacuum distilled oil pretreated with the composite solvents was matched to the standard base oil 500N and 150N, found in close agreement and could be used for similar purpose.

Nonhazardous solvent composition and method for cleaning metal surfaces

International Nuclear Information System (INIS)

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

1993-01-01

A solvent composition for displacing greasy and oily contaminants as well as water and/or aqueous residue from metallic surfaces, especially surfaces of radioactive materials so that such surfaces can be wiped clean of the displaced contaminants, water and/or aqueous residue. The solvent composition consists essentially of a blend of nonpolar aliphatic hydrocarbon solvent having a minimum flash point of about 140 F and 2 to 25 volume percent of a polar solvent having a flash point sufficiently high so as to provide the solvent composition with a minimum flash point of at least 140 F. The solvent composition is nonhazardous so that when it is used to clean the surfaces of radioactive materials the waste in the form of paper or cloth wipes, lab coats and the like used in the cleaning operation is not considered to be mixed waste composed of a hazardous solvent and a radioactive material

Supercritical solvent extraction of oil sand bitumen

Science.gov (United States)

Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

2017-08-01

The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

Sustainable development of gree solvent separation process

OpenAIRE

Lisickov, Kiril; Fidancevska, Emilija; Grujic, Radoslav; Srebrenkoska, Vineta; Kuvendziev, Stefan

2011-01-01

Solvents defi ne a major part of the environmental performance of processes in the chemical industry and impact on cost, safety and health issues. The idea of green solvents expresses the goal to minimize the environmental impact resulting from the use of solvents in chemical production. In spite of conventional separation methods, precise process green technologies are based on the application of modern processes and process equipment as well as control and management...

19F NMR spectroscopy in monitoring fluorinated-solvent regeneration

International Nuclear Information System (INIS)

Ogorodnikov, V.D.; Bordunov, V.V.

1987-01-01

Extensive use is made of solvents such as trichloroethylene, freon-133, and perchloroethylene because they are good solvents for inorganic, plant, and animal greases, while the solvents can be recovered and there is no fire hazard. In this paper, the authors examined methods to monitor spent solution regeneration rapidly and with high accuracy. The authors tested perfluorinated telomeric alcohols as solvents for cleaning engineering components which have melting points of 60-120 degrees celsius. The higher working temperatures and the increased energy consumption are disadvantages of these solvents, but these are compensated for by the scope for using them virtually in the solid, liquid, and vapor states. The authors' proposed technology is based on solvents with melting points over 40 degrees celsius which produce virtually no wastes. The telomeric alcohols are recovered after cooling to normal conditions by separation from the oil by filtration and centrifugation, and they can be used in the next purification cycle. When the solvents have been regenerated, the petroleum products such as industrial oils can be reused for their original purpose. However, quantitative data are required on the solvent contents in the oil and the oil contents in the solvent in order to determine the degree of regeneration and the modes to be used. The authors have also proposed a quantitative method of determining traces of these alcohols in oils and residual oils in the solvent by fluorine NMR. All measurements were made with a BS497 NMR spectrometer

Full scale solvent extraction remedial results

International Nuclear Information System (INIS)

Cash, A.B.

1992-01-01

Sevenson Extraction Technology, Inc. has completed the development of the Soil Restoration Unit (initially developed by Terra-Kleen Corporation), a mobile, totally enclosed solvent extraction treatment facility for the removal of organic contaminated media is greater by a closed loop, counter current process that recycles all solvents. The solvents used are selected for the individual site dependant upon the contaminants, such as PCB's, oil, etc. and the soil conditions. A mixture of up to fourteen non-toxic solvents can be used for complicated sites. The full scale unit has been used to treat one superfund site, the Traband Site in Tulsa, Oklahoma, and is currently treating another superfund site, the Pinette's Salvage Yard Site in Washburn, Maine. The full scale Soil Restoration Unit has also been used at a non-superfund site, as part of a TSCA Research and Development permit. The results from these sites will be discussed in brief herein, and in more detail in the full paper

Solvent annealing induced phase separation and dewetting in PMMA∕SAN blend film: film thickness and solvent dependence.

Science.gov (United States)

You, Jichun; Zhang, Shuangshuang; Huang, Gang; Shi, Tongfei; Li, Yongjin

2013-06-28

The competition between "dewetting" and "phase separation" behaviors in polymer blend films attracts significant attention in the last decade. The simultaneous phase separation and dewetting in PMMA∕SAN [poly(methyl methacrylate) and poly(styrene-ran-acrylonitrile)] blend ultrathin films upon solvent annealing have been observed for the first time in our previous work. In this work, film thickness and annealing solvent dependence of phase behaviors in this system has been investigated using atomic force microscopy and grazing incidence small-angle X-ray scattering (GISAXS). On one hand, both vertical phase separation and dewetting take place upon selective solvent vapor annealing, leading to the formation of droplet∕mimic-film structures with various sizes (depending on original film thickness). On the other hand, the whole blend film dewets the substrate and produces dispersed droplets on the silicon oxide upon common solvent annealing. GISAXS results demonstrate the phase separation in the big dewetted droplets resulted from the thicker film (39.8 nm). In contrast, no period structure is detected in small droplets from the thinner film (5.1 nm and 9.7 nm). This investigation indicates that dewetting and phase separation in PMMA∕SAN blend film upon solvent annealing depend crucially on the film thickness and the atmosphere during annealing.

Solvent extraction of thorium(IV) with dibutyldithiophosphoric acid in various organic solvents

International Nuclear Information System (INIS)

Curtui, M.; Haiduc, I.

1994-01-01

The extraction of thorium(IV) from perchlorate solutions with di-n-butyldithiophosphoric acid (HBudtp) in various organic solvents occurs through an ion exchange mechanism. The extracted species in the organic phase is an eight-coordinate complex Th(Budtp) 4 . The higher values of the distribution ratio obtained in HBudtp-benzene-water system than in HBudtp-n-butanol-water system are explained by higher solubility of the complex species in nonpolar solvents. The position of the extraction curves in the pH-range lower than 0.7 reduces the complexation of thorium(IV) with Budtp - in the aqueous phase and also the hydrolysis process. (author) 8 refs.; 4 figs.; 1 tab

DEMONSTRATION OF THE NEXT-GENERATION CAUSTIC-SIDE SOLVENT EXTRACTION SOLVENT WITH 2-CM CENTRIGUGAL CONTRACTORS USING TANK 49H WASTE AND WASTE SIMULANT

Energy Technology Data Exchange (ETDEWEB)

Pierce, R.; Peters, T.; Crowder, M.; Pak, D.; Fink, S.; Blessing, R.; Washington, A.; Caldwell, T.

2011-11-29

Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet using MaxCalix for the decontamination of high level waste (HLW). The demonstration was completed using a 12-stage, 2-cm centrifugal contactor apparatus at the Savannah River National Laboratory (SRNL). This represents the first CSSX process demonstration of the MaxCalix solvent system with Savannah River Site (SRS) HLW. Two tests lasting 24 and 27 hours processed non-radioactive simulated Tank 49H waste and actual Tank 49H HLW, respectively. A solvent extraction system for removal of cesium from alkaline solutions was developed utilizing a novel solvent invented at the Oak Ridge National Laboratory (ORNL). This solvent consists of a calix[4]arene-crown-6 extractant dissolved in an inert hydrocarbon matrix. A modifier is added to the solvent to enhance the extraction power of the calixarene and to prevent the formation of a third phase. An additional additive is used to improve stripping performance and to mitigate the effects of any surfactants present in the feed stream. The process that deploys this solvent system is known as Caustic Side Solvent Extraction (CSSX). The solvent system has been deployed at the Savannah River Site (SRS) in the Modular CSSX Unit (MCU) since 2008.

Extractability of Lanthanoids(III) into Solvents Contributing to Environmental Protection

International Nuclear Information System (INIS)

Hasegawa, Y.; Hara, M.

1999-01-01

To perform effective mutual separation of lanthanoids(III) by solvent extraction with avoiding several problems caused by diffusion of organic solvents into air and into water , into commercial available mixed solvents, aliphatic and aromatic solvents consisting of carbon number of 9 to 12, which have high flash points, the extraction of lanthanoid(III) thiocyanates with trioctylphosphine oxide has been measured and the equilibrium constants have been determined across lanthanoid series. Then the extraction constants were compared with those of single solvents, hexane and benzene , widely being used as solvents for liquid-liquid extraction. The extraction constants obtained for the aliphatic mixed solvents are very similar to those for hexane across lanthanoid series. The variation of the constants for aromatic mixed solvents is also similar to that for benzene. The pattern of the variation of the distribution ratio under a constant condition across the series is similar to each other, either using the aliphatic solvents or using aromatic ones, except for in the middle of the series. Accordingly, the use of the high molecular weight mixed aromatic solvents would be recommendable as organic solvents in the mutual separation of lanthanoids from the point of view of safety for fire and health for the people handling the extraction

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

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%.

Solvent Handbook Database System user's manual

International Nuclear Information System (INIS)

1993-03-01

Industrial solvents and cleaners are used in maintenance facilities to remove wax, grease, oil, carbon, machining fluids, solder fluxes, mold release, and various other contaminants from parts, and to prepare the surface of various metals. However, because of growing environmental and worker-safety concerns, government regulations have already excluded the use of some chemicals and have restricted the use of halogenated hydrocarbons because they affect the ozone layer and may cause cancer. The Solvent Handbook Database System lets you view information on solvents and cleaners, including test results on cleaning performance, air emissions, recycling and recovery, corrosion, and non-metals compatibility. Company and product safety information is also available

Indium recovery by solvent extraction

International Nuclear Information System (INIS)

Fortes, Marilia Camargos Botelho

1999-04-01

Indium has been recovered as a byproduct from residues generated from the sulfuric acid leaching circuits in mineral plants for zinc recovery. Once its recovery comes from the slags of other metals recovery, it is necessary to separate it from the other elements which usually are present in high concentrations. Many works have been approaching this separation and indicate the solvent extraction process as the main technique used. In Brazilian case, indium recovery depends on the knowledge of this technique and its development. This paper describes the solvent extraction knowledge for the indium recovery from aqueous solutions generated in mineral plants. The results for determination of the best experimental conditions to obtain a high indium concentration solution and minimum iron poisoning by solvent extraction with di (2-ethylhexyl)-phosphoric acid (D2EHPA) solubilized in isoparafin and exxsol has been presented. (author)

Virtual colorimetric sensor array: single ionic liquid for solvent discrimination.

Science.gov (United States)

Galpothdeniya, Waduge Indika S; Regmi, Bishnu P; McCarter, Kevin S; de Rooy, Sergio L; Siraj, Noureen; Warner, Isiah M

2015-04-21

There is a continuing need to develop high-performance sensors for monitoring organic solvents, primarily due to the environmental impact of such compounds. In this regard, colorimetric sensors have been a subject of intense research for such applications. Herein, we report a unique virtual colorimetric sensor array based on a single ionic liquid (IL) for accurate detection and identification of similar organic solvents and mixtures of such solvents. In this study, we employ eight alcohols and seven binary mixtures of ethanol and methanol as analytes to provide a stringent test for assessing the capabilities of this array. The UV-visible spectra of alcoholic solutions of the IL used in this study show two absorption bands. Interestingly, the ratio of absorbance for these two bands is found to be extremely sensitive to alcohol polarity. A virtual sensor array is created by using four different concentrations of IL sensor, which allowed identification of these analytes with 96.4-100% accuracy. Overall, this virtual sensor array is found to be very promising for discrimination of closely related organic solvents.

Uranium refining by solvent extraction

International Nuclear Information System (INIS)

Kraikaew, J.

1996-01-01

The yellow cake refining was studied in both laboratory and semi-pilot scales. The process units mainly consist of dissolution and filtration, solvent extraction, and precipitation and filtration. Effect of flow ratio (organic flow rate/ aqueous flow rate) on working efficiencies of solvent extraction process was studied. Detailed studies were carried out on extraction, scrubbing and stripping processes. Purity of yellow cake product obtained is high as 90.32% U 3 O 8

Solvent extraction for spent nuclear fuel reprocessing plant

International Nuclear Information System (INIS)

Masui, Jinichi

1986-01-01

The purex process provides a solvent extraction method widely used for separating uranium and plutonium from nitric acid solution containing spent fuel. The Tokai Works has adopted the purex process with TPB-n dodecane as the extraction agent and a mixer settler as the solvent extraction device. The present article outlines the solvent extraction process and discuss the features of various extraction devices. The chemical principle of the process is described and a procedure for calculating the number of steps for countercurrent equilibrium extraction is proposed. Discussion is also made on extraction processes for separating and purifying uranium and plutonium from fission products and on procedures for managing these processes. A small-sized high-performance high-reliability device is required for carrying out solvent extraction in reprocessing plants. Currently, mixer settler, pulse column and centrifugal contactor are mainly used in these plants. Here, mixer settler is comparted with pulse column with respect to their past achievements, design, radiation damage to solvent, operation halt, controllability and maintenance. Processes for co-extraction, partition, purification and solvent recycling are described. (Nogami, K.)

Solvent jet desorption capillary photoionization-mass spectrometry.

Science.gov (United States)

Haapala, Markus; Teppo, Jaakko; Ollikainen, Elisa; Kiiski, Iiro; Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

2015-03-17

A new ambient mass spectrometry method, solvent jet desorption capillary photoionization (DCPI), is described. The method uses a solvent jet generated by a coaxial nebulizer operated at ambient conditions with nitrogen as nebulizer gas. The solvent jet is directed onto a sample surface, from which analytes are extracted into the solvent and ejected from the surface in secondary droplets formed in collisions between the jet and the sample surface. The secondary droplets are directed into the heated capillary photoionization (CPI) device, where the droplets are vaporized and the gaseous analytes are ionized by 10 eV photons generated by a vacuum ultraviolet (VUV) krypton discharge lamp. As the CPI device is directly connected to the extended capillary inlet of the MS, high ion transfer efficiency to the vacuum of MS is achieved. The solvent jet DCPI provides several advantages: high sensitivity for nonpolar and polar compounds with limit of detection down to low fmol levels, capability of analyzing small and large molecules, and good spatial resolution (250 μm). Two ionization mechanisms are involved in DCPI: atmospheric pressure photoionization, capable of ionizing polar and nonpolar compounds, and solvent assisted inlet ionization capable of ionizing larger molecules like peptides. The feasibility of DCPI was successfully tested in the analysis of polar and nonpolar compounds in sage leaves and chili pepper.

Ions, solutes and solvents, oh my!

Energy Technology Data Exchange (ETDEWEB)

Kemp, Daniel David [Iowa State Univ., Ames, IA (United States)

2009-08-01

Modern methods in ab initio quantum mechanics have become efficient and accurate enough to study many gas-phase systems. However, chemists often work in the solution phase. The presence of solvent molecules has been shown to affect reaction mechanisms1, lower reaction energy barriers2, participate in energy transfer with the solute3 and change the physical properties of the solute4. These effects would be overlooked in simple gas phase calculations. Careful study of specific solvents and solutes must be done in order to fully understand the chemistry of the solution phase. Water is a key solvent in chemical and biological applications. The properties of an individual water molecule (a monomer) and the behavior of thousands of molecules (bulk solution) are well known for many solvents. Much is also understood about aqueous microsolvation (small clusters containing ten water molecules or fewer) and the solvation characteristics when bulk water is chosen to solvate a solute. However, much less is known about how these properties behave as the cluster size transitions from the microsolvated cluster size to the bulk. This thesis will focus on species solvated with water clusters that are large enough to exhibit the properties of the bulk but small enough to consist of fewer than one hundred solvent molecules. New methods to study such systems will also be presented.

Green Michael addition of thiols to electron deficient alkenes using KF/alumina and recyclable solvent or solvent-free conditions

Energy Technology Data Exchange (ETDEWEB)

Lenardao, Eder J.; Trecha, Danusia O.; Ferreira, Patricia da C.; Jacob, Raquel G.; Perin, Gelson [Universidade Federal de Pelotas (UFPEL), Pelotas, RS (Brazil). Inst. de Quimica e Geociencias. Lab. de Sintese Organica Limpa (LASOL)]. E-mail: lenardao@ufpel.edu.br

2009-07-01

A general, clean and easy method for the conjugated addition of thiols to citral promoted by KF/Al{sub 2}O{sub 3} under solvent-free or using glycerin as recyclable solvent at room temperature is described. It was found that the solvent-free protocol is applicable to the direct reaction of thiophenol with the essential oil of lemon grass (Cymbopogon citratus) to afford directly 3,7-dimethyl-3-(phenylthio)oct-6-enal, a potential bactericide agent. The method was extended to other electron-poor alkenes with excellent results. For the solvent-free protocol, the use of microwave irradiation facilitated the procedure and accelerates the reaction. The catalytic system and glycerin can be reused up to three times without previous treatment with comparable activity. (author)

Activity coefficients of solutes in binary solvents

International Nuclear Information System (INIS)

Gokcen, N.A.

1982-01-01

The activity coefficients in dilute ternary systems are discussed in detail by using the Margules equations. Analyses of some relevant data at high temperatures show that the sparingly dissolved solutes in binary solvents follow complex behavior even when the binary solvents are very nearly ideal. It is shown that the activity data on the solute or the binary system cannot permit computation of the remaining activities except for the regular solutions. It is also shown that a fourth-order equation is usually adequate in expressing the activity coefficient of a solute in binary solvents at high temperatures. When the activity data for a binary solvent are difficult to obtain in a certain range of composition, the activity data for a sparingly dissolved solute can be used to supplement determination of the binary activities

Theoretical and experimental study of mixed solvent electrolytes

International Nuclear Information System (INIS)

Cummings, P.T.; O'Connell, J.P.

1990-01-01

In the original proposal to study mixed solvent electrolyte solutions, four major goals were formulated: fundamental modeling of mixed solvent electrolytes using numerically solved integral equation approximation theories; evaluation of intermolecular pair potential models by computer simulation of selected systems for comparison with experiment and the numerical integral equation studies; development of fundamentally based correlations for the thermodynamic properties of mixed solvent electrolyte solutions using analytically solvable statistical mechanical models; and extension of experimental database on mixed solvent electrolytes by performing vapor-liquid equilibrium measurements on selected systems. This paper discusses the progress on these goals

Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

International Nuclear Information System (INIS)

Li, Song; Feng, Guang; Cummings Peter, T; Zhang, Pengfei; Fulvio Pasquale, F; Hillesheim Patrick, C; Dai, Sheng

2014-01-01

The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance–electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation. (paper)

Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

Directory of Open Access Journals (Sweden)

Wadood Taher Mohammed

2015-02-01

Full Text Available This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN and N-methyl – 2 - pyrrolidone (NMP as extractants . Also the effect of five parameters (stirring speed :150 , 250 , 350 , and 450 rpm, temperature (30 , 40 , 45 , and 50 oC, oxidant/simulated diesel fuel ratio (0.5 , 0.75 , 1 , and 1.5 , catalyst/oxidant ratio(0.125,0.25,0.5,and0.75 , and solvent/simulated diesel fuel ratio(0.5,0.6,0.75,and1 were examined as well as solvent type. The results exhibit that the highest removal of sulfur is 98.5% using NMP solvent while it is 95.8% for ACN solvent. The set of conditions that show the highest sulfur removal is: stirring speed of 350 rpm , temperature 50oC , oxidant/simulated diesel fuel ratio 1 , catalyst/oxidant ratio 0.5 , solvent/simulated diesel fuel ratio 1. These best conditions were applied upon real diesel fuel (produced from Al-Dora refinerywith 1000 ppm sulfur content . It was found that sulfur removal was 64.4% using ACN solvent and 75% using NMP solvent.

Measurement of oxygen transfer from air into organic solvents

DEFF Research Database (Denmark)

Ramesh, Hemalata; Mayr, Torsten; Hobisch, Mathias

2016-01-01

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...... 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...... For the first time, we demonstrate on-line oxygen measurements in non-aqueous media using a novel optical sensor. The sensor was used to measure oxygen concentration in various organic solvents including toluene, THF, isooctane, DMF, heptane and hexane (which have all been shown suitable for several biological...

Hazardous Solvent Substitution Data System tutorial

International Nuclear Information System (INIS)

Twitchell, K.E.; Skinner, N.L.

1993-07-01

This manual is the tutorial for the Hazardous Solvent Substitution Data System (HSSDS), an online, comprehensive system of information on alternatives to hazardous solvents and related subjects. The HSSDS data base contains product information, material safety data sheets, toxicity reports, usage reports, biodegradable data, product chemical element lists, and background information on solvents. HSSDS use TOPIC reg-sign to search for information based on a query defined by the user. TOPIC provides a full text retrieval of unstructured source documents. In this tutorial, a series of lessons is provided that guides the user through basic steps common to most queries performed with HSSDS. Instructions are provided for both window-based and character-based applications

Gas chromatographic analysis of extractive solvent in reprocessing plants

International Nuclear Information System (INIS)

Marlet, B.

1984-01-01

Operation of a reprocessing plant using the Purex process is recalled and analytical controls for optimum performance are specified. The aim of this thesis is the development of analytical methods using gas chromatography required to follow the evolution of the extraction solvent during spent fuel reprocessing. The solvent at different concentrations, is analysed along the reprocessing lines in organic or aqueous phases. Solvent degradation interferes with extraction and decomposition products are analysed. The solvent becomes less and less efficient, also it is distilled and quality is checked. Traces of solvent should also be checked in waste water. Analysis are made as simple as possible to facilitate handling of radioactive samples [fr

The influence of solvent processing on polyester bioabsorbable polymers.

Science.gov (United States)

Manson, Joanne; Dixon, Dorian

2012-01-01

Solvent-based methods are commonly employed for the production of polyester-based samples and coatings in both medical device production and research. The influence of solvent casting and subsequent drying time was studied using thermal analysis, spectroscopy and weight measurement for four grades of 50 : 50 poly(lactic-co-glycolic acid) (PLGA) produced by using chloroform, dichloromethane, and acetone. The results demonstrate that solvent choice and PLGA molecular weight are critical factors in terms of solvent removal rate and maintaining sample integrity, respectively. The protocols widely employed result in high levels of residual solvent and a new protocol is presented together with solutions to commonly encountered problems.

Improvement in solvent tolerance by exogenous glycerol in Pseudomonas sp. BCNU 106.

Science.gov (United States)

Choi, H J; Lim, B R; Park, Y J; Joo, W H

2017-08-01

Solvent hypertolerant Pseudomonas sp. BCNU 106 still has some underlying growth limitation in solvents. Therefore, efficient mass cultivation methods are needed to pursue its applications in biotechnology. Pseudomonas sp. BCNU 106 was cultured in a medium supplemented with 0·05 mol l -1 glycerol and cell survival was monitored during its cultivation in the presence of 1% (v/v) toluene. Exogenously supplemented glycerol provided more protection against damage caused by toluene stress and conferred higher solvent tolerance of Pseudomonas sp. BCNU 106 to toluene compared to control Pseudomonas sp. BCNU 106 without the supplementation of glycerol. This low-cost mass cultivation method can be used to efficiently apply solvent-tolerant bacteria in biotransformation and biodegradation. Protection against toluene and improvement in bacterial cell growth by supplementation of glycerol in the presence of toluene are demonstrated in this study. This result can be used to solve growth-related hindrances of solvent-tolerant bacteria and establish their low-cost mass cultivation, thereby broadening their industrial and environmental applications. © 2017 The Society for Applied Microbiology.

High temperature solvent extraction of oil shale and bituminous coal using binary solvent mixtures

Energy Technology Data Exchange (ETDEWEB)

Goetz, G.K.E. [Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle, RWTH Aachen (Germany)

1997-12-31

A high volatile bituminous coal from the Saar Basin and an oil shale from the Messel deposit, both Germany, were extracted with binary solvent mixtures using the Advanced Solvent Extraction method (ASE). Extraction temperature and pressure were kept at 100 C, respectively 150 C, and 20,7 MPa. After the heating phase (5 min) static extractions were performed with mixtures (v:v, 1:3) of methanol with toluene, respectively trichloromethane, for further 5 min. Extract yields were the same or on a higher level compared to those from classical soxhlet extractions (3 days) using the same solvents at 60 C. Comparing the results from ASE with those from supercritical fluid extraction (SFE) the extract yields were similar. Increasing the temperature in ASE releases more soluble organic matter from geological samples, because compounds with higher molecular weight and especially more polar substances were solubilized. But also an enhanced extraction efficiency resulted for aliphatic and aromatic hydrocarbons which are used as biomarkers in Organic Geochemistry. Application of thermochemolysis with tetraethylammonium hydroxide (TEAH) using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) on the extraction residues shows clearly that at higher extraction temperatures minor amounts of free fatty acids or their methyl esters (original or produced by ASE) were trapped inside the pore systems of the oil shale or the bituminous coal. ASE offers a rapid and very efficient extraction method for geological samples reducing analysis time and costs for solvents. (orig.)

Suppression of Protonated Organic Solvents in NMR Spectroscopy Using a Perfect Echo Low-Pass Filtration Pulse Sequence.

Science.gov (United States)

Howe, Peter W A

2018-04-03

Proton NMR spectra are usually acquired using deuterated solvents, but in many cases it is necessary to obtain spectra on samples in protonated solvents. In these cases, the intense resonances of the protonated solvents need to be suppressed to maximize sensitivity and spectral quality. A wide range of highly effective solvent suppression methods have been developed, but additional measures are needed to suppress the 13 C satellites of the solvent. Because the satellites represent 1.1% of the original solvent signal, they remain problematic if unsuppressed. The recently proposed DISPEL pulse sequences suppress 13 C satellites extremely effectively, and this Technical Note demonstrates that combining DISPEL and presaturation results in exceptionally effective solvent suppression. An important element in the effectiveness is volume selection, which is inherent within the DISPEL sequence. Spectra acquired in protonated dimethlysulfoxide and tetrahydrofuran show that optimum results are obtained by modifying the phase cycle, cycling the pulse-field gradients, and using broadband 13 C inversion pulses to reduce the effects of radiofrequency offset and inhomogeneity.

The solvent effects on dimethyl phthalate investigated by FTIR characterization, solvent parameter correlation and DFT computation

Science.gov (United States)

Chen, Yi; Zhang, Hui; Zhou, Wenzhao; Deng, Chao; Liao, Jian

2018-06-01

This study set out with the aim of investigating the solvent effects on dimethyl phthalate (DMP) using FTIR characterization, solvent parameter correlation and DFT calculation. DMP exposed to 17 organic solvents manifested varying shift in the carbonyl stretching vibration frequency (νCdbnd O). Non-alkanols induced Band I and alkanols produced Band I and Band II. Through correlating the νCdbnd O with the empirical solvent scales including acceptor parameter (AN), Schleyer's linear free energy parameter (G), and linear free salvation energy relationships (LSER), Band I was mainly ascribed to non-specific effects from either non-alkanols or alkanol polymers ((alkanol)n). νCdbnd O of the latter indicated minor red shift and less variability compared to the former. An assumption was made and validated about the sequestering of hydroxyl group by the bulky hydrophobic chain in (alkanol)n, creating what we refer to as "screening effects". Ab initio calculation, on the other hand, provided insights for possible hydrogen binding between DMP and (ethanol)n or between ethanol monomers. The two components of Band I observed in inert solvents were assigned to the two Cdbnd O groups adopting differentiated conformations. This in turn prompted our consideration that hydrogen binding was highly selective in favor of lowly associated (alkanol)n and the particular Cdbnd O group having relatively less steric hindrance and stronger electron-donating capacity. Band II was therefore believed to derive from hydrogen-bond interactions mainly in manner of 1:1 and 1:2 DMP-(alkanol)n complexes.

21 CFR 173.280 - Solvent extraction process for citric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Solvent extraction process for citric acid. 173.280... HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and Related Substances § 173.280 Solvent extraction process for citric acid. A solvent extraction process for recovery of citric acid from...

Catalytic coal liquefaction with treated solvent and SRC recycle

Science.gov (United States)

Garg, Diwakar; Givens, Edwin N.; Schweighardt, Frank K.

1986-01-01

A process for the solvent refining of coal to distillable, pentane soluble products using a dephenolated and denitrogenated recycle solvent and a recycled, pentane-insoluble, solvent-refined coal material, which process provides enhanced oil-make in the conversion of coal.

Efficient Regeneration of Physical and Chemical Solvents for CO₂ Capture

Energy Technology Data Exchange (ETDEWEB)

Tande, Brian [Univ. of North Dakota, Grand Forks, ND (United States); Seames, Wayne [Univ. of North Dakota, Grand Forks, ND (United States); Benson, Steve [Univ. of North Dakota, Grand Forks, ND (United States)

2013-12-01

The objective of this project was to evaluate the use of composite polymer membranes and porous membrane contactors to regenerate physical and chemical solvents for capture of carbon dioxide (CO₂) from synthesis gas or flue gas, with the goal of improving the energy efficiency of carbon capture. Both a chemical solvent (typical for a post-combustion capture of CO₂ from flue gas) and a physical solvent (typical for pre- combustion capture of CO₂ from syngas) were evaluated using two bench-scale test systems constructed for this project. For chemical solvents, polytetrafluoroethylene and polypropylene membranes were found to be able to strip CO₂ from a monoethanolamine (MEA) solution with high selectivity without significant degradation of the material. As expected, the regeneration temperature was the most significant parameter affecting the CO₂ flux through the membrane. Pore size was also found to be important, as pores larger than 5 microns lead to excessive pore wetting. For physical solvents, polydimethyl-siloxane (PDMS)-based membranes were found to have a higher CO₂ permeability than polyvinylalcohol (PVOH) based membranes, while also minimizing solvent loss. Overall, however, the recovery of CO₂ in these systems is low – less than 2% for both chemical and physical solvents – primarily due to the small surface area of the membrane test apparatus. To obtain the higher regeneration rates needed for this application, a much larger surface area would be needed. Further experiments using, for example, a hollow fiber membrane module could determine if this process could be commercially viable.

Investigation of the Use of a Bio-Derived Solvent for Non-Solvent-Induced Phase Separation (NIPS Fabrication of Polysulfone Membranes

Directory of Open Access Journals (Sweden)

Xiaobo Dong

2018-05-01

Full Text Available Organic solvents, such as N-methyl-2-pyrrolidone (NMP and dimethylacetamide (DMAc, have been traditionally used to fabricate polymeric membranes. These solvents may have a negative impact on the environment and human health; therefore, using renewable solvents derived from biomass is of great interest to make membrane fabrication sustainable. Methyl-5-(dimethylamino-2-methyl-5-oxopentanoate (Rhodiasolv PolarClean is a bio-derived, biodegradable, nonflammable and nonvolatile solvent. Polysulfone is a commonly used polymer to fabricate membranes due to its thermal stability, strong mechanical strength and good chemical resistance. From cloud point curves, PolarClean showed potential to be a solvent for polysulfone. Membranes prepared with PolarClean were investigated in terms of their morphology, porosity, water permeability and protein rejection, and were compared to membranes prepared with traditional solvents. The pores of polysulfone/PolarClean membranes were sponge-like, and the membranes displayed higher water flux values (176.0 ± 8.8 LMH along with slightly higher solute rejection (99.0 ± 0.51%. On the other hand, PSf/DMAc membrane pores were finger-like with lower water flux (63.1 ± 12.4 LMH and slightly lower solute rejection (96 ± 2.00% when compared to PSf/PolarClean membranes.

Glutathione reductase: solvent equilibrium and kinetic isotope effects

International Nuclear Information System (INIS)

Wong, K.K.; Vanoni, M.A.; Blanchard, J.S.

1988-01-01

Glutathione reductase catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). The kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent kinetic isotope effects. With NADPH or GSSG as the variable substrate, at a fixed, saturating concentration of the other substrate, solvent kinetic isotope effects were observed on V but not V/K. Plots of Vm vs mole fraction of D 2 O (proton inventories) were linear in both cases for the yeast, spinach, and human erythrocyte enzymes. When solvent kinetic isotope effect studies were performed with DTNB instead of GSSG as an alternate substrate, a solvent kinetic isotope effect of 1.0 was observed. Solvent kinetic isotope effect measurements were also performed on the asymmetric disulfides GSSNB and GSSNP by using human erythrocyte glutathione reductase. The Km values for GSSNB and GSSNP were 70 microM and 13 microM, respectively, and V values were 62 and 57% of the one calculated for GSSG, respectively. Both of these substrates yield solvent kinetic isotope effects greater than 1.0 on both V and V/K and linear proton inventories, indicating that a single proton-transfer step is still rate limiting. These data are discussed in relationship to the chemical mechanism of GSSG reduction and the identity of the proton-transfer step whose rate is sensitive to solvent isotopic composition. Finally, the solvent equilibrium isotope effect measured with yeast glutathione reductase is 4.98, which allows us to calculate a fractionation factor for the thiol moiety of GSH of 0.456

Equilibrium disorders in workers exposed to mixed solvents.

Science.gov (United States)

Giorgianni, Concetto; Tanzariello, Mariagiuseppina; De Pasquale, Domenico; Brecciaroli, Renato; Spatari, Giovanna

2018-02-06

Organic solvents cause diseases of the vestibular system. However, little is known regarding the correlation between vestibular damage and exposure to organic solvents below threshold limit values. The best measure by which to evaluate vestibular disorders is static and dynamic posturography. The aim of this study was to evaluate equilibrium disorders via static and dynamic posturography in workers without clear symptoms and exposed to low doses of mixed solvents. 200 subjects were selected. Using an Otometrics device (Madsen, Denmark), all subjects endured static and dynamic posturography testing with both eyes-open and eyes-closed conditions. Results were compared with a control group of unexposed individuals. Based on the obtained data, the following results can be drawn: (a) subjects exposed to mixtures of solvents show highly significant differences regarding all static and dynamic posturography parameters in comparison to the control group; (b) posturography testing has proven to be a valid means by which to detect subliminal equilibrium disorders in subjects exposed to solvents. We can confirm that refinery workers exposed to mixtures of solvents can present subliminal equilibrium disorders. Early diagnosis of the latter is made possible by static and dynamic posturography.

The impact of oil dispersant solvent on performance

International Nuclear Information System (INIS)

Fiocco, R.J.; Lessard, R.R.; Canevari, G.P.; Becker, K.W.; Daling, P.S.

1995-01-01

Modern oil spill dispersant formulations are concentrated blends of surface active agents (surfactants) in a solvent carrier system. The surfactants are effective for lowering the interfacial tension of the oil slick and promoting and stabilizing oil-in-water dispersions. The solvent system has 2 key functions: (1) reduce viscosity of the surfactant blend to allow efficient dispersant application, and (2) promote mixing and diffusion of the surfactant blend into the oil film. A more detailed description than previously given in the literature is proposed to explain the mechanism of chemical dispersion and illustrate how the surfactant is delivered by the solvent to the oil-water interface. Laboratory data are presented which demonstrate the variability in dispersing effectiveness due to different solvent composition, particularly for viscous and emulsified test oils with viscosities up to 20,500 mPa·s. Other advantages of improved solvent components can include reduced evaporative losses during spraying, lower marine toxicity and reduced protective equipment requirements. Through this improved understanding of the role of the solvent, dispersants which are more effective over a wider range of oil types are being developed

THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 16 MOLAR AND 8 MOLAR NITRIC ACID

International Nuclear Information System (INIS)

Fondeur, F; David Hobbs, D; Samuel Fink, S

2007-01-01

Thermal and spectroscopic analyses were performed on multiple layers formed from contacting Caustic Side Solvent Extraction (CSSX) solvent with 1 M or 3 M nitric acid. A slow chemical reaction occurs (i.e., over several weeks) between the solvent and 1 M or 3 M nitric acid as evidenced by color changes and the detection of nitro groups in the infrared spectrum of the aged samples. Thermal analysis revealed that decomposition of the resulting mixture does not meet the definition of explosive or deflagrating material

Effect of solvent extraction on Tunisian esparto wax composition

Directory of Open Access Journals (Sweden)

Saâd Inès

2016-08-01

Full Text Available The increase of needs for renewable and vegetable based materials will help to drive the market growth of vegetable waxes. Because of their highly variable composition and physicochemical properties, plant waxes have found numerous applications in the: food, cosmetic, candle, coating, polish etc... The aim of this project is to determine the effect of solvent extraction (petroleum ether and ethanol on Tunisian esparto wax composition. The GC-MS was applied in order to determine the waxes compositions. Then, physicochemical parameters of these two samples of waxes: acid value, saponification value, iodine value and melting point were measured in order to deduct their properties and possible fields of uses. Results showed that esparto wax composition depended on the solvent extraction and that major components of the two samples of waxes were: alkanes, esters of fatty acids and phenols. Furthermore, esparto waxes were characterized by an antioxidant and antibacterial activities but the potential of these activities depended on the solvent of wax extraction.

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...

Solvent extraction in the nuclear fuel cycle

International Nuclear Information System (INIS)

Eccles, H.; Naylor, A.

1987-01-01

Solvent extraction techniques have been used in the uranium nuclear fuel cycle in three main areas; concentration of uranium from ore leach liquor, purification of ore concentrates and fuel reprocessing. Solvent extraction has been extended to the removal of transuranic elements from active waste liquor, the recovery of uranium from natural sources and the recovery of noble metals from active waste liquor. Schemes are presented for solvent extraction of uranium using the Amex or Dapex process; spent fuel reprocessing and the Purex process. Recent and future developments of the techniques are outlined. (UK)

Computing pKa Values in Different Solvents by Electrostatic Transformation.

Science.gov (United States)

Rossini, Emanuele; Netz, Roland R; Knapp, Ernst-Walter

2016-07-12

We introduce a method that requires only moderate computational effort to compute pKa values of small molecules in different solvents with an average accuracy of better than 0.7 pH units. With a known pKa value in one solvent, the electrostatic transform method computes the pKa value in any other solvent if the proton solvation energy is known in both considered solvents. To apply the electrostatic transform method to a molecule, the electrostatic solvation energies of the protonated and deprotonated molecular species are computed in the two considered solvents using a dielectric continuum to describe the solvent. This is demonstrated for 30 molecules belonging to 10 different molecular families by considering 77 measured pKa values in 4 different solvents: water, acetonitrile, dimethyl sulfoxide, and methanol. The electrostatic transform method can be applied to any other solvent if the proton solvation energy is known. It is exclusively based on physicochemical principles, not using any empirical fetch factors or explicit solvent molecules, to obtain agreement with measured pKa values and is therefore ready to be generalized to other solute molecules and solvents. From the computed pKa values, we obtained relative proton solvation energies, which agree very well with the proton solvation energies computed recently by ab initio methods, and used these energies in the present study.

40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Contents of... Manufacturing Pt. 63, Subpt. VVVV, Table 5 Table 5 to Subpart VVVV of Part 63—Default Organic HAP Contents of Solvents and Solvent Blends As specified in § 63.5758(a)(6), when detailed organic HAP content data for...

Relation between the interfacial tension in an organic solvent-water system and the parameters of the solvating capacity of the solvent

International Nuclear Information System (INIS)

Nikitin, S.D.; Shmidt, V.S.

1987-01-01

It was shown that there is a linear relation between the empirical DE (diluent effect) and E/sub T/ parameters, which characterize the solvating capacity of the solvent, and the interfacial tension in an organic solvent-water two-phase system. Analysis of the sample correlation coefficients shows that the relation between the interfacial tension and the DE parameters of the solvents is closer to linear than the corresponding relation for the E/sub T/ parameters. During analysis of the data for 31 solvents it was established that the largest inverse correlation coefficient r = -0.98 is obtained with an equation of the DE = a + bσ/rho 1/3, type, were a and b are constants, and rho is the density of the solvent. The regression equation has the following form: DE = 7.586 - 0.147 σ/rho 1/3. Since the interfacial activity of hydrophobic surfactants decreases linearly with increase in the DE values, it follows from the obtained equation that decrease of the interfacial tension at the water-organic solvent interface must lead to a decrease in the interfacial activity of hydrophobic surfactants present in the system

DESIGNING GREENER SOLVENTS

Science.gov (United States)

Computer-aided design of chemicals and chemical mixtures provides a powerful tool to help engineers identify cleaner process designs and more-benign alternatives to toxic industrial solvents. Three software programs are discussed: (1) PARIS II (Program for Assisting the Replaceme...

Solvent-assisted polymer micro-molding

Institute of Scientific and Technical Information of China (English)

HAN LuLu; ZHOU Jing; GONG Xiao; GAO ChangYou

2009-01-01

The micro-molding technology has played an important role in fabrication of polymer micro-patterns and development of functional devices.In such a process,suitable solvent can swell or dissolve the polymer films to decrease their glass transition temperature (Tg) and viscosity and thereby improve flowing ability.Consequently,it is easy to obtain the 2D and 3D patterns with high fidelity by the solvent-assisted micro-molding.Compared with the high temperature molding,this technology overcomes some shortcomings such as shrinking after cooling,degradation at high temperature,difficulty in processing some functional materials having high Tg,etc.It can be applied to making patterns not only on polymer monolayers but also on polyelectrolyte multilayers.Moreover,the compressioninduced patterns on the multilayers are chemically homogenous but physically heterogeneous.In this review,the controlling factors on the pattern quality are also discussed,including materials of the mold,solvent,pressure,temperature and pattern density.

Measuring solvent barrier properties of paper

International Nuclear Information System (INIS)

Bollström, Roger; Saarinen, Jarkko J; Toivakka, Martti; Räty, Jukka

2012-01-01

New methods for measuring barrier properties against solvents, acids and bases on dispersion coated paper were developed and investigated. Usability, reliability and repeatability were compared both between the new methods and with the standardized method for measuring barrier properties against water vapor. Barrier properties could be measured with all methods and the results obtained by the different methods were in correlation with each other. A qualitative method based on a trace color provided an indicative result, whereas further developed methods also took into account the durability. The effective barrier lifetime could be measured by measuring the conductivity through the substrate as a function of time, or by utilizing a glass prism where the change in refractive index caused by penetrated liquid was monitored, also as a function of time. Barrier properties against water and humidity were also measured and were found not to be predictors for barrier properties against either solvents, or acids or bases, which supports the need to develop new methods

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp.

Directory of Open Access Journals (Sweden)

Renil eAnthony

2015-01-01

Full Text Available Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (UTEX LB2396. Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. All solvent extracts contained hexadecanoic acid, linoleic acid and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%, cyclohexane (0.14% and hexane (0.11%. This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Partially Fluorinated Solvent as a co-solvent for the Non-aqueous Electrolyte of Li/air Battery

Science.gov (United States)

2010-11-11

ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP), respectively, as a co-solvent for the non-aqueous electrolyte of Li–air battery. Results...fluorinated solvents on the discharge performance of Li–air bat- tery. For this purpose, we here selectmethyl nonafluorobutyl ether ( MFE ) and tris...196, (2011) pgs. 2867-2870 14. ABSTRACT In this workwestudy methyl nonafluorobutyl ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP

Photophysical properties of coumarin-120: Unusual behavior in nonpolar solvents

International Nuclear Information System (INIS)

Pal, Haridas; Nad, Sanjukta; Kumbhakar, Manoj

2003-01-01

Photophysical properties of coumarin-120 (C120; 7-amino-4-methyl-1,2-benzopyrone) dye have been investigated in different solvents using steady-state and time-resolved fluorescence and picosecond laser flash photolysis (LFP) and nanosecond pulse radiolysis (PR) techniques. C120 shows unusual photophysical properties in nonpolar solvents compared to those in other solvents of moderate to higher polarities. Where the Stokes shifts (Δν-bar=ν-bar abs -ν-bar fl ), fluorescence quantum yields (Φ f ), and fluorescence lifetimes (τ f ) show more or less linear correlation with the solvent polarity function Δf={(ε-1)/(2ε+1)-(n 2 -1)/(2n 2 +1)}, all these parameters are unusually lower in nonpolar solvents. Unlike in other solvents, both Φ f and τ f in nonpolar solvents are also strongly temperature dependent. It is indicated that the excited singlet (S 1 ) state of C120 undergoes a fast activation-controlled nonradiative deexcitation in nonpolar solvents, which is absent in all other solvents. LFP and PR studies indicate that the intersystem crossing process is negligible for the present dye in all the solvents studied. Photophysical behavior of C120 in nonpolar solvent has been rationalized assuming that in these solvents the dye exists in a nonpolar structure, with its 7-NH 2 group in a pyramidal configuration. In this structure, since the 7-NH 2 group is bonded to the 1,2-benzopyrone moiety by a single bond, the former group can undergo a fast flip-flop motion, which in effect causes the fast nonradiative deexcitation of the dye excited state. In moderate to higher polarity solvents, it is indicated that the dye exists in an intramolecular charge-transfer structure, where the bond between 7-NH 2 group and the 1,2-benzopyrone moiety attains substantial double bond character. In this structure, the flip-flop motion of the 7-NH 2 group is highly restricted and thus there is no fast nonradiative deexcitation process for the excited dye

Thermodynamic properties of L-Theanine in different solvents

International Nuclear Information System (INIS)

Zhou, Fuli; Hou, Baohong; Tao, Xiaolong; Hu, Xiaoxue; Huang, Qiaoyin; Zhang, Zaixiang; Wang, Yongli; Hao, Hongxun

2017-01-01

Highlights: • The solubility data of L-Theanine in different solvents were measured by using an equilibrium method. • Several models were used to correlate the experimental solubility data. • The mixing thermodynamic properties were calculated. - Abstract: The solubility data of L-Theanine in pure water and three kinds of water + organic solvent mxitures were measured in temperature ranges from (278.15 to 13.15) K by using an equilibrium method. The results show that the solubility of L-Theanine increases with the increasing of temperature in all selected solvents. The modified Apelblat equation and the λ-h model were applied to correlate the solubility data in pure water, while the modified Apelblat equation, the λ-h model, the NRTL model and the Jouyban–Acree model were applied to correlate the solubility data in binary solvent mixtures. Furthermore, the mixing thermodynamic properties of L-Theanine in different solvents were also calculated based on the NRTL model and experimental solubility data.

27 CFR 20.113 - Proprietary solvents general-use formula.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Proprietary solvents... Formulas and Statements of Process General-Use Formulas § 20.113 Proprietary solvents general-use formula. (a) A proprietary solvent is any article made with any other ingredients combined with the...

Remediation of Contaminated Soils by Solvent Flushing

NARCIS (Netherlands)

Augustijn, Dionysius C.M.; Jessup, Ron E.; Rao, P. Suresh C.; Wood, A. Lynn

1994-01-01

Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, and increases the

Performance of thermally-chargeable supercapacitors in different solvents.

Science.gov (United States)

Lim, Hyuck; Zhao, Cang; Qiao, Yu

2014-07-07

The influence of solvent on the temperature sensitivity of the electrode potential of thermally-chargeable supercapacitors (TCSs) is investigated. For large electrodes, the output voltage is positively correlated with the dielectric constant of solvent. When nanoporous carbon electrodes are used, different characteristics of system performance are observed, suggesting that possible size effects must be taken into consideration when the solvent molecules and solvated ions are confined in a nanoenvironment.

Solvent refining of low-temperature tar with liquid ammonia

Energy Technology Data Exchange (ETDEWEB)

Ishida, K

1953-01-01

The middle fractions of low-temperature tar were treated with mixed solutions of H/sub 2/O and liquid NH/sub 3/ at 0/sup 0/ and 20/sup 0/, and with liquid NH/sub 3/ at -10, 0, + 10, and 20/sup 0/, and phase equilibrium between tar acids, neutral oil, and solvents were studied. The distribution ratio ranged from less than 1 to greater than 1 when the solvent contained about 20 percent (by weight) H/sub 2/O. When the solvent contained less than 85 percent (by weight) NH/sub 3/, the yield of extract was small but the purity of phenols in the extracted oil was above 90 percent. Solvent containing about 85 percent NH/sub 3/ (by weight) is considered optimum for separating tar acids from oils. A novel definition is proposed for solvent selectivity as the difference between the concentration of the solute in the extract layer, on a solvent-free basis, and the concentration in the raffinate layer.

Trace elements retained in washed nuclear fuel reprocessing solvents

International Nuclear Information System (INIS)

Gray, L.W.; MacMurdo, K.W.

1979-09-01

Analysis of purified TBP extractant from solvent extraction processes at Savannah River Plant showed several stable elements and several long-lived radioisotopes. Stable elements Al, Na, Br, Ce, Hg, and Sm are found in trace quantities in the solvent. The only stable metallic element consistently found in the solvent was Al, with a concentration which varies from about 30 ppM to about 10 ppM. The halogens Br and Cl appear to be found in the solvent systems as organo halides. Radionuclides found were principally 106 Ru, 129 I, 3 H, 235 U, and 239 Pu. The 129 I concentration was about 1 ppM in the first solvent extraction cycle of each facility. In the other cycles, 129 I concentration varied from about 0.1 to 0.5 ppM. Both 129 I and 3 H appear to be in the organic solvent as a result of exchange with hydrogen

Simulation of equilibrium distribution data in a solvent extraction system

International Nuclear Information System (INIS)

Mondal, S.; Giriyalkar, A.B.; Singh, A.K.; Singh, D.K.; Hubli, R.C.

2014-01-01

In hydrometallurgy, solvent extraction has been proved to be the purification method to recover metal in high-pure form from impure solution. Any solvent extraction process is complex and based on some operating parameters which always lure the scientists to model them. Operating parameters like aqueous to organic volume ratio and concentration of feed are related to required number of stages for a product with specific recovery. So to determine final feed concentration or aqueous to organic volume ratio for a specific extractant concentration, one needs to carry out a number of extraction experiments tediously supported by analysis. Here an attempt is being made to model the distribution of solute between organic and aqueous phases with minimum analytical and experimental support for any system. The model can predict the effect on solvent extraction for a change in the aqueous to organic volume ratio i.e. slope of operating line, percentage loading of solvent, feed concentration, solvent concentration, number of stages and in the process it can help in optimizing conditions for the best result from a solvent extraction system. Uranium-7% TBP in dodecane system was taken up to validate the model. The predicted values of the model was tallied against uranium distribution between aqueous and organic phases in a running mixer settler. The equation for operating line i.e. straight line is derived from O/A=1.5 and considering barren organic contains 2 ppm uranium: y 1 = 0.667x 0 - .002. The extraction isotherm i.e. parabola equation came as : x 1 = 0.003y 0 2 + 0.723y 0 considering three points i.e. (0,0), (13,16.7) (uranium analysis for first stage of mixer-settler) and (25, 30.69) (feed concentration, loading capacity of solvent). Using these two equations the results that were obtained, predicted the solute distribution across different stages exactly as it is in the running mixer settler. Individual isotherms could also be drawn with the predicted results from the

[Chemical hazards when working with solvent glues].

Science.gov (United States)

Domański, Wojciech; Makles, Zbigniew

2012-01-01

Solvent glues are used in a wide variety of industries, e.g., textile, footwear and rubber. The problem of workers' exposure to solvent vapors is rarely tackled within the area of occupational safety and health in small and medium-sized enterprises. In order to assess exposure to solvents, organic solvents emitted by glues were identified in the samples of workplace air. The concentration of acetone, benzene, cyclohexane, ethylbenzene, n-hexane, methylcyclohexane, butyl acetate and toluene were determined. The obtained results evidenced the presence of cyclohexane, ethylbenzene, ethylcyclohexane, heptane, n-hexane, o-xylene, methylcyclohexane, methylcyclopentane, butyl acetate and toluene in workplace air. The concentration of those compounds in workplace air was low, usually below 0.15 of MAC. At some workstations the presence of benzene was also observed. Occupational risk was assessed at workstations where gluing took place. It showed that the risk at those workstations was medium or low.

Deposition dynamics of multi-solvent bioinks

Science.gov (United States)

Kaneelil, Paul; Pack, Min; Cui, Chunxiao; Han, Li-Hsin; Sun, Ying

2017-11-01

Inkjet printing cellular scaffolds using bioinks is gaining popularity due to the advancement of printing technology as well as the growing demands of regenerative medicine. Numerous studies have been conducted on printing scaffolds of biomimetic structures that support the cell production of human tissues. However, the underlying physics of the deposition dynamics of bioinks remains elusive. Of particular interest is the unclear deposition dynamics of multi-solvent bioinks, which is often used to tune the micro-architecture formation. Here we systematically studied the effects of jetting frequency, solvent properties, substrate wettability, and temperature on the three-dimensional deposition patterns of bioinks made of Methacrylated Gelatin and Carboxylated Gelatin. The microflows inside the inkjet-printed picolitre drops were visualized using fluorescence tracer particles to decipher the complex processes of multi-solvent evaporation and solute self-assembly. The evolution of droplet shape was observed using interferometry. With the integrated techniques, the interplay of solvent evaporation, biopolymer deposition, and multi-drop interactions were directly observed for various ink and substrate properties, and printing conditions. Such knowledge enables the design and fabrication of a variety of tissue engineering scaffolds for potential use in regenerative medicine.

Qualitative and quantitative evaluation of solvent systems for countercurrent separation.

Science.gov (United States)

Friesen, J Brent; Ahmed, Sana; Pauli, Guido F

2015-01-16

Rational solvent system selection for countercurrent chromatography and centrifugal partition chromatography technology (collectively known as countercurrent separation) studies continues to be a scientific challenge as the fundamental questions of comparing polarity range and selectivity within a solvent system family and between putative orthogonal solvent systems remain unanswered. The current emphasis on metabolomic investigations and analysis of complex mixtures necessitates the use of successive orthogonal countercurrent separation (CS) steps as part of complex fractionation protocols. Addressing the broad range of metabolite polarities demands development of new CS solvent systems with appropriate composition, polarity (π), selectivity (σ), and suitability. In this study, a mixture of twenty commercially available natural products, called the GUESSmix, was utilized to evaluate both solvent system polarity and selectively characteristics. Comparisons of GUESSmix analyte partition coefficient (K) values give rise to a measure of solvent system polarity range called the GUESSmix polarity index (GUPI). Solvatochromic dye and electrical permittivity measurements were also evaluated in quantitatively assessing solvent system polarity. The relative selectivity of solvent systems were evaluated with the GUESSmix by calculating the pairwise resolution (αip), the number of analytes found in the sweet spot (Nsw), and the pairwise resolution of those sweet spot analytes (αsw). The combination of these parameters allowed for both intra- and inter-family comparison of solvent system selectivity. Finally, 2-dimensional reciprocal shifted symmetry plots (ReSS(2)) were created to visually compare both the polarities and selectivities of solvent system pairs. This study helps to pave the way to the development of new solvent systems that are amenable to successive orthogonal CS protocols employed in metabolomic studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Collapse in two good solvents, swelling in two poor solvents: defying the laws of polymer solubility?

Science.gov (United States)

Mukherji, Debashish; Marques, Carlos M; Kremer, Kurt

2018-01-17

In this work we discuss two mirror but distinct phenomena of polymer paradoxical properties in mixed solvents: co-non-solvency and co-solvency. When a polymer collapses in a mixture of two miscible good solvents the phenomenon is known as co-non-solvency, while co-solvency is a phenomenon that is associated with the swelling of a polymer in poor solvent mixtures. A typical example of co-non-solvency is provided by poly(N-isopropylacrylamide) in aqueous alcohol, while poly(methyl methacrylate) in aqueous alcohol shows co-solvency. We discuss these two phenomena to compare their microscopic origins and show that both can be understood within generic universal concepts. A broad range of polymers is therefore expected to exhibit these phenomena where specific chemical details play a lesser role than the appropriate combination of interactions between the trio of molecular components.

Structuring of polymer solutions upon solvent evaporation

NARCIS (Netherlands)

Schaefer, C.; van der Schoot, P.|info:eu-repo/dai/nl/102140618; Michels, J. J.

2015-01-01

The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady solvent evaporation. In contrast to what is the case for a classical, thermal quench

Analysis of cesium extracting solvent using GCMS and HPLC

International Nuclear Information System (INIS)

White, T.L.; Herman, C.C.; Crump, S.L.; Marinik, A.R.; Lambert, D.P.; Eibling, R.E.

2007-01-01

A high-level waste (HLW) remediation process scheduled to begin in 2007 at the Savannah River Site is the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). The MCU will use a hydrocarbon solvent (diluent) containing a cesium extractant, a calix[4]arene compound, to extract radioactive cesium from caustic HLW. The resulting decontaminated HLW waste or raffinate will be processed into grout at the Saltstone Production Facility (SPF). The cesium containing CSSX stream will undergo washing with dilute nitric acid followed by stripping of the cesium nitrate into a very dilute nitric acid or the strip effluent stream and the CSSX solvent will be recycled. The Defense Waste Processing Facility (DWPF) will receive the strip effluent stream and immobilize the cesium into borosilicate glass. Excess CSSX solvent carryover from the MCU creates a potential flammability problem during DWPF processing. Bench-scale DWPF process testing was performed with simulated waste to determine the fate of the CSSX solvent components. A simple high performance liquid chromatography (HPLC) method was developed to identify the modifier (which is used to increase Cs extraction and extractant solubility) and extractant within the DWPF process. The diluent and trioctylamine (which is used to suppress impurity effect and ion-pair disassociation) were determined using gas chromatography mass spectroscopy (GCMS). To close the organic balance, two types of sample preparation methods were needed. One involved extracting aqueous samples with methylene chloride or hexane, and the second was capturing the off gas of the DWPF process using carbon tubes and rinsing the tubes with carbon disulfide for analysis. This paper addresses the development of the analytical methods and the bench-scale simulated waste study results. (author)

Coordination conversion of cobalt(II) in binary aqueous-organic solvents

Energy Technology Data Exchange (ETDEWEB)

Khvostova, N.O.; Karapetyan, G.O.; Yanush, O.V.

1985-11-01

It has been shown that the thermochromic conversions of cobalt(II) in binary solvents are influenced by a number of factors: the nature of the solvent, the strength of the complexes of octahedral symmetry formed, the outer-sphere influence of the solvent on the complexes, the form of the anion, the solvation of the participants in the reaction, and the interaction of the components of the solvent with one another. A correlation between the strength and the spectral position of the absorption bands of the complexes of the activator has been established, and a spectroscopic criterion for selecting the solvents has been proposed. The expediency of using binary solvents to create effective thermochromic media with variable phototransmission has been substantiated.

ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

Science.gov (United States)

Hodgson, James R.; McCool, Alex (Technical Monitor)

2001-01-01

Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

Enzymes from solvent-tolerant microbes: useful biocatalysts for non-aqueous enzymology.

Science.gov (United States)

Gupta, Anshu; Khare, S K

2009-01-01

Solvent-tolerant microbes are a newly emerging class that possesses the unique ability to thrive in the presence of organic solvents. Their enzymes adapted to mediate cellular and metabolic processes in a solvent-rich environment and are logically stable in the presence of organic solvents. Enzyme catalysis in non-aqueous/low-water media is finding increasing applications for the synthesis of industrially important products, namely peptides, esters, and other trans-esterification products. Solvent stability, however, remains a prerequisite for employing enzymes in non-aqueous systems. Enzymes, in general, get inactivated or give very low rates of reaction in non-aqueous media. Thus, early efforts, and even some recent ones, have aimed at stabilization of enzymes in organic media by immobilization, surface modifications, mutagenesis, and protein engineering. Enzymes from solvent-tolerant microbes appear to be the choicest source for studying solvent-stable enzymes because of their unique ability to survive in the presence of a range of organic solvents. These bacteria circumvent the solvent's toxic effects by virtue of various adaptations, e.g. at the level of the cytoplasmic membrane, by degradation and transformation of solvents, and by active excretion of solvents. The recent screening of these exotic microbes has generated some naturally solvent-stable proteases, lipases, cholesterol oxidase, cholesterol esterase, cyclodextrin glucanotransferase, and other important enzymes. The unique properties of these novel biocatalysts have great potential for applications in non-aqueous enzymology for a range of industrial processes.

Solvent distillation studies for a purex reprocessing plant

International Nuclear Information System (INIS)

Ginisty, C.; Guillaume, B.

1990-01-01

A distillation system has been developed for regeneration of Purex solvent and will be implemented for the first time in a reprocessing plant. The results are described and analyzed, with emphasis on laboratory experiments which were made with a radioactive plant solvent. Particularly the distillation provides a good separation of solvent degradation products, which was verified by measurements of interfacial tension and plutonium or ruthenium retention. 16 refs., 3 figs., 5 tabs

Thermodynamic equilibrium of hydroxyacetic acid in pure and binary solvent systems

International Nuclear Information System (INIS)

Huang, Qiaoyin; Xie, Chuang; Li, Yang; Su, Nannan; Lou, Yajing; Hu, Xiaoxue; Wang, Yongli; Bao, Ying; Hou, Baohong

2017-01-01

Highlights: • Solubility of hydroxyacetic acid in mono-solvents and binary solvent mixtures was measured. • Modified Apelblat, NRTL and Wilson model were used to correlate the solubility data in pure solvents. • CNIBS/R-K and Jouyban-Acree model were used to correlate the solubility in binary solvent mixtures. • The mixing properties were calculated based on the NRTL model. - Abstract: The solubility of hydroxyacetic acid in five pure organic solvents and two binary solvent mixtures were experimentally measured from 273.15 K to 313.15 K at atmospheric pressure (p = 0.1 MPa) by using a dynamic method. The order of solubility in pure organic solvents is ethanol > isopropanol > n-butanol > acetonitrile > ethyl acetate within the investigated temperature range, except for temperature lower than 278 K where the solubility of HA in ethyl acetate is slightly larger than that in acetonitrile. Furthermore, the solubility data in pure solvents were correlated with the modified Apelblat model, NRTL model, and Wilson model and that in the binary solvents mixtures were fitted to the CNIBS/R-K model and Jouyban-Acree model. Finally, the mixing thermodynamic properties of hydroxyacetic acid in pure and binary solvent systems were calculated and discussed.

300 area solvent evaporator interim status closure plan: Revision 2

International Nuclear Information System (INIS)

1989-02-01

This document describes activities for the closure of a hazardous waste tank treatment facility operated by the US Department of Energy-Richland Operations Office (DOE-RL) and co-operated by the Westinghouse Hanford Company (WHC). This treatment facility was a solvent evaporator located in the 300 Area of the Hanford Site, from 1975 to 1985 on behalf of DOE-RL. The 300 Area Solvent Evaporator (300 ASE) was a modified load lugger (dumpster) in which solvent wastes were evaporated. Some of the solvents were radioactively contaminated because they came from a degreaser which processed bare uranium metal billets from the N Reactor Fuel Manufacturing Facility. The waste was composed of perchloroethylene, trichloroethylene, 1,1,1-trichloroethane, ethyl acetate/bromine solution, paint shop solvents and possibly some used oil. Also, small amounts of uranium, copper, zirconium and possibly beryllium were present in the degreaser solvents as particulates. Radioactive and non-radioactive solvents were not segregated in the 300 ASE, and the entire mixture was regarded as mixed waste

Molecular simulations of electrolyte structure and dynamics in lithium-sulfur battery solvents

Science.gov (United States)

Park, Chanbum; Kanduč, Matej; Chudoba, Richard; Ronneburg, Arne; Risse, Sebastian; Ballauff, Matthias; Dzubiella, Joachim

2018-01-01

The performance of modern lithium-sulfur (Li/S) battery systems critically depends on the electrolyte and solvent compositions. For fundamental molecular insights and rational guidance of experimental developments, efficient and sufficiently accurate molecular simulations are thus in urgent need. Here, we construct a molecular dynamics (MD) computer simulation model of representative state-of-the art electrolyte-solvent systems for Li/S batteries constituted by lithium-bis(trifluoromethane)sulfonimide (LiTFSI) and LiNO3 electrolytes in mixtures of the organic solvents 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL). We benchmark and verify our simulations by comparing structural and dynamic features with various available experimental reference systems and demonstrate their applicability for a wide range of electrolyte-solvent compositions. For the state-of-the-art battery solvent, we finally calculate and discuss the detailed composition of the first lithium solvation shell, the temperature dependence of lithium diffusion, as well as the electrolyte conductivities and lithium transference numbers. Our model will serve as a basis for efficient future predictions of electrolyte structure and transport in complex electrode confinements for the optimization of modern Li/S batteries (and related devices).

Effect of Different Solvents on the Measurement of Phenolics and the Antioxidant Activity of Mulberry (Morus atropurpurea Roxb.) with Accelerated Solvent Extraction.

Science.gov (United States)

Yang, Jiufang; Ou, XiaoQun; Zhang, Xiaoxu; Zhou, ZiYing; Ma, LiYan

2017-03-01

The effects of 9 different solvents on the measurement of the total phenolics and antioxidant activities of mulberry fruits were studied using accelerated solvent extraction (ASE). Sixteen to 22 types of phenolics (flavonols, flavan-3-ols, flavanol, hydroxycinnamic acids, hydroxybenzoic acids, and stilbenes) from different mulberry extracts were characterized and quantified using HPLC-MS/MS. The principal component analysis (PCA) was used to determine the suitable solvents to distinguish between different classes of phenolics. Additionally, the phenolic extraction abilities of ASE and ultrasound-assisted extraction (UAE) were compared. The highest extraction efficiency could be achieved by using 50% acidified methanol (50MA) as ASE solvents with 15.14 mg/gallic acid equivalents g dry weight of mulberry fruit. The PCA results revealed that the 50MA followed by 50% acidified acetone (50AA) was the most efficient solvent for the extraction of phenolics, particularly flavonols (627.12 and 510.31 μg/g dry weight, respectively), while water (W) was not beneficial to the extraction of all categories of phenolics. Besides, the results of 3 antioxidant capability assays (DPPH, ABTS free radical-scavenging assay, and ferric-reducing antioxidant power assay) showed that water-based organic solvents increased the antioxidant capabilities of the extracts compared with water or pure organic solvents. ASE was more suitable for the extraction of phenolics than UAE. © 2017 Institute of Food Technologists®.

Recovery of acid-degraded tributyl phosphate by solvent extraction

International Nuclear Information System (INIS)

Young, G.C.; Holladay, D.W.

1981-01-01

During nuclear fuel reprocessing the organic solvent becomes loaded with various acidic degradation products, which can be effectively removed through solvent extraction. Studies have been made with a small bench-scale solvent extraction system to optimize such parameters as pH of aqueous phase, phase ratio, residence time, flow rates, and temperature. The necessary decontamination factors have been obtained for various degradation products during continuous solvent extraction in one stage, with the aqueous phase being recycled. The aqueous phase contains compounds that can be degraded to gases to minimize waste disposal problems

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp

Energy Technology Data Exchange (ETDEWEB)

Anthony, Renil [Department of Mechanical Engineering, Ohio University, Athens, OH (United States); Stuart, Ben, E-mail: stuart@ohio.edu [Department of Civil Engineering, Ohio University, Athens, OH (United States)

2015-01-20

Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates, and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (University of Texas at Austin LB2396). Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. The lipid extracts were derivatized and analyzed using gas chromatography–mass spectroscopy. All solvent extracts contained hexadecanoic acid, linoleic acid, and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%), cyclohexane (0.14%), and hexane (0.11%). This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp

International Nuclear Information System (INIS)

Anthony, Renil; Stuart, Ben

2015-01-01

Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates, and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (University of Texas at Austin LB2396). Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. The lipid extracts were derivatized and analyzed using gas chromatography–mass spectroscopy. All solvent extracts contained hexadecanoic acid, linoleic acid, and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%), cyclohexane (0.14%), and hexane (0.11%). This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Into the depths of deep eutectic solvents

NARCIS (Netherlands)

Rodriguez, N.; Alves da Rocha, M.A.; Kroon, M.C.

2015-01-01

Ionic liquids (ILs) have been successfully tested in a wide range of applications; however, their high price and complicated synthesis make them infeasible for large scale implementation. A decade ago, a new generation of solvents so called deep eutectic solvents (DESs) was reported for the first

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

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

Directory of Open Access Journals (Sweden)

O’neil W. Guthrie

2016-01-01

Full Text Available Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

Science.gov (United States)

Guthrie, O'neil W.; Wong, Brian A.; McInturf, Shawn M.; Reboulet, James E.; Ortiz, Pedro A.; Mattie, David R.

2016-01-01

Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures. PMID:26885406

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction.

Science.gov (United States)

Guthrie, O'neil W; Wong, Brian A; McInturf, Shawn M; Reboulet, James E; Ortiz, Pedro A; Mattie, David R

2016-01-01

Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

Solvent induced supramolecular anisotropy in molecular gels

Energy Technology Data Exchange (ETDEWEB)

Rogers, Michael A., E-mail: mroger09@uoguelph.ca [Department of Food Science, University of Guelph, Guelph, Ontario, N3C3X9 (Canada); Corradini, Maria G. [Department of Food Science, University of Massachusetts Amherst, Amherst, MA, 01003 (United States); Emge, Thomas [Department of Chemistry and Biochemistry, Rutgers University, New Brunswick, NJ, 08901 (United States)

2017-06-15

Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

Double Solvent for Extracting Rare Earth Concentrate

International Nuclear Information System (INIS)

Bintarti, AN; Bambang EHB

2007-01-01

An extraction process to rare earth concentrate which contain elements were yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), gadolinium (Gd) and dysprosium (Dy) which were dissolved in to nitric acid has been done. The experiment of the extraction by double solvent in batch to mix 10 ml of the feed with 10 ml solvent contained the pair of solvent was TBP and TOA, D2EHPA and TOA, TBP and D2EHPA in cyclohexane as tinner. It was selected a right pairs of solvent for doing variation such as the acidity of the feed from 2 - 6 M and the time of stirring from 5 - 25 minutes gave the good relatively extraction condition to Dy element such as using 10 % volume of TOA in D2EHPA and cyclohexane, the acidity of the feed 3 M and the time stirring 15 minutes produced coefficient distribution to dysprosium = 0.586 and separation factor Dy-Ce = ∼ (unlimited); Dy-Nd = 4.651. (author)

Solvent induced supramolecular anisotropy in molecular gels

International Nuclear Information System (INIS)

Rogers, Michael A.; Corradini, Maria G.; Emge, Thomas

2017-01-01

Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

Solvent vapor annealing of an insoluble molecular semiconductor

KAUST Repository

Amassian, Aram

2010-01-01

Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

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.

Viscous fingering effects in solvent displacement of heavy oil

Energy Technology Data Exchange (ETDEWEB)

Cuthiell, D. [Suncor Energy, Fort McMurray, AB (Canada); Kissel, G.; Jackson, C.; Frauenfeld, T.W.J.; Fisher, D. [Alberta Research Council, Devon, AB (Canada); Rispler, K. [Saskatchewan Research Council, Saskatoon, SK (Canada)

2004-07-01

Vapour Extraction (VAPEX) is a solvent-based process that is analogous to steam-assisted gravity drainage (SAGD) for the recovery of heavy oil. A cyclic solvent process is preferred for thin reservoirs, particularly primary-depleted reservoirs. In a cyclic steam stimulation process, a solvent is injected into the reservoir for a period of time before oil is produced from the well. Viscous fingering is a phenomena that characterizes several solvent-based processes for the recovery of heavy oil. A combined experimental and simulation study was conducted to characterize viscous fingering under heavy oil recovery conditions (high ratio of oil to solvent viscosity). Four experiments were conducted in heavy oil-saturated sand packs. Three involved injection of a miscible, liquid solvent at the bottom of the sand pack. The heavy oil in these experiments was displaced upwardly. The fourth experiment involved top-down injection of a gaseous solvent. The miscible liquid displacement was dominated by one solvent finger which broke through to a producing well at the other end of the sand pack. Breakthrough times were similar to that at lower viscosity. The fourth experiment showed fingering along with features of a gravity-driven VAPEX process. Key features of the experiment and realistic fingering patterns were numerically simulated using a commercial reservoir simulator. It was emphasized that accurate modelling of dispersion is necessary in matching the observed phenomena. The simulations should include the capillary effects because of their significance for gaseous fingering and the VAPEX processes. 17 refs., 2 tabs., 20 figs.

TRUEX process solvent cleanup with solid sorbents

International Nuclear Information System (INIS)

Tse, Pui-Kwan; Reichley-Yinger, L.; Vandegrift, G.F.

1989-01-01

Solid sorbents, alumina, silica gel, and Amberlyst A-26 have been tested for the cleanup of degraded TRUEX-NPH solvent. A sodium carbonate scrub alone does not completely remove acidic degradation products from highly degraded solvent and cannot restore the stripping performance of the solvent. By following the carbonate scrub with either neutral alumina or Amberlyst A-26 anion exchange resin, the performance of the TRUEX-NPH is substantially restored. The degraded TRUEX-NPH was characterized before and after treatment by supercritical fluid chromatography. Its performance was evaluated by americium distribution ratios, phase-separation times, and lauric acid distribution coefficients. 17 refs., 2 figs., 5 tabs

Assessing the Impact of Chlorinated-Solvent Sites on Metropolitan Groundwater Resources

OpenAIRE

Brusseau, Mark L.; Narter, Matthew

2013-01-01

Chlorinated-solvent compounds are among the most common groundwater contaminants in the U.S.A. The majority of the many sites contaminated by chlorinated-solvent compounds are located in metropolitan areas, and most such areas have one or more chlorinated-solvent contaminated sites. Thus, contamination of groundwater by chlorinated-solvent compounds may pose a potential risk to the sustainability of potable water supplies for many metropolitan areas. The impact of chlorinated-solvent sites on...

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.

Reformulation of Maxwell's equations to incorporate near-solute solvent structure.

Science.gov (United States)

Yang, Pei-Kun; Lim, Carmay

2008-09-04

Maxwell's equations, which treat electromagnetic interactions between macroscopic charged objects in materials, have explained many phenomena and contributed to many applications in our lives. Derived in 1861 when no methods were available to determine the atomic structure of macromolecules, Maxwell's equations assume the solvent to be a structureless continuum. However, near-solute solvent molecules are highly structured, unlike far-solute bulk solvent molecules. Current methods cannot treat both the near-solute solvent structure and time-dependent electromagnetic interactions in a macroscopic system. Here, we derive "microscopic" electrodynamics equations that can treat macroscopic time-dependent electromagnetic field problems like Maxwell's equations and reproduce the solvent molecular and dipole density distributions observed in molecular dynamics simulations. These equations greatly reduce computational expense by not having to include explicit solvent molecules, yet they treat the solvent electrostatic and van der Waals effects more accurately than continuum models. They provide a foundation to study electromagnetic interactions between molecules in a macroscopic system that are ubiquitous in biology, bioelectromagnetism, and nanotechnology. The general strategy presented herein to incorporate the near-solute solvent structure would enable studies on how complex cellular protein-ligand interactions are affected by electromagnetic radiation, which could help to prevent harmful electromagnetic spectra or find potential therapeutic applications.

A smooth and differentiable bulk-solvent model for macromolecular diffraction

Energy Technology Data Exchange (ETDEWEB)

Fenn, T. D. [Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford, California (United States); Schnieders, M. J. [Department of Chemistry, Stanford, California (United States); Brunger, A. T., E-mail: brunger@stanford.edu [Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford, California (United States); Departments of Neurology and Neurological Sciences, Structural Biology and Photon Science, Stanford, California (United States)

2010-09-01

A new method for modeling the bulk solvent in macromolecular diffraction data based on Babinet’s principle is presented. The proposed models offer the advantage of differentiability with respect to atomic coordinates. Inclusion of low-resolution data in macromolecular crystallography requires a model for the bulk solvent. Previous methods have used a binary mask to accomplish this, which has proven to be very effective, but the mask is discontinuous at the solute–solvent boundary (i.e. the mask value jumps from zero to one) and is not differentiable with respect to atomic parameters. Here, two algorithms are introduced for computing bulk-solvent models using either a polynomial switch or a smoothly thresholded product of Gaussians, and both models are shown to be efficient and differentiable with respect to atomic coordinates. These alternative bulk-solvent models offer algorithmic improvements, while showing similar agreement of the model with the observed amplitudes relative to the binary model as monitored using R, R{sub free} and differences between experimental and model phases. As with the standard solvent models, the alternative models improve the agreement primarily with lower resolution (>6 Å) data versus no bulk solvent. The models are easily implemented into crystallographic software packages and can be used as a general method for bulk-solvent correction in macromolecular crystallography.

A smooth and differentiable bulk-solvent model for macromolecular diffraction

International Nuclear Information System (INIS)

Fenn, T. D.; Schnieders, M. J.; Brunger, A. T.

2010-01-01

A new method for modeling the bulk solvent in macromolecular diffraction data based on Babinet’s principle is presented. The proposed models offer the advantage of differentiability with respect to atomic coordinates. Inclusion of low-resolution data in macromolecular crystallography requires a model for the bulk solvent. Previous methods have used a binary mask to accomplish this, which has proven to be very effective, but the mask is discontinuous at the solute–solvent boundary (i.e. the mask value jumps from zero to one) and is not differentiable with respect to atomic parameters. Here, two algorithms are introduced for computing bulk-solvent models using either a polynomial switch or a smoothly thresholded product of Gaussians, and both models are shown to be efficient and differentiable with respect to atomic coordinates. These alternative bulk-solvent models offer algorithmic improvements, while showing similar agreement of the model with the observed amplitudes relative to the binary model as monitored using R, R free and differences between experimental and model phases. As with the standard solvent models, the alternative models improve the agreement primarily with lower resolution (>6 Å) data versus no bulk solvent. The models are easily implemented into crystallographic software packages and can be used as a general method for bulk-solvent correction in macromolecular crystallography

Ultrasonic aqueous cleaning as a replacement for chlorinated solvent cleaning

International Nuclear Information System (INIS)

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

1992-01-01

The Oak Ridge Y-12 Plant has been involved in the replacement of chlorinated solvents since 1982. One of the most successful replacement efforts has been the substitution of vapor degreasers or soak tanks using chlorinated solvents with ultrasonic cleaning using aqueous detergents. Recently, funding was obtained from the Department of Energy Office (DOE) of Technology Development to demonstrate this technology. A unit has been procured and installed in the vacuum pump shop area to replace the use of a solvent soak tank. Initially, the solvents used in the shop were CFC-113 and a commercial brand cleaner which contained both perchloroethylene and methylene chloride. While the ultrasonic unit was being procured, a terpene-based solvent was used. Generally, parts were soaked overnight in order to soften baked-on vanish. Many times, wire brushing was used to help remove remaining contamination. Initial testing with the ultrasonic cleaner indicated cleaning times of 20 min were as effective as the overnight solvent soaks in removing contamination. Wire brushing was also not required following the ultrasonic cleaning as was sometimes required with the solvent soak

Morphological control in polymer solar cells using low-boiling-point solvent additives

Science.gov (United States)

Mahadevapuram, Rakesh C.

In the global search for clean, renewable energy sources, organic photovoltaics (OPVs) have recently been given much attention. Popular modern-day OPVs are made from solution-processible, carbon-based polymers (e.g. the model poly(3-hexylthiophene) that are intimately blended with fullerene derivatives (e.g. [6,6]-phenyl-C71-butyric acid methyl ester) to form what is known as the dispersed bulk-heterojunction (BHJ). This BHJ architecture has produced some of the most efficient OPVs to date, with reports closing in on 10% power conversion efficiency. To push efficiencies further into double digits, many groups have identified the BHJ nanomorphology---that is, the phase separations and grain sizes within the polymer: fullerene composite---as a key aspect in need of control and improvement. As a result, many methods, including thermal annealing, slow-drying (solvent) annealing, vapor annealing, and solvent additives, have been developed and studied to promote BHJ self-organization. Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in BHJ OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole mobilities, and shunt leakage currents. Dependence on solvent parameters and applicability beyond P3HT system was also investigated.

Method for Selection of Solvents for Promotion of Organic Reactions

DEFF Research Database (Denmark)

Gani, Rafiqul; Jiménez-González, Concepción; Constable, David J.C.

2005-01-01

is to produce, for a given reaction, a short list of chemicals that could be considered as potential solvents, to evaluate their performance in the reacting system, and, based on this, to rank them according to a scoring system. Several examples of application are given to illustrate the main features and steps......A method to select appropriate green solvents for the promotion of a class of organic reactions has been developed. The method combines knowledge from industrial practice and physical insights with computer-aided property estimation tools for selection/design of solvents. In particular, it employs...... estimates of thermodynamic properties to generate a knowledge base of reaction, solvent and environment related properties that directly or indirectly influence the rate and/or conversion of a given reaction. Solvents are selected using a rules-based procedure where the estimated reaction-solvent properties...

Understanding Solvent Manipulation of Morphology in Bulk-Heterojunction Organic Solar Cells.

Science.gov (United States)

Chen, Yuxia; Zhan, Chuanlang; Yao, Jiannian

2016-10-06

Film morphology greatly influences the performance of bulk-heterojunction (BHJ)-structure-based solar cells. It is known that an interpenetrating bicontinuous network with nanoscale-separated donor and acceptor phases for charge transfer, an ordered molecular packing for exciton diffusion and charge transport, and a vertical compositionally graded structure for charge collection are prerequisites for achieving highly efficient BHJ organic solar cells (OSCs). Therefore, control of the morphology to obtain an ideal structure is a key problem. For this solution-processing BHJ system, the solvent participates fully in film processing. Its involvement is critical in modifying the nanostructure of BHJ films. In this review, we discuss the effects of solvent-related methods on the morphology of BHJ films, including selection of the casting solvent, solvent mixture, solvent vapor annealing, and solvent soaking. On the basis of a discussion on interaction strength and time between solvent and active materials, we believe that the solvent-morphology-performance relationship will be clearer and that solvent selection as a means to manipulate the morphology of BHJ films will be more rational. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Volatile solvents as drugs of abuse: focus on the cortico-mesolimbic circuitry.

Science.gov (United States)

Beckley, Jacob T; Woodward, John J

2013-12-01

Volatile solvents such as those found in fuels, paints, and thinners are found throughout the world and are used in a variety of industrial applications. However, these compounds are also often intentionally inhaled at high concentrations to produce intoxication. While solvent use has been recognized as a potential drug problem for many years, research on the sites and mechanisms of action of these compounds lags behind that of other drugs of abuse. In this review, we first discuss the epidemiology of voluntary solvent use throughout the world and then consider what is known about their basic pharmacology and how this may explain their use as drugs of abuse. We next present data from preclinical and clinical studies indicating that these substances induce common addiction sequelae such as dependence, withdrawal, and cognitive impairments. We describe how toluene, the most commonly studied psychoactive volatile solvent, alters synaptic transmission in key brain circuits such as the mesolimbic dopamine system and medial prefrontal cortex (mPFC) that are thought to underlie addiction pathology. Finally, we make the case that activity in mPFC circuits is a critical regulator of the mesolimbic dopamine system's ability to respond to volatile solvents like toluene. Overall, this review provides evidence that volatile solvents have high abuse liability because of their selective effects on critical nodes of the addiction neurocircuitry, and underscores the need for more research into how these compounds induce adaptations in neural circuits that underlie addiction pathology.

Solvent management in a reprocessing plant

International Nuclear Information System (INIS)

Guillaume, B.; Germain, M.; Puyou, M.; Rouyer, H.

1987-01-01

Solvent management in large capacity reprocessing plant is studied to limit production of organic wastes. Chemical processing increases life time of solvent. Low pressure distillation allows the recycling of TBP and diluent at a low activity level. Besides heavy degradation products are eliminated. For the safety the flash point of distillated diluent increases slightly. Tests on an industrial scale started in 1985 and since more than 500 cubic meters were treated [fr

Exploring a multi-scale method for molecular simulation in continuum solvent model: Explicit simulation of continuum solvent as an incompressible fluid.

Science.gov (United States)

Xiao, Li; Luo, Ray

2017-12-07

We explored a multi-scale algorithm for the Poisson-Boltzmann continuum solvent model for more robust simulations of biomolecules. In this method, the continuum solvent/solute interface is explicitly simulated with a numerical fluid dynamics procedure, which is tightly coupled to the solute molecular dynamics simulation. There are multiple benefits to adopt such a strategy as presented below. At this stage of the development, only nonelectrostatic interactions, i.e., van der Waals and hydrophobic interactions, are included in the algorithm to assess the quality of the solvent-solute interface generated by the new method. Nevertheless, numerical challenges exist in accurately interpolating the highly nonlinear van der Waals term when solving the finite-difference fluid dynamics equations. We were able to bypass the challenge rigorously by merging the van der Waals potential and pressure together when solving the fluid dynamics equations and by considering its contribution in the free-boundary condition analytically. The multi-scale simulation method was first validated by reproducing the solute-solvent interface of a single atom with analytical solution. Next, we performed the relaxation simulation of a restrained symmetrical monomer and observed a symmetrical solvent interface at equilibrium with detailed surface features resembling those found on the solvent excluded surface. Four typical small molecular complexes were then tested, both volume and force balancing analyses showing that these simple complexes can reach equilibrium within the simulation time window. Finally, we studied the quality of the multi-scale solute-solvent interfaces for the four tested dimer complexes and found that they agree well with the boundaries as sampled in the explicit water simulations.

Microfluidic Extraction of Biomarkers using Water as Solvent

Science.gov (United States)

Amashukeli, Xenia; Manohara, Harish; Chattopadhyay, Goutam; Mehdi, Imran

2009-01-01

A proposed device, denoted a miniature microfluidic biomarker extractor (mu-EX), would extract trace amounts of chemicals of interest from samples, such as soils and rocks. Traditionally, such extractions are performed on a large scale with hazardous organic solvents; each solvent capable of dissolving only those molecules lying within narrow ranges of specific chemical and physical characteristics that notably include volatility, electric charge, and polarity. In contrast, in the mu-EX, extractions could be performed by use of small amounts (typically between 0.1 and 100 L) of water as a universal solvent. As a rule of thumb, in order to enable solvation and extraction of molecules, it is necessary to use solvents that have polarity sufficiently close to the polarity of the target molecules. The mu-EX would make selection of specific organic solvents unnecessary, because mu-EX would exploit a unique property of liquid water: the possibility of tuning its polarity to match the polarity of organic solvents appropriate for extraction of molecules of interest. The change of the permittivity of water would be achieved by exploiting interactions between the translational states of water molecules and an imposed electromagnetic field in the frequency range of 300 to 600 GHz. On a molecular level, these interactions would result in disruption of the three-dimensional hydrogen-bonding network among liquid-water molecules and subsequent solvation and hydrolysis of target molecules. The mu-EX is expected to be an efficient means of hydrolyzing chemical bonds in complex macromolecules as well and, thus, enabling analysis of the building blocks of these complex chemical systems. The mu-EX device would include a microfluidic channel, part of which would lie within a waveguide coupled to an electronically tuned source of broad-band electromagnetic radiation in the frequency range from 300 to 600 GHz (see figure). The part of the microfluidic channel lying in the waveguide would

Influence of solvents on species crossover and capacity decay in non-aqueous vanadium redox flow batteries: Characterization of acetonitrile and 1, 3 dioxolane solvent mixture

Science.gov (United States)

Bamgbopa, Musbaudeen O.; Almheiri, Saif

2017-02-01

The importance of the choice of solvent in a non-aqueous redox flow battery (NARFB) cannot be overemphasized. Several studies demonstrated the influence of the solvent on electrolyte performance in terms of reaction rates, energy/power densities, and efficiencies. In this work, we investigate capacity decay as a direct consequence of varying reactant crossover rates through membranes in different solvent environments. Specifically, we demonstrate the superiority of an 84/16 vol% acetonitrile/1,3 dioxolane solvent mixture over pure acetonitrile in terms of energy efficiency (up to 89%) and capacity retention for vanadium NARFBs - while incorporating a Nafion 115 membrane. The permeability of Nafion to the vanadium acetylacetonate active species is an order of magnitude lower when pure acetonitrile is replaced by the solvent mixture. A method to estimate relative membrane permeability is formulated from numerical analysis of self-discharge experimental data. Furthermore, tests on a modified Nafion/SiO2 membrane, which generally offered low species permeability, also show that different solvents alter membrane permeability. Elemental and morphological analyses of cycled Nafion and NafionSi membranes in different solvent environments indicate that different crossover rates induced by the choice of solvent during cycling are due to changes in the membrane microstructure, intrinsic permeability, swelling rates, and chemical stability.

Research on solvent extraction process for reprocessing of Th-U fuel from HTGR

International Nuclear Information System (INIS)

Bao Borong; Wang Gaodong; Qian Jun

1992-05-01

The unique properties of spent fuel from HTGR (high temperature gas cooled reactor) have been analysed. The single solvent extraction process using 30% TBP for separation and purification of Th-U fuel has been studied. In addition, the solvent extraction process for second uranium purification is also investigated to meet different needs of reprocessing and reproduction of Th-U spent fuel from HTGR

Theoretical study of solvent effects on the coil-globule transition

Science.gov (United States)

Polson, James M.; Opps, Sheldon B.; Abou Risk, Nicholas

2009-06-01

The coil-globule transition of a polymer in a solvent has been studied using Monte Carlo simulations of a single chain subject to intramolecular interactions as well as a solvent-mediated effective potential. This solvation potential was calculated using several different theoretical approaches for two simple polymer/solvent models, each employing hard-sphere chains and hard-sphere solvent particles as well as attractive square-well potentials between some interaction sites. For each model, collapse is driven by variation in a parameter which changes the energy mismatch between monomers and solvent particles. The solvation potentials were calculated using two fundamentally different methodologies, each designed to predict the conformational behavior of polymers in solution: (1) the polymer reference interaction site model (PRISM) theory and (2) a many-body solvation potential (MBSP) based on scaled particle theory introduced by Grayce [J. Chem. Phys. 106, 5171 (1997)]. For the PRISM calculations, two well-studied solvation monomer-monomer pair potentials were employed, each distinguished by the closure relation used in its derivation: (i) a hypernetted-chain (HNC)-type potential and (ii) a Percus-Yevick (PY)-type potential. The theoretical predictions were each compared to results obtained from explicit-solvent discontinuous molecular dynamics simulations on the same polymer/solvent model systems [J. Chem. Phys. 125, 194904 (2006)]. In each case, the variation in the coil-globule transition properties with solvent density is mostly qualitatively correct, though the quantitative agreement between the theory and prediction is typically poor. The HNC-type potential yields results that are more qualitatively consistent with simulation. The conformational behavior of the polymer upon collapse predicted by the MBSP approach is quantitatively correct for low and moderate solvent densities but is increasingly less accurate for higher densities. At high solvent densities

Safety confirmation study of TRUEX solvent by accelerating rate calorimeter (ARC)

International Nuclear Information System (INIS)

Sato, Yoshihiko; Hirumachi, Suguru; Takeda, Shinso; Kanazawa, Yoshito; Sasaya, Shinji

1999-02-01

In order to confirm the engineering safety on the TRUEX solvent (mixed solvent of CMPO/TBP/n-dodecane) for separating the transuranics from high-level activity liquid waste in advanced nuclear fuel recycling technological R and D, thermal behavior and pressure behavior in heating PUREX solvent (mixed solvent of 30% TBP-n-dodecane), TRUEX solvent and in the exothermic reaction of TRUEX solvent etc. and nitric acid in sealed adiabatic system which was severer condition than actual plant were measured by using accelerating rate calorimeter (ARC). The Arrhenius parameters (activation energy and frequency factor) which are necessary for the evaluation of reaction rate was examined from the measurement data in ARC. Analytical method and analysis condition of reaction products were examined in order to clarify chemical form of reaction products in exothermic reaction between solvent and nitric acid in ARC, and the qualitative evaluation was carried out. Main results are shown in the following. 1) TBP, CMPO, n-dodecane and 10 M nitric acid hardly exothermed in the simple substance. 2) On the solvent phase after the solvent contacted with 10 M nitric acid and the equilibrium has been attained (single-phase sample), the heat quantity per unit sample weight of the TRUEX solvent tended to be bigger than that of the PUREX solvent when heat quantity was evaluated in ARC. However, on the mixed sample of solvent and 10 M nitric acid enclosed in a sample container simultaneously (two phase system sample), the heat quantity per unit solvent weight was almost equivalent for PUREX solvent and TRUEX solvent. 3) The kinetic analysis was carried out, and on the TBP-10 M nitric acid single-phase sample, the activation energy of the reaction was evaluated to be 118 kJ/mol. Its activation energy was approximately equal to 112 kJ/mol by Nichols. The reaction rate constant was calculated, and it was shown that reaction rate constants of PUREX solvent-10 M nitric acid single-phase sample and

Impaired colour vision in workers exposed to organic solvents: A systematic review.

Science.gov (United States)

Betancur-Sánchez, A M; Vásquez-Trespalacios, E M; Sardi-Correa, C

2017-01-01

To evaluate recent evidence concerning the relationship between the exposure to organic solvents and the impairment of colour vision. A bibliographic search was conducted for scientific papers published in the last 15 years, in the LILACS, PubMed, Science Direct, EBSCO, and Cochrane databases that included observational studies assessing the relationship between impairment in colour vision and exposure to organic solvents. Eleven studies were selected that were performed on an economically active population and used the Lanthony D-15 desaturated test (D-15d), measured the exposure to organic solvents, and included unexposed controls. It was found that there is a statistically significant relationship between the exposure to organic solvents and the presence of an impairment in colour vision. The results support the hypothesis that exposure to organic solvents could induce acquired dyschromatopsia. The evaluation of colour vision with the D-15d test is simple and sensitive for diagnosis. More studies need to be conducted on this subject in order to better understand the relationship between impaired colour vision and more severe side effects caused by this exposure. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Comparison Pore Aggregate Levels After Extraction With Solvents Pertamax Plus And Gasoline

Science.gov (United States)

Anggraini, Muthia

2017-12-01

Loss of asphalt content extraction results become problems in Field Work For implementing parties. The use of solvents with high octane (pertamax plus) for the extraction, dissolving the asphalt more than gasoline. By comparing the levels of aggregate pores after using solvent extraction pertamax plus compared to gasoline could answer that pertamax plus more solvent dissolves the bitumen compared to gasoline. This study aims to obtain comparative levels of porous aggregate mix AC-WC after using solvent extraction pertamax plus compared to gasoline. This study uses the aggregate that has been extracted from the production of asphalt mixtures, when finisher and after compaction field. The method used is the assay of coarse and fine aggregate pores, extraction of bitumen content to separate the aggregate with bitumen. Results of testing the total absorption after extraction using a solvent preta max plus in the production of asphalt mixtures 0.80%, while gasoline solvent 0.67% deviation occurs 0.13%. In the finisher after the solvent extraction preta max plus 0.77%, while 0.67% gasoline solvent occurs deviation of 0.1%. At the core after extraction and solvent pertamax plus 0.71%, while gasoline solvent 0.60% 0.11% deviation occurs. The total water absorption after extraction using a solvent pertamax plus greater than gasoline. This proves that the solvent dissolves pertamax plus more asphalt than gasoline.

Initiate test loop irradiations of ALSEP process solvent

Energy Technology Data Exchange (ETDEWEB)

Peterman, Dean R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, Lonnie G. [Idaho National Lab. (INL), Idaho Falls, ID (United States); McDowell, Rocklan G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-09-01

This report describes the initial results of the study of the impacts of gamma radiolysis upon the efficacy of the ALSEP process and is written in completion of milestone M3FT-14IN030202. Initial irradiations, up to 100 kGy absorbed dose, of the extraction section of the ALSEP process have been completed. The organic solvent used for these experiments contained 0.05 M TODGA and 0.75 M HEH[EHP] dissolved in n-dodecane. The ALSEP solvent was irradiated while in contact with 3 M nitric acid and the solutions were sparged with compressed air in order to maintain aerated conditions. The irradiated phases were used for the determination of americium and europium distribution ratios as a function of absorbed dose for the extraction and stripping conditions. Analysis of the irradiated phases in order to determine solvent composition as a function of absorbed dose is ongoing. Unfortunately, the failure of analytical equipment necessary for the analysis of the irradiated samples has made the consistent interpretation of the analytical results difficult. Continuing work will include study of the impacts of gamma radiolysis upon the extraction of actinides and lanthanides by the ALSEP solvent and the stripping of the extracted metals from the loaded solvent. The irradiated aqueous and organic phases will be analyzed in order to determine the variation in concentration of solvent components with absorbed gamma dose. Where possible, radiolysis degradation product will be identified.

Hydrothermal liquefaction of de-oiled Jatropha curcas cake using Deep Eutectic Solvents (DESs) as catalysts and co-solvents.

Science.gov (United States)

Alhassan, Yahaya; Kumar, Naveen; Bugaje, Idris M

2016-01-01

Biomass liquefaction using ionic liquids (ILs) as catalysts has received appreciable attention, in renewable fuels and chemicals production, recently. However, issues associated with the production cost, long reaction time and use of volatile solvents are undeniably challenging. Thus, Deep Eutectic Solvents (DESs) emerged as promising and potential ILs substitutes. The hydrothermal liquefaction of de-oiled Jatropha curcas cake was catalyzed by four synthesized DESs as catalysts and co-solvents for selective extraction. Proximate and ultimate analyses including ash, moisture and carbon contents of bio-crude produced varied slightly. The higher heating values found ranges from 21.15 ± 0.82 MJ/kg to 24.30 ± 0.98 MJ/kg. The bio-crude yields obtained using ChCl-KOH DES was 43.53 wt% and ChCl-p-TsOH DES was 38.31 wt%. Bio-crude yield using ChCl-FeCl3 DES was 30.80 wt%. It is suggested that, the selectivity of bio-crude could be improved, by using DESs as catalyst and co-solvent in HTL of biomass such as de-oiled J. curcas cake. Copyright © 2015 Elsevier Ltd. All rights reserved.

Computer-Aided Solvent Screening for Biocatalysis

DEFF Research Database (Denmark)

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

2013-01-01

constrained properties related to chemical reaction equilibrium, substrate and product solubility, water solubility, boiling points, toxicity and others. Two examples are provided, covering the screening of solvents for lipase-catalyzed transesterification of octanol and inulin with vinyl laurate....... 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....

Isotope effects in ion-exchange equilibria in aqueous and mixed solvent systems

International Nuclear Information System (INIS)

Gupta, A.R.

1979-01-01

Isotope effects in ion-exchange equilibria in aqueous and mixed solvents are analyzed in terms of the general features of ion-exchange equilibria and of isotope effects in chemical equilibria. The special role of solvent fractionation effects in ion-exchange equilibria in mixed solvents is pointed out. The various situations arising in isotope fractionation in ion exchange in mixed solvents due to solvent fractionation effects are theoretically discussed. The experimental data on lithium isotope effects in ion-exchange equilibria in mixed solvents are shown to conform to the above situations. The limitations of ion-exchange equilibria in mixed solvents for isotope fractionation are pointed out. 3 tables

"Winterização" de óleo de pescado via solvente Winterization of fish oil with solvent

Directory of Open Access Journals (Sweden)

Daniele Colembergue Cunha

2009-03-01

Full Text Available O fracionamento de óleos via "winterização" consiste numa cristalização fracionada, na qual os triacilgliceróis de óleos e gorduras são separados pela cristalização parcial na fase líquida. O objetivo deste trabalho consistiu na determinação das variáveis significativas e das condições operacionais do processo de "winterização" via solvente do óleo de pescado. Como matéria-prima empregou-se o óleo de pescado bruto de indústrias pesqueiras, o qual foi branqueado. Na etapa de "winterização", o óleo branqueado foi resfriado progressivamente em três estágios, de 30 ºC até -5 ºC. Foram estudados os seguintes fatores: tipo de solvente, proporção de solvente e agitação no segundo estágio do resfriamento. As composições de ácidos graxos dos óleos de pescado foram determinadas através de cromatografia gasosa. Foram analisadas as variações percentuais dos ácidos graxos insaturados e dos ácidos graxos saturados. As condições recomendadas para o processo foram o emprego de hexano como solvente, na proporção de 40% em relação à massa de óleo, e sem o emprego de agitação no segundo estágio do resfriamento. Sob tais condições, obteve-se um óleo com teor de ácidos graxos poli-insaturados (PUFA de 64,3%, sendo observado um aumento no percentual dos ácidos graxos insaturados de aproximadamente 9,2% e uma redução de 13,4% dos saturados, em relação ao óleo branqueado de pescado.The process of winterization consists of fractional crystallization, in which the triglycerides of oils and fats are separate by the partial crystallization in the liquid phase. The objective of this work was to evaluate significant variables and the operational conditions in the solvent winterization process of the fish oil. The crude fish oil from fishery industries was bleached and used as raw material. During the winterization step, the bleached oil was cooled progressively from 30 ºC to 5 ºC in three phases. The solvent

Spent solvent treatment process at Rokkasho Reprocessing Plant

International Nuclear Information System (INIS)

Sasaki, Akihiro; Saka, Munenori; Araya, Toshiyuki; Kitamura, Tomohiro; Wakamatsu, Toshiyuki

2005-01-01

In order to dispose of spent organic solvent and diluent produced by the PUREX method, it is desirable that it should be in stable form for easy handling. For this reason, spent solvent is reduced to powder form and further molded so that it becomes easier to handle for temporary storage at Rokkasho Reprocessing Plant (RRP). In this paper, the treatment unit for reducing spent solvent to powder form and the treatment unit for modeling the powder are introduced as well as their treatment results during Chemical Test. (author)

Proceedings of ISEC 2008, International Solvent Extraction Conference - Solvent Extraction: Fundamentals to Industrial Applications

International Nuclear Information System (INIS)

Moyer, Bruce A.

2008-01-01

The North American industry has employed major solvent-extraction processes to support a wide range of separations including but not limited to chemical, metallurgical, nuclear, biochemical, pharmaceutical, and petroleum applications. The knowledge enabling these separations has been obtained through fundamental studies in academe, government and industry. The International Solvent Extraction Conferences have been and continue to be a major gathering of scientists, engineers, operators, and vendors from around the world, who present new findings since the last meeting, exchange ideas, make business contacts, and conduct collegial discussions. The ISEC 2008 program emphasizes fundamentals to industrial applications of solvent extraction, particularly how this broad spectrum of activities is interconnected and has led to the implementation of novel processes. The oral and poster sessions have been organized into seven topics: Fundamentals; Novel Reagents, Materials and Techniques; Nuclear Fuel Reprocessing; Hydrometallurgy and Metals Extraction; Analytical and Preparative Applications; Biotechnology, Pharmaceuticals, Life-Science Products, and Organic Products; and Process Chemistry and Engineering. Over 350 abstracts were received, resulting in more than 260 manuscripts published in these proceedings. Five outstanding plenary presentations have been identified, with five parallel sessions for oral presentations and posters. In recognition of the major role solvent extraction (SX) plays in the hydrometallurgical and nuclear industries, these proceedings begin with sections focusing on hydrometallurgy, process chemistry, and engineering. More fundamental topics follow, including sections on novel reagents, materials, and techniques, featuring novel applications in analytical and biotechnology areas. Despite the diversity of topics and ideas represented, however, the primary focus of the ISEC community continues to be metals extraction. Four papers from these

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.

Occupational exposure to organic solvents and sleep-disordered breathing.

Science.gov (United States)

Ulfberg, J; Carter, N; Talbäck, M; Edling, C

1997-01-01

To investigate whether people with occupational exposure to organic solvents have a higher prevalence of obstructive sleep apnea syndrome (OSAS) than the general population and to examine the relationship between snoring and exposure to organic solvents. Consecutive patients, aged 30-64 years, referred during a 3-year period to the sleep laboratory at Avesta Hospital, Sweden, because of suspected OSAS made up the patient groups. Following admission, patients underwent a simplified sleep apnea investigation and were divided into two groups, OSAS (n = 320) and snorers (n = 443). A random sample of 296 men and 289 women aged 30-64 years obtained from a register of all country residents maintained by the county tax authority served as referents (controls). Both patients and referents responded to two questionnaires, including questions about occupation, exposure to organic solvents, and other chemical and physical agents. Men with OSAS or snoring and women with snoring had more often been occupationally exposed to organic solvents than the referents, showing an almost twofold increase in risk for those exposed during whole workdays. For men, the risk of OSAS or snoring increased with increasing exposure. The result indicates that occupational exposure to organic solvents might cause sleep apnea. A new observation is that even snoring could be caused by exposure to organic solvents. It is important to elucidate whether exposure to organic solvents is a cause of OSAS, because such a finding may have important implications for prevention and treatment of sleep disturbances.

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 optim......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...... 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...

A prototype study with solvent extraction on industrial scale

International Nuclear Information System (INIS)

Hernandez, M.E.

1990-01-01

The need for uranium purification has generated the study of different methods in order for purification to be achieved, having had excellent results in the laboratory with ionic exchange methods, extraction by means of solvents and chromatography. Pilot experiments of the ionic exchange method have been performed, using as experimentation equipment the columns of ionic exchange, attaining some results without concreting the objectives. Likewise several experiments in mixer-settlers have been performed for the purification of uranium by the solvent extraction method, where there were serious problems with the formation of a third incontrollable phase, and also, due to the later, low purification of the uranium when distributing from one phase to the other. Knowing these problems brought on by the performed experiments in mixer-setters by groups of researchers interested in this part of the nuclear fuel, the task of designing a prototype of extraction with solvents of the mixer-settler type was undertaken in the project 'Models and simulation of equipment and processes of the refinement and conversion department'. The purification of uranium as uranyl nitrate [UO 2 (NO 3 ) 2 ] was developed, establishing the conditions for the equipment operation, concluding that, with some relatively simple adjustements, it is possible to apply in different areas, taking note of the specific needs of mining, cosmetics, perfume and pharmaceutical areas. (Author)

Solvent effects in ionic liquids: empirical linear energy-density relationships.

Science.gov (United States)

Cerda-Monje, A; Aizman, A; Tapia, R A; Chiappe, C; Contreras, R

2012-07-28

Multiparameter linear energy-density relationships to model solvent effects in room temperature ionic liquids (RTILs) are introduced and tested. The model incorporates two solvent dependent and two specific solute-solvent parameters represented by a set of electronic indexes derived from the conceptual density functional theory. The specific solute-solvent interactions are described in terms of the electronic chemical potential for proton migration between the anion or cation and the transition state structure of a specific reaction. These indexes provide a quantitative estimation of the hydrogen bond (HB) acceptor basicity and the hydrogen bond donor acidity of the ionic solvent, respectively. A sound quantitative scale of HB strength is thereby obtained. The solvent dependent contributions are described by the global electrophilicity of the cation and nucleophilicity of the anion forming the ionic liquid. The model is illustrated for the kinetics of cycloaddition of cyclopentadiene towards acrolein. In general, cation HB acidity outweighs the remaining parameters for this reaction.

Apparatus and method for removing solvent from carbon dioxide in resin recycling system

Science.gov (United States)

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

2009-01-06

A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

Effect of solvent blending on cycling characteristics of lithium

Energy Technology Data Exchange (ETDEWEB)

Morita, Masayuki; Matsuda, Yoshiharu

1987-07-01

The suitability of electrolytes using mixed solvents has been examined for ambient temperature, rechargeable lithium batteries. Sulfolane (S) and dimethylsulfoxide (DMSO) have been used as base solvents because of their high permittivity, and ethers such as 1,2-dimethoxyethane (DME) have been blended as a low viscosity co-solvent. This blending has been found to yield electrolytes with a high conductivity, and maximum values are observed in solutions with 40-90 mol% ether. The cycling characteristics of lithium are also improved by blending the ethers. The coulombic efficiencies on a nickel substrate are greater than or equal to 80% in S-DME/LiPF/sub 6/ and DMSO-DME/LiPF/sub 6/ solutions. The lithium electrode characteristics are markedly dependent on the type of co-solvent ether, as well as on the electrolytic salt. The results of the conductance behaviour and the electrode characteristics are discussed in terms of ionic structure in the mixed solvent and the state of the electrode/electrolyte interphase.

Aerosols released from solvent fire accidents in reprocessing plants

International Nuclear Information System (INIS)

Jordan, S.; Lindner, W.

1985-01-01

Thermodynamic, aerosol characterizing and radiological data of solvent fires in reprocessing plants have been established in experiments. These are the main results: Depending on the ventilation in the containment, kerosene-TBP mixtures burn at a rate up to 120 kg/m 2 h. The aqueous phase of inorganic-organic mixtures might be released during the fire. The gaseous reaction products contain unburnable acidic compounds. Solvents with TBP-nitrate complex shows higher (up to 25%) burning rates than pure solvents (kerosene-TBP). The nitrate complex decomposes violently at about 130 0 C with a release of acid and unburnable gases. Up to 20% of the burned kerosene-TBP solvents are released during the fire in the form of soot particles, phosphoric acid and TBP decomposition products. The particles have an aerodynamic mass median diameter of about 0.5 μm and up to 1.5% of the uranium fixed in the TBP-nitrate complex is released during solvent fires. (orig.)

Depleted depletion drives polymer swelling in poor solvent mixtures.

Science.gov (United States)

Mukherji, Debashish; Marques, Carlos M; Stuehn, Torsten; Kremer, Kurt

2017-11-09

Establishing a link between macromolecular conformation and microscopic interaction is a key to understand properties of polymer solutions and for designing technologically relevant "smart" polymers. Here, polymer solvation in solvent mixtures strike as paradoxical phenomena. For example, when adding polymers to a solvent, such that all particle interactions are repulsive, polymer chains can collapse due to increased monomer-solvent repulsion. This depletion induced monomer-monomer attraction is well known from colloidal stability. A typical example is poly(methyl methacrylate) (PMMA) in water or small alcohols. While polymer collapse in a single poor solvent is well understood, the observed polymer swelling in mixtures of two repulsive solvents is surprising. By combining simulations and theoretical concepts known from polymer physics and colloidal science, we unveil the microscopic, generic origin of this collapse-swelling-collapse behavior. We show that this phenomenon naturally emerges at constant pressure when an appropriate balance of entropically driven depletion interactions is achieved.

Electrolytes including fluorinated solvents for use in electrochemical cells

Science.gov (United States)

Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan

2015-07-07

Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include ion-supplying salts and fluorinated solvents capable of maintaining single phase solutions with the salts at between about -30.degree. C. to about 80.degree. C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and increase safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Fluorinated salts, such as fluoroalkyl-substituted LiPF.sub.6, fluoroalkyl-substituted LiBF.sub.4 salts, linear and cyclic imide salts as well as methide salts including fluorinated alkyl groups, may be used due to their solubility in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene or, more specifically, a cyclic phosphazene and/or one or more ionic liquids.

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.

NMR and Solvent Effect Study on the Thymine-Adenine-Thymine ...

African Journals Online (AJOL)

... discussed about the plotted graphs of relative energies versus dielectric constants of our considered solvents. Thus, we can drastically conclude that the dielectric permittivity of the solvent is a key factor that determines the chemical behavior of DNA in solution. Keywords: TAT sequence; solvent effect; NMR parameters; ...

27 CFR 20.112 - Special industrial solvents general-use formula.

Science.gov (United States)

2010-04-01

... solvents general-use formula. 20.112 Section 20.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND... AND RUM Formulas and Statements of Process General-Use Formulas § 20.112 Special industrial solvents general-use formula. (a) A special industrial solvent is any article made with any other ingredients...

SAGE 2.0 SOLVENT ALTERNATIVES GUIDE - USER'S GUIDE

Science.gov (United States)

The guide provides instruction for using the SAGE (Solvent Alternatives Guide) software system, version 2.O. It assumes that the user is familiar with the fundamentals of operating a personal computer under the Microsoft disk operating system (MS-DOS). AGE recommends solvent repl...

SAGE 2.1: SOLVENT ALTERNATIVES GUIDE: USER'S GUIDE

Science.gov (United States)

The guide provides instruction for using the SAGE (Solvent Alternatives GuidE) software system, version 2.1. SAGE recommends solvent replacements in cleaning and degreasing operations. It leads the user through a question-and-answer session. The user's responses allow the system ...

MOLECULAR THERMODYNAMICS IN THE DESIGN OF SUBSTITUTE SOLVENTS

Science.gov (United States)

The use of physical properties and fluid behavior from molecular thermodynamics can lead to better decision making in the design of substitute solvents and can greatly reduce the expense and time required to find substitutes compared to designing solvents by experiment. this pape...

Influence of solvent absorption on the migration of Irganox 1076 from LDPE

NARCIS (Netherlands)

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

2002-01-01

The effect of solvent absorption on additive migration was studied by relating the diffusion coefficient (D) of Irganox 1076 to the maximum solvent absorption of different solvents in low-density polyethylene (LDPE) film. Solvents tested were ethanol, isopropanol, isooctane, ethylacetate,

Unexpected solvent effects on the UV/Vis absorption spectra of o-cresol in toluene and benzene: in contrast with non-aromatic solvents.

Science.gov (United States)

Zheng, Dong; Yuan, Xiang-Ai; Ma, Haibo; Li, Xiaoxiong; Wang, Xizhang; Liu, Ziteng; Ma, Jing

2018-03-01

Cresol is a prototype molecule in understanding intermolecular interactions in material and biological systems, because it offers different binding sites with various solvents and protonation states under different pH values. It is found that the UV/Vis absorption spectra of o -cresol in aromatic solvents (benzene, toluene) are characterized by a sharp peak, unlike the broad double-peaks in 11 non-aromatic solvents. Both molecular dynamics simulations and electronic structure calculations revealed the formation of intermolecular π-complexation between o -cresol and aromatic solvents. The thermal movements of solvent and solute molecules render the conformations of o -cresol changing between trans and cis isomers. The π-interaction makes the cis configuration a dominant isomer, hence leading to the single keen-edged UV/Vis absorption peak at approximately 283 nm. The free conformation changes between trans and cis in aqueous solution rationalize the broader absorption peaks in the range of 260-280 nm. The pH dependence of the UV/Vis absorption spectra in aqueous solutions is also rationalized by different protonation states of o -cresol. The explicit solvent model with long-ranged interactions is vital to describe the effects of π-complexation and electrostatic interaction on the UV/Vis absorption spectra of o -cresol in toluene and alkaline aqueous (pH > 10.3) solutions, respectively.

The Solvent Effectiveness on Extraction Process of Seaweed Pigment

Directory of Open Access Journals (Sweden)

Warkoyo Warkoyo

2011-09-01

Full Text Available Eucheuma cottonii seaweed is a species of seaweed cultured in Indonesian waters, because its cultivation is relatively easy and inexpensive. It has a wide variety of colors from green to yellow green, gray, red and brown, indicating photosynthetic pigments, such as chlorophyll and carotenoids. An important factor in the effectiveness of pigment extraction is the choice of solvent. The correct type of solvent in the extraction method of specific natural materials is important so that a pigment with optimum quality that is also benefical to the society can be produced. The target of this research is to obtain a high quality solvent type of carotenoid pigment. This research was conducted using a randomized block design with three (3 replications involving two factors namely solvent type (4 levels: aceton, ethanol, petroleum benzene, hexan & petroleum benzene and seaweed color (3 levels: brown, green and red. Research results indicated that each solvent reached a peak of maximal absorbance at  410-472 nm, namely carotenoids. The usage of acetone solvent gave the best pigment quality. Brown, green and red seaweed have pigment content of 1,28 mg/100 g; 0,98 mg/100 g; 1,35 mg/100 g and rendement of 6,24%; 4,85% and 6,65% respectively.

Drug and Solvent Abuse Among Ahwaz\\'s Elderlies

Directory of Open Access Journals (Sweden)

Abdolrahim Asadollahi

2007-10-01

Full Text Available Objectives: There are researches to point epidemiology of addiction to drugs, chemical and solvent abuse in elderlies. Drug and Solvent abuse is considered as one of these addictions. This study was point to chemical abuse among elderly population of Ahwaz an Iranian city during year of 2007. Methods & Materials: Research method is description-exploration with use to questionnaire, clinical interview and survey of medical and clinical reports among volunteer clients. Statistical community is all elderly population at one of citizen region in Ahwaz city (Iran. Seventy four dossiers were considered via random sampling; with 30 Elder volunteer clients been interviewed and replied to Elderly Drug Abuse Questionnaire (EDAQ. Results: Signification of hypothesis with X2 test was considered significant relation between age and addiction record variables to solvent abuse; this relation is very significant to second value of drug's derivations such as Morphine, Codeine, Tebaine and Heroine. Interview showed psychological dependent due to appeal them to solvent abuse. Kind of abuse among elderly was snuffing and abuse of medicine drugs which were been recommended to them by their physician. Conclusion: Although study of solvent and chemical abuse's epidemiology pointed less average of this addiction in samples, should be considered important and notice in studies. Finally, researchers were suggested to avoid of this new drug abuse and so to control behavior and interaction of these addicted and their behavior development; it's better to control on distribution of solvent and glue materials and recommending of medicine drug via physicians visiting exderlies.

Solvent Optimization for Efficient Enzymatic Monoacylglycerol Production Based on a Glycerolysis Reaction

DEFF Research Database (Denmark)

Damstrup, Marianne; Jensen, Tine; Sparsø, Flemming V.

2005-01-01

This study was aimed at screening solvent systems of varying polarities to identify suitable solvents for efficient and practical enzymatic glycerolysis. Several pure solvents and solvent mixtures were screened in a batch reaction system consisting of glycerol, sunflower oil, and Novozymo (R) 435...

Magnetic effects on the solvent properties investigated by molecular dynamics simulation

Energy Technology Data Exchange (ETDEWEB)

Moosavi, Fatemeh, E-mail: moosavibaigi@um.ac.ir; Gholizadeh, Mostafa

2014-03-15

This paper investigates how an external constant magnetic field in the Z-direction affects the performance of a solvent. The molecular dynamics simulation comprised common inorganic and organic solvents including water, acetone, acetonitrile, toluene, and n-hexane at the ambient temperature and pressure. A static magnetic field applied in the simulation process is able to reduce the solvent mobility in the solution in order to enhance the solvent–solute reaction. Simulation results show that the diffusivity decreases because of increasing the effective interactions. Besides, magnetic field reduces the volume of the solvent and increases the strength of the hydrogen bonds by maximizing attractive electrostatic and vdW interactions caused by changes in the radial distribution function of the solvents. Hydrogen-bonding characteristics of solvents investigated by molecular dynamics simulations were evidence for the hydrogen bonding strength of O···H that is a more efficient intermolecular hydrogen-bonding in comparison with N···H. - Highlights: • Molecular dynamics simulation technique investigates the effect of magnetic field on transport dynamics inside the solvent bulk. • External constant magnetic field influences on intermolecular interactions, thermophysics, and transport properties of the solvents. • Applying magnetic field strengthened hydrogen bond maximizes attractive electrostatic interactions, charge distribution becomes stronger, and the molecule mobility is demoted. • The low diffusivity of the solvents in the solutions increases the performance of the interactions and promotes the interactions. • On introducing a magnetic field of flux density parallel to the Z-direction, solvent acts as an obstacle to diffusion of solutes.

Dense chlorinated solvents and other DNAPLs in groundwater

DEFF Research Database (Denmark)

Broholm, K.

1996-01-01

Anmeldelse af Pankow,J.F. & Cherry,J.A.: Dense chlorinated solvents and other DNAPLs in groundwater. Waterloo Press, Portland, Oregon, USA, 1996......Anmeldelse af Pankow,J.F. & Cherry,J.A.: Dense chlorinated solvents and other DNAPLs in groundwater. Waterloo Press, Portland, Oregon, USA, 1996...

Solvent extraction of gold using ionic liquid based process

Science.gov (United States)

Makertihartha, I. G. B. N.; Zunita, Megawati; Rizki, Z.; Dharmawijaya, P. T.

2017-01-01

In decades, many research and mineral processing industries are using solvent extraction technology for metal ions separation. Solvent extraction technique has been used for the purification of precious metals such as Au and Pd, and base metals such as Cu, Zn and Cd. This process uses organic compounds as solvent. Organic solvents have some undesired properties i.e. toxic, volatile, excessive used, flammable, difficult to recycle, low reusability, low Au recovery, together with the problems related to the disposal of spent extractants and diluents, even the costs associated with these processes are relatively expensive. Therefore, a lot of research have boosted into the development of safe and environmentally friendly process for Au separation. Ionic liquids (ILs) are the potential alternative for gold extraction because they possess several desirable properties, such as a the ability to expanse temperature process up to 300°C, good solvent properties for a wide range of metal ions, high selectivity, low vapor pressures, stability up to 200°C, easy preparation, environmentally friendly (commonly called as "green solvent"), and relatively low cost. This review paper is focused in investigate of some ILs that have the potentials as solvent in extraction of Au from mineral/metal alloy at various conditions (pH, temperature, and pressure). Performances of ILs extraction of Au are studied in depth, i.e. structural relationship of ILs with capability to separate Au from metal ions aggregate. Optimal extraction conditon in order to gain high percent of Au in mineral processing is also investigated.

Molecular and ionic hydrogen bond formation in fluorous solvents.

Science.gov (United States)

O'Neal, Kristi L; Weber, Stephen G

2009-01-08

There are only a few studies of noncovalent association in fluorous solvents and even fewer that are quantitative. A full understanding, particularly of stoichiometry and binding strength of noncovalent interactions in fluorous solvents could be very useful in improved molecular-receptor-based extractions, advancements in sensor technologies, crystal engineering, and supramolecular chemistry. This work investigates hydrogen bonding between heterocyclic bases and a perfluoropolyether with a terminal carboxylic acid group (Krytox 157FSH (1)), chiefly in FC-72 (a mixture of perfluorohexanes). In particular, we were interested in whether or not proton transfer occurs, and if so, under what conditions in H-bonded complexes. Continuous variations experiments show that in FC-72 weaker bases (pyrazine, pyrimidine, and quinazoline) form 1:1 complexes with 1, whereas stronger bases (quinoline, pyridine, and isoquinoline) form 1:3 complexes. Ultraviolet and infrared spectral signatures reveal that the 1:1 complexes are molecular (B.HA) whereas the 1:3 complexes are ionic (BH+.A-HAHA). Infrared spectra of 1:3 ionic complexes are discussed in detail. Literature and experimental data on complexes between N-heterocyclic bases and carboxylic acids in a range of solvents are compiled to compare solvent effects on proton transfer. Polar solvents support ionic hydrogen bonds at a 1:1 mol ratio. In nonpolar organic solvents, ionic hydrogen bonds are only observed in complexes with 1:2 (base/acid) stoichiometries. In fluorous solvents, a larger excess of acid, 1:3, is necessary to facilitate proton transfer in hydrogen bonds between carboxylic acids and the bases studied.

Solvents effects on crystallinity and dissolution of β-artemether.

Science.gov (United States)

Xu, Jianghui; Singh, Vikramjeet; Yin, Xianzhen; Singh, Parbeen; Wu, Li; Xu, Xiaonan; Guo, Tao; Sun, Lixin; Gui, Shuangying; Zhang, Jiwen

2017-03-01

β-artemether (ARM) is a widely used anti-malarial drug isolated from the Chinese antimalarial plant, Artemisia annua. The solvent effects on crystal habits and dissolution of ARM were thoroughly investigated and discussed herein. The ARM was recrystallized in nine different solvents of varied polarity, namely, methanol, ethanol, isopropanol, tetrahydrofuran, dichloromethane, trichloromethane, ethyl acetate, acetone and hexane by solvent evaporation method. The obtained crystals were morphologically characterized using scanning electron microscope (SEM). The average sizes of crystals were 1.80-2.64 μm calculated from microscopic images using Image-Pro software. No significant change in chemical structure was noticed after recrystallization and the specific band at 875 cm -1 wavenumber (C-O-O-C) confirmed the presence of most sensitive functional group in the ARM chemical structure. The existence and production of two polymorphic forms, polymorph A and polymorph B, was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The data suggested that the fabrication of polymorph B can be simply obtained from the recrystallization of ARM in a specific solvent. Significant effects of solvent polarity, crystals shapes and sizes on drug dissolution were noticed during in vitro dissolution test. The release kinetics were calculated and well fitted by the Higuchi and Hixon-Crowell models. The ARM-methanol and ARM-hexane showed highest and slowest dissolution, respectively, due to the effects of solvent polarity and crystal morphologies. Overall, proper selection of the solvents for the final crystallization of ARM helps to optimize dissolution and bioavailability for a better delivery of anti-malarial drug.

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.

Accelerated Solvent Extraction: An Innovative Sample Extraction Technique for Natural Products

International Nuclear Information System (INIS)

Hazlina Ahmad Hassali; Azfar Hanif Abd Aziz; Rosniza Razali

2015-01-01

Accelerated solvent extraction (ASE) is one of the novel techniques that have been developed for the extraction of phytochemicals from plants in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yield and enhance the quality of extracts. This technique combines elevated temperatures and pressure with liquid solvents. This paper gives a brief overview of accelerated solvent extraction technique for sample preparation and its application to the extraction of natural products. Through practical examples, the effects of operational parameters such as temperature, volume of solvent used, extraction time and extraction yields on the performance of ASE are discussed. It is demonstrated that ASE technique allows reduced solvent consumption and shorter extraction time, while the extraction yields are even higher than those obtained with conventional methods. (author)

Results of Analyses of the Next Generation Solvent for Parsons

International Nuclear Information System (INIS)

Peters, T.; Washington, A.; Fink, S.

2012-01-01

Savannah River National Laboratory (SRNL) prepared a nominal 150 gallon batch of Next Generation Solvent (NGS) for Parsons. This material was then analyzed and tested for cesium mass transfer efficiency. The bulk of the results indicate that the solvent is qualified as acceptable for use in the upcoming pilot-scale testing at Parsons Technology Center. This report describes the analysis and testing of a batch of Next Generation Solvent (NGS) prepared in support of pilot-scale testing in the Parsons Technology Center. A total of ∼150 gallons of NGS solvent was prepared in late November of 2011. Details for the work are contained in a controlled laboratory notebook. Analysis of the Parsons NGS solvent indicates that the material is acceptable for use. SRNL is continuing to improve the analytical method for the guanidine.

Efficient production of fatty acid methyl ester from waste activated bleaching earth using diesel oil as organic solvent.

Science.gov (United States)

Kojima, Seiji; Du, Dongning; Sato, Masayasu; Park, Enoch Y

2004-01-01

Fatty acid methyl ester (FAME) production from waste activated bleaching earth (ABE) discarded by the crude oil refining industry was investigated using fossil fuel as a solvent in the esterification of triglycerides. Lipase from Candida cylindracea showed the highest stability in diesel oil. Using diesel oil as a solvent, 3 h was sufficient to obtain a yield of approximately 100% of FAME in the presence of 10% lipase from waste ABE. Kerosene was also a good solvent in the esterification of triglycerides embedded in the waste ABE. Fuel analysis showed that the FAME produced using diesel oil as a solvent complied with the Japanese diesel standard and the 10% residual carbon amount was lower than that of FAME produced using other solvents. Use of diesel oil as solvent in the FAME production from the waste ABE simplified the process, because there was no need to separate the organic solvent from the FAME-solvent mixture. These results demonstrate a promising reutilization method for the production of FAME, for use as a biodiesel, from industrial waste resources containing waste vegetable oils.

Catalog solvent extraction: anticipate process adjustments

International Nuclear Information System (INIS)

Campbell, S.G.; Brass, E.A.; Brown, S.J.; Geeting, M.W.

2008-01-01

The Modular Caustic-Side Solvent Extraction Unit (MCU) utilizes commercially available centrifugal contactors to facilitate removal of radioactive cesium from highly alkaline salt solutions. During the fabrication of the contactor assembly, demonstrations revealed a higher propensity for foaming than was initially expected. A task team performed a series of single-phase experiments that revealed that the shape of the bottom vanes and the outer diameter of those vanes are key to the successful deployment of commercial contactors in the Caustic-Side Solvent Extraction Process. (authors)

Accelerated solvent extraction (ASE) - a fast and automated technique with low solvent consumption for the extraction of solid samples (T12)

International Nuclear Information System (INIS)

Hoefler, F.

2002-01-01

Full text: Accelerated solvent extraction (ASE) is a modern extraction technique that significantly streamlines sample preparation. A common organic solvent as well as water is used as extraction solvent at elevated temperature and pressure to increase extraction speed and efficiency. The entire extraction process is fully automated and performed within 15 minutes with a solvent consumption of 18 ml for a 10 g sample. For many matrices and for a variety of solutes, ASE has proven to be equivalent or superior to sonication, Soxhlet, and reflux extraction techniques while requiring less time, solvent and labor. First ASE has been applied for the extraction of environmental hazards from solid matrices. Within a very short time ASE was approved by the U.S. EPA for the extraction of BNAs, PAHs, PCBs, pesticides, herbicides, TPH, and dioxins from solid samples in method 3545. Especially for the extraction of dioxins the extraction time with ASE is reduced to 20 minutes in comparison to 18 h using Soxhlet. In food analysis ASE is used for the extraction of pesticide and mycotoxin residues from fruits and vegetables, the fat determination and extraction of vitamins. Time consuming and solvent intensive methods for the extraction of additives from polymers as well as for the extraction of marker compounds from herbal supplements can be performed with higher efficiencies using ASE. For the analysis of chemical weapons the extraction process and sample clean-up including derivatization can be automated and combined with GC-MS using an online ASE-APEC-GC system. (author)

Study on electrohydrodynamic jetting performance of organic solvents

Energy Technology Data Exchange (ETDEWEB)

Lee, Soo Hong; Nguyen, Xuan Hung; Gim, Yeong Hyeon; Ko, Han Seo [Sungkyunkwan University, Suwon (Korea, Republic of)

2015-11-15

The electrohydrodynamic (EHD) inkjet method is a printing technology using electricity. This technique allows for the printing of EML (Emission layer) materials, usually used for OLED devices, on a substrate. In this study, ejection experiments were performed with various solvents to verify which of them is properly ejected in the EHD method. The solvents employed were dielectric liquids with low viscosity and it was confirmed that among them two solvents, 1,2-Dichlorobenzene (DCB) and 1,2-Dichloroethane (DCE), produced the pulsating cone-Jet mode and stable cone-jet mode well. In addition, experiments were conducted to find out how the voltage and applied flux influence the ejection mode, in order to apply the result to the ejection control. It was found that the selected solvent was easily ejected and printed, due to the free surface charge and charge density determined by the dielectric constant. Finally, a patterning experiment was performed to verify proper printing.

Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

Energy Technology Data Exchange (ETDEWEB)

McCarty, P. L.; Spormann, Alfred M.; Criddle, Craig, S.

2003-12-11

three to five times, leading to a more rapid clean-up of the DNAPL zone. The most favored electron donor to add is one which partitions well with the chlorinated solvent or can be concentrated near it. Unfortunately, an ideal electron donor, such as vegetable oil, is difficult to introduce and mix with DNAPL in the ground, doing this properly remains an engineering challenge. Numerical model studies have indicated that several factors may significantly influence the rate and extent of enhancement, including the inhibitory effects of PCE and cDCE, the level of ED concentration, DNAPL configuration, and competition for ED. Such factors need to be considered when contemplating engineered DNAPL bioremediation. Pseudomonas stuzeri KC is an organism that transforms CT to carbon dioxide and chloride without the formation of the hazardous intermediate, chloroform. This is accomplished by production and secretion of a molecule called PDTC. This study was direct ed towards determining how PDTC works. Cu (II) at a ratio of 1:1 Cu to PDTC was found to result in the most rapid CT transformation, confirming that the PDTC-Cu complex is both a reactant and a catalyst in CT transformation. CT degradation requires that the PDTC be in a reduced form, which is generated by contact with cell components. Fe(II) inhibits CT transformation by PDTC. Studies indicated that this inhibition is enhanced by some compound or factor in the supernatant with molecular weight greater than 10,000 Da. We have made progress in determining what this factor might be, but have not yet been able to identify it. In related studies, we found that CT transformation by another organism, Shewanella oneidensis MR1, also involves an excreted factor, but this factor is different from PDTC and results in chloroform transformation as an intermediate. Our studies have indicated that this factor is similar to vitamin K2, and we have also confirmed that vitamin K2 does transform C T into chloroform.

Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

International Nuclear Information System (INIS)

McCarty, P. L.; Spormann, Alfred M.; Criddle, Craig S.

2003-01-01

three to five times, leading to a more rapid clean-up of the DNAPL zone. The most favored electron donor to add is one which partitions well with the chlorinated solvent or can be concentrated near it. Unfortunately, an ideal electron donor, such as vegetable oil, is difficult to introduce and mix with DNAPL in the ground, doing this properly remains an engineering challenge. Numerical model studies have indicated that several factors may significantly influence the rate and extent of enhancement, including the inhibitory effects of PCE and cDCE, the level of ED concentration, DNAPL configuration, and competition for ED. Such factors need to be considered when contemplating engineered DNAPL bioremediation. Pseudomonas stuzeri KC is an organism that transforms CT to carbon dioxide and chloride without the formation of the hazardous intermediate, chloroform. This is accomplished by production and secretion of a molecule called PDTC. This study was direct ed towards determining how PDTC works. Cu (II) at a ratio of 1:1 Cu to PDTC was found to result in the most rapid CT transformation, confirming that the PDTC-Cu complex is both a reactant and a catalyst in CT transformation. CT degradation requires that the PDTC be in a reduced form, which is generated by contact with cell components. Fe(II) inhibits CT transformation by PDTC. Studies indicated that this inhibition is enhanced by some compound or factor in the supernatant with molecular weight greater than 10,000 Da. We have made progress in determining what this factor might be, but have not yet been able to identify it. In related studies, we found that CT transformation by another organism, Shewanella oneidensis MR1, also involves an excreted factor, but this factor is different from PDTC and results in chloroform transformation as an intermediate. Our studies have indicated that this factor is similar to vitamin K2, and we have also confirmed that vitamin K2 does transform C T into chloroform

Photonic crystal based sensor for organic solvents and for solvent-water mixtures.

Science.gov (United States)

Fenzl, Christoph; Hirsch, Thomas; Wolfbeis, Otto S

2012-12-12

Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is of violet color if placed in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied in some detail. We show that such films are capable of monitoring the water content of ethanol/water mixtures, where only 1% (v/v) of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol (v/v) results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible and response times are <1 s.

Photonic Crystal Based Sensor for Organic Solvents and for Solvent-Water Mixtures

Directory of Open Access Journals (Sweden)

Otto S. Wolfbeis

2012-12-01

Full Text Available Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is of violet color if placed in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied in some detail. We show that such films are capable of monitoring the water content of ethanol/water mixtures, where only 1% (v/v of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol (v/v results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible and response times are <1 s.

40 CFR 427.90 - Applicability; description of the solvent recovery subcategory.

Science.gov (United States)

2010-07-01

... solvent recovery subcategory. 427.90 Section 427.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Solvent Recovery Subcategory § 427.90 Applicability; description of the solvent recovery subcategory. The...

Solvent effect on redox properties of hexanethiolate monolayer-protected gold nanoclusters.

Science.gov (United States)

Su, Bin; Zhang, Meiqin; Shao, Yuanhua; Girault, Hubert H

2006-11-02

The capacitance of monolayer-protected gold nanoclusters (MPCs), C(MPC), in solution has been theoretically reconsidered from an electrostatic viewpoint, in which an MPC is considered as an isolated charged sphere within two dielectric layers, the intrinsic coating monolayer, and the bulk solvent. The model predicts that the bulk solvent provides an important contribution to C(MPC) and influences the redox properties of MPCs. This theoretical prediction is then examined experimentally by comparing the redox properties of MPCs in four organic solvents: 1,2-dichloroethane (DCE), dichloromethane (DCM), chlorobenzene (CB), and toluene (TOL), in all of which MPCs have excellent solubility. Furthermore, this set of organic solvents features a dielectric constant in a range from 10.37 (DCE) to 2.38 (TOL), which is wide enough to probe the solvent effect. In these organic solvents, tetrahexylammonium bis(trifluoromethylsulfonyl)imide (THATf2N) is used as the supporting electrolyte. Cyclic and differential pulse voltammetric results provide concrete evidence that, despite the monolayer protection, the solvent plays a significant effect on the properties of MPCs in solution.

γIrradiation induced formation of PCB-solvent adducts in aliphatic solvents

International Nuclear Information System (INIS)

Lepine, F.; Milot, S.; Gagne, N.

1990-01-01

γIrradiation induced formation of PCB-solvent adducts was investigated as a model for PCB residues in irradiated food. Formation of cyclohexyl adducts of PCBs was found to be significant when pure PCB congeners and Aroclor mixture were irradiated in cyclohexane and cyclohexene. Reaction pathways were investigated, and the effects of oxygen and electron scavenger were studied

Industrial rag cleaning process for the environmentally safe removal of petroleum-based solvents

International Nuclear Information System (INIS)

Fierro, J.V.

1993-01-01

A process for the cleaning of industrial rags contaminated with environmentally unsafe petroleum-based solvent is described, comprising the step of: (a) placing a load of the industrial rags in a mechanically driven rotary drum; (b) revolving the drum at a high speed sufficient to physically extract liquid petroleum-based solvent contaminate from the industrial rags; (c) routing the extracted petroleum-based solvent contaminate from the rotary drum to a waste solvent collection line for environmentally safe disposal; (d) revolving the rotary drum to cause a tumbling of the industrial rags while maintaining the temperature within the drum at below the flash point of the petroleum-based solvent; (e) intermittently forcing cold air and hot air through the rotary drum to vaporize solvent from the industrial rags; (f) routing the vaporized petroleum-based solvent contaminant from the rotary drum to a condenser wherein the petroleum-based solvent contaminate is condensed and thereafter further routing said condensed solvent to a waste collection line for environmentally safe disposal; and (g) cleaning the industrial rags in the presence of a dry cleaning solvent to remove residual petroleum-based solvents and soil

Studies on catalytic hydrotreating of recycled solvents from coal liquefaction process. Part 1. Characteristics changes of recycled solvents during hydrotreating

Energy Technology Data Exchange (ETDEWEB)

Morimura, Y.; Nakata, S.; Yokota, Y.; Shirota, Y.; Nakamura, M. [Chiyoda Corp., Tokyo (Japan); Mitarai, Y. [Sumitomo Metal Mining Co. Ltd., Tokyo (Japan); Inoue, Y. [Nippon Ketjen Co. Ltd., Tokyo (Japan)

1995-07-01

A bituminous coal liquefaction process, called the NEDOL process, is under development by the New Energy and Industrial Technology Development Organization (NEDO). Important features of this process include the capacity to produce hydrogen-donatable solvents, obtained by hydrogenation of middle distillates of coal derived oils, and to recycle these solvents to a liquefaction stage as hydrogen donor solvents. These recycled solvents, obtained by liquefaction of Wandoan coal, and their catalytic hydrotreated oils, have been extensively characterized, using a variety of analytical methods. The following items have been examined and are discussed in this study: (1) Influence of chemical hydrogen consumption on the reactivities of hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO) and hydrogenation of aromatic-rings, during hydrotreating; (2) Changes in composition of hydrocarbon types, nitrogen- and oxygen-containing compounds, as a function of chemical hydrogen consumption; (3) Changes of average molecular weights; (4) Characteristics changes of oxygen- and nitrogen-containing compounds, and reactivities of HDO and HDN; (5) Characteristics changes of donatable hydrogen as a function of a degree of hydrogenation ({delta}fa). 14 refs., 14 figs., 3 tabs.

Temporal epileptic seizures and occupational exposure to solvents

DEFF Research Database (Denmark)

Jacobsen, M; Bælum, Jesper; Bonde, J P

1994-01-01

Long term exposure to organic solvents is usually not considered as a possible cause of chronic epileptic seizures. A case that shows a remarkable coincidence between exposure to organic solvents and occurrence of epileptic seizures is reported. The man was a 58 year old sign writer with lifelong...

Micro-Encapsulation of non-aqueous solvents for energy-efficient carbon capture

Energy Technology Data Exchange (ETDEWEB)

Stolaroff, Joshua K; Ye, Congwang; Oakdale, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Baker, Sarah; Nugyen, Du; Smith, William; Aines, Roger

2016-11-14

Here, we demonstrate micro-encapsulation of several promising designer solvents: an IL, PCIL, and CO2BOL. We develop custom polymers that cure by UV light in the presence of each solvent while maintaining high CO2 permeability. We use several new process strategies to accommodate the viscosity and phase changes. We then measure and compare the CO2 absorption rate and capacity as well as the multi-cycle performance of the encapsulated solvents. These results are compared with previous work on encapsulated sodium carbonate solution. The prospects for designer solvents to reduce the cost of post-combustion capture and the implications for process design with encapsulated solvents are discussed.

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.

Decontamination of radioactive contaminated protective wear using dry cleaning solvent

International Nuclear Information System (INIS)

Muthiah, Pushpa; Chitra, S.; Paul, Biplob

2013-01-01

Liquid waste generated by conventional decontamination of radioactive contaminated cotton protective wear using detergent affects the chemical treatment of the plant. To reduce the generation of aqueous detergent waste, dry cleaning of cotton protective wear, highly soiled with oil and grease towards decontamination was tried with organic solvents. Mineral turpentine oil (MTO) among various other organic solvents was identified as a suitable organic solvent. As MTO leaves characteristic odour on the cloth, various commercial fragrances for the removal of the odour were tried. Application of the optimised dry cleaning solvent and commercial fragrance was adopted in plant scale operation. (author)

Dynamic behaviour of solvent contactors in fuel reprocessing plants- an analysis

Energy Technology Data Exchange (ETDEWEB)

Raju, R P; Siddiqui, H R [Nuclear Waste Management Group, Bhabha Atomic Research Centre, Mumbai (India); Murthy, K K; Kansra, V P [Fuel Reprocessing Group, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Fuel reprocessing plants carry out separation of useful fissile and fertile materials from spent nuclear fuels by isolating highly radioactive fission products using solvent extraction method. In the fuel reprocessing step of nuclear fuel cycle, optimisation of process parameters in the PUREX flowsheet design is of great importance particularly on account of the need to realize high degree of recovery of fissile and fertile materials and to ensure proper control on concentrations of fissile element in process streams for avoidance of criticality. In counter-current solvent contactors of PUREX flowsheet there are a variety of processes conditions which may cause plutonium accumulations that requires attention to ascertain safe Pu concentrations within the contactors. A study was carried out using the PUREX process mathematical model Solvent Extraction Program Having Interacting Solutes (SEPHIS) for pulsed solvent contactors in PREFRE-1, Tarapur and PREFRE-2, Kalpakkam flowsheets for optimising the process parameters in plutonium purification cycles. The study was extended to predict the behaviour of contactors handling plutonium bearing solutions under certain anticipated deviations in the process parameters. Modifications wherever necessary were carried out to the original SEPHIS code. This paper discusses the results obtained during this analysis. (author). 2 figs., 2 tabs.

CO{sub 2}-based supercritical fluids as environmentally-friendly processing solvents

Energy Technology Data Exchange (ETDEWEB)

Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Pierce, T. [Los Alamos National Lab., NM (United States). Physical Organic Chemistry Group; Tiefert, K. [Hewlett-Packard Co., Inc., Santa Clara, CA (United States)

1999-03-01

The production of integrated circuits involves a number of discrete steps that utilize hazardous or regulated solvents. Environmental, safety and health considerations associated with these chemicals have prompted a search for alternative, more environmentally benign, solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Supercritical CO{sub 2} (SCCO{sub 2}) is an excellent choice for IC manufacturing processes since it is non-toxic, non-flammable, inexpensive, and is compatible with all substrate and metallizations systems. Also, conditions of temperature and pressure needed to achieve the supercritical state are easily achievable with existing process equipment. The authors first describe the general properties of supercritical fluids, with particular emphasis on their application as alternative solvents. Next, they review some of the work which has been published involving the use of supercritical fluids, and particularly CO{sub 2}, as they may be applied to the various steps of IC manufacture, including wafer cleaning, thin film deposition, etching, photoresist stripping, and waste treatment. Next, they describe the research work conducted at Los Alamos, on behalf of Hewlett-Packard, on the use of SCCO{sub 2} in a specific step of the IC manufacturing process: the stripping of hard-baked photoresist.

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

Chemical engineering aspect of solvent extraction in mineral processing

International Nuclear Information System (INIS)

Dara, S.S.; Jakkikar, M.S.

1975-01-01

Solvent extraction process, types of solvents used, types of extraction, distribution isotherm and McCabe-Thiele diagram for process design, equipment for the process, operating parameters and applications are described. (M.G.B.)

Solvent effects on lasing characteristics for Rh B laser dye

Energy Technology Data Exchange (ETDEWEB)

Peter, Jaison, E-mail: jaison.peter@gmail.com [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India); Kumar, Mahesh [Department of Applied Chemistry, Cochin University of Science and Technology, Cochin 682022 (India); Ananad, V.R.; Saleem, Rasool; Sebastian, Ananthu; Radhakrishnan, P.; Nampoori, V.P.N.; Vallabhan, C.P.G. [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India); Prabhu, Radhakrishna [School of Engineering, Robert Gordon University, Aberdeen AB10 1FR, Scotland (United Kingdom); Kailasnath, M. [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India)

2016-01-15

We demonstrate pulsed, photopumped multimode laser emission in the visible spectral range from rhodamine B dye dissolved in various solvents. The laser emission is characterized by a well-defined, low threshold pump power at which the emission spectral intensity dramatically increases and collapsed into several dominant laser modes with reduced mode spacing and spectral width. The modes were found to originate from the subcavities formed by the plane-parallel walls of the cuvette containing the gain medium. The cavity lasing spectral structure and the numbers of longitudinal modes were easily controlled by changing the solvents. A shift in the emission spectra has been also observed by changing the solvents will allow a limited range of tuning of laser emission wavelength. We also determined the gain coefficient and stimulated emission cross-section for the Rh B dye dissolved liquid laser system. A detailed discussion of the solvent effect in the lasing characteristics of Rh B in different solution is explained along with the computational data. - Highlights: • Report multimode laser emission from rhodamine B dye dissolved in various solvents. • Modes are originated from the plane-parallel walls of the cuvette. • Spectral range and the number of modes can be controlled by changing the solvents. • Changing solvents also allows a limited range of tuning of laser emission.

Bioremediation potential of a newly isolate solvent tolerant strain Bacillus thermophilus PS11

Directory of Open Access Journals (Sweden)

PAYEL SARKAR

2012-01-01

Full Text Available The increased generation of solvent waste has been stated as one of the most critical environmental problems. Though microbial bioremediation has been widely used for waste treatment but their application in solvent waste treatment is limited since the solvents have toxic effects on the microbial cells. A solvent tolerant strain of Bacillus thermophilus PS11 was isolated from soil by cyclohexane enrichment. Transmission electron micrograph of PS11 showed convoluted cell membrane and accumulation of solvents in the cytoplasm, indicating the adaptation of the bacterial strain to the solvent after 48h of incubation. The strain was also capable of growing in presence of wide range of other hydrophobic solvents with log P-values below 3.5. The isolate could uptake 50 ng/ml of uranium in its initial 12h of growth, exhibiting both solvent tolerance and metal resistance property. This combination of solvent tolerance and metal resistance will make the isolated Bacillus thermophilus PS11 a potential tool for metal bioremediation in solvent rich wastewaters.

Adsorption of flexible polymer chains on a surface: Effects of different solvent conditions

Science.gov (United States)

Martins, P. H. L.; Plascak, J. A.; Bachmann, M.

2018-05-01

Polymer chains undergoing a continuous adsorption-desorption transition are studied through extensive computer simulations. A three-dimensional self-avoiding walk lattice model of a polymer chain grafted onto a surface has been treated for different solvent conditions. We have used an advanced contact-density chain-growth algorithm, in which the density of contacts can be directly obtained. From this quantity, the order parameter and its fourth-order Binder cumulant are computed, as well as the corresponding critical exponents and the adsorption-desorption transition temperature. As the number of configurations with a given number of surface contacts and monomer-monomer contacts is independent of the temperature and solvent conditions, it can be easily applied to get results for different solvent parameter values without the need of any extra simulations. In analogy to continuous magnetic phase transitions, finite-size-scaling methods have been employed. Quite good results for the critical properties and phase diagram of very long single polymer chains have been obtained by properly taking into account the effects of corrections to scaling. The study covers all solvent effects, going from the limit of super-self-avoiding walks, characterized by effective monomer-monomer repulsion, to poor solvent conditions that enable the formation of compact polymer structures.

Centrifugal contractors for laboratory-scale solvent extraction tests

International Nuclear Information System (INIS)

Leonard, R.A.; Chamberlain, D.B.; Conner, C.

1995-01-01

A 2-cm contactor (minicontactor) was developed and used at Argonne National Laboratory for laboratory-scale testing of solvent extraction flowsheets. This new contactor requires only 1 L of simulated waste feed, which is significantly less than the 10 L required for the 4-cm unit that had previously been used. In addition, the volume requirements for the other aqueous and organic feeds are reduced correspondingly. This paper (1) discusses the design of the minicontactor, (2) describes results from having applied the minicontactor to testing various solvent extraction flowsheets, and (3) compares the minicontactor with the 4-cm contactor as a device for testing solvent extraction flowsheets on a laboratory scale

Solvent sensitivity of smart 3D-printed nanocomposite liquid sensor

Science.gov (United States)

Aliheidari, Nahal; Ameli, Amir; Pötschke, Petra

2018-03-01

Fused deposition modeling (FDM) is one of the 3D printing methods that has attracted significant attention. In this method, small and complex samples with nearly no limitation in geometry can be fabricated layer by layer to form end-use parts. This work investigates the liquid sensing behavior of FDM printed flexible thermoplastic polyurethane, TPU filled with multiwalled carbon nanotubes, MWCNTs. The sensing capability of printed TPU-MWCNT was studied as a function of MWCNT content and infill density in response to different solvents, i.e., ethanol, acetone and toluene. The solvents were selected based on their widespread use and importance in medical and industrial applications. U-shaped liquid sensors with 2, 3 and 4wt.% MWCNT content were printed at three different infill densities of 50, 75 and 100%. Solvent sensitivity was then characterized by immersing the sensors in the solvents and measuring the resistance evolution over 25s. The results indicated a sensitivity order of acetone > toluene > ethanol, which was in agreement with the predictions of FloryHiggins solubility equation. For all the solvents, the sensitivity was enhanced as the infill density of the printed samples was decreased. This was attributed to the increased surface area to volume ratio and shortened diffusion paths. The MWCNT content was also observed to have a profound effect on the sensitivity; in samples with partial infill, the sensitivity was found to be inversely proportional to the MWCNT content, such that the highest resistance change was obtained for nanocomposites with the lowest MWCNT content of 2wt.%. For instance, a resistance increase of more than 10 times was obtained in 25 s once TPU-2wt.%MWCNT with 50% infill was tested against acetone. The results of this work reveals that highly sensitive liquid sensors can be fabricated with the aid of 3D printing without the need for complex processing methods.

Thin porphyrin composite membranes with enhanced organic solvent transport

KAUST Repository

Phuoc, Duong; Anjum, Dalaver H.; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

2018-01-01

Extending the stability of polymeric membranes in organic solvents is important for applications in chemical and pharmaceutical industry. Thin-film composite membranes with enhanced solvent permeance are proposed, using porphyrin as a building block

STABILITY OF A CYLINDRICAL SOLUTE-SOLVENT INTERFACE: EFFECT OF GEOMETRY, ELECTROSTATICS, AND HYDRODYNAMICS.

Science.gov (United States)

Li, B O; Sun, Hui; Zhou, Shenggao

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 assumed to be incompressible and is described by the Stokes equation. The solute is modeled simply by the ideal-gas law. All the viscous force, hydrostatic pressure, solute-solvent van der Waals interaction, surface tension, and electrostatic force are balanced at the solute-solvent interface. We model the electrostatics by Poisson's equation in which the solute-solvent interface is treated as a dielectric boundary that separates the low-dielectric solute from the high-dielectric solvent. For a cylindrical geometry, we find multiple cylindrically shaped equilibrium interfaces that describe polymodal (e.g., dry and wet) states of hydration of an underlying molecular system. These steady-state solutions exhibit bifurcation behavior with respect to the charge density. For their linearized systems, we use the projection method to solve the fluid equation and find the dispersion relation. Our asymptotic analysis shows that, for large wavenumbers, the decay rate is proportional to wavenumber with the proportionality half of the ratio of surface tension to solvent viscosity, indicating that the solvent viscosity does affect the stability of a solute-solvent interface. Consequences of our analysis in the context of biomolecular interactions are discussed.

Natural deep eutectic solvents as new potential media for green technology

International Nuclear Information System (INIS)

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

2013-01-01

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

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

Effect of HEH[EHP] impurities on the ALSEP solvent extraction process

Energy Technology Data Exchange (ETDEWEB)

Holfeltz, Vanessa E. [Nuclear Chemistry and Engineering Group, Pacific Northwest National Laboratory, Richland, WA, USA; School of Nuclear Science and Engineering, Oregon State University, Corvallis, OR, USA; Campbell, Emily L. [Nuclear Chemistry and Engineering Group, Pacific Northwest National Laboratory, Richland, WA, USA; Peterman, Dean R. [Aqueous Separations and Radiochemistry Department, Idaho National Laboratory, Idaho Falls, ID, USA; Standaert, Robert F. [Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Department of Biochemistry & amp, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA; Biology & amp, Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Shull Wollan Center — a Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Paulenova, Alena [School of Nuclear Science and Engineering, Oregon State University, Corvallis, OR, USA; Lumetta, Gregg J. [Nuclear Chemistry and Engineering Group, Pacific Northwest National Laboratory, Richland, WA, USA; Levitskaia, Tatiana G. [Nuclear Chemistry and Engineering Group, Pacific Northwest National Laboratory, Richland, WA, USA

2017-12-20

In solvent extraction processes, organic phase impurities can negatively impact separation factors, hydrolytic performance, and overall system robustness. This affects the process-level viability of a separation concept and necessitates knowledge of the behavior and mechanisms to control impurities in the solvent. The most widespread way through which impurities are introduced into a system is through impure extractants and/or diluents used to prepare the solvent, and often development of new purification schemes to achieve the desired level of purity is needed. In this work, the acidic extractant, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP])—proposed for application in extractive processes aimed at separating trivalent minor actinides from lanthanides and other fission products—is characterized with respect to its common impurities and their impact on Am(III) stripping in the Actinide Lanthanide SEParation (ALSEP) system. To control impurities in HEH[EHP], existing purification technologies commonly applied for the acidic organophosphorus reagents are reviewed, and a new method specific to HEH[EHP] purification is presented.

Dispersions of Goethite Nanorods in Aprotic Polar Solvents

Directory of Open Access Journals (Sweden)

Delphine Coursault

2017-10-01

Full Text Available Colloidal suspensions of anisotropic nanoparticles can spontaneously self-organize in liquid-crystalline phases beyond some concentration threshold. These phases often respond to electric and magnetic fields. At lower concentrations, usual isotropic liquids are observed but they can display very strong Kerr and Cotton-Mouton effects (i.e., field-induced particle orientation. For many examples of these colloidal suspensions, the solvent is water, which hinders most electro-optic applications. Here, for goethite (α-FeOOH nanorod dispersions, we show that water can be replaced by polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP and dimethylsulfoxide (DMSO, without loss of colloidal stability. By polarized-light microscopy, small-angle X-ray scattering and electro-optic measurements, we found that the nematic phase, with its field-response properties, is retained. Moreover, a strong Kerr effect was also observed with isotropic goethite suspensions in these polar aprotic solvents. Furthermore, we found no significant difference in the behavior of both the nematic and isotropic phases between the aqueous and non-aqueous dispersions. Our work shows that goethite nanorod suspensions in polar aprotic solvents, suitable for electro-optic applications, can easily be produced and that they keep all their outstanding properties. It also suggests that this solvent replacement method could be extended to the aqueous colloidal suspensions of other kinds of charged anisotropic nanoparticles.

Dealing with the chlorinated solvent situation at the Oak Ridge Y-12 Plant

International Nuclear Information System (INIS)

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

1993-01-01

Recent events regarding health and environmental problems associated with the use of chlorinated solvents have prompted the Oak Ridge Y-12 Plant to investigate substitutes for these materials. Since 1987, the purchase of chlorinated solvents at the Y-12 Plant has been reduced by 92%. This has been accomplished by substituting chlorinated solvent degreasing with ultrasonic aqueous detergent cleaning and by substituting chlorinated solvents with less toxic, environmentally friendly solvents for hand-wiping applications. Extensive studies of cleaning ability, compabitility, and effects on welding, bonding, and painting have been conducted to gain approval for use of these solvents. Toxicity and waste disposal were also assessed for the solvents

Effect of solvent composition on dispersing ability of reaction sialon suspensions.

Science.gov (United States)

Xu, Xin; Oliveira, Marta; Ferreira, José M F

2003-03-15

This work focuses on the optimization of the rheological behavior of suspensions considering different solvent compositions. The effects of methyl ethyl ketone (MEK)/ethanol (E) solvent mixtures on reaction sialon suspensions were investigated by measuring sedimentation behavior, adsorption of dispersant, and flow behavior. It was shown that both the flow behavior and the sedimentation behavior strongly depended on selection of solvent composition. Using 3 wt% KD1 as dispersant, well-dispersed colloidal suspensions could be obtained in MEK-rich solvents. The suspensions with 60 vol% MEK/40 vol% E as solvent could be fitted to the Bingham model with very low yield stress, while suspensions with pure MEK or ethanol-rich mixtures as solvent showed pseudo plastic behavior with relatively high yield stress values. A model was proposed to explain the different flow behaviors of suspensions considering the different configurations of dispersant at particles' surfaces.

Cleaning of spent solvent and method of processing cleaning liquid waste

International Nuclear Information System (INIS)

Ozawa, Masaki; Kawada, Tomio; Tamura, Nobuhiko.

1993-01-01

Spent solvents discharged from a solvent extracting step mainly comprise n-dodecane and TBP and contain nuclear fission products and solvent degradation products. The spent solvents are cleaned by using a sodium chloride free detergent comprising hydrazine oxalate and hydrazine carbonate in a solvent cleaning device. Nitric acid is added to the cleaning liquid wastes containing spent detergents extracted from the solvent cleaning device, to control an acid concentration. The detergent liquid wastes of controlled acid concentration are sent to an electrolysis oxidation bath as electrolytes and electrochemically decomposed in carbonic acid gas, nitrogen gas and hydrogen gas. The decomposed gases are processed as off gases. The decomposed liquid wastes are processed as a waste nitric acid solution. This can provide more effective cleaning. In addition, the spent detergent can be easily decomposed in a room temperature region. Accordingly, the amount of wastes can be decreased. (I.N.)

Hydrocarbon solvent exposure data: compilation and analysis of the literature.

Science.gov (United States)

Caldwell, D J; Armstrong, T W; Barone, N J; Suder, J A; Evans, M J

2000-01-01

An occupational exposure database for hydrocarbon solvent end-use applications was constructed from the published literature. The database provides exposure assessment information for such purposes as regulatory risk assessments, support of industry product stewardship initiatives, and identification of applications in which limited exposure data are available. It is quantitative, documented, and based on credible data. Approximately 350 articles containing quantitative hydrocarbon solvent exposure data were identified using a search of computer databases of published literature. Many articles did not report sufficient details of the exposure data for inclusion in the database (e.g., full-shift exposure or task-based exposure data). Others were excluded because only limited summary statistics were provided, which precluded statistical analysis of the data (e.g., arithmetic mean concentration presented, but no sample number). Following evaluation, 16,880 hydrocarbon solvent exposure measurements from 99 articles were entered into a database for analysis. Methods used to identify and evaluate published solvent exposure data are described along with more detailed analysis of worker exposure to hydrocarbon solvents in three major end-use applications: painting and coating, printing, and adhesives. Solvent exposures were evaluated against current ACGIH threshold limit values (TLVs) and trends were identified. Limited quantitative data are available prior to 1970. In general, reported hydrocarbon solvent exposures decreased fourfold from 1960 to 1998, were below the TLVs applicable to specific hydrocarbon solvents at the time, and on average have been below 40% of the TLV since 1980. The database already has proved valuable; however, the utility of published exposure data could be further improved if authors consistently reported essential data elements and supporting information.

Solvent production by engineered Ralstonia eutropha: channeling carbon to biofuel.

Science.gov (United States)

Chakravarty, Jayashree; Brigham, Christopher J

2018-06-01

Microbial production of solvents like acetone and butanol was a couple of the first industrial fermentation processes to gain global importance. These solvents are important feedstocks for the chemical and biofuel industry. Ralstonia eutropha is a facultatively chemolithoautotrophic bacterium able to grow with organic substrates or H 2 and CO 2 under aerobic conditions. This bacterium is a natural producer of polyhydroxyalkanoate biopolymers. Recently, with the advances in the development of genetic engineering tools, the range of metabolites R. eutropha can produce has enlarged. Its ability to utilize various carbon sources renders it an interesting candidate host for synthesis of renewable biofuel and solvent production. This review focuses on progress in metabolic engineering of R. eutropha for the production of alcohols, terpenes, methyl ketones, and alka(e)nes using various resources. Biological synthesis of solvents still presents the challenge of high production costs and competition from chemical synthesis. Better understanding of R. eutropha biology will support efforts to engineer and develop superior microbial strains for solvent production. Continued research on multiple fronts is required to engineer R. eutropha for truly sustainable and economical solvent production.

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.

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...

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

DEFF Research Database (Denmark)

Mitrofanov, Igor; Sin, Gürkan; Gani, Rafiqul

system engineering view that emphasizes a systematic and generic solution framework to solvent selection problems is presented. The framework integrates different methods and tools to manage the complexity and solve a wide range of problems in efficient and flexible manner. Its software implementation...

Innovative polymeric system (IPS) for solvent-free lipophilic drug transdermal delivery via dissolving microneedles.

Science.gov (United States)

Dangol, Manita; Yang, Huisuk; Li, Cheng Guo; Lahiji, Shayan Fakhraei; Kim, Suyong; Ma, Yonghao; Jung, Hyungil

2016-02-10

Lipophilic drugs are potential drug candidates during drug development. However, due to the need for hazardous organic solvents for their solubilization, these drugs often fail to reach the pharmaceutical market, and in doing so highlight the importance of solvent free systems. Although transdermal drug delivery systems (TDDSs) are considered prospective safe drug delivery routes, a system involving lipophilic drugs in solvent free or powder form has not yet been described. Here, we report, for the first time, a novel approach for the delivery of every kind of lipophilic drug in powder form based on an innovative polymeric system (IPS). The phase transition of powder form of lipophilic drugs due to interior chemical bonds between drugs and biodegradable polymers and formation of nano-sized colloidal structures allowed the fabrication of dissolving microneedles (DMNs) to generate a powerful TDDS. We showed that IPS based DMN with powder capsaicin enhances the therapeutic effect for treatment of the rheumatic arthritis in a DBA/1 mouse model compared to a solvent-based system, indicating the promising potential of this new solvent-free platform for lipophilic drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

Organic solvents improve hydrocarbon desorption and biodegradation in highly contaminated weathered soils

Energy Technology Data Exchange (ETDEWEB)

Garcia-Rivero, M. [Tecnologico de Estudios Superiores de Ecatepec, Mexico City (Mexico); Saucedo-Casteneda, G.; Gutierrez-Rojas, M. [Autonoma Metropolitan Univ., Mexico City (Mexico). Dept. of Biotechnology

2007-07-15

A toluene-based microbial slurry phase system was used to remediate hydrocarbons (HC) in highly contaminated soil samples collected from a site next to a working refinery in Mexico. Initial HC concentrations of the samples were 237.2 {+-} 16,6 g kg{sup -1} in dry soil. The microbial consortium consisted of 10 different strains in a mineral solution. Non-polar solvents used in the phase system included hexane, benzene, and toluene. Polar solvents included n-butanol, acetone, and methanol. The bioavailability of the HCs was increased using both polar and nonpolar solvents in order to promote desorption from the soil and to enhance overall HC biodegradation. HC desorption was analyzed in an abiotic system. Respiration and residual HCs were examined after a period of 30 days in order to compare the effects of the 2 solvents. The biodegradation extracts were then fractionated in a silica gel column to determine if the solvents actually enhanced the biodegradation of specific HC fractions. The study showed that induced dipole interactions forces resulted when nonpolar molecules were dissolved into a nonpolar solvent. Results for desorption and solubility varied among the 6 solvents. Higher dielectric constants resulted in higher solubility and desorption of HCs for nonpolar solvents, while the opposite effect was observed for polar solvents. It was concluded that toluene produced better biodegradation results than any of the milder solvents. 34 refs., 4 tabs., 1 fig.

On the Evaporation Kinetics of [60] Fullerene in Aromatic Organic Solvents

KAUST Repository

Amer, Maher S.; Wang, Wenhu; Kollins, Kaitlin N; Altalebi, Hasanain; Schwingenschlö gl, Udo

2018-01-01

We investigate the effect of C60 fullerene nanospheres on the evaporation kinetics of a number of aromatic solvents with different levels of molecular association, namely, benzene, toluene, and chlorobenzene. The dependence of the evaporation rate on the fullerene concentration is not monotonic but rather exhibits maxima and minima. The results strongly support the notion of molecular structuring within the liquid solvent controlled by the nature of fullerene/solvent interaction and the level of molecular association within the solvent itself.

On the Evaporation Kinetics of [60] Fullerene in Aromatic Organic Solvents

KAUST Repository

Amer, Maher S.

2018-04-03

We investigate the effect of C60 fullerene nanospheres on the evaporation kinetics of a number of aromatic solvents with different levels of molecular association, namely, benzene, toluene, and chlorobenzene. The dependence of the evaporation rate on the fullerene concentration is not monotonic but rather exhibits maxima and minima. The results strongly support the notion of molecular structuring within the liquid solvent controlled by the nature of fullerene/solvent interaction and the level of molecular association within the solvent itself.

Anti-solvent co-crystallization of carbamazepine and saccharin.

Science.gov (United States)

Wang, In-Chun; Lee, Min-Jeong; Sim, Sang-Jun; Kim, Woo-Sik; Chun, Nan-Hee; Choi, Guang J

2013-06-25

The co-crystal approach has been investigated extensively over the past decade as one of the most promising methods to enhance the dissolution properties of insoluble drug substances. Co-crystal powders are typically produced by mechanical grinding (neat or wet) or a solution method (evaporation or cooling). In this study, high-purity carbamazepine-saccharin (CBZ-SAC) co-crystals were manufactured by a novel method, anti-solvent addition. Among various solvents, methanol was found to perform well with water as the anti-solvent for the co-crystallization of CBZ and SAC. When water was added to the methanol solution of CBZ and SAC at room temperature under agitation, nucleation of CBZ-SAC co-crystals occurred within 2-3 min. Co-crystallization was complete after 30 min, giving a solid yield as high as 84.5% on a CBZ basis. The effects of initial concentrations, focusing on the SAC/CBZ ratio, were examined to establish optimal conditions. The whole anti-solvent co-crystallization process was monitored at-line via ATR-FTIR analysis of regularly sampled solutions. The nucleation and crystal growth of CBZ-SAC co-crystals were detected by a significant increase in absorption in the range of 2400-2260 cm(-1), associated with the formation of hydrogen bonds between the carbonyl group in CBZ and the N-H of SAC. When CBZ hydrates were formed as impurities during anti-solvent co-crystallization, the hydrogen bonding between methanol and water was reduced greatly, primarily due to the incorporation of water molecules into the CBZ crystal lattice. In conclusion, an anti-solvent approach can be used to produce highly pure CBZ-SAC co-crystal powders with a high solid yield. Copyright © 2013 Elsevier B.V. All rights reserved.

Benchmarking Continuum Solvent Models for Keto-Enol Tautomerizations.

Science.gov (United States)

McCann, Billy W; McFarland, Stuart; Acevedo, Orlando

2015-08-13

Experimental free energies of tautomerization, ΔGT, were used to benchmark the gas-phase predictions of 17 different quantum mechanical methods and eight basis sets for seven keto-enol tautomer pairs dominated by their enolic form. The G4 method and M06/6-31+G(d,p) yielded the most accurate results, with mean absolute errors (MAE's) of 0.95 and 0.71 kcal/mol, respectively. Using these two theory levels, the solution-phase ΔGT values for 23 unique tautomer pairs composed of aliphatic ketones, β-dicarbonyls, and heterocycles were computed in multiple protic and aprotic solvents. The continuum solvation models, namely, polarizable continuum model (PCM), polarizable conductor calculation model (CPCM), and universal solvation model (SMD), gave relatively similar MAE's of ∼1.6-1.7 kcal/mol for G4 and ∼1.9-2.0 kcal/mol with M06/6-31+G(d,p). Partitioning the tautomer pairs into their respective molecular types, that is, aliphatic ketones, β-dicarbonyls, and heterocycles, and separating out the aqueous versus nonaqueous results finds G4/PCM utilizing the UA0 cavity to be the overall most accurate combination. Free energies of activation, ΔG(‡), for the base-catalyzed keto-enol interconversion of 2-nitrocyclohexanone were also computed using six bases and five solvents. The M06/6-31+G(d,p) reproduced the ΔG(‡) with MAE's of 1.5 and 1.8 kcal/mol using CPCM and SMD, respectively, for all combinations of base and solvent. That specific enolization was previously proposed to proceed via a concerted mechanism in less polar solvents but shift to a stepwise mechanism in more polar solvents. However, the current calculations suggest that the stepwise mechanism operates in all solvents.

Self-reported hearing performance in workers exposed to solvents

Directory of Open Access Journals (Sweden)

Adrian Fuente

2013-02-01

Full Text Available OBJECTIVE: To compare hearing performance relating to the peripheral and central auditory system between solvent-exposed and non-exposed workers. METHODS: Forty-eight workers exposed to a mixture of solvents and 48 non-exposed control subjects of matched age, gender and educational level were selected to participate in the study. The evaluation procedures included: pure-tone audiometry (500 - 8,000 Hz, to investigate the peripheral auditory system; the Random Gap Detection test, to assess the central auditory system; and the Amsterdam Inventory for Auditory Disability and Handicap, to investigate subjects' self-reported hearing performance in daily-life activities. A Student t test and analyses of covariance (ANCOVA were computed to determine possible significant differences between solvent-exposed and non-exposed subjects for the hearing level, Random Gap Detection test and Amsterdam Inventory for Auditory Disability and Handicap. Pearson correlations among the three measures were also calculated. RESULTS: Solvent-exposed subjects exhibited significantly poorer hearing thresholds for the right ear than non-exposed subjects. Also, solvent-exposed subjects exhibited poorer results for the Random Gap Detection test and self-reported poorer listening performance than non-exposed subjects. Results of the Amsterdam Inventory for Auditory Disability and Handicap were significantly correlated with the binaural average of subject pure-tone thresholds and Random Gap Detection test performance. CONCLUSIONS: Solvent exposure is associated with poorer hearing performance in daily life activities that relate to the function of the peripheral and central auditory system.

Non-conventional solvents in liquid phase microextraction and aqueous biphasic systems.

Science.gov (United States)

An, Jiwoo; Trujillo-Rodríguez, María J; Pino, Verónica; Anderson, Jared L

2017-06-02

The development of rapid, convenient, and high throughput sample preparation approaches such as liquid phase microextraction techniques have been continuously developed over the last decade. More recently, significant attention has been given to the replacement of conventional organic solvents used in liquid phase microextraction techniques in order to reduce toxic waste and to improve selectivity and/or extraction efficiency. With these objectives, non-conventional solvents have been explored in liquid phase microextraction and aqueous biphasic systems. The utilized non-conventional solvents include ionic liquids, magnetic ionic liquids, and deep eutectic solvents. They have been widely used as extraction solvents or additives in various liquid phase microextraction modes including dispersive liquid-liquid microextraction, single-drop microextraction, hollow fiber-liquid phase microextraction, as well as in aqueous biphasic systems. This review provides an overview into the use of non-conventional solvents in these microextraction techniques in the past 5 years (2012-2016). Analytical applications of the techniques are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Preferential solvation of fluorenone and 4-hydroxyfluorenone in binary solvent mixtures

International Nuclear Information System (INIS)

Jozefowicz, Marek; Heldt, Janina R.

2003-01-01

Preferential solvation of fluorenone and 4-hydroxyfluorenone in binary solvent mixtures has been studied using steady-state spectroscopic measurements. This study concerns the solvent-induced shift of the absorption and fluorescence spectra of both molecules in two solvent mixtures, i.e., cyclohexane-tetrahydrofuran and cyclohexane-ethanol. The first system contains polar solute molecules, fluorenone and 4-hydroxyfluorenone, in a mixture of polar aprotic (tetrahydrofuran) and non-polar (cyclohexane) solvents. In the second solvents mixture, hydrogen bonding with solute molecules (ethanol) may occur. The results of spectroscopic measurements are analysed using theoretical models of Bakshiev, Mazurenko and Suppan which describe preferential solvation phenomena. In the case of cyclohexane-tetrahydrofuran mixtures, the deviation from linearity in the absorption and fluorescence solvatochromic shifts vs. the solution polarity is due to non-specific dipolar solvent-solute interactions. For cyclohexane-ethanol binary mixtures, both non-specific and specific (hydrogen bond and proton-relay tautomerization) interactions contribute to the observed solvatochromism

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.

Effect of solvent and temperature on solution-crystallized terfenadine

International Nuclear Information System (INIS)

Leitao, M. Luisa P.; Canotilho, Joao; Ferreira, Simone C.R.; Sousa, Adriano T.; Simoes Redinha, J.

2004-01-01

The aim of this work was to understand the crystallization process of terfenadine in solution. Cooling of saturated solutions prepared at 50 deg. C at different temperatures, evaporating the solvent from nearly saturated solutions at a certain temperature, and exposing ethanol solutions of terfenadine to water vapour atmosphere were the techniques used for obtaining terfenadine specimens. The characterization of these specimens was carried out by thermal microscopy, differential thermal analysis, thermogravimetry and powder X-ray diffraction. Crystalline phases, amorphous solids, and solvates were identified. For the solvents used in the present study, the crystallinity degree of terfenadine decreases from ethanol-water to ethanol and from this to methanol. Decreasing the temperature promotes the formation of amorphous solid material; at low temperatures, methanol and ethanol solvates are also formed. Desolvation, following the terfenadine aggregation process in solution accounts for the different behaviour found for the solvents and for the effect of temperature on the structure. The role of the solvent as structure-mediator is explained on the grounds of the values previously published for the enthalpy of solution of terfenadine in the solvents under study

General Solvent-dependent Strategy toward Enhanced Oxygen Reduction Reaction in Graphene/Metal Oxide Nanohybrids: Effects of Nitrogen-containing Solvent

Science.gov (United States)

Kao, Wei-Yao; Chen, Wei-Quan; Chiu, Yu-Hsiang; Ho, Yu-Hsuan; Chen, Chun-Hu

2016-11-01

A general solvent-dependent protocol directly influencing the oxygen reduction reaction (ORR) in metal oxide/graphene nanohybrids has been demonstrated. We conducted the two-step synthesis of cobalt oxide/N-doped graphene nanohybrids (CNG) with solvents of water, ethanol, and dimethylformamide (DMF), representing tree typical categories of aqueous, polar organic, and organic N-containing solvents commonly adopted for graphene nanocomposites preparation. The superior ORR performance of the DMF-hybrids can be attributed to the high nitrogen-doping, aggregation-free hybridization, and unique graphene porous structures. As DMF is the more effective N-source, the spectroscopic results support a catalytic nitrogenation potentially mediated by cobalt-DMF coordination complexes. The wide-distribution of porosity (covering micro-, meso-, to macro-pore) and micron-void assembly of graphene may further enhance the diffusion kinetics for ORR. As the results, CNG by DMF-synthesis exhibits the high ORR activities close to Pt/C (i.e. only 8 mV difference of half-wave potential with electron transfer number of 3.96) with the better durability in the alkaline condition. Additional graphene hybrids comprised of iron and manganese oxides also show the superior ORR activities by DMF-synthesis, confirming the general solvent-dependent protocol to achieve enhanced ORR activities.

The use of organic solvents in mutagenicity testing.

Science.gov (United States)

Abbondandolo, A; Bonatti, S; Corsi, C; Corti, G; Fiorio, R; Leporini, C; Mazzaccaro, A; Nieri, R; Barale, R; Loprieno, N

1980-10-01

13 organic substances (dimethylsulfoxide, methanol, ethanol, n-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, dl-sec-amyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, 1,4-diethylene dioxide, acetone, methyl acetate and formamide) were considered from the standpoint of their use as solvents for water-insoluble chemicals to be tested for mutagenicity. First, the effect of these solvents on cell survival was studied in the yeast Schizosaccharomyces pombe and in V79 Chinese hamster cells. 8 solvents showing relatively low toxicity on either cell system (dimethylsulfoxide, ethanol, ethylene glycol, ethylene glycol monomethyl ether, 1,4-diethylene dioxide, acetone, methyl acetate and formamide) were tested for their effect on aminopyrine demethylase. 4 solvents (ethanol, 1,4-diethylene dioxide, methyl acetate and formamide) showed a more or less pronounced adverse effect on the microsomal enzymic activity. The remaining 4 and methanol (whose effect on aminopyrine demethylase was not testable) were assayed for mutagenicity in S. pombe. They all gave negative results both with and without the post-mitochondrial fraction from mouse liver.

Solvent extraction: the coordination chemistry behind extractive metallurgy.

Science.gov (United States)

Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B

2014-01-07

The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents.

Changing the Mechanism for CO ₂ Hydrogenation Using Solvent-Dependent Thermodynamics

Energy Technology Data Exchange (ETDEWEB)

Burgess, Samantha A. [Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Appel, Aaron M. [Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Linehan, John C. [Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Wiedner, Eric S. [Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA

2017-10-23

A critical scientific challenge for utilization of CO2 is the development of catalyst systems that do not depend upon expensive or environmentally unfriendly reagents, such as precious metals, strong organic bases, and organic solvents. We have used thermodynamic insights to predict and demonstrate that the HCoI(dmpe)2 catalyst system, previously described for use in organic solvents, can hydrogenate CO2 to formate in water with bicarbonate as the only added reagent. Replacing tetrahydrofuran as the solvent with water changes the mechanism for catalysis by altering the thermodynamics for hydride transfer to CO2 from a key dihydride intermediate. The need for a strong organic base was eliminated by performing catalysis in water due to the change in mechanism. These studies demonstrate that the solvent plays a pivotal role in determining the reaction thermodynamics and thereby catalytic mechanism and activity. The research was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Highχ block copolymers for directed self-assembly patterning without the need for topcoat or solvent annealing

Science.gov (United States)

Xu, Kui; Hockey, Mary Ann; Calderas, Eric; Guerrero, Douglas; Sweat, Daniel; Fiehler, Jeffrey

2017-03-01

High-χ block copolymers for directed self-assembly (DSA) patterning that do not need topcoat or solvent annealing have been developed. A variety of functionalities have been successfully added into the block copolymers, such as balanced surface energy between the polymer blocks, outstandingly high χ, tunable glass transition temperature (Tg), and selective crosslinking. Perpendicular orientation control, as desired for patterning, of the block copolymers can be simply achieved by thermal annealing due to the equal surface energy of the polymer blocks at the annealing temperatures, which allows avoiding solvent annealing or top-coat. The χ value can be tuned up to achieve L0 as low as 8-10 nm for lamellar-structured block copolymers and hole/pillar size as small as 5-6 nm for cylinder-structured block copolymers. The Tg of the block copolymers can be tuned to improve the kinetics of thermal annealing by enhancing the polymer chain mobility. Block-selective crosslinking facilitates the pattern transfer by mitigating pattern collapse during wet etching and improving oxygen plasma etching selectivity between the polymer blocks. This paper provides an introductory review of our high-χ block copolymer materials with various functionalities for achieving improved DSA performance.

A radiochemical technique for the establishment of a solvent-independent scale of ion activities in amphiprotic solvents

International Nuclear Information System (INIS)

Kim, J.I.; Duschner, H.; Born, H.J.

1975-01-01

The radiochemical determination of solubilities of hardly soluble compounds of silver (Ph 4 BAg, AgCl), by means of Ag-110m in amphiprotic solutions is used for setting-up a solvent-independent scale of ion activities based on the concept of the media effect. The media effects of the salts are calculated from the solubility data of the Ag compounds in question. The splitting into the media effects of single ions takes place with the extrathermodynamic assumption of the same media effects for large ions, such as Ph 4 B - = Ph 4 As - . A standardized ion activity scale in connection with the activity coefficients for the solvent in question can be established with water as the basic state of the chemical potential. As the sum of the media effects of the single ions gives the media effect of the salt concerned, which is easily obtained from data which are experimentally accessible (solubility, vapour pressure, ion exchange ect.), this method leads to single ion activities of a large number of ions in a multitude of solvents. (orig./LH) [de

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 approximatio...

Recovery of plutonium from solvent wash solutions

International Nuclear Information System (INIS)

Kyser, E.A.

1992-01-01

A number of potential alternatives to the acid hydrolysis recovery of Pu were investigated. The most promising alternative for short-term use appears to be an anion exchange process that would eliminate the long boiling times and the multiple-pass concentration steps needed with the solvent extraction process because it separates the Pu from the dibutyl phosphate (DBP) while at the same time concentrating the Pu. However, restart of the Primary Recovery Column (PRC) to process this solution would require significant administrative effort. The original boiling recovery by acid hydrolysis followed by solvent extraction is probably the most expedient way to process the Pu-DBP-carbonate solution currently stored in tank 13.5 even with its long processing times and dilute product concentration. Anion exchange of a heat stabilized acidified solution is a more efficient process, but requires restart of the PRC. Extended-boiling acid hydrolysis or anion exchange of a heat stabilized acidified solution provide two well developed alternatives for recovery of the Pu from the tank 13.5 carbonate. Further work defining additional recovery processes is not planned at this time

SOLVENT HOLD TANK SAMPLE RESULTS FOR MCU-13-189, MCU-13-190, AND MCU-13-191: QUARTERLY SAMPLE FROM SEPTEMBER 2013

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F.; Taylor-Pashow, K.

2013-10-31

Savannah River National Laboratory (SRNL) analyzed solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-13-189, MCU-13-190, and MCU-13-191 received on September 4, 2013 are reported. The results show that the solvent (remaining heel in the SHT tank) at MCU contains excess Isopar L and a deficit concentration of modifier and trioctylamine when compared to the standard MCU solvent. As with the previous solvent sample results, these analyses indicate that the solvent does not require Isopar L trimming at this time. Since MCU is switching to NGS, there is no need to add TOA nor modifier. SRNL also analyzed the SHT sample for {{sup 137}Cs content and determined the measured value is within tolerance and the value has returned to levels observed in 2011.

Self-reported hearing performance in workers exposed to solvents Autoevaluación de funciones auditivas en trabajadores expuestos a solventes Autoavaliação de funções auditivas em trabalhadores expostos a solventes

Directory of Open Access Journals (Sweden)

Adrian Fuente

2013-02-01

Full Text Available OBJECTIVE: To compare hearing performance relating to the peripheral and central auditory system between solvent-exposed and non-exposed workers. METHODS: Forty-eight workers exposed to a mixture of solvents and 48 non-exposed control subjects of matched age, gender and educational level were selected to participate in the study. The evaluation procedures included: pure-tone audiometry (500 - 8,000 Hz, to investigate the peripheral auditory system; the Random Gap Detection test, to assess the central auditory system; and the Amsterdam Inventory for Auditory Disability and Handicap, to investigate subjects' self-reported hearing performance in daily-life activities. A Student t test and analyses of covariance (ANCOVA were computed to determine possible significant differences between solvent-exposed and non-exposed subjects for the hearing level, Random Gap Detection test and Amsterdam Inventory for Auditory Disability and Handicap. Pearson correlations among the three measures were also calculated. RESULTS: Solvent-exposed subjects exhibited significantly poorer hearing thresholds for the right ear than non-exposed subjects. Also, solvent-exposed subjects exhibited poorer results for the Random Gap Detection test and self-reported poorer listening performance than non-exposed subjects. Results of the Amsterdam Inventory for Auditory Disability and Handicap were significantly correlated with the binaural average of subject pure-tone thresholds and Random Gap Detection test performance. CONCLUSIONS: Solvent exposure is associated with poorer hearing performance in daily life activities that relate to the function of the peripheral and central auditory system.OBJETIVO: Comparar el desempeño de las actividades diarias relacionadas a funciones del sistema auditivo periférico y central entre trabajadores expuestos y no expuestos a solventes. MÉTODOS: Participaron del estudio, 96 trabajadores, siendo 48 expuestos a solventes y no expuestos, pareados

Percolation characteristics of solvent invasion in rough fractures under miscible conditions

Science.gov (United States)

Korfanta, M.; Babadagli, T.; Develi, K.

2017-10-01

Surface roughness and flow rate effects on the solvent transport under miscible conditions in a single fracture are studied. Surface replicas of seven different rocks (marble, granite, and limestone) are used to represent different surface roughness characteristics each described by different mathematical models including three fractal dimensions. Distribution of dyed solvent is investigated at various flow rate conditions to clarify the effect of roughness on convective and diffusive mixing. After a qualitative analysis using comparative images of different rocks, the area covered by solvent with respect to time is determined to conduct a semi-quantitative analysis. In this exercise, two distinct zones are identified, namely the straight lines obtained for convective (early times) and diffusive (late times) flow. The bending point between these two lines is used to point the transition between the two zones. Finally, the slopes of the straight lines and the bending points are correlated to five different roughness parameters and the rate (Peclet number). It is observed that both surface roughness and flow rate have significant effect on solvent spatial distribution. The largest area covered is obtained at moderate flow rates and hence not only the average surface roughness characteristic is important, but coessentially total fracture surface area needs to be considered when evaluating fluid distribution. It is also noted that the rate effect is critically different for the fracture samples of large grain size (marbles and granite) compared to smaller grain sizes (limestones). Variogram fractal dimension exhibits the strongest correlation with the maximum area covered by solvent, and display increasing trend at the moderate flow rates. Equations with variogram surface fractal dimension in combination with any other surface fractal parameter coupled with Peclet number can be used to predict maximum area covered by solvent in a single fracture, which in turn can be

Solvent for urethane adhesives and coatings and method of use

Science.gov (United States)

Simandl, Ronald F.; Brown, John D.; Holt, Jerrid S.

2010-08-03

A solvent for urethane adhesives and coatings, the solvent having a carbaldehyde and a cyclic amide as constituents. In some embodiments the solvent consists only of miscible constituents. In some embodiments the carbaldehyde is benzaldehyde and in some embodiments the cyclic amide is N-methylpyrrolidone (M-pyrole). An extender may be added to the solvent. In some embodiments the extender is miscible with the other ingredients, and in some embodiments the extender is non-aqueous. For example, the extender may include isopropanol, ethanol, tetrahydro furfuryl alcohol, benzyl alcohol, Gamma-butyrolactone or a caprolactone. In some embodiments a carbaldehyde and a cyclic amide are heated and used to separate a urethane bonded to a component.

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....

Separation of Hydridocarbonyltris(triphenylphosphine) Rhodium (I) Catalyst Using Solvent Resistant Nano filtration Membrane

International Nuclear Information System (INIS)

Razak, N.S.A.; Hilmi Mukhtar; Maizatul, S. Shaharun; Mohd, F. Taha

2013-01-01

An investigation was conducted into the nano filtration of rhodium tris(triphenyl-phosphine) [HRh(CO)(PPh3)3] catalyst used in the hydroformylation of olefins. The large size of the catalyst (>400 Da) - relative to other components of the reaction provides the opportunity for a membrane separation based on retention of the catalyst species while permeating the solvent. The compatibility of the solvent-polyimide membrane (STARMEMTM 122 and STARMEMTM 240) combinations was assessed in terms of the membrane stability in solvent plus non-zero solvent flux at 2.0 MPa. The morphology of the membrane was studied by field emission scanning electron microscopy (FESEM). The solvent flux and membrane rejection of HRh(CO)(PPh3)3 was then determined for the catalyst-solvent-membrane combination in a dead-end pressure cell. Good HRh(CO)(PPh3)3 rejection (>0.93) coupled with good solvent fluxes (>72 L/ m 2 h 1 at 2.0 MPa) were obtained in one of the systems tested. The effect of pressure and catalyst concentration on the solvent flux and catalyst rejection was conducted. Increasing pressure substantially improved both solvent flux and catalyst rejection, while increasing catalyst concentration was found to be beneficial in terms of substantial increases in catalyst rejection without significantly affecting the solvent flux. (author)

Combination pulsed electric field with ethanol solvent for Nannochloropsis sp. extraction

Science.gov (United States)

Nafis, Ghazy Ammar; Mumpuni, Perwitasari Yekti; Indarto, Budiman, Arief

2015-12-01

Nowadays, energy is one of human basic needs. As the human population increased, energy consumption also increased. This condition causes energy depletion. In case of the situation, alternative energy is needed to replace existing energy. Microalgae is chosen to become one of renewable energy resource, especially biodiesel, because it contains high amount of lipid instead of other feedstock which usually used. Fortunately, Indonesia has large area of water and high intensity of sunlight so microalgae cultivation becomes easier. Nannochloropsis sp., one of microalgae species, becomes the main focus because of its high lipid content. Many ways to break the cell wall of microalgae so the lipid content inside the microalgae will be released, for example conventional extraction, ultrasonic wave extraction, pressing, and electrical method. The most effective way for extraction is electrical method such as pulsed electric field method (PEF). The principal work of this method is by draining the electrical current into parallel plate. Parallel plate will generate the electrical field to break microalgae cell wall and the lipid will be released. The aim of this work is to evaluate two-stage procedure for extraction of useful components from microalgae Nannochloropsis sp. The first stage of this procedure includes pre-treatment of microalgae by ethanol solvent extraction and the second stage applies the PEF extraction using a binary mixture of water and ethanol solvent. Ethanol is chosen as solvent because it's safer to be used and easier to be handled than other solvent. Some variables that used to study the most effective operation conditions are frequency and duty cycle for microalgae. The optimum condition based on this research are at frequency 1 Hz and duty cycle 13%.

Physiology of solvent tolerance in Pseudomonas putida S12

NARCIS (Netherlands)

Isken, S.

2000-01-01

Hydrophobic organic solvents, like toluene, are toxic for living organisms. This toxicity is an important drawback in the environmental biotechnology as well as in the application of solvents in the production of fine chemicals by whole-cell biotransformations. The effects of organic

Substitution of Organic Solvents in Selected Industrial Cleaning Processes

DEFF Research Database (Denmark)

Jacobsen, Thomas; Rasmussen, Pia Brunn

1997-01-01

Volatile organic solvents (VOC)are becoming increasingly unwanted in industrial processes. Substitution of VOC with non-volatile, low-toxic compounds is a possibility to reduce VOC-use. It has been successfully demonstrated, that organic solvents used in cleaning processes in sheet offset printing...

40 CFR 52.246 - Control of dry cleaning solvent vapor losses.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of dry cleaning solvent vapor... cleaning solvent vapor losses. (a) For the purpose of this section, “dry cleaning operation” means that process by which an organic solvent is used in the commercial cleaning of garments and other fabric...

Solvent extraction for remediation of manufactured gas plant sites

International Nuclear Information System (INIS)

Luthy, R.G.; Dzombak, D.A.; Peters, C.; Ali, M.A.; Roy, S.B.

1992-12-01

This report presents the results of an initial assessment of the feasibility of solvent extraction for removing coal tar from the subsurface or for treating contaminated soil excavated at manufactured gas plant (MGP) sites. In situ solvent extraction would involve injection, recovery, and reclamation for reinjection of an environmentally-benign, water-miscible solvent. Accelerated dissolution and removal of coaltar from the subsurface might be desirable as a remedial approach if excavation is not practical (e.g., the site underlies facilities in current use), direct pumping of coal tar is ineffective, and bioremediation is not feasible because of the presence of high concentrations of coal tar. Both laboratory experiments and engineering evaluations were performed to provide a basis for the initial feasibility assessment. Laboratory work included identification and evaluation of promising solvents, measurement of fundamental properties of coal tar-solvent-water systems, and measurement of rates of dissolution of coal tar in porous media into flowing solvent-water solutions. Engineering evaluations involved identification of common hydrogeologic features and contaminant distributions at MGP sites, and identification and evaluation of possible injection-recovery well deployment schemes. A coupled flow-chemistry model was developed for simulation of the in situ process and evaluation of the well deployment schemes. Results indicate that in situsolvent extraction may be able to recover a significant amount of coal tar from the subsurface within a reasonable time frame (on the order of one year or so) provided that subsurface conditions are conducive to process implementation. Some important implementation issues remain to be addressed

Solvent-cast three-dimensional printing of multifunctional microsystems.

Science.gov (United States)

Guo, Shuang-Zhuang; Gosselin, Frédérick; Guerin, Nicolas; Lanouette, Anne-Marie; Heuzey, Marie-Claude; Therriault, Daniel

2013-12-20

The solvent-cast direct-write fabrication of microstructures is shown using a thermoplastic polymer solution ink. The method employs the robotically controlled microextrusion of a filament combined with a rapid solvent evaporation. Upon drying, the increased rigidity of the extruded filament enables the creation of complex freeform 3D shapes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method of purifying phosphoric acid after solvent extraction

International Nuclear Information System (INIS)

Kouloheris, A.P.; Lefever, J.A.

1979-01-01

A method of purifying phosphoric acid after solvent extraction is described. The phosphoric acid is contacted with a sorbent which sorbs or takes up the residual amount of organic carrier and the phosphoric acid separated from the organic carrier-laden sorbent. The method is especially suitable for removing residual organic carrier from phosphoric acid after solvent extraction uranium recovery. (author)

21 CFR 878.4730 - Surgical skin degreaser or adhesive tape solvent.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical skin degreaser or adhesive tape solvent... Surgical skin degreaser or adhesive tape solvent. (a) Identification. A surgical skin degreaser or an adhesive tape solvent is a device that consists of a liquid such as 1,1,2-trichloro-1,2,2-trifluoroethane...

Recovery of hafnium values from loaded extraction solvent

International Nuclear Information System (INIS)

Abodishish, H.A.

1989-01-01

This patent describes an improvement in a process for recovering high purity hafnium hydroxide from a methyl isobutyl ketone organic solvent that is substantially free of sulfate ions and contains hafnium thiocyanate and thiocyanic acid. The improvement comprising reacting the organic solvent with ammonia to produce a reaction product in the form of a methyl isobutyl ketone organic solvent that is substantially free of sulfate ions and contains ammonium thiocyanite solution and hafnium hydroxide; separating the constituents of the reaction product in accordance with their respective specific gravities to produce a hafnium hydroxide sludge as one of the separation products; and removing the liquid component of the sludge to yield a high purity hafnium hydroxide ready for calcination to hafnium oxide

Crosslinked copolyazoles with a zwitterionic structure for organic solvent resistant membranes

KAUST Repository

Chisca, Stefan

2015-01-01

The preparation of crosslinked membranes with a zwitterionic structure based on a facile reaction between a newly synthesized copolyazole with free OH groups and (3-glycidyloxypropyl)trimethoxysilane (GPTMS) is reported. The new OH-functionalized copolyazole is soluble in common organic solvents, such as tetrahydrofuran (THF), dimethylsulfoxide (DMSO), N,N′-dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP) and can be easily processed by phase inversion. After crosslinking with GPTMS, the membranes acquire high solvent resistance. We show the membrane performance and the influence of the crosslinking reaction conditions on the thermal stability, surface polarity, pore morphology, and solvent resistance. By using UV-spectroscopy we monitored the solvent resistance of the membranes in four aggressive solvents (THF, DMSO, DMF and NMP) for 30 days. After this time, only minor changes (less than 2%) were detected for membranes subjected to a crosslinking reaction for 6 hours or longer. Our data suggest that the novel crosslinked membranes can be used for industrial applications in wide harsh environments in the presence of organic solvents.

Supramolecular Chirality: Solvent Chirality Transfer in Molecular Chemistry and Polymer Chemistry

Directory of Open Access Journals (Sweden)

Michiya Fujiki

2014-08-01

Full Text Available Controlled mirror symmetry breaking arising from chemical and physical origin is currently one of the hottest issues in the field of supramolecular chirality. The dynamic twisting abilities of solvent molecules are often ignored and unknown, although the targeted molecules and polymers in a fluid solution are surrounded by solvent molecules. We should pay more attention to the facts that mostly all of the chemical and physical properties of these molecules and polymers in the ground and photoexcited states are significantly influenced by the surrounding solvent molecules with much conformational freedom through non-covalent supramolecular interactions between these substances and solvent molecules. This review highlights a series of studies that include: (i historical background, covering chiral NaClO3 crystallization in the presence of d-sugars in the late 19th century; (ii early solvent chirality effects for optically inactive chromophores/fluorophores in the 1960s–1980s; and (iii the recent development of mirror symmetry breaking from the corresponding achiral or optically inactive molecules and polymers with the help of molecular chirality as the solvent use quantity.

Development of spent solvent treatment process by a submerged combustion technique

International Nuclear Information System (INIS)

Uchiyama, Gunzo; Maeda, Mitsuru; Fujine, Sachio; Amakawa, Masayuki; Uchida, Katsuhide; Chida, Mitsuhisa

1994-01-01

An experimental study using a bench-scale equipment of 1 kg-simulated spent solvents per hour has been conducted in order to evaluate the applicability of a submerged combustion technique to the treatment of spent solvents contaminated with TRU elements. This report describes the experimental results on the combustion characteristics of the simulated spent solvents of tri-n-butyl phosphate and/or n-dodecane, and on the distribution behaviors of combustion products such as phosphoric acid, Ru, I, Zr and lanthanides as TRU simulants in the submerged combustion process. Also the experimental results of TRU separation from phosphoric acid solution by co-precipitation using bismuth phosphate are reported. It was shown that the submerged combustion technique was applicable to the treatment of spent solvents including the distillation residues of the solvent. Based on the experimental data, a new treatment process of spent solvent was proposed which consisted of submerged combustion, co-precipitation using bismuth phosphate, ceramic membrane filtration, cementation of TRU lean phosphate, and vitrification of TRU rich waste. (author)

Filming the Birth of Molecules and Accompanying Solvent Rearrangement

DEFF Research Database (Denmark)

Lee, Jae Hyuk; Wulff, Michael; Bratos, Savo

2013-01-01

Molecules are often born with high energy and large-amplitude vibrations. In solution, a newly formed molecule cools down by transferring energy to the surrounding solvent molecules. The progression of the molecular and solute−solvent cage structure during this fundamental process has been elusiv...

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...

Solvent Carryover Characterization and Recovery for a 10-inch Single Stage Centrifugal Contactor

International Nuclear Information System (INIS)

Lentsch, R.D.; Stephens, A.B.; Leung, D.T.; Baffling, K.E.; Harmon, H.D.; Suggs, P.C.

2006-01-01

A test program has been performed to characterize the organic solvent carryover and recovery from centrifugal contactors in the Caustic-side Solvent Extraction (CSSX) process. CSSX is the baseline design for removing cesium from salt solutions for Department of Energy (DOE) Savannah River Site's Salt Waste Processing Facility. CSSX uses a custom solvent to extract cesium from the salt solution in a series of single stage centrifugal contactors. Meeting the Waste Acceptance Criteria at the Defense Waste Processing Facility and Saltstone, as well as plant economics, dictate that solvent loss should be kept to a minimum. Solvent droplet size distribution in the aqueous outlet streams of the CSSX contactors is of particular importance to the design of solvent recovery equipment. Because insufficient solvent droplet size data existed to form a basis for the recovery system design, DOE funded the CSSX Solvent Carryover Characterization and Recovery Test (SCCRT). This paper presents the droplet size distribution of solvent and concentration in the contactor aqueous outlet streams as a function of rotor speed, bottom plate type, and flow rate. It also presents the performance data of a prototype coalescer. (authors)

Justification of the solvent choice for the industrial amizon substance production

Directory of Open Access Journals (Sweden)

V. A. Georgiyants

2014-08-01

Full Text Available INTRODUCTION In recent years, the rapid development gets implementing principles of quality management in the pharmaceutical industry. It should be noted that instead of the mechanical control of the quality associated with the chemical characteristics of pharmaceutical substances and drugs innovative ways to ensure the quality associated primarily with the understanding of the processes occurring during the manufacturing process come. Objective: To study solvent selection for the industrial production of methiodide benzyl amide isonicotinic acid substance considering the conception “Quality by design”. MATERIALS AND METHODS Solution of 0.1 moles of isonicotinic acid in 0.12 moles of benzylamine was heated at 160-185°C during 4-5 hours while distilling off water and excess benzylamine. The resulting melt - cooled isonicotinic acid benzylamide was dissolved in acetone and filtered. It was used in further synthesis without further purification. 0.1 moles of isonicotinic acid benzylamide was dissolved in0.6 litersof a suitable solvent and 0.12 mole of methyl iodide was added to the solution at room temperature. The mixture was heated at 40-50 ° C for 3-4 hours, the reaction mixture was cooled, filtered the product was dried. After calculating the aim product was recrystallized from an appropriate solvent. Isonicotinic acid benzylamide iodomethylate quantitative content was determined by acid-base titration in non-aqueous medium (fixing the endpoint - potentiometrically. The impurity content benzylamide isonicotinic acid – by HPLC. RESULTS AND DISCUSSION When solvent have been chosen we took into account previously developed scheme of laboratory synthesis. We guided primarily data about security and efficiency. The least toxic solvents conventionally used in pharmaceutical production , included 2- propanol and ethanol (limit of residual amounts of these solvents, allowable HFC substances was 0.5 % and 1 %, respectively. Therefore, these

Dissolution of covalent adaptable network polymers in organic solvent

Science.gov (United States)

Yu, Kai; Yang, Hua; Dao, Binh H.; Shi, Qian; Yakacki, Christopher M.

2017-12-01

It was recently reported that thermosetting polymers can be fully dissolved in a proper organic solvent utilizing a bond-exchange reaction (BER), where small molecules diffuse into the polymer, break the long polymer chains into short segments, and eventually dissolve the network when sufficient solvent is provided. The solvent-assisted dissolution approach was applied to fully recycle thermosets and their fiber composites. This paper presents the first multi-scale modeling framework to predict the dissolution kinetics and mechanics of thermosets in organic solvent. The model connects the micro-scale network dynamics with macro-scale material properties: in the micro-scale, a model is developed based on the kinetics of BERs to describe the cleavage rate of polymer chains and evolution of chain segment length during the dissolution. The micro-scale model is then fed into a continuum-level model with considerations of the transportation of solvent molecules and chain segments in the system. The model shows good prediction on conversion rate of functional groups, degradation of network mechanical properties, and dissolution rate of thermosets during the dissolution. It identifies the underlying kinetic factors governing the dissolution process, and reveals the influence of different material and processing variables on the dissolution process, such as time, temperature, catalyst concentration, and chain length between cross-links.

Solvents in Organic Synthesis: Replacement and Multi-step Reaction Systems

DEFF Research Database (Denmark)

Gani, Rafiqul; Gómez, Paola Arenas; Folic, Milica

2008-01-01

Solvents are widely used as reaction media in the chemical, fine chemical and pharmaceutical industries, but they present numerous environmental, health and safety (EHS) challenges that need to be managed and are subject to increasing regulatory scrutiny. The above issues, together with the princ...

Recovery of uranium from 30 vol % tributyl phosphate solvents containing dibutyl phosphate

International Nuclear Information System (INIS)

Mailen, J.C.; Tallent, O.K.

1986-01-01

A number of solid sorbents were tested for the removal of uranium and dibutyl phosphate (DBP) from 30% tributyl phosphate (TBP) solvent. The desired clean uranium product can be obtained either by removing the DBP, leaving the uranium in the solvent for subsequent stripping, or by removing the uranium, leaving the DBP in the solvent for subsequent treatment. The tests performed show that it is relatively easy to preferentially remove uranium from solvents containing uranium and DBP, but quite difficult to remove DBP preferentially. The current methods could be used by removing the uranium (as by a cation exchange resin) and then using either an anion exchange resin in the hydroxyl form or a conventional treatment with a basic solution to remove the DBP. Treatment of a solvent with a cation exchange resin could be useful for recovery of valuable metals from solvents containing DBP and might be used to remove cations before scrubbing a solvent with a basic solution to minimize emulsion formation. 6 refs., 9 figs

Comparative study of aqueous and solvent methods for cleaning metals

International Nuclear Information System (INIS)

Briggs, J.L.; Goad, H.A.

1976-01-01

Studies were performed to determine the comparative effectiveness of solvent and aqueous detergent methods for cleaning various metals. The metals investigated included 304L stainless steel, beryllium, uranium-6.5 wt percent niobium alloy, and unalloyed uranium ( 238 U). The studies were initiated in response to governmental regulations restricting the use of some chlorinated solvents. Results showed that aqueous detergent cleaning was more effective than solvents, i.e. trichloroethylene and methyl chloroform, for the removal of light industrial soils. The subsequent adoption of aqueous cleaning at this plant has facilitated waste disposal, which contributed to recorded economic savings. The controlled use of aqueous detergents is environmentally acceptable and has decreased the hazards of fire and toxicity that are generally associated with solvents. 8 tables, 15 figures

Non-Ideal Behavior in Solvent Extraction

International Nuclear Information System (INIS)

Zalupski, Peter

2011-01-01

This report presents a summary of the work performed to meet FCR and 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 and 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.

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.

Influences of surface and solvent on retention of HEMA/mixture components after evaporation.

Science.gov (United States)

Garcia, Fernanda C P; Wang, Linda; Pereira, Lúcia C G; de Andrade e Silva, Safira M; Júnior, Luiz M; Carrilho, Marcela Rocha de Oliveira

2010-01-01

This study examined the retention of solvents within experimental HEMA/solvent primers after two conditions for solvent evaporation: from a free surface or from dentine surface. Experimental primers were prepared by mixing 35% HEMA with 65% water, methanol, ethanol or acetone (v/v). Aliquots of each primer (50 microl) were placed on glass wells or they were applied to the surface of acid-etched dentine cubes (2mm x 2mm x 2mm) (n=5). For both conditions (i.e. from free surface or dentine cubes), change in primers mass due to solvent evaporation was gravimetrically measured for 10min at 51% RH and 21 degrees C. The rate of solvent evaporation was calculated as a function of loss of primers mass (%) over time. Data were analysed by two-way ANOVA and Student-Newman-Keuls (pevaporation rate (%/min) depending on the solvent present in the primer and the condition for evaporation (from free surface or dentine cubes) (pevaporation for HEMA/acetone primer was almost 2- to 10-times higher than for HEMA/water primer depending whether evaporation occurred, respectively, from a free surface or dentine cubes. The rate of solvent evaporation varied with time, being in general highest at the earliest periods. The rate of solvent evaporation and its retention into HEMA/solvent primers was influenced by the type of the solvent and condition allowed for their evaporation.

Interference from ordinarily used solvents in the outcomes of Artemia salina lethality test

Directory of Open Access Journals (Sweden)

Sahgal Geethaa

2013-01-01

Full Text Available Methanol, ethanol, Tween 20 and dimethyl sulfoxide (DMSO are widely used as dissolving agents in Artemia salina lethality test (aka brine shrimp lethality test [BSLT] to screen the pharmaceutical properties of natural products. Nevertheless, there is lack of toxicity level of these solvents against brine shrimp. High concentration of these organic solvent might be toxic for this zoology invertebrate and interfere in the experimental outcomes. To avoid this, permissible concentration of the solvents used in BSLT was identified. BSLT was performed to evaluate the toxicity effect of Tween 20, methanol, ethanol and DMSO at 24 h post-treatment time point against A. salina. The suggested maximum working concentration (v/v for DMSO, methanol, ethanol was found to be 1.25% and that for Tween 20 was 0.16%. LC 50 for the solvents were 8.5% (DMSO, 6.4% (methanol, 3.4% (ethanol and 2.5% (Tween 20. The findings have shown a toxicity level among the solvents in descending order as Tween 20 > ethanol > methanol > DMSO. DMSO is a safer solvent to be used in BSLT compared with other tested solvents, whereas Tween 20 has been shown to be the most stringent solvent among the tested solvents. The findings are resourcefully useful to avoid interference of solvents in the assessment of natural products using BSLT.

Chemical approach to solvent removal during nanoencapsulation: its application to preparation of PLGA nanoparticles with non-halogenated solvent

Energy Technology Data Exchange (ETDEWEB)

Lee, Youngme [Ewha Womans University, College of Pharmacy (Korea, Republic of); Sah, Eric [University of Notre Dame, College of Science (United States); Sah, Hongkee, E-mail: hsah@ewha.ac.kr [Ewha Womans University, College of Pharmacy (Korea, Republic of)

2015-11-15

The objective of this study was to develop a new oil-in-water emulsion-based nanoencapsulation method for the preparation of PLGA nanoparticles using a non-halogenated solvent. PLGA (60–150 mg) was dissolved in 3 ml of methyl propionate, which was vortexed with 4 ml of a 0.5–4 % polyvinyl alcohol solution. This premix was sonicated for 2 min, added into 30 ml of the aqueous polyvinyl alcohol solution, and reacted with 3 ml of 10 N NaOH. Solvent removal was achieved by the alkaline hydrolysis of methyl propionate dissolved in an aqueous phase into water-soluble methanol and sodium propionate. It was a simple but effective technique to quickly harden nanoemulsion droplets into nanoparticles. The appearing PLGA nanoparticles were recovered by ultracentrifugation and/or dialysis, lyophilized with trehalose, and redispersed by water. This nanoencapsulation technique permitted a control of their mean diameters over 151.7 ± 3.8 to 440.2 ± 22.2 nm at mild processing conditions. When the aqueous polyvinyl alcohol concentration was set at ≥1 %, nanoparticles showed uniform distributions with polydispersity indices below 0.1. There were no significant changes in their mean diameters and size distribution patterns before and after lyophilization. When mestranol was encapsulated into nanoparticles, the drug was completely nanoencapsulated: depending on experimental conditions, their encapsulation efficiencies were determined to be 99.4 ± 7.2 to 105.8 ± 6.3 %. This simple, facile nanoencapsulation technique might have versatile applications for the preparation of polymeric nanoparticulate dosage forms.Graphical AbstractSchematic illustration of an innovative chemical approach to solvent removal during nanoencapsulation. Methyl propionate present in the aqueous continuous phase reacts with sodium hydroxide, thereby producing methanol and sodium propionate. Its alkaline hydrolysis allows the continuous extraction of the solvent out of nanoemulsion

Chemical approach to solvent removal during nanoencapsulation: its application to preparation of PLGA nanoparticles with non-halogenated solvent

International Nuclear Information System (INIS)

Lee, Youngme; Sah, Eric; Sah, Hongkee

2015-01-01

The objective of this study was to develop a new oil-in-water emulsion-based nanoencapsulation method for the preparation of PLGA nanoparticles using a non-halogenated solvent. PLGA (60–150 mg) was dissolved in 3 ml of methyl propionate, which was vortexed with 4 ml of a 0.5–4 % polyvinyl alcohol solution. This premix was sonicated for 2 min, added into 30 ml of the aqueous polyvinyl alcohol solution, and reacted with 3 ml of 10 N NaOH. Solvent removal was achieved by the alkaline hydrolysis of methyl propionate dissolved in an aqueous phase into water-soluble methanol and sodium propionate. It was a simple but effective technique to quickly harden nanoemulsion droplets into nanoparticles. The appearing PLGA nanoparticles were recovered by ultracentrifugation and/or dialysis, lyophilized with trehalose, and redispersed by water. This nanoencapsulation technique permitted a control of their mean diameters over 151.7 ± 3.8 to 440.2 ± 22.2 nm at mild processing conditions. When the aqueous polyvinyl alcohol concentration was set at ≥1 %, nanoparticles showed uniform distributions with polydispersity indices below 0.1. There were no significant changes in their mean diameters and size distribution patterns before and after lyophilization. When mestranol was encapsulated into nanoparticles, the drug was completely nanoencapsulated: depending on experimental conditions, their encapsulation efficiencies were determined to be 99.4 ± 7.2 to 105.8 ± 6.3 %. This simple, facile nanoencapsulation technique might have versatile applications for the preparation of polymeric nanoparticulate dosage forms.Graphical AbstractSchematic illustration of an innovative chemical approach to solvent removal during nanoencapsulation. Methyl propionate present in the aqueous continuous phase reacts with sodium hydroxide, thereby producing methanol and sodium propionate. Its alkaline hydrolysis allows the continuous extraction of the solvent out of nanoemulsion

Directed Assembly of Janus Cylinders by Controlling the Solvent Polarity.

Science.gov (United States)

Kim, Jongmin; Choi, Chang-Hyung; Yeom, Su-Jin; Eom, Naye; Kang, Kyoung-Ku; Lee, Chang-Soo

2017-08-01

This study demonstrates the possibility of controlling the directed self-assembly of microsized Janus cylinders by changing the solvent polarity of the assembly media. Experimental results are analyzed and theoretical calculations of the free energy of adhesion (ΔG ad ) are performed to elucidate the underlying basic principles and investigate the effects of the solvent on the self-assembled structures. This approach will pave a predictive route for controlling the structures of assembly depending on the solvent polarity. In particular, we find that a binary solvent system with precisely controlled polarity induces directional assembly of the microsized Janus cylinders. Thus, the formation of two-dimensional (2D) and three-dimensional (3D) assembled clusters can be reliably tuned by controlling the numbers of constituent Janus cylinders in a binary solvent system. Finally, this approach is expanded to stepwise assembly, which forms unique microstructures via secondary growth of primary seed clusters formed by the Janus cylinders. We envision that this investigation is highly promising for the construction of desired superstructures using a wide variety of polymeric Janus microparticles with chemical and physical multicompartments.

Solvent Bonding for Fabrication of PMMA and COP Microfluidic Devices.

Science.gov (United States)

Wan, Alwin M D; Moore, Thomas A; Young, Edmond W K

2017-01-17

Thermoplastic microfluidic devices offer many advantages over those made from silicone elastomers, but bonding procedures must be developed for each thermoplastic of interest. Solvent bonding is a simple and versatile method that can be used to fabricate devices from a variety of plastics. An appropriate solvent is added between two device layers to be bonded, and heat and pressure are applied to the device to facilitate the bonding. By using an appropriate combination of solvent, plastic, heat, and pressure, the device can be sealed with a high quality bond, characterized as having high bond coverage, bond strength, optical clarity, durability over time, and low deformation or damage to microfeature geometry. We describe the procedure for bonding devices made from two popular thermoplastics, poly(methyl-methacrylate) (PMMA), and cyclo-olefin polymer (COP), as well as a variety of methods to characterize the quality of the resulting bonds, and strategies to troubleshoot low quality bonds. These methods can be used to develop new solvent bonding protocols for other plastic-solvent systems.

Cleanup of Savannah River Plant solvent using solid sorbents

International Nuclear Information System (INIS)

Mailen, J.C.; Tallent, O.K.

1985-04-01

The degradation products produced in Purex solvent by exposure to nitric acid and radiation can be divided into two groups: those which are removed by scrubbing with sodium carbonate solutions and those which are not; these latter materials are called secondary degradation products. This study investigated the use of solid sorbents for removal of the secondary degradation products from first-cycle Savannah River Plant solvent that had been previously washed with sodium carbonate solution. Silica gel, activated charcoal, macroreticular resin, attapulgite clay and activated alumina were the sorbents investigated in preliminary testing. Activated alumina was found to be most effective for improving phase separation of the solvent from sodium carbonate solutions and for increasing the interfacial tension. The activated alumina was also the sorbent most useful for removing complexants which retain plutonium at low acidity, but it was less effective in removing anionic surfactants and ruthenium. We found that the capacity of the activated alumina was greatly improved by drying the solvent before treatment

Selective metal-vapor deposition on solvent evaporated polymer surfaces

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Koji; Tsujioka, Tsuyoshi, E-mail: tsujioka@cc.osaka-kyoiku.ac.jp

2015-12-31

We report a selective metal-vapor deposition phenomenon based on solvent printing and evaporation on polymer surfaces and propose a method to prepare fine metal patterns using maskless vacuum deposition. Evaporation of the solvent molecules from the surface caused large free volumes between surface polymer chains and resulted in high mobility of the chains, enhancing metal-vapor atom desorption from the surface. This phenomenon was applied to prepare metal patterns on the polymer surface using solvent printing and maskless metal vacuum deposition. Metal patterns with high resolution of micron scale were obtained for various metal species and semiconductor polymer substrates including poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and poly(3-hexylthiophene-2,5-diyl). - Highlights: • Selective metal-vapor deposition using solvent evaporation on polymer was attained. • Metal patterns with high resolution were obtained for various metal species. • This method can be applied to achieve fine metal-electrodes for polymer electronics.

Extraction of Aromatics from Heavy Naphtha Using Different Solvents

International Nuclear Information System (INIS)

EI-Bassuoni, A.A.; Esmael, K.K.

2004-01-01

Aromatic hydrocarbons are very important to the petrochemical industry. Among these are benzene, toluene and xylene (BTX), which are basic raw materials for the production of a number of important petrochemicals. There are many processes used to separate aromatic from non aromatic such as fractionation, azeotropic distillation and liquid I liquid extraction, etc. Liquid - liquid extraction is unique, efficiently used for heat sensitive, close boiling components and for separation of components not possible by other unit operations and it could be done at ambient temperature makes it more energy efficient. The choice of solvent depends on the properties and boiling range of the feedstock. Through the years, a lot of selective solvents has been proposed and selected for the physical separation of aromatics in liquid liquid extraction. Among the selection criteria are the stability,. chemical compatibility, availability, environmental hazards and price of the solvent. But the basic solvent properties that make it efficient are selectivity and capacity

Action of solvents on torbanite and the nature of extracted products

Energy Technology Data Exchange (ETDEWEB)

Dulhunty, J A

1943-01-01

Tests were made on torbanite with polar and nonpolar solvents under various conditions. Torbanite undergoes no change when heated below 250/sup 0/C, but depolymerization of the organic matter, absorption of solvent, and swelling and softening of the torbanite occurred between 250 and 300/sup 0/C, although no appreciable quantity of soluble product was formed. Between 300 and 350/sup 0/C depolymerization continued and more solvent was absorbed, which caused swelling, softening, and partial breakdown of the physical structure of torbanite. The intimate mixture of torbanite and solvent produced a jellylike mass, which could not be filtered. Continued heating between 350 and 400/sup 0/C caused the organic matter to dissolve in the solvent and produced a complete breakdown in the physical structure of the torbanite. The extracts consisted largely of heavy paraffin compounds, including waxes.

Interaction of organic solvent with a subbituminous coal below pyrolysis temperature

Energy Technology Data Exchange (ETDEWEB)

Lindsey, D.; Grens, E.A.

1978-06-01

The interactions of a subbituminous coal with certain binary organic solvent mixtures have been studied at 250/sup 0/C. Mixtures of pyridine, quinoline, piperidine, tetrahydroquinoline, and ethylenediamine with either toluene or tetralin were contacted with coal in a successive batch, stirred reactor, the extractions being carried to near completion. Two distinct behaviors of extraction yield as a function of composition have been identified. In the majority of the solvent mixtures the extraction yield increases linearly with increasing concentration of the more active solvent. When the active solvent is ethylenediamine, however, the extraction yield increases rapidly when small concentrations of ethylenediamine are used but then levels out close to its maximum value in a 50 to 50 mix. This behavior is an indication that, except in the case of ethylenediamine, the activity of solvent mixtures is a function of bulk solution properties.

An organic solvent-, detergent-, and thermo-stable alkaline protease from the mesophilic, organic solvent-tolerant Bacillus licheniformis 3C5.

Science.gov (United States)

Rachadech, W; Navacharoen, A; Ruangsit, W; Pongtharangkul, T; Vangnai, A S

2010-01-01

Bacillus licheniformis 3C5, isolated as mesophilic bacterium, exhibited tolerance towards a wide range of non-polar and polar organic solvents at 45 degrees C. It produced an extracellular organic solvent-stable protease with an apparent molecular mass of approximately 32 kDa. The inhibitory effect of PMSF and EDTA suggested it is likely to be an alkaline serine protease. The protease was active over abroad range of temperatures (45-70 degrees C) and pH (8-10) range with an optimum activity at pH 10 and 65 degrees C. It was comparatively stable in the presence ofa relatively high concentration (35% (v/v)) of organic solvents and various types of detergents even at a relatively high temperature (45 degrees C). The protease production by B. licheniformis 3C5 was growth-dependent. The optimization of carbon and nitrogen sources for cell growth and protease production revealed that yeast extract was an important medium component to support both cell growth and the protease production. The overall properties of the protease produced by B. licheniformis 3C5 suggested that this thermo-stable, solvent-stable, detergent-stable alkaline protease is a promising potential biocatalyst for industrial and environmental applications.

Biomass catalysis and solvents; Biomasse catalyse et solvants

Energy Technology Data Exchange (ETDEWEB)

Pioch, D [CIRAD-AMIS, programme Agro-Alimentaire, 34 - Montpellier (France); Pouilloux, Y; Barrault, J [Centre National de la Recherche Scientifique (CNRS UMR 6503), ESIP, Lab. de Catalyse en Chimie Organique, 86 - Poitiers (France); and others

2000-07-01

How to develop new technics and products and at the same time to respect the environment? The biomass seems to be an interesting domain in this framework and this document allows the selection of performing products obtain by biomass. Among these products the solvents economic and environmental advantages or consequences are discussed. A great part is also devoted to the voc emissions, bound to the solvents.

Polystyrene Microbeads by Dispersion Polymerization: Effect of Solvent on Particle Morphology

Directory of Open Access Journals (Sweden)

Lei Jinhua

2014-01-01

Full Text Available Polystyrene microspheres (PS were synthesized by dispersion polymerization in ethanol/2-Methoxyethanol (EtOH/EGME blend solvent using styrene (St as monomer, azobisisobutyronitrile (AIBN as initiator, and PVP (polyvinylpyrrolidone K-30 as stabilizer. The typical recipe of dispersion polymerization is as follows: St/Solvent/AIBN/PVP = 10 g/88 g/0.1 g/2 g. The morphology of polystyrene microspheres was characterized by the scanning electron microscopy (SEM and the molecular weights of PS particles were measured by the Ubbelohde viscometer method. The effect of ethanol content in the blend solvent on the morphology and molecular weight of polystyrene was studied. We found that the size of polystyrene microspheres increased and the molecular weight of polystyrene microspheres decreased with the decreasing of the ethanol content in the blend solvent from 100 wt% to 0 wt%. What is more, the size monodispersity of polystyrene microspheres was quite good when the pure ethanol or pure 2-Methoxyethanol was used; however when the blend ethanol/2-Methoxyethanol solvent was used, the polystyrene microspheres became polydisperse. We further found that the monodispersity of polystyrene microspheres can be significantly improved by adding a small amount of water into the blend solvent; the particles became monodisperse when the content of water in the blend solvent was up to 2 wt%.

Guessing unknown and disordered solvent molecules with squeeze in the structure validation platon

International Nuclear Information System (INIS)

Weng, S.

2014-01-01

This report describes the assignment of the nature and number of solvent molecules in the refinement of several solvated crystal structures without a prior knowledge of the solvent system used for crystallization for the cases when the solvent molecule cannot be properly modeled. The solvent molecules can be assigned even for twinned crystal structures. (author)

Purification of degraded TBP solvent using macroreticular anion exchange resin

International Nuclear Information System (INIS)

Kartha, P.K.S.; Kutty, P.V.E.; Janaradanan, C.; Ramanujam, A.; Dhumwad, R.K.

1989-01-01

Tri-n-butyl phosphate (TBP) diluted with a suitable diluent is commonly used for solvent extraction in Purex process for the recovery of uranium and plutonium from irradiated nuclear fuels. This solvent gets degraded due to various factors, the main degradation product being dibutyl phosphoric acid (HDBP). A solvent cleanup step is generally incorporated in the process for removing the degradation products from the used solvent. A liquid-liquid cleanup system using sodium carbonate or sodium hydroxide solution is routinely used. Considering certain advantages, like the possibility of loading the resin almost to saturation capacity and the subsequent disposal of the spent resin by incineration and the feasibility of adopting it to the process, a liquid-solid system has been tried as an alternate method, employing various available macroreticular anion exchange resins in OH - form for the sorption of HDBP from TBP. After standardizing the various conditions for the satisfactory removal of HDBP from TBP using synthetic mixtures, resins were tested with process solvent in batch contacts. The parameters studied were (1) capacity of different resins for HDBP sorption (2) influence of acidity, uranium and HDBP on the sorption behaviour of the latter (3) removal of fission products from the solvent by the resin and (4) regeneration and recycling of the resin. (author). 2 figs., 13 tabs., 17 refs

The solvent extraction of alkali metal ions with β-diketones

International Nuclear Information System (INIS)

Munakata, Megumu; Niina, Syozo; Shimoji, Noboru

1974-01-01

This work was undertaken to investigate effects of solvent and chelating-agent on the solvent extraction of alkali metal ions by seven β-diketones, acetylacetone (Acac), benzoylacetone (BzA), dipivaloylmethane (DPM), dibenzoylmethane (DBM), thenoyltrifluoloacetone (TTA), benzoyltrifluoroacetone (BFA) and hexafluoroacetylacetone (HFA), and to separate lithium from alkali metals. The extraction of alkali metals increase with increasing donor power of the solvent: i.e., benzene Na>K>Rb>Cs, which is also the order in which the adduct formation of these β-diketone chelates with donor solvents increase. The adduct formations between β-diketone chelates of alkali metals and donor solvents markedly enhance the solubilities of the chelates in solvents and, consequently, the extractabilities of alkali metals with β-diketones. Lithium was extracted with TTA in ether at such a low base concentration that sodium, potassium, rubidium and cesium were hardly extracted, and this enabled to separate lithium from other metals by the use of rubidium hydroxide (0.02 M). An attempt has been made to isolate alkali metal β-diketone chelates and some chelates have been obtained as crystals. The infrared absorption bands arising from C=O and C.=C of TTA shift to lower frequencies in the alkali metal chelates with TTA, and consequently, β-diketones is suggested to coordinate to alkali metal as a bidentate ligand. (JPN)

Perpendicular Structure Formation of Block Copolymer Thin Films during Thermal Solvent Vapor Annealing: Solvent and Thickness Effects

Directory of Open Access Journals (Sweden)

Qiuyan Yang

2017-10-01

Full Text Available Solvent vapor annealing of block copolymer (BCP thin films can produce a range of interesting morphologies, especially when the perpendicular orientation of micro-domains with respect to the substrate plays a role. This, for instance, allows BCP thin films to serve as useful templates for nanolithography and hybrid materials preparation. However, precise control of the arising morphologies is essential, but in most cases difficult to achieve. In this work, we investigated the solvent and thickness effects on the morphology of poly(styrene-b-2 vinyl pyridine (PS-b-P2VP thin films with a film thickness range from 0.4 L0 up to 0.8 L0. Ordered perpendicular structures were achieved. One of the main merits of our work is that the phase behavior of the ultra-high molecular weight BCP thin films, which hold a 100-nm sized domain distance, can be easily monitored via current available techniques, such as scanning electron microscope (SEM, atomic force microscope (AFM, and transmission electron microscope (TEM. Systematic monitoring of the self-assembly behavior during solvent vapor annealing can thus provide an experimental guideline for the optimization of processing conditions of related BCP films systems.

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

Directory of Open Access Journals (Sweden)

Hassan Ali Durrani

2012-04-01

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

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.

Measurement of dielectric constant of organic solvents by indigenously developed dielectric probe

Science.gov (United States)

Keshari, Ajay Kumar; Rao, J. Prabhakar; Rao, C. V. S. Brahmmananda; Ramakrishnan, R.; Ramanarayanan, R. R.

2018-04-01

The extraction, separation and purification of actinides (uranium and plutonium) from various matrices are an important step in nuclear fuel cycle. One of the separation process adopted in an industrial scale is the liquid-liquid extraction or solvent extraction. Liquid-liquid extraction uses a specific ligand/extractant in conjunction with suitable diluent. Solvent extraction or liquid-liquid extraction, involves the partitioning of the solute between two immiscible phases. In most cases, one of the phases is aqueous, and the other one is an organic solvent. The solvent used in solvent extraction should be selective for the metal of interest, it should have optimum distribution ratio, and the loaded metal from the organic phase should be easily stripped under suitable experimental conditions. Some of the important physical properties which are important for the solvent are density, viscosity, phase separation time, interfacial surface tension and the polarity of the extractant.

Solvent degradation and cleanup: a survey and recent ORNL studies

International Nuclear Information System (INIS)

Mailen, J.C.; Tallent, O.K.

1984-01-01

This paper surveys the mechanisms for degradation of the tributyl phosphate and diluent components of Purex solvent by acid and radiation, reviews the problems encountered in plant operations resulting from the presence of these degradation products, and discusses methods for minimizing the formation of degradation products and accomplishing their removal. Scrubbing solutions containing sodium carbonate or hydroxylamine salts and secondary cleanup of solvents using solid sorbents are evaluated. Finally, recommendations for improved solvent cleanup are presented. 50 references, 4 figures, 3 tables

Effect of solvent-controlled aggregation on the intrinsic emission properties of PAMAM dendrimers

International Nuclear Information System (INIS)

Jasmine, Maria J.; Kavitha, Manniledam; Prasad, Edamana

2009-01-01

Solvent-induced aggregation and its effect on the intrinsic emission properties of amine, hydroxy and carboxylate terminated, poly(amidoamine) (PAMAM) dendrimers have been investigated in glycerol, ethylene glycol, methanol, ethylene diamine and water. Altering the solvent medium induces remarkable changes in the intrinsic emission properties of the PAMAM dendrimers at identical concentration. Upon excitation at 370 nm, amine terminated PAMAM dendrimer exhibits an intense emission at 470 nm in glycerol, ethylene glycol as well as glycerol-water mixtures. Conversely, weak luminescence is observed for hydroxy and carboxylate terminated PAMAM dendrimers in the same solvent systems. When the solvent is changed to ethylene diamine, hydroxy terminated PAMAM exhibits intense blue emission at 425 nm. While the emission intensity is varied when the solvent milieu is changed, excited state lifetime values of PAMAM dendrimers remain independent of the solvent used. UV-visible absorption and dynamic light scattering (DLS) experiments confirm the formation of solvent-controlled dendrimer aggregates in the systems. Comparison of the fluorescence and DLS data reveals that the size distribution of the dendrimer aggregates in each solvent system is distinct, which control the intrinsic emission intensity from PAMAM dendrimers. The experimental results suggest that intrinsic emission intensity from PAMAM dendrimers can be regulated by proper selection of solvents at neutral conditions and room temperature

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)....

Effect of solvent concentration on performance of polysulfone membrane for filtration and separation

Science.gov (United States)

Syafiq Mohamad Sofian, Muhamad; Zaini Yunos, Muhamad; Ahmad, Azlinnorazia; Harun, Zawati; Akhair, Siti Hajar Mohd; Adibah Raja Ahmad, Raja; Hafeez Azhar, Faiz; Rashid, Abdul Qaiyyum Abd; Ismail, Al Emran

2017-08-01

This study was conducted to investigate the effect of solvent concentration on the performance of polysulfone membrane via airbrush spray method. The solvent concentration was varied from 73% to 80% in dope solution. The study also investigated airbrush processing parameter such as spray time and distance at different solvent concentration. The prepared membrane was characterized in respect to its morphology and the performance of the membrane were evaluated via gas permeability performance. This study found that the membrane fiber size was reduced as solvent concentration increases. When time increased the diameter of fiber also increased. The distance also affected the fiber size, when the distance increased the diameter of fiber became smaller. 80% of solvent concentration has better filtration and separation ability compared to other solvent due to its porosity and morphology. From the gas permeability cell testing it shows that the permeability is increasing as the solvent concentration decrease.

On the solubility of nicotinic acid and isonicotinic acid in water and organic solvents

International Nuclear Information System (INIS)

Abraham, Michael H.; Acree, William E.

2013-01-01

Highlights: ► Solubilities of nicotinic acid and isonicotinic acids in organicsolvents have been determined. ► Solubilities are used to calculate Abraham descriptors for the two acids. ► These descriptors then yield water-solvent and gas-solvent partitions into numerous solvents. ► The solubility of the neutral acids in water is obtained. ► The method is straightforward and can be applied to any set of compound solubilities. -- Abstract: We have determined the solubility of nicotinic acid in four solvents and the solubility of isonicotinic acid in another four solvents. These results, together with literature data on the solubility of nicotinic acid in five other organic solvents and isonicotinic acid in four other organic solvents, have been analyzed through two linear Gibbs energy relationships in order to extract compound properties, or descriptors, that encode various solute–solvent interactions. The descriptors for nicotinic acid and isonicotinic acid can then be used in known equations for partition of solutes between water and organic solvents to predict partition coefficients and then further solubility in a host of organic solvents, as well as to predict a number of other physicochemical properties

Effect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review.

Science.gov (United States)

Miazek, Krystian; Kratky, Lukas; Sulc, Radek; Jirout, Tomas; Aguedo, Mario; Richel, Aurore; Goffin, Dorothee

2017-07-04

In this review, the effect of organic solvents on microalgae cultures from molecular to industrial scale is presented. Traditional organic solvents and solvents of new generation-ionic liquids (ILs), are considered. Alterations in microalgal cell metabolism and synthesis of target products (pigments, proteins, lipids), as a result of exposure to organic solvents, are summarized. Applications of organic solvents as a carbon source for microalgal growth and production of target molecules are discussed. Possible implementation of various industrial effluents containing organic solvents into microalgal cultivation media, is evaluated. The effect of organic solvents on extraction of target compounds from microalgae is also considered. Techniques for lipid and carotenoid extraction from viable microalgal biomass (milking methods) and dead microalgal biomass (classical methods) are depicted. Moreover, the economic survey of lipid and carotenoid extraction from microalgae biomass, by means of different techniques and solvents, is conducted.

Acids and bases solvent effects on acid-base strenght

CERN Document Server

Cox, Brian G

2013-01-01

Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

CALmsu contactor for solvent extraction with integrated flowrate meters

International Nuclear Information System (INIS)

Siddiqui, I.A.; Shah, B.V.; Theyyunni, T.K.

1994-01-01

Mixer-settlers are widely used as contactors in solvent extraction processes. In the nuclear industry, solvent extraction techniques are used for the separation and purification of a range of materials. A major difficulty is faced in the nuclear industry due to the constraints on the design of the equipment and its operation by the presence of radioactive materials in process solutions. The development of CALmsu contactor was necessitated by the requirements of the operating environment in radiochemical plants. This contactor is a mixer-settler designed to use a CALMIX (combined air lifting and mixing device) static mixer. The CALMIX comprises two air lifts which raise the liquid phases to a highly turbulent mixing zone situated above the lifts. Its principle and construction are simple, and it is compact in size. It is a passive device and needs no maintenance. It has proved to be efficient during extensive testing. The simple and efficient CALmsu contactor internals are specially engineered for use of CALMIX mixer. It has been extensively tested in pilot plant for extraction and stripping of uranium, recovery of uranium from thorium by THOREX process and for treatment of degraded solvents. A model for the design of CALmsu contactors has been evolved and based on this model a software for engineering design of CALMIX and CALmsu contactors of throughput between 50 and 3000 lph has been developed. (author)

Solvent extraction of zirconium

International Nuclear Information System (INIS)

Kim, S.S.; Yoon, J.H.

1981-01-01

The extraction of zirconium(VI) from an aqueous solution of constant ionic strength with versatic acid-10 dissolved in benzen was studied as a function of pH and the concentration of zirconium(VI) and organic acid. The effects of sulphate and chlorine ions on the extraction of the zirconium(VI) were briefly examined. It was revealed that (ZrOR 2 .2RH) is the predominant species of extracted zirconium(VI) in the versatic acid-10. The chemical equation and the apparent equilibrium constants thereof have been determined as follows. (ZrOsup(2+))aq+ 2(R 2 H 2 )sub(org) = (ZrOR 2 .2RH)sub(org)+2(H + )aq Ksub(Zr) = (ZrOR 2 .2RH)sub(org)(H + ) 2 /(ZrOsup(2+))sub(aq)(R 2 H 2 )sup(2)sub(org) = 3.3 x 10 -7 . The synergistic effects of TBP and D2EHPA were also studied. In the mixed solvent with 0.1M TBP, the synergistic effect was observed, while the mixed solvent with D2EHPA showed the antisynergistic effect. (Author)

Effect of the Solvent Temperatures on Dynamics of Serine Protease Proteinase K

Directory of Open Access Journals (Sweden)

Peng Sang

2016-02-01

Full Text Available To obtain detailed information about the effect of the solvent temperatures on protein dynamics, multiple long molecular dynamics (MD simulations of serine protease proteinase K with the solute and solvent coupled to different temperatures (either 300 or 180 K have been performed. Comparative analyses demonstrate that the internal flexibility and mobility of proteinase K are strongly dependent on the solvent temperatures but weakly on the protein temperatures. The constructed free energy landscapes (FELs at the high solvent temperatures exhibit a more rugged surface, broader spanning range, and higher minimum free energy level than do those at the low solvent temperatures. Comparison between the dynamic hydrogen bond (HB numbers reveals that the high solvent temperatures intensify the competitive HB interactions between water molecules and protein surface atoms, and this in turn exacerbates the competitive HB interactions between protein internal atoms, thus enhancing the conformational flexibility and facilitating the collective motions of the protein. A refined FEL model was proposed to explain the role of the solvent mobility in facilitating the cascade amplification of microscopic motions of atoms and atomic groups into the global collective motions of the protein.

Collection methodology evaluation and solvents analysis/mixtures solvents in the air in work ambient: methanol in MEG mixture (methanol 33%, ethanol 60% and gasoline 7%); Avaliacao de metodologia de coleta e analise de solventes/misturas de solventes no ar em ambiente de trabalho: metanol em mistura MEG (metanol 33%, etanol 60% e gasolina 7%)

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Luiza Maria Nunes

1995-07-01

This thesis presents a proposal for evaluation of collection and solvent/solvent mixtures analysis methodology for the air in the work environment by studying the following issues of present solvents: historical aspects; methanol - properties and toxicity; collection methodology evaluation, and gases and vapors analysis in the air; experimental data. The denominated mixture MEG - methanol, ethanol and gasoline is analyzed in terms of its chemical characteristics. The author concludes the work detaching that the methodology presented can only be used for short duration measurements in concentrations peaks studies.

Extraction of europium with thenoyltrifluoroacetone into alcohol, ketone and ester solvents

International Nuclear Information System (INIS)

Akiba, K.; Kanno, T.

1980-01-01

The effect of solvent has been studied on the extraction of tris-thenoyltrifluoroacetone (TTA) chelate of europium(III). Donor-active solvents (S) greatly promote the extraction owing to the formation of solvate species EuA 3 .mS (m = 1,2). Linear relations were established between the distribution of ratios of europium (Dsub(Eu)) and the partition constants of TTA (Psub(HA)); log Dsub(Eu) (at a definite pA) = a log Psub(HA) + b, where constants a and b were empirically determined for each series of solvents. The regularity is interpreted in terms of dual roles of solvent as donor and as medium. (author)

ELECTROCHEMICAL BEHAVIOUR OF METHYLENE BLUE IN NON-AQUEOUS SOLVENTS

International Nuclear Information System (INIS)

Caram, J.A.; Suárez, J.F. Martínez; Gennaro, A.M.; Mirífico, M.V.

2015-01-01

Graphical abstract: Display Omitted - Highlights: • The dye is electro-reduced in two separated monoelectronic charge transfers. • Solvent/supporting electrolyte/acid/base modifies the electrochemical parameters. • A dissociation equilibrium of the dye in non-aqueous solvent is proposed. • The electro-generated and stable dye-radical is also chemically produced in EDA or KOH/DMF. • A new species is reversibly formed in KOH/EtOH or ACN. - Abstract: The electrochemical behaviour of methylene blue in solution of non-aqueous solvents with different supporting electrolytes was studied by cyclic voltammetry. Dye electro-reduction presents two well-defined processes of monoelectronic charge transfer yielding a free radical in the first process and an anion in the second electron transfer. Free radical and anion are long living species in some of the studied media. Effects of supporting electrolyte and solvent on the peak potentials, the peak current functions and the reversibility of the charge transfer processes are reported. A dissociation equilibrium of the dye in solution of non-aqueous solvents and the acid or base added determine markedly the electrochemical responses. In the particular cases of KOH/DMF or EDA basic media the chemical formation of the stable methylene blue radical was detected and it was characterized by EPR spectroscopy. A general reaction scheme is proposed

EVALUATION OF SOLVENTS EFFICIENCY IN CONDENSATE BANKING REMOVAL

OpenAIRE

CORREA, TOMAS; TIAB, DJEBBAR; RESTREPO, DORA PATRICIA

2009-01-01

This work describes experimental design and tests performed to simulate gas condensate reservoir conditions below dew point in the laboratory using three different compositions of synthetic gas condensate. Methanol, propanol and methylene chloride are the solvents used to remove the condensate banking and improve the gas effective permeability near to the wellbore. Solvents are injected in Berea sandstone rock with similar petrophysical properties in order to compare the efficiency at removin...

3DRISM-HI-D2MSA: an improved analytic theory to compute solvent structure around hydrophobic solutes with proper treatment of solute–solvent electrostatic interactions

KAUST Repository

Cao, Siqin

2017-12-22

The 3D reference interaction site model (3DRISM) is a powerful tool to study the thermodynamic and structural properties of liquids. However, for hydrophobic solutes, the inhomogeneity of the solvent density around them poses a great challenge to the 3DRISM theory. To address this issue, we have previously introduced the hydrophobic-induced density inhomogeneity theory (HI) for purely hydrophobic solutes. To further consider the complex hydrophobic solutes containing partial charges, here we propose the D2MSA closure to incorporate the short-range and long-range interactions with the D2 closure and the mean spherical approximation, respectively. We demonstrate that our new theory can compute the solvent distributions around real hydrophobic solutes in water and complex organic solvents that agree well with the explicit solvent molecular dynamics simulations.

3DRISM-HI-D2MSA: an improved analytic theory to compute solvent structure around hydrophobic solutes with proper treatment of solute–solvent electrostatic interactions

KAUST Repository

Cao, Siqin; Zhu, Lizhe; Huang, Xuhui

2017-01-01

The 3D reference interaction site model (3DRISM) is a powerful tool to study the thermodynamic and structural properties of liquids. However, for hydrophobic solutes, the inhomogeneity of the solvent density around them poses a great challenge to the 3DRISM theory. To address this issue, we have previously introduced the hydrophobic-induced density inhomogeneity theory (HI) for purely hydrophobic solutes. To further consider the complex hydrophobic solutes containing partial charges, here we propose the D2MSA closure to incorporate the short-range and long-range interactions with the D2 closure and the mean spherical approximation, respectively. We demonstrate that our new theory can compute the solvent distributions around real hydrophobic solutes in water and complex organic solvents that agree well with the explicit solvent molecular dynamics simulations.

3DRISM-HI-D2MSA: an improved analytic theory to compute solvent structure around hydrophobic solutes with proper treatment of solute–solvent electrostatic interactions

Science.gov (United States)

Cao, Siqin; Zhu, Lizhe; Huang, Xuhui

2018-04-01

The 3D reference interaction site model (3DRISM) is a powerful tool to study the thermodynamic and structural properties of liquids. However, for hydrophobic solutes, the inhomogeneity of the solvent density around them poses a great challenge to the 3DRISM theory. To address this issue, we have previously introduced the hydrophobic-induced density inhomogeneity theory (HI) for purely hydrophobic solutes. To further consider the complex hydrophobic solutes containing partial charges, here we propose the D2MSA closure to incorporate the short-range and long-range interactions with the D2 closure and the mean spherical approximation, respectively. We demonstrate that our new theory can compute the solvent distributions around real hydrophobic solutes in water and complex organic solvents that agree well with the explicit solvent molecular dynamics simulations.

Solvent-extraction methods applied to the chemical analysis of uranium. III. Study of the extraction with inert solvents

International Nuclear Information System (INIS)

Vera Palomino, J.; Palomares Delgado, F.; Petrement Eguiluz, J. C.

1964-01-01

The extraction of uranium on the trace level is studied by using tributylphosphate as active agent under conditions aiming the attainment of quantitative extraction by means of a single step process using a number of salting-out agents and keeping inside the general lines as reported in two precedent papers. Two inert solvents were investigated, benzene and cyclohexane, which allowed to derive the corresponding empirical equations describing the extraction process and the results obtained were compared with those previously reported for solvents which, like ethyl acetate and methylisobuthylketone, favour to a more or less extend the extraction of uranium. (Author) 4 refs

Design and construction of an interceptor system for radioactively contaminated solvent

International Nuclear Information System (INIS)

Weiss, T.G. Jr.; Blickwedehl, R.R.

1991-01-01

During the conduct of fuel reprocessing operations at the Western New York Nuclear Service Center from 1966 to 1972, the site operator disposed of spent solvent by shallow land burial in the area used for disposal of solid radioactive waste. The spent solvent was placed in twenty-two 3785 liter (1000-gallon) steel tanks which were then placed in eight 6-meter-deep burial holes. With the passage of time groundwater entered the tanks displacing the solvent (a mixture of tributyl phosphate and n-dodecane) and allowing it to enter the surrounding groundwater system. The solvent, which is lighter than water, floated to the surface of the groundwater within the burial holes and began to migrate laterally through cracks caused by weathering. In 1983, after the US Department of Energy (DOE) initiated efforts for the West Valley Demonstration Project (WVDP), trace amounts of solvent were encountered in a monitoring well near the perimeter of the burial area. Since the initial discovery, extensive studies and continued monitoring have been conducted of the solvent migration. In the fall of 1989, this monitoring showed evidence of further on-site migration of the solvent within the disposal area. In response, the DOE authorized West Valley Nuclear Services Company, Inc. (WVNS) to proceed with the design and construction of a trench system to intercept the flow of solvent and prevent it from discharging to nearby streams. Since the solvent and the contaminated groundwater samples taken in the area exhibited high levels of Iodine-129 in an organic complex, it was necessary to construct a pretreatment facility. An important aspect of the trench construction was the management of contaminated soil and construction water. Contaminated soils were placed into storage containers and held for future treatment and disposal. All water pumped from the trench during construction was stored in large bladder tanks, analyzed for hazardous constituents, and upon finding none, was discharged

The solvent absorption-extractive distillation (SAED) process for ethanol recovery from gas/vapor streams

Energy Technology Data Exchange (ETDEWEB)

Dale, M.C.

1993-12-31

A low energy system for ethanol recovery and dehydration has been developed. This system utilizes a solvent for (1) absorption of ethanol vapors, and then the same solvent for (2) extractive distillation. The ideal solvent for this process would have a high affinity for ethanol, and no affinity for water. Heavy alcohols such as dodecanol, and tridecanol, some phosphorals, and some fatty acids have been determined to meet the desired specifications. These solvents have the effect of making water more volatile than ethanol. Thus, a water stream is taken off initially in the dehydration column, and a near anhydrous ethanol stream is recovered from the ethanol/solvent stripper column. Thus the solvent serves dual uses (1) absorption media, and (2) dehydration media. The SAED process as conceptualized would use a solvent similar to solvents used for direct extractive separation of ethanol from aqueous ethanol solutions.

The disposal of radioactive solvent waste

International Nuclear Information System (INIS)

Dean, B.; Baker, W.T.

1976-01-01

As the use of radioisotope techniques increases, laboratories are faced with the problem of disposing of considerable quantities of organic solvent and aqueous liquid wastes. Incineration or collection by a waste contractor both raise problems. Since most of the radiochemicals are preferentially water soluble, an apparatus for washing the radiochemicals out into water and discharging into the normal drainage system in a high diluted form is described. Despite the disadvantages (low efficiency, high water usuage, loss of solvent in presence of surface active agents, precipitation of phosphors from dioxan based liquids) it is felt that the method has some merit if a suitably improved apparatus can be designed at reasonable cost. (U.K.)

Solvent (acetone-butanol: ab) production

Science.gov (United States)

This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities, such as corn and molasses, was an important historical fermentation. Unfortunately,...

Solvent extraction columns

International Nuclear Information System (INIS)

Middleton, P.; Smith, J.R.

1979-01-01

In pulsed columns for use in solvent extraction processes, e.g. the reprocessing of nuclear fuel, the horizontal perforated plates inside the column are separated by interplate spacers manufactured from metallic neutron absorbing material. The spacer may be in the form of a spiral or concentric circles separated by radial limbs, or may be of egg-box construction. Suitable neutron absorbing materials include stainless steel containing boron or gadolinium, hafnium metal or alloys of hafnium. (UK)

Versatile Production of Poly(Epsilon-Caprolactone Fibers by Electrospinning Using Benign Solvents

Directory of Open Access Journals (Sweden)

Liliana Liverani

2016-04-01

Full Text Available The electrospinning technique is widely used for the fabrication of micro- and nanofibrous structures. Recent studies have focused on the use of less toxic and harmful solvents (benign solvents for electrospinning, even if those solvents usually require an accurate and longer process of optimization. The aim of the present work is to demonstrate the versatility of the use of benign solvents, like acetic acid and formic acid, for the fabrication of microfibrous and nanofibrous electrospun poly(epsilon-caprolactone mats. The solvent systems were also shown to be suitable for the fabrication of electrospun structures with macroporosity, as well as for the fabrication of composite electrospun mats, fabricated by the addition of bioactive glass (45S5 composition particles in the polymeric solution.

Caustic-Side Solvent Extraction Chemical and Physical Properties Progress in FY 2000 and FY 2001.

Energy Technology Data Exchange (ETDEWEB)

Moyer, BA

2002-04-17

The purpose of this work was to provide chemical- and physical-property data addressing the technical risks of the Caustic-Side Solvent Extraction (CSSX) process as applied specifically to the removal of cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site. As part of the overall Salt Processing Project, this effort supported decision-making in regards to selecting a preferred technology among three alternatives: (1) CSSX, (2) nonelutable ion-exchange with an inorganic silicotitanate material and (3) precipitation with tetraphenylborate. High risks, innate to CSSX, that needed specific attention included: (1) chemical stability of the solvent matrix, (2) radiolytic stability of the solvent matrix, (3) proof-of-concept performance of the proposed process flowsheet with simulated waste, and (4) performance of the CSSX flowsheet with actual SRS high-level waste. This body of work directly addressed the chemical-stability risk and additionally provided supporting information that served to plan, carry out, and evaluate experiments conducted by other CSSX investigators addressing the other high risks. Information on cesium distribution in extraction, scrubbing, and stripping served as input for flowsheet design, provided a baseline for evaluating solvent performance under numerous stresses, and contributed to a broad understanding of the effects of expected process variables. In parallel, other measurements were directed toward learning how other system components distribute in the flowsheet. Such components include the solvent components themselves, constituents of the waste, and solvent-degradation products. Upon understanding which components influence flowsheet performance, it was then possible to address in a rational fashion how to clean up the solvent and maintain its stable function.

ASAView: Database and tool for solvent accessibility representation in proteins

Directory of Open Access Journals (Sweden)

Fawareh Hamed

2004-05-01

Full Text Available Abstract Background Accessible surface area (ASA or solvent accessibility of amino acids in a protein has important implications. Knowledge of surface residues helps in locating potential candidates of active sites. Therefore, a method to quickly see the surface residues in a two dimensional model would help to immediately understand the population of amino acid residues on the surface and in the inner core of the proteins. Results ASAView is an algorithm, an application and a database of schematic representations of solvent accessibility of amino acid residues within proteins. A characteristic two-dimensional spiral plot of solvent accessibility provides a convenient graphical view of residues in terms of their exposed surface areas. In addition, sequential plots in the form of bar charts are also provided. Online plots of the proteins included in the entire Protein Data Bank (PDB, are provided for the entire protein as well as their chains separately. Conclusions These graphical plots of solvent accessibility are likely to provide a quick view of the overall topological distribution of residues in proteins. Chain-wise computation of solvent accessibility is also provided.

Thermodynamics of 4’-bromomethyl-2-cyanobiphenyl in different solvents

International Nuclear Information System (INIS)

Yang, Jingxiang; Wu, Hong; Wang, Yongli; Luan, Qinghua; Zhang, Jie; Wang, Guan; Hao, Hongxun

2015-01-01

Highlights: • The melting properties of OTBNBr were investigated. • The solubility of OTBNBr in eight selected organic solvents has been determined. • The interaction of solvents molecules plays a dominated role in the dissolving behavior. • The experimental solubility data in pure solvents were well correlated by four models. • The activity coefficient and temperature dependence of van’t Hoff enthalpy were investigated. - Abstract: The melting properties and the heat capacity of the solid state and the melt state 4’-bromomethyl-2-cyanobiphenyl (OTBNBr) were determined. The enthalpy, entropy and Gibbs free energy of fusion were also calculated. The solubility of OTBNBr in eight organic solvents was experimentally measured at temperatures from (283.15 to 323.15) K by using a static method. The reasons for the differences of the solubility of OTBNBr in various solvents are discussed by using the intermolecular interaction. Furthermore, the experimental solubility values were well correlated by the modified Apelblat equation, the λh equation, the Wilson model and the van’t Hoff equation. Finally, the temperature dependence of the activity coefficient and the van’t Hoff enthalpy in the tested solutions was investigated and is discussed

Porous polymeric membranes with thermal and solvent resistance

KAUST Repository

Pulido, Bruno

2017-05-30

Polymeric membranes are highly advantageous over their ceramic counterparts in terms of the simplicity of the manufacturing process, cost and scalability. Their main disadvantages are low stability at temperatures above 200 °C, and in organic solvents. We report for the first time porous polymeric membranes manufactured from poly(oxindolebiphenylylene) (POXI), a polymer with thermal stability as high as 500 °C in oxidative conditions. The membranes were prepared by solution casting and phase inversion by immersion in water. The asymmetric porous morphology was characterized by scanning electronic microscopy. The pristine membranes are stable in alcohols, acetone, acetonitrile and hexane, as well as in aqueous solutions with pH between 0 and 14. The membrane stability was extended for application in other organic solvents by crosslinking, using various dibromides, and the efficiency of the different crosslinkers was evaluated by thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). POXI crosslinked membranes are stable up to 329 °C in oxidative conditions and showed organic solvent resistance in polar aprotic solvents with 99% rejection of Red Direct 80 in DMF at 70 °C. With this development, the application of polymeric membranes could be extended to high temperature and harsh environments, fields currently dominated by ceramic membranes.

Solvent extraction of radionuclides from aqueous tank waste

International Nuclear Information System (INIS)

Moyer, B.A.; Bonnesen, P.V.; Sachleben, R.A.

1997-01-01

This task aims toward the development of efficient solvent-extraction processes for the removal of the fission products 99 Tc, 90 Sr, and 137 Cs from alkaline tank wastes. Processes already developed or proposed entail direct treatment of the waste solution with the solvent and subsequent stripping of the extracted contaminants from the solvent into a dilute aqueous solution. Working processes to remove Tc(and SR) separately and Cs separately have been developed; the feasibility of a combined process is under investigation. Since Tc, Sr, and Cs will be vitrified together in the high-level fraction, however, a process that could separate Tc, Sr, and Cs simultaneously, as opposed to sequentially, potentially offers the greatest impact. A figure presents a simplified diagram of a proposed solvent-extraction cycle followed by three possible treatments for the stripping solution. Some degree of recycle of the stripping solution (option a) is expected. Simple evaporation (option c) is possible prior to vitrification; this offers the greatest possible volume reduction with simple operation and no consumption of chemicals, but it is energy intensive. However, if the contaminants are concentrated (option b) by fixed-bed technology, the energy penalty of evaporation can be avoided and vitrification facilitated without any additional secondary waste being produced

Highly efficient secondary dewatering of dewatered sewage sludge using low boiling point solvents.

Science.gov (United States)

He, Chao; Chena, Chia-Lung; Xu, Zhirong; Wang, Jing-Yuan

2014-01-01

Secondary dewatering of dewatered sludge is imperative to make conventional drying and incineration of sludge more economically feasible. In this study, a secondary dewatering of dewatered sludge with selected solvents (i.e. acetone and ethanol) followed by vacuum filtration and nature drying was investigated to achieve in-depth dewatering. After the entire secondary dewatering process, the sludge was shown to be odourless and the organic matter content was greatly retained. Increased mean particle size of sludge after solvent contact improved solid-liquid separation. With an acetone/sludge ratio of 3:1 (mL:g) in solvent contact and subsequent nature drying at ambient temperature after 24 h, the moisture content of sludge can be reduced to a level less than 20%. It is found that the polysaccharides were mainly precipitated by acetone, whereas the release ratios of protein and DNA were increased significantly as the added acetone volumes were elevated. During nature drying, accumulated evaporation rates of the sludge after solvent contact were 5-6 times higher than original dewatered sludge. Furthermore, sludge after acetone contact had better nature drying performance than ethanol. The two-stage dewatering involves solvent contact dewatering and solvent enhanced evaporation dewatering. Through selecting an appropriate solvent/sludge ratio as well as economical solvents and minimizing the solvent loss in a closed-pilot system, this dewatering process can be competitive in industrial applications. Therefore, this solvent-aided secondary dewatering is an energy-saving technology for effective in-depth dewatering of dewatered sludge and subsequent sludge utilization.

Solvent consumption in non-catalytic alcohol solvolysis of biorefinery lignin

DEFF Research Database (Denmark)

Nielsen, J. B.; Jensen, A.; Schandel, Christian Bækhøj

2017-01-01

Lignin solvolysis in supercritical alcohols provides a method for producing a deoxygenated liquid bio-oil. Solvent consumption is however inevitable and due to the high cost of alcohols, relative to a bio-oil product, it can hinder commercial viability. In order to investigate the reactions...... of solvent consumption we studied solvolysis of biorefinery lignin in several primary alcohols. Lignin solvolysis in methanol, ethanol, 1-propanol and 1-butanol performed similarly with respect to bio-oil composition; however, methanol gave much lower bio-oil yield. Solvent consumption increases...... with reaction temperature for all alcohols and from 10 wt% at 300 °C to 35 wt% at 400 °C when using ethanol. The mechanism for solvent consumption was found mainly to take place through three different reactions: direct decomposition to gas through decarbonylation, formation of light condensation products...

Heat-Activated Persulfate Oxidation of Chlorinated Solvents in Sandy Soil

Directory of Open Access Journals (Sweden)

Jialu Liu

2014-01-01

Full Text Available Heat-activated persulfate oxidative treatment of chlorinated organic solvents containing chlorinated ethenes and ethanes in soil was investigated with different persulfate dosages (20 g/L, 40 g/L, and 60 g/L and different temperatures (30°C, 40°C, and 50°C. Chlorinated organic solvents removal was increased as persulfate concentration increase. The persulfate dosage of 20 g/L with the highest OE (oxidant efficiency value was economically suitable for chlorinated organic solvents removal. The increasing temperature contributed to the increasing depletion of chlorinated organic solvents. Chlorinated ethenes were more easily removed than chlorinated ethanes. Moreover, the persulfate depletion followed the pseudo-first-order reaction kinetics (kps=0.0292 [PS]0+0.0008, R2=0.9771. Heat-activated persulfate appeared to be an effective oxidant for treatment of chlorinated hydrocarbons.

Cooling crystallization of Indomethacin from different organic solvents

DEFF Research Database (Denmark)

Malwade, Chandrakant Ramkrishna; Qu, Haiyan

, 25, 35, and 45 °C. The solvents with varying polarities (ethanol, methanol, ethyl acetate, acetone, acetonitrile, and dichloromethane) were used for solubility measurement. Maximum solubility of IMC was observed in acetone, while acetonitrile showed the lowest solubility. Solid phase analysis...... of excess solute with XRPD and Raman spectroscopy confirmed formation of IMC solvate in acetone, methanol and dichloromethane at 15 °C. Based on solubility of IMC, the solvents ethanol, ethyl acetate, acetone, and dichloromethane were selected for crystallization experiments. Nucleation kinetics of IMC...... in selected solvents was investigated through the measurement of induction time at 5 °C and 15 °C. Longer induction times were observed for IMC in ethanol at both temperatures compared to the one in acetone. Metastable α form of IMC was obtained from ethanol, while solvate of IMC was produced from acetone....

Construction of isotherms in solvent extraction of copper

Directory of Open Access Journals (Sweden)

Cvetkovski Vladimir B.

2009-01-01

Full Text Available The aim of this work is construction of equilibrium isotherms in solvent extraction. Technological parameters have been predicted for treatment of mine water by solvent extraction and electrowining. Two stages of extractions and one stage of stripping have been predicted for copper recovery by analyzing the equilibrium isotherms. The process was performed on mine water with 2,5 g/dm3 Cu2+, 3 g/dm Fe2+, pH 1,8, using 9 vol% LIX 984N in kerosene (organic solvent, with 95 and 98% stages efficiencies, respectively. This course produced an advanced electrolyte solution, suitable for electrowining and cathodic copper recovery, containing 51 g/dm3 Cu2+ and 160g/dm3 H2SO4 from a 30 g/dm3 Cu and 190 g/dm3 H2SO4.

A novel technique to determine concentration-dependent solvent dispersion in Vapex

Energy Technology Data Exchange (ETDEWEB)

Abukhalifeh, H.; Lohi, A.; Upreti, S. R. [Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada)

2009-07-01

Vapex (vapor extraction of heavy oil and bitumen) is a promising recovery technology because it consumes low energy, and is very environmentally-friendly. The dispersion of solvents into heavy oil and bitumen is a crucial transport property governing Vapex. The accurate determination of solvent dispersion in Vapex is essential to effectively predict the amount and time scale of oil recovery as well to optimize the field operations. In this work, a novel technique is developed to experimentally determine the concentration-dependent dispersion coefficient of a solvent in Vapex process. The principles of variational calculus are utilized in conjunction with a mass transfer model of the experimental Vapex process. A computational algorithm is developed to optimally compute solvent dispersion as a function of its concentration in heavy oil. The developed technique is applied to Vapex utilizing propane as a solvent. The results show that dispersion of propane is a unimodal function of its concentration in bitumen. (author)

A Novel Technique to Determine Concentration-Dependent Solvent Dispersion in Vapex

Directory of Open Access Journals (Sweden)

Hadil Abukhalifeh

2009-10-01

Full Text Available Vapex (vapor extraction of heavy oil and bitumen is a promising recovery technology because it consumes low energy, and is very environmentally-friendly. The dispersion of solvents into heavy oil and bitumen is a crucial transport property governing Vapex. The accurate determination of solvent dispersion in Vapex is essential to effectively predict the amount and time scale of oil recovery as well to optimize the field operations. In this work, a novel technique is developed to experimentally determine the concentration-dependent dispersion coefficient of a solvent in Vapex process. The principles of variational calculus are utilized in conjunction with a mass transfer model of the experimental Vapex process. A computational algorithm is developed to optimally compute solvent dispersion as a function of its concentration in heavy oil. The developed technique is applied to Vapex utilizing propane as a solvent. The results show that dispersion of propane is a unimodal function of its concentration in bitumen.

Thin-film composite crosslinked polythiosemicarbazide membranes for organic solvent nanofiltration (OSN)

KAUST Repository

Aburabie, Jamaliah

2015-01-01

In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes reported up to now. Integrally skinned asymmetric PTSC membranes were prepared by the phase inversion process and crosslinked with an aromatic bifunctional crosslinker to improve the solvent stability. TFC membranes were obtained via interfacial polymerization using trimesoyl chloride (TMC) and diaminopiperazine (DAP) monomers. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement.The membranes exhibited high fluxes toward solvents like tetrahydrofuran (THF), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) ranging around 20L/m2 h at 5bar with a molecular weight cut off (MWCO) of around 1000g/mol. The PTSC-based thin-film composite membranes are very stable toward polar aprotic solvents and they have potential applications in the petrochemical and pharmaceutical industry.

Agglomeration of Celecoxib by Quasi Emulsion Solvent Diffusion Method: Effect of Stabilizer

Directory of Open Access Journals (Sweden)

Maryam Maghsoodi

2016-12-01

Full Text Available Purpose: The quasi-emulsion solvent diffusion (QESD has evolved into an effective technique to manufacture agglomerates of API crystals. Although, the proposed technique showed benefits, such as cost effectiveness, that is considerably sensitive to the choice of a stabilizer, which agonizes from a absence of systemic understanding in this field. In the present study, the combination of different solvents and stabilizers were compared to investigate any connections between the solvents and stabilizers. Methods: Agglomerates of celecoxib were prepared by QESD method using four different stabilizers (Tween 80, HPMC, PVP and SLS and three different solvents (methyl acetate, ethyl acetate and isopropyl acetate. The solid state of obtained particles was investigated by differential scanning calorimetry (DSC and Fourier transform infrared (FT-IR spectroscopy. The agglomerated were also evaluated in term of production yield, distribution of particles and dissolution behavior. Results: The results showed that the effectiveness of stabilizer in terms of particle size and particle size distribution is specific to each solvent candidate. A stabilizer with a lower HLB value is preferred which actually increased its effectiveness with the solvent candidates with higher lipophilicity. HPMC appeared to be the most versatile stabilizer because it showed a better stabilizing effect compared to other stabilizers in all solvents used. Conclusion: This study demonstrated that the efficiency of stabilizers in forming the celecoxib agglomerates by QESD was influenced by the HLB of the stabilizer and lipophilicity of the solvents.

Effects of polar protic solvents on dual emissions of 3 ...

Indian Academy of Sciences (India)

TECS

Figure 1. Scheme of the ESIPT reaction of 3-hydroxy- chromone, 1. Chart 1. Chemical structures of the studied ... Materials and methods. Absorption and ... 85. Table 1. Spectroscopic properties of 3HC dyes in different polar solvents.a. Solvent.

Ion and solvent diffusion and ion conduction of PC-DEC and PC-DME binary solvent electrolytes of LiN(SO2CF3)2

International Nuclear Information System (INIS)

Hayamizu, Kikuko; Aihara, Yuichi

2004-01-01

Two binary mixed solvent systems typically used for lithium batteries were studied by measuring the self-diffusion coefficients of the solvent, lithium ion and anion, independently by using the multi-nuclear pulsed field-gradient spin-echo (PGSE) 1 H, 7 Li and 19 F NMR method. One system was propylene carbonate (PC) and diethyl carbonate (DEC) system and the other binary system was PC and 1,2-dimethoxyethane (DME), and the lithium salt used was LiN(SO 2 CF 3 ) 2 (LiTFSI). The relative ratio of the PC was changed from zero (pure DME and DEC) to 100% (pure PC) in the DME-PC and the DEC-PC systems, respectively. The self-diffusion coefficients of the solvents were measured with and without the lithium salt, and the two solvents had almost the same diffusion coefficient in the DEC-PC system, while DME diffused faster than PC in the DME-PC system. In the electrolytes the solvents diffused the fastest, followed by the anion with the lithium ion diffusing the slowest. The degree of ion dissociation was estimated for each electrolyte by comparing the ionic conductivities estimated from the ion diffusion and those measured directly by the electrochemical method

Solvent cleanup using base-treated silica gel solid adsorbent

International Nuclear Information System (INIS)

Tallent, O.K.; Mailen, J.C.; Pannell, K.D.

1984-06-01

A solvent cleanup method using silica gel columns treated with either sodium hydroxide (NaOH) or lithium hydroxide (LiOH) has been investigated. Its effectiveness compares favorably with that of traditional wash methods. After treatment with NaOH solution, the gels adsorb HNO 3 , dibutyl phosphate (DBP), UO 2 2+ , Pu 4+ , various metal-ion fission products, and other species from the solvent. Adsorption mechanisms include neutralization, hydrolysis, polymerization, and precipitation, depending on the species adsorbed. Sodium dibutyl phosphate, which partially distributes to the solvent from the gels, can be stripped with water; the stripping coefficient ranges from 280 to 540. Adsorption rates are diffusion controlled such that temperature effects are relatively small. Recycle of the gels is achieved either by an aqueous elution and recycle sequence or by a thermal treatment method, which may be preferable. Potential advantages of this solvent cleanup method are that (1) some operational problems are avoided and (2) the amount of NaNO 3 waste generated per metric ton of nuclear fuel reprocessed would be reduced significantly. 19 references, 6 figures, 12 tables

Capacitive Imaging For Skin Characterization and Solvent Penetration

OpenAIRE

Xiao, P; Zhang, X; Bontozoglou, C

2016-01-01

Capacitive contact imaging has shown potential in measuring skin properties including hydration, micro relief analysis, as well as solvent penetration measurements . Through calibration we can also measure the absolute permittivity of the skin, and from absolute permittivity we then work out the absolute water content (or solvent content) in skin. In this paper, we present our latest study of capacitive contact imaging for skin characterization, i.e. skin hydration and skin damages etc. The r...

Leaching and solvent extraction at Mary Kathleen Uranium Ltd

International Nuclear Information System (INIS)

Richmond, G.D.

1978-01-01

Mary Kathleen Uranium Ltd. recommenced operations in early 1976 following a twelve year period of care and maintenance. Several sections of the plant were modified or completely changed for the second operation. The most important change was the replacement of ion exchange with solvent extraction as the means of purifying and upgrading uranium rich solutions. Most of the problems experienced in the solvent extraction system originate from the leach liquor which has a strong tendency to form stable emulsions. This has been countered by some careful control of leaching conditions and by closer observation of operations in the solvent extraction area. Most problems have now been resolved and plant recoveries are quite satisfactory

Solvent extraction of platinum with thiobenzanilide. Separation of platinum from copper

International Nuclear Information System (INIS)

Shkil', A.N.; Zolotov, Yu.A.

1989-01-01

The solvent extraction of micro concentrations of platinum has been investigated from hydrochloric acid media using thiobenzanilide in the presence of SnCl 2 and KI. In the presence of SnCl 2 platinum is extracted rapidly and to significant completion. Conditions have been developed for the quantitative extraction of platinum. The authors have also examined the solvent extraction of copper(II) using thiobenzanilide, interference due to copper(II) and iron(III) on solvent extraction of platinum, and methods to suppress this interference. A procedure has also been developed for the separation of platinum from copper. Solvent extraction of metals was studied using radioactive isotopes: 197 Pt, 64 Cu, 59 Fe, 198 Au, 109 Pd, 110m Ag

Effect of di-butyl phosphate on flash point of PUREX solvent

International Nuclear Information System (INIS)

Srivastav, Ravi Kant; Kumar, Shekhar; Balasubramonian, S.; Kamachi Mudali, U.; Natarajan, R.

2015-01-01