Browse detailed TOC, Tables, Figures, Charts and Companies mentioned in Aliphatic Hydrocarbon Solvents Market research report @ http://www.absolutereports.com/global-aliphatic-hydrocarbon-solvents-market-research-report-2016-10446419. Table of Content Includes:. 1.Aliphatic Hydrocarbon Solvents Market Competition by Manufacturers. 2.Aliphatic Hydrocarbon Solvents Production, Revenue (Value), Price Trend by Type. 3.Aliphatic Hydrocarbon Solvents Manufacturing Cost Analysis. 4.Aliphatic Hydrocarbon Solvents Market Effect Factors Analysis. Further in the report, the Aliphatic Hydrocarbon Solvents market is examined for price, cost and gross. These three points are analysed for types, companies and regions. In continuation with this data sale price is for various types, applications and region is also included. The Aliphatic Hydrocarbon Solvents Industry for major regions is given. Additionally, type wise and application wise figures are also given.. Market Segment by Regions, this report splits ...
Solvent vapor annealing of block copolymer thin films can produce a range of morphologies different from the equilibrium bulk morphology. By systematically varying the flow rate of two different solvent vapors (toluene and n-heptane) and an inert gas, phase maps showing the morphology versus vapor pressure of the solvents were constructed for 45 kg/mol polystyrene-block-polydimethylsiloxane diblock copolymer films of different thicknesses. The final morphology was correlated with the swelling of the block copolymer and homopolymer films and the solvent vapor annealing conditions. Self-consistent field theory is used to model the effects of solvent swelling. These results provide a framework for predicting the range of morphologies available under different solvent vapor conditions, which is important in lithographic applications where precise control of morphology and critical dimensions are essential.. ...
Highly polar solvent-induced disproportionation of a cationic Pt(II)-diimine complex containing an o-semiquinonatoHighly polar solvent-induced disproportionation of a cationic Pt(II)-diimine complex containing an o-semiquinonato ...
Research Summary: The report presents detailed overview of the Solvent Compositions and Mixtures market in the world and regions (CIS countries in particular) by contemplating and analyzing its various parameters. Firstly, brief introduction is provided. Thus, solvent compositions and mixtures properties, application areas and manufacturing technologies are considered. Further goes the analysis of global solvent compositions and […].... ...
Background: Pesticides and organic solvents are two classes of neurotoxic substances regularly used in agriculture. Pesticides have been studied in relation to a range of nervous system effects, and have been repeatedly shown to relate to depression in agricultural workers. Likewise, occupational solvent exposure is recognized as a risk factor for central nervous system effects, including mood disturbances and cognitive impairment, across various industries. Many gaps in knowledge regarding the effects of chronic exposure to these substances on mental/neurological health in agricultural workers still exist. The specific aims of the current analysis were to 1.) Estimate associations between metrics of a.) pesticide exposure and b.) organic solvent exposure and results from the Center for Epidemiologic Studies Depression Scale of depressed mood; and 2.) Estimate associations between questionnaire-based organic solvent exposure metrics and measures of central nervous system function assessed from a battery
A solvent is a substance, that becomes a solution by dissolving a solid, liquid, or gaseous solute. A solvent is usually a liquid, but can also be a solid or gas. The most common solvent in everyday life is water.. Most other commonly-used solvents are organic (carbon-containing) chemicals. These are called organic solvents. Solvents usually have a low boiling point and evaporate easily or can be removed by distillation, thereby leaving the dissolved substance behind. Solvents should therefore not react chemically with the dissolved compounds - they have to be inert. Solvents can also be used to extract soluble compounds from a mixture, the most common example is the brewing of coffee or tea with hot water. Solvents are usually clear and colorless liquids and many have a characteristic smell. The concentration of a solution is the amount of compound that is dissolved in a certain volume of solvent. The solubility is the maximal amount of compound that is soluble in a certain volume of solvent at ...
New York City, NY: November 13, 2019 - Published via (Wired Release) - The industry analysis report identifying hidden opportunities of Aprotic Solvent Market, which will help to expand operations in the existing markets. The prime goal of the market study is to give a detailed assessment of the Aprotic Solvent business based on type, sector as well as geography. It also offers geological study into several regions with market growth, production, consumption, and revenue. An in-depth study examining the potential of the market and also offers data and estimates on the market structure, dynamics, and trends. The research report looks into growth strategies employed by key players, and how these strategies are poised to change the competitive dynamics in the aprotic solvent market over the forecast period.. Recent News Stories Shows How The Aprotic Solvent Market report presents a top to the bottom picture of product specification, innovation, product type, and production analysis considering ...
Aliphatic Hydrocarbon Solvents and Thinners Market Insights 2018, is a professional and in-depth study on the current state of the global Aliphatic Hydrocarbon Solvents and Thinners industry with a focus on the Global market. The report provides key statistics on the market status of the Aliphatic Hydrocarbon Solvents and Thinners manufacturers and is a valuable source of guidance and direction for companies and individuals interested in the industry. Overall, the report provides an in-depth insight of 2018-2025 global Aliphatic Hydrocarbon Solvents and Thinners market covering all important parameters. Request Sample…. Read More ...
Co-Solvent vapor degreasing is the long term cleaning process of the future.. Normal vapor degreasing uses a single solvent to clean and rinse parts. Because the solvent must be boiled in a single solvent vapor degreasing system only solvent with no flash points can be used.. Solvents with no flash points are found only in chemistries based in Chlorine, Bromine or Fluorine. While all of these can be used in vapor degreasers, they each face serious problems, which can be avoided in a co-solvent system.. Chlorinated solvents all have either environmental issues such as ozone depletion or low-level air pollution in the form of volatile organic compounds (VOCs) or heath issues being suspected carcinogens or reproductive hazards. Some industries such as electronics manufacturing avoid using chlorinated and brominated solvents during the manufacturing process.. Brominated solvents are also ozone depleters, VOCs, suspected carcinogens and reproductive hazards.. Fluorinated solvents are not ozone ...
TY - JOUR. T1 - Solvent-induced dimensional changes in EDTA-demineralized dentin matrix. AU - Pashley, D. H.. AU - Agee, K. A.. AU - Nakajima F R Tay, M.. AU - Carvalho, R. M.. AU - Terada, R. S.S.. AU - Harmon, F. J.. AU - Lee, W. K.. AU - Rueggeberg, F. A.. PY - 2001/6/21. Y1 - 2001/6/21. N2 - The purpose of this study was to test the null hypothesis that the re-expansion of dried matrix and the shrinkage of moist, demineralized dentin is not influenced by polar solvents. Dentin disks were prepared from mid-coronal dentin of extracted human third molars. After complete demineralization in 0.5M of EDTA (pH 7), the specimens were placed in the well of a device that measures changes in matrix height in real time. Dry, collapsed matrices were created by blowing dry N2 on the specimens until they shrank to a stable plateau. Polar solvents [water, methanol, ethanol, n-propanol, n-butanol, formamide, ethylene glycol, hydroxyethyl methacrylate (HEMA), or mixtures of water-HEMA] as model primers then ...
Solvent-induced two-photon absorption cross sections are calculated for a push-pull molecule in solutions using both self-consistent reaction field and internal finite field approaches. It is shown analytically and numerically that the results from the two methods can be connected through induced local reaction field factors. The two-photon cross sections of the studied push-pull polyene are found to be rather insensitive to the choice of cavity shape. The solvent dependence of the two-photon absorption displays a pattern different from that of the first hyperpolarizability.. ...
There is researched the process of low-temperature decomposition of vanadium-containing titanomagnetite in a non-aqueous solvent environment in the following system: monoatomic aliphatic alcohol ROH (R = C7–C8) — mineral acid (HCl). The process of titanomagnetite decomposition by a non-aqueous solvent is found to be affected by the aliphatic alcohol structure, acid concentration in the extract, and the non-aqueous phase and solid phase ratio. According to the influence efficiency on titanomagnetite, the researched alcohols are different in the following range: n-heptanol > n-octanol > iso-octanol. This correlates with the alcohols’ dielectric constant. During the titanomagnetite decomposition process in a non-aqueous environment, it is found that ferrous iron chloride and vanadium are concentrated in the one phase, ferric iron chloride — in the extract, and titanium — in the hardly decomposable mineral part. The stability of non-aqueous solvent in time has been
Unique Solvent Effects on Visible-Light CO2 Reduction over Ruthenium(II)-Complex/Carbon Nitride Hybrid PhotocatalystsUnique Solvent Effects on Visible-Light CO2 Reduction over Ruthenium(II)-Complex/Carbon Nitride Hybrid Photocatalysts ...
Note for Guidance on Impurities: Residual Solvents. The European Agency for the Evaluation of Medicinal Products Human Medicines Evaluation Unit. CPMP/ICH/283/95, March 1998, ICH Harmonised Tripartite Guideline Q3C. The limits for residual solvents given in Ph Eur, USP and JP are based on the Guidelines for Residual Solvents (CPMP/ICH/283/95, March 1998) which were adopted by the International Conference on Harmonization (ICH) for registration of pharmaceuticals for human use and prescribe limits for the content of solvents which may retain in active substances, excipients and medicinal products after processing. The residual solvents are listed in Appendix 1 by common names and structures. They were evaluated for their possible risk to human health and placed into one of three classes as follows:. Class 1 solvents: Known human carcinogens, strongly suspected human carcinogens, and environmental hazards. They are listed in Table 1.. Class 2 solvents (solvents to be limited): Non-genotoxic animal ...
Search results for inorganic solvents at Sigma-Aldrich Contact verified Inorganic Solvents Manufacturers, Inorganic Solvents suppliers, Inorganic Solvents exporters wholesalers, producers, traders in India. inorganic solvents list Wholesalers Directory - find Popular Products from 4 inorganic solvents list online Wholesalers from China. Chlorinated solvents are one of the contaminants most fre- are used to describe rates of transformation of inorganic chemicalspeciesinaqueoussolution . Q3D: Impurities: Guideline for Elemental Impurities . list of inorganic solvents Wholesalers Directory - find Popular Products from 0 list of inorganic solvents online Wholesalers from China. Acid-Base Reactions in Organic Solvents. Read about company and Inorganic Zinc coating provides anti-rust spray corrosion resistance for salt water & solvents for chemical plants, refineries, coastal & offshore installations. The most common solvent, water, is an example of an inorganic solvent. These are carbon based Pioneer ...
Theoretical studies on glycyl-alanyl and seryl dipeptides were performed to determine the probable backbone and side-group conformations that are preferred for solvent interaction. By following the method of Lee & Richards [(1971) J. Mol. Biol. 55, 379-400], a solute molecule is represented by a set of interlocking spheres of appropriate van der Waals radii assigned to each atom, and a solvent (water) molecule is rolled along the envelope of the van der Waals surface, and the surface accessible to the solvent molecule, and hence the solvent accessibility for a particular conformation of the solute molecule, is computed. From the calculated solvent accessibilities for various conformations, solvation maps for dipeptides were constructed. These solvation maps suggest that the backbone polar atoms could interact with solvent molecules selectively, depending on the backbone conformation. A conformation in the right-handed bridge (zetaR) region is favoured for both solvent interaction and intrachain ...
Using enrichment procedures, 45 organic solvent-tolerant lipase producer bacterial strains were screened from areas contaminated by oil and organic solvents. Among the strains, 15 isolates exhibited extreme stability toward organic solvents and high lipolytic activity. The NEB-1 isolate which was later identified as Pseudomonas sp. strain NEB-1 by biochemical tests and 16S rDNA gene sequence analysis was selected based on extremely high tolerance to organic solvents and maximum lipase production. Biochemical studies revealed that the crude lipase was stable at temperatures between 20 ºC and 60 ºC and pH ranges of 4 to 11 for 1 h. Optimum pH and temperature of the enzyme were revealed to be 9.5 and 70 ºC, respectively. The crude lipase showed remarkable tolerance in presence of different organic solvents with a broad range of hydrophobicity characteristics. The solvent stable lipase showed an attractive potency for application in biocatalysis in non-aqueous systems and biodiesel
article{cb52f0c6-0700-4b46-948b-c6b9df03eca7, abstract = {,p,Solvent effects on the decomposition of formic acid over a Co(111) surface were studied via density functional theory calculations combined with a continuum implicit solvation model. The solvents used here were water, methanol, and acetone. The adsorption energies of key intermediates, the activation barriers and the rate and equilibrium constants of various elementary reactions in vacuum and in the solvents were obtained. Solvent presences decrease the adsorption energies of species. Formic acid decomposition on the surface goes through HCOO rather than COOH both in vacuum and in the solvents. The most favorable decomposition pathways in vacuum and in acetone are HCOOH → HCOO → HCO → CO. The corresponding rate determining steps are HCOO deoxidation to HCO with activation barriers of 0.78 and 0.76 eV, respectively. In the presences of water and methanol, the preferred pathways are shifted to HCOOH → HCOO → HCOO-m → ...
Degree of crystallinity, crystal morphology, and crystallite size affect many physical properties of semi-crystalline polyesters, including mechanical strength, optical clarity, and biodegradability. Inspired by the literature related to solvent vapor annealing (SVA) in block copolymer films and solvent-induced crystallization in semi-crystalline polymers, we are studying how SVA treatments impact crystal morphology. Using poly(ε-caprolactone) as a model polymer for our studies, we have conducted in-situ grazing incidence wide-angle X-ray scattering experiments to determine when/if polymer crystals dissolve during solvent uptake and at what solvent concentrations recrystallization occurs during solvent removal. Additionally, we have examined polymer morphology across multiple length scales using a combination of optical microscopy, profilometry, and atomic force microscopy ...
Poly (caprolactone) (PCL) particles with the size distribution from 1 to 100 μm were prepared through solvent-induced phase separation, in which polyvinyl-alcohol (PVA) was used as the matrix-forming polymer to stabilize PCL particles. The cloud point data of PCL-acetone-water was determined by the titration method. PCL-acetone and PVA-water solutions, PCL-PVA gel, and PCL particles suspension were recorded by a digital camera. The morphology of PCL-PVA suspension and PCL particles were observed by optical microscopy and scanning electron microscopy, respectively. The size distribution of PCL particles was investigated by a particle size analyzer. Results from differential scanning calorimeter indicated that the main interaction between PCL and PVA were mediated through hydrogen bonding ...
Resonance Raman spectroscopy was used to probe the effect of solvent polarity on the molecular structure and isomerization dynamics of $4-nitro-4^\prime -dimethylaminoazobenzene$ (DA). In addition, the influence of the polarity and the relaxation behavior of the solvent on the mode-specific vibrational and solvent reorganization energies was investigated. Raman spectra were recorded in solvents with different polarity parameters, n-hexane and benzene, using 11 excitation wavelengths in the range 450-550 nm, scanning every 10 nm using the tunable laser pulse output of an optical parametric oscillator. It was observed that the solvent polarity plays a major role in influencing the excited-state potential energy surfaces of DA. The plot of resonance Raman intensities versus excitation wavelength (Raman excitation profiles) of the Franck-Condon-active fundamentals of DA shows that in n-hexane, the locally excited state is more favorable than that in benzene where the charge-transfer state is more ...
Preface. 1. Modern theories of continuum models.. 1.1 The physical model (J. Tomasi).. 1.2 Integral equation approaches for continuum models (E. Cances).. 1.3 Cavity surfaces and their discretization (C. Pomelli).. 1.4 A Lagrangian formulation for continuum models (M. Caricato, G. Scalmani, M. Frisch).. 1.5 The quantum mechanical formulation of continuum models (R. Cammi).. 1.6 Nonlocal solvation theories (V. Basilevsky & G.N. Chuev).. 1.7 Continuum models for excited states (B. Mennucci).. 2. Properties and spectroscopies.. 2.1 Computational modeling of the solvent effect on NMR molecular parameters by a Polarizable Continuum Model (J. Sadlej & M. Pecul).. 2.2 EPR spectra of organic free radicals in solution from an integrated computational approach (V. Barone, P. Cimino & M. Pavone).. 2.3 Continuum Solvation Approaches to Vibrational Properties (C. Cappelli).. 2.4 Vibrational Circular Dichroism (P. Stephens & F.J. Devlin).. 2.5 Solvent effects on natural optical activity (M. Pecul & K. ...
This study indicates that maternal occupational exposure to solvents may be associated with higher rates of ASD in their children. These results should be interpreted with caution given that this association did not remain significant after correcting the P-values for multiple comparisons. However, these results are consistent with earlier reports that have identified solvents as a potential risk factor for ASD.5 9 28 Research in the non-ASD population has found that solvents can be absorbed into the blood via skin or lungs.29 Water-soluble solvents may be cleared out of the body in urine or faeces, but many solvents are retained in organs including the brain. Solvents can also be metabolised into more toxic secondary substances (eg, methyl-butyl ketone, n-hexane) that are associated with a number of neurological effects and changes.29 In infants, solvents have been found to interfere with the glial guidance process which inhibits neuritic outgrowth.30 Infants of mothers who have been exposed to ...
In this work, we have investigated theoretically the structure/hyperpolarizability correlations of push-pull molecules sing a two-form two-state model. For this, we have defined a parameter MIX characterizing the mixing between the two-limiting resonance forms and thus ruling the molecular structure and polarization. Also, we have analyzed the solvent effect on the structure and on the polarizabilities of push-pull molecules using the Onsager reaction field theory. We have shown that the dependences of the linear and nonlinear polarizabilities on the solvent dielectric constant look similar to the structure/(hyper)polarizability correlations. Finally, we have investigated experimentally the solvent effect on a series of push-pull polyenes of increasing length. In particular, we have determined the scalar (mu) g(Beta) (0) product (where (mu) g is the ground-state dipole and (Beta) (0) the vector part of static quadratic hyperpolarizability tensor) in different solvents using the ...
Within the framework of the Peyrard-Bishop model for DNA melting, sharp denaturation temperature profiles can currently be obtained only if anharmonic base-pair stacking interactions are considered. We show that, when solvent interactions are included, a sharp denaturation of the DNA double helix is obtained without the need for anharmonic nearest-neighbor interactions. Using the concept of pseudo-Schrodinger equations we discuss the analogy of these transition to quantum-mechanical tunneling, and in particular we show that the sharp transitions are similar to resonant tunneling.. Full text not available from this repository.. ...
This multicentre case-control study of 1906 cases and 5565 controls provides no evidence of any association between occupational exposure to organic solvents and meningioma in the overall study population or in women or men separately. There were also no significant trends of increasing risk with either increasing cumulative exposure or duration of exposure. However, interpretation of these negative findings should take into account the strengths and limitations of the study.. While the INTEROCC study is the largest case-control study conducted to date investigating associations between occupational exposure to organic solvents and meningioma, the relatively low-exposure prevalence in the study population limited its power to identify significant associations and in particular after stratification by gender. Potential sources of selection and recall bias in the design and conduct of the INTERPHONE study on which this study was based have been addressed in detail elsewhere;28 ,36 however, these ...
India Market Study on Solvents. Industrial solvents are compounds where a solute is dissolved to create a solution. Solvents can either be organic or inorganic and the former is further subdivided into three types - oxygenated solvents, hydrocarbon solvents, and halogenated solvents. We have conducted an in-depth study of the India solvents m
The solvent effect on the self-assembly of polystyrene (PS) colloidal spheres for the fabrication of colloidal crystals (CCs) using the horizontal deposition method was investigated. Solvents containing water and ethanol of different volume fractions were examined. Samples were characterized using scanning electron microscopy and UV-vis-near-infrared spectroscopy techniques. It was found that the surface morphology and local structure of the CCs were significantly affected by the solvent. It was also observed that by adding minute quantity of a tetraethyl orthosilicate sol into the colloidal suspension, well ordered three-dimensional PS CCs without cracks were obtained. Experimental conditions were optimized and high-quality CCs in larger domains were fabricated with PS spheres as big as 2 μm in diameter. The success in fabricating CCs using colloidal spheres larger than 1.5 μm in diameter represents a significant work, especially when applications in photonics and tissue engineering are ...
Solvent programmable polymers (SPPs) were developed based on restricted rotation with the ability to respond and remember the stimuli-induced properties. The SPP was prepared via Ring Opening Metathesis Polymerization (ROMP). The recognition properties of SPPs can be modulated by heating in different solvents. At elevated temperatures, the carboxylic acid recognition groups have free rotation and can switch their relative orientations in response to the solvent. On cooling to room temperature, these solvent-induced changes were saved due to restricted rotation about the Caryl-Nimide bonds. Thus, the orientation of the carboxylic acid groups were maintained even when the imprinting solvent is removed or exchanged. The solvent-induced changes are also reversible, and the binding properties can be modulated by cycling between heating the polymer in a polar and nonpolar solvent. The solvent responsive behavior will fall off with |50% crosslinking. Thermodynamic studies showed large enthalpic terms and very
Polar solvents are distinguished by their large partial charges, as opposed to nonpolar solvents, which are more electrically neutral. Chemists recognize two groups of polar solvents, protic and...
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A variety of environmental factors affect fluorescence emission, including interactions between the fluorophore and surrounding solvent molecules (dictated by solvent polarity). This interactive tutorial explores relaxation effects and associated spectral shifts that occur as a function of solvent polarity.
In order to make the model more computationally efficient it has to be simplified. First and most natural simplification concerns the treatment of the solvent. In contrast to explicit solvent, which treats every water molecule in atomic detail, implicit solvent represents the effect of water molecules through effective potentials acting on the protein. As a consequence, a large reduction in the total number of degrees of freedom in the simulated system is achieved. In the present work, simulations with implicit solvent model ran about five times faster than the equivalent explicit solvent model, allowing us to extend the total simulation time by that amount. Another benefit of treating solvent implicitly is accelerated conformational dynamics of the protein. In explicit solvents, the dynamics of solute molecules is controlled by the solvents viscosity or internal friction. The magnitude of the friction is used as a parameter in implicit solvent simulations and thus can be varied to obtain ...
Recent estimates by the pharmaceutical and fine chemical industry have suggested solvents account for the majority of the waste produced in a typical batch process. Solvents are also subject to a number of regulatory controls. For these reasons there has been a large amount of interest in ways to reduce hazardous solvent use and find benign substitutes.. The Alternative Solvents technology platform promotes the use of more sustainable solvents - supercritical / liquid CO2, bio-based solvents and solvents made from waste - as replacements for conventional organic solvents. Here lies an opportunity to reduce the environmental impact of industrial processes as well as making them safer.. Our goal is to develop, apply and promote the implementation of safer, greener and more sustainable solvents into industry. The platform focuses on the use of alternative solvents in a wide range of applications.. Some of the applications already developed using supercritical or bio-based solvents include:. ...
Non-aqueous solvents are removed from a substrate, e.g., paper, by contacting the substrate with a condensable, vaporous heat transfer medium that is in a superheated state, e.g., superheated steam, and maintaining said substrate in contact with said superheated heat transfer medium, while also maintaining said heat transfer medium in superheated state, for a period of time sufficient to effect removal of said non-aqueous liquid from said substrate without concomitant condensation of said superheated heat transfer medium thereon. The superheated heat transfer medium, as well as being the source of energy for evaporating the solvent, acts as a solvent vapor transport medium. Upon evaporation of the solvent, the solvent vapor-heat transfer medium mixture can be sent to a recovery zone to easily recover said solvent via condensation of the mixture and thereby avoid the discharge of said solvent vapors into the atmosphere.
Oxidative cyclizations of a variety of heteroatom nucleophiles onto unactivated olefins are catalyzed by palladium(II) and pyridine in the presence of molecular oxygen as the sole stoichiometric oxidant in a nonpolar solvent (toluene). Reactivity studies of a number of N-ligated palladium complexes show that chelating ligands slow the reaction. Nearly identical conditions are applicable to five different types of nucleophiles: phenols, primary alcohols, carboxylic acids, a vinylogous acid, and amides. Electron-rich phenols are excellent substrates, and multiple olefin substitution patterns are tolerated. Primary alcohols undergo oxidative cyclization without significant oxidation to the aldehyde, a fact that illustrates the range of reactivity available from various Pd(II) salts under differing conditions. Alcohols can form both fused and spirocyclic ring systems, depending on the position of the olefin relative to the tethered alcohol; the same is true of the acid derivatives. The racemic ...
Kinetic solvent effects on hydroxylic hydrogen atom abstractions are independent of the nature of the abstracting radical. Two extreme tests using vitamin E and phenol
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In a study of the solvent effect on the α-effect, second-order rate constants (kNu-) have been determined spectrophotometrically for reactions of a series of substituted phenyl acetates with butan-2,3-dione monoximate (Ox-, α-nucleophile) and p-chlorophenoxide (p-ClPhO-, reference nucleophile) in DMSO-H2O (DMSO = dimethyl sulfoxide) mixtures of varying compositions at 25.0 ± 0.1 °C. The magnitude of the α-effect, kOX-/k p-ClPhO-, increases as the DMSO content in the medium increases up to 40-50 mol %, reaching 500, one of the largest α-effect values, and then decreases on further addition of DMSO, resulting in a bell-shaped α-effect profile regardless of the nature of the substrates. The magnitude of the α-effect is found to be significantly dependent on the substrates (or, more quantitatively, on βnuc). Thus, βnuc is an important predictor of the magnitude of the α-effect. The bell-shaped α-effect profile found in the present system is attributed to the differential change in the ...
TY - JOUR. T1 - Ultrafast measurements of the dynamics of solvation in polar and non-dipolar solvents. AU - Gardecki, J.. AU - Horng, M. L.. AU - Papazyan, A.. AU - Maroncelli, Mark. PY - 1995/1/1. Y1 - 1995/1/1. N2 - The dynamics of solvation of the probe solute coumarin 153 has been measured with ∼ 100 fs time resolution using the fluorescence upconversion technique. A wide variety of solvents, including polar aprotic solvents, hydrogen bonding solvents, and non-dipolar solvents have been examined. For all solvents of even moderate polarity (ε{lunate}0,5), the solvation dynamics observed follows the predictions simple models based on the solvents bulk dielectric response. For a number of non-dipolar solvents such as dioxane and benzene, for which ε{lunate}10,5, we observe surprisingly large time-dependent shifts, which seem to reflect the solute interacting with the large quadrupole (and higher multipole) moments of the solvent molecules. These dynamics represent a solvation distinct ...
A micellar acidic surfactant solvent composition of enhanced oil/organic solvency and method of preparing and using same. The oil solvency of a propoxylated/ethoxylated surfactant and alcohol micellar acidizing system is enhanced by controlling or selecting the molar ratio of alcohol to surfactant as a linearly increasing function of acid concentration. The oil solvency is further enhanced and selectively controlled by addition of an oil solvent (e.g., aromatic hydrocarbons, aromatic acid esters, ketones, CS2, etc.) to the micelle.
Aqueous amine solutions are the most used solvents for chemical absorption of CO2. Substituting part of the water by organic solvents in aqueous amine solutions aims to take advantage of the lower partial pressure and higher CO2 solubility. In this work, the influence of four organic solvents on solution density, viscosity, N2O solubility and absorption kinetics are studied. The organic solvents, Monoethylene Glycol (MEG), Diethylene Glycol (DEG), Triethylene Glycol (TEG) and CARBITOL, are blended with two amine solutions: MEA and DEEA-MAPA blend. The results show that the addition of organic solvents increases the density and viscosity. Furthermore, the N2O solubility, used to estimate the physical solubility of CO2 into a reactive system, increases when part of the water is substituted with an organic solvent. The kinetic experiments with a double stirred cell showed that in case of aqueous 5 M MEA, the substitution of part of the water increases both the mass transfer and kinetic coefficients ...
Global Aprotic Solvents Market to Reach US$21.8 Billion by the Year 2027 Amid the COVID-19 crisis, the global market for Aprotic Solvents estimated at US$17.1 ...
The rate of absorption of CO2 into amines in hydrophilic and hydrophobic solvent mixtures was studied in this work using a stopped-flow apparatus and a stirred-tank reactor. Monoethanolamine (MEA, primary amine) and N-methyl benzylamine (NMBZA, aromatic secondary amine) are chosen for this study and diluted in hydrophobic or hydrophilic solvents at different temperatures
Protein 3D structures, determined largely by their amino acid sequences, have been considered as an essential factor for better understanding the function of proteins [1-3]. However, it is exceedingly difficult to directly predict proteins 3D structures from amino acid sequences [4]. Identifying structure properties, such as secondary structure, solvent accessibility or contact number can provide useful insights into the 3D structures [5-7]. Accurate prediction of structural characteristics from the primary sequence is a crucial intermediate step in protein 3D structure prediction [8, 9].. The solvent accessibility (solvent accessible surface area) is defined as the surface region of a residue that is accessible to a rounded solvent while probing the surface of that residue [10]. Solvent burial residues have a particularly strong association with packed amino acids during the folding process [11], and exposed residues give a useful insight into protein-protein interactions and protein stability ...
Rate constants have been measured for the reaction of the light hydrogen isotope muonium with benzene and 2,3-dimethylbutadiene-1,3 in the gas phase and in several solvents. Comparison with H atom data reveals (1) appreciable kinetic isotope effects, (2) a strong contribution of tunnelling for the activated reaction with benzene, (3) encounter controlled reaction for Mu addition to the diene, (4) a mass dependence of the diffusion constant of hydrogen isotopes in solution, and (5) an enhancement of the rate constant in solution over that in the gas phase by a factor, except for water, of the inverse Ostwald solubility coefficient for hydrogen. The isotope-dependent reduction of the solvent effect in water is tentatively ascribed to the dynamics of the clathrate-like structure when the hydrogen atom reacts.. ...
Coordinative halogen bonds have recently gained interest for the assembly of supramolecular capsules. Ion mobility-mass spectrometry and theoretical calculations now reveal the well-defined gas-phase structures of dimeric and hexameric [N⋯I+⋯N] halogen-bonded capsules with counterions located inside their cavities as guests. The solution reactivity of the large hexameric capsule shows the intriguing solvent-dependent equilibrium between the hexamer and an unprecedented pentameric [N⋯I+⋯N] halogen-bonded capsule, when the solvent is changed from chloroform to dichloromethane. The intrinsic flexibility of the cavitands enables this novel structure to adopt a pseudo-trigonal bipyramidal geometry with nine [N⋯I+⋯N] bonds along the edges and two pyridine binding sites uncomplexed. ...
substrates. This ebook seeks to reinforce our figuring out of acids and bases through reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is expounded the place attainable to that during water, yet correlations and contrasts among solvents also are presented.. Fundamental historical past fabric is supplied within the preliminary chapters: quantitative features of acid-base equilibria, together with definitions and relationships among resolution pH and species distribution; the impact of molecular constitution on acid strengths; and acidity in aqueous answer. Solvent houses are reviewed, in addition to the significance of the interplay energies of solvent molecules with (especially) ions; the power of solvents to take part in hydrogen bonding and to just accept ...
It is known that solvent and solvent effect play an important role in many catalytic reactions. Here the effects of solvent on acid catalyzed glucose conversion to HMF were investigated. Ab initio molecular dynamics and metadynamics simulations were used to investigate the reaction mechanisms and associated barriers in various water/DMSO mixtures. The multi-dimensional free energy surfaces (FES) obtained allows accurate determination of both the reaction free energies and barriers in different solvent systems. In addition, complementary experiments were carried out to determine the HMF yields and validate the effects of solvents on sugar reactions. Solvent is found to play a critical role during proton catalyzed sugar reactions. Solvent affects reaction pathways and associated barriers significantly. The thermodynamic equilibrium and the kinetic reaction rate constants were also determined and compared with available experimental data ...
The design of novel solvents for process improvements has stemmed much interest in recent years (Bardow et al., 2010, Folić et al., 2007, Oyarzun et al., 2011). Solvents are used in many industrial processes for separation of useful products from a feed. Consequently improvements in solvent performance are sought after for a more efficient and cost effective process. The properties desired in a solvent vary from process to process and include selectivity, volatility, flammability, toxicity, viscosity, heat capacity and reaction kinetics. Often a trade-off has to be reached between the desired properties as not all desired properties may be achievable within one solvent.. In order to optimize system performance, both process and solvent parameters must be optimized. The simultaneous optimization of a process and solvent is a challenging task. Although process parameters may be continuously optimized, solvent properties are discrete and therefore pose a major hurdle in the optimization process. ...