Mixture Of Carbon Disulfide Research Articles

Melamine-functionalization of the carbonyl-rich polymers for iodine vapor and Hg2+ capture

The solvent and catalyst in the Friedel-Crafts acylation play an important role in the chemical structure and porosity of the polymers. Herein, the mixture of carbon disulfide (CS2) and nitrobenzene (PhNO2) was employed as the solvent and (CF3SO3)2Sn was applied as the catalyst, and the carbonyl-rich polymers were successfully prepared based on the Friedel-Crafts acylation. The prepared polymers possessed moderate Brunauer-Emmet-Teller (BET) surface area (SBET, 446 m2/g), pore volume (Vtotal, 0.21 cm3/g) and unique microporosity. The abundant carbonyl groups on the polymers afforded its further chemical modification. The subsequent melamine (MA) functionalization according to the Schiff base reaction offered the resulting polymers high SBET (up to 680 m2/g), Vtotal (up to 1.01 cm3/g) and nitrogen (N) content (up to 50.04 %). The adsorption experiments revealed that TPA-TPC-10MA with the largest Vtotal (1.01 cm3/g) adsorbed iodine (I2) vapor efficiently, with the maximum capacity of 505 wt%, whereas TPA-TPC-8MA containing the highest N content (50.04 %) removed Hg2+ efficiently, with the maximum capacity of 781 mg/g, and different adsorption mechanism was clarified in detail.

Investigation of photoelectric behaviors of silver sulfide particles in different surroundings.

Silver sulfide (Ag2S) is a traditional semiconductor material, however, the photoelectric properties of Ag2S particles under different environments are still lacking. In this paper, we reported the preparation of Ag2S particles and their photoelectric properties under different environments. Results showed that the photoelectric performance of Ag2S particles was closely related to the environment. It was found that a copper phthalocyanine coating could improve the light response, the mixture of alcohols and air could increase the photoconductivity, and the mixture of carbon disulfide and air could decrease the photoconductivity. The mechanism of the effect of various experimental conditions on photoelectric properties was also discussed.

A multi-tool structural change investigation of Indian vitrinite rich bituminous coal due to CS2/NMP interaction

Solvents are important constituent in the coal liquefaction process as they act as hydrogen donors and serve as hydrogen shuttles between hydrogen and coal. A mixture of carbon disulfide (CS2) and N- methyl-2-pyrrolidinone (NMP) (1:1, v/v) was used as a solvent for a study of an Indian coal that was kept for swelling. The study of coal swelling provides valuable information, such as, determining the highest energy bond that can be broken by a particular solvent or by a mixture of solvents. It can be concluded from the results that maximum swelling and extraction yield are achieved by a CS2/NMP mixed solvent. The structure change of coal before and after its interaction with the solvent was also studied using techniques such as Fourier-transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), and X-ray powder diffraction (XRD). FTIR indicated that the mixed solvent caused a decrease in the solvent viscosity, enabling the solvent to penetrate more quickly into the coal structure. XRD structural parameters concluded a decrease in aromaticity and stacking height and an increase in the interplanar spacing of raw coal after the swelling process. This was due to a decrease in the crystalline carbon along with an increase in amorphous carbon. XRD results indicated that the four parallelogram-shaped aromatic sheets were parallelly connected. This was also clearly observed in HRTEM images. This work will be helpful in the understanding and development of coal liquefaction technology.

Stokes–Einstein–Debye Failure in Molecular Orientational Diffusion: Exception or Rule?

The Stokes-Einstein-Debye (SED) expression is used routinely to relate orientational molecular diffusivity quantitatively to viscosity. However, it is well-known that Einstein's equations are derived from hydrodynamic theory for the diffusion of a Brownian particle in a homogeneous fluid and examples of SED breakdown and failure for molecular diffusion are not unusual. Here, using optical Kerr-effect spectroscopy to measure orientational diffusion for solutions of guanidine hydrochloride in water and mixtures of carbon disulfide with hexadecane, we show that these two contrasting systems each show pronounced exception to the SED relation and ask if it is reasonable to expect molecular diffusion to be a simple function of viscosity.

Determination of 11 priority pollutant phenols in wastewater using dispersive liquid—liquid microextraction followed by high-performance liquid chromatography—diode-array detection

Dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography-diode-array detection was applied for the extraction and determination of 11 priority pollutant phenols in wastewater samples. The analytes were extracted from a 5-mL sample solution using a mixture of carbon disulfide as the extraction solvent and acetone as the dispersive solvent. After extraction, solvent exchange was carried out by evaporating the solvent and then reconstituting the residue in a mixture of methanol-water (30:70). The influences of different experimental dispersive liquid-liquid microextraction parameters such as extraction solvent type, dispersive solvent type, extraction and dispersive solvent volume, salt addition, and pH were studied. Under optimal conditions, namely pH 2, 165-microL extraction solvent volume, 2.50-mL dispersive solvent volume, and no salt addition, enrichment factors and limits of detection ranged over 30-373 and 0.01-1.3 microg/L, respectively. The relative standard deviation for spiked wastewater samples at 10 microg/L of each phenol ranged between 4.3 and 19.3% (n = 5). The relative recovery for wastewater samples at a spiked level of 10 microg/L varied from 65.5 to 108.3%.

Molecular dynamics investigation with the time resolved optical Kerr effect on the CS2–C6H6 mixtures

An investigation of the molecular dynamics in pure liquids and in mixtures through the technique of time resolved optical Kerr effect is performed. The samples studied were the mixtures of carbon disulfide (CS(2)) with benzene (C(6)H(6)). The molecular dynamics of the pure liquids is briefly discussed while the main results are obtained for the mixtures. A slow dynamics component is observed for the optical heterodyne detected optical Kerr effect transient decaying exponentially with time constants on picosecond time scale. The fast subpicosend time relaxations are analyzed in terms of the nondiffusive component of the spectral response that is associated with the molecular dynamics. The modifications of the spectrum are quantified, and the explanation of the observed changes is given in terms of the structural interaction configurations that produced changes in the intermolecular potential within which the molecules execute librational motions.

Catalytic Hydrogenation of Extracts from Coal and Their Thermal Reactivity

Upper Freeport coal was extracted using a mixture of carbon disulfide and N-methyl-2-pyrrolidinone (CS2/NMP) under ultrasonic irradiation at room temperature. The CS2/NMP-soluble fraction (CS2/NMP-...

Synthesis and Application of Isothiocyanato Derivatives of Nucleosides

Abstract3′‐Deoxy‐3′‐isothiocyanatothymidine (4), 3′,5′‐protected 2′‐deoxy‐2′‐isothiocyanatouridine (8), and 2′,3′‐dideoxy‐2′‐isothiocyanatouridine (14), respectively, have been prepared from the corresponding 2′‐ or 3′‐amino derivatives. SnCl2, Bu3SnH, and dithiothreitol were employed to reduce the 2′‐ or 3′‐azido derivatives to give the aminonucleosides which served as starting materials for the thiocarbonylation. Thiocarbonylation, by either a mixture of carbon disulfide and mercuric oxide or N,N′‐thiocarbonyldiimidazole, leads directly to the target molecules in high yields. Furthermore, the direct transformation of azidonucleosides into the corresponding isothiocyanto derivatives via treatment of phosphanimine nucleosides with CS2 is described. Th activity of the isothiocyanate group is used for covalent coupling of different linking molecules or dyes to the carbohydrate moiety of the nucleosides.

Validation of a Test Method for the Measurement of Methanol Emissions from Stationary Sources

Title III of the 1990 Clean Air Act Amendments designated methanol as a pollutant to be regulated. The U.S. Environmental Protection Agency (EPA), through a contract with Research Triangle Institute, has developed a method for measuring methanol emissions from stationary sources. The methanol sampling train (MST) consists of a glass-lined heated probe, two condensate knockout traps, and three sorbent cartridges packed with Anasorb 747. Samples are desorbed with a 1:1 mixture of carbon disulfide (CS2) and N,N-dimethylformamide (DMF). Condensate water and CS2/ DMF samples are analyzed by gas chromatography with flame ionization detection. The MST has a practical quantitation limit of approximately 3 ppm for a 20-L sample. Samples were shown to be stable for at least two weeks after collection. Field tests of the MST and the National Council of the Paper Industry for Air and Stream Improvement (NCASI) methanol sampling method were conducted at two pulp and paper mills. Sampling and analysis procedures followed EPA Method 301 requirements. The sampling location for the first field test was the inlet vent to a softwood bleach plant scrubber, where the methanol concentration was approximately 30 ppm. The mean recovery of spike was 108.3% for the MST method and 81.6% for the NCASI method. Although neither method showed significant bias at the 95% confidence level, the between-methods bias was significantly different. A second field test was conducted at a vent from a black liquor oxidation tank where the methanol concentration was approximately 350 ppm. Mean spike recoveries were 96.6 and 94.2% for the MST and NCASI methods, respectively. The biases of the two methods and the between-methods bias were not significantly different for the second field test.

Line shape analysis of the depolarized Rayleigh spectra of CS2/PS mixtures

Mixtures of carbon disulfide and polystyrene with the composition 0, 5%, 20%, 40%, 60%, 80%, 100% by weight of CS2 have been studied using depolarized Rayleigh scattering experiments within the temperature range of 263–313 K. The spectral ranges between 20 and 150 cm−1 were described in the reduced representation by the 3-parameter-Mori-function, indicating that most of the spectral features depend more on the CS2 compound than on the polymer matrix. The concept of analyzing the line shapes of liquid systems by separating the logarithmic spectrum into various distinct regions with characteristic slope parameters was successfully applied to the CS2/polystyrene mixtures and indicates the existence of liquid CS2 microstructures in the mixtures and the applicability of the dipole-induced dipole mechanism to the investigated system.

Wetting transition of a binary liquid due to suppression of electrostatic forces.

When a phase-separated mixture of carbon disulfide and nitromethane is put in contact with borosilicate glass, a thick nitromethane-rich wetting layer generally results. The long-range force responsible for this layer is believed to be electrostatic in nature and caused by ionization of hydroxyl groups on the glass surface. We have used a capillary-rise epxeriment to examine the effect on the state of wetting of suppressing this force through the addition of a soluble salt, tetrabutylammonium iodide. We find that for small salt concentrations (0.1M) the glass appears to remain completely wet to within at least 40 K of ${\mathit{T}}_{\mathit{c}}$, but that for larger concentrations (g0.2M) the glass is incompleely wet for temperatures T(${\mathit{T}}_{\mathit{c}}$-25 K). At T\ensuremath{\approxeq}(${\mathit{T}}_{\mathit{c}}$-25 K) the system undergoes a wetting transition from incomplete to complete wetting. The appearance of this wetting transition seems to result from the complete removal of the long-range electrostatic interaction.

Stimulated Raman scattering and four-wave mixing from a mixture of carbon disulfide and phenylethanol in a hollow optical fiber

We observe, for what is to our knowledge the first time, stimulated Raman scattering and four-wave mixing in a liquid-core optical fiber filled with a mixture of carbon disulfide and phenylethanol pumped by the frequencydoubled output of a Q-switched YAG laser (lambda = 532.1 nm). The frequencies of the stimulated Raman scattering and four-wave mixing spectra are specified, and theoretical interpretations are also given.

Crystal and molecular structure of two calix[6]arenes:p-Isopropylcalix[6]arene andp-tert-butylcalix[6]arene?benzene(1?3) complex

The isopropyl derivative crystallizes from a mixture of carbon disulfide and benzene in the orthorhombic system: Space groupP21nb, a=17.420(3),b=17.708(3),c=18.972(3) A,V=5852(3) A,Z=4. Thet-butyl derivative crystallizes from benzene, but the crystal is a complex (1∶3), space groupPĪ,a=15,065(5),b=19.103(3),c=13.878(3) A, α=106.95(2), β=102.72(2), γ=80.61(2),V=3703(2) A3,Z=2. Refinement led toR=0.185 for 1512 reflections for the isopropyl derivative, a sufficiently high number to establish the conformation of the molecule; for thet-butyl complexR=0.12 for 7340 reflections. Intramolecular hydrogen bonds are given as well as comparison of the conformation of both compounds. Thet-butyl groups and the benzene molecules are disordered but the isopropyl groups are not.

Soret effect in forced Rayleigh scattering

In forced Rayleigh scattering of mixtures or suspensions the temperature gratings generate, by the Soret effect, concentration gratings that may be very important since they produce both a phase and an amplitude grating superimposed on the principal one. The experimental evidence of their influence was given by Thyagarajan and Lallemand using a mixture of carbondisulfide and ethanol. In this paper we study the temporal behaviour of the concentration grating versus the sample properties and its effect on the detected diffracted beam. Explicit expressions are given for the output intensity taking into account both the generated amplitude and phase gratings.

Application of Total Reflection Long Capillary Cell to Determination of Fluoride in Drinking Water

Colorimetric determination of fluoride ion in drinking water was done with a long capillary cell (LCC) (length:0.7-4m). When a solution whose refractive index exceeds that of the cell material (Pyrex=1.474) is put into the capillary, a wave-guide(total reflection) cell is obtained, its transmissibility to source light is independent of cell shape. Color development was based on the la-ALC method: lanthanum-alizarin complexone was added to the sample. The fluoro-lanthanum-alizarin complexone which formed was combined with N, N-diethylaniline and extracted into isoamyl alcohol. Fluoride complex extracted to isoamyl alcohol was mixed with a mixture of carbon disulfide and acetone (the final refractive index of analyte solution=1.57). Extension of cell length longer than 1m provided highly sensitive colorimetry.Enhancement of absorption was O.5-2.5×103times in magnitude by using 4m LCC. Detection limit and recovery of this method were 10ng/l and 93-104% (for 50μg/l), respectively. The present method was applied to the determination of fluoride in drinking water collected around Tokyo.

溶媒抽出後の残さ炭の粘結性

Caking property, such as Roga index and crucible swelling number, of the residual coals from the extractions was measured. The extractions were done using 1: 1 mixtures of carbon disulfide with pyridine, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone, respectively. The following results were obtained.1) Roga indexes of residual coals from the extraction with the mixture were higher than those for the Soxhlet extraction with pyridine, in similar extraction yield. This may be attributed to a slight oxidation in Soxhlet extraction, since careful air removal from the Soxhlet apparatus gave similar high Roga indexes with those for the extractions with the mixture.2) In the extractions of Shin-yubari and Zao Zhuang coals with the mixtures Roga indexes of both residual coals decreased with increasing extraction yields. Zao Zhuang coal showed pronounced decrease in Roga index than Shin-yubari coal. This indicates that both coals are different from each other in chemical structures, molecular weight distributions, and degrees of cross-linking, although they have similar carbon content (%)

Effect of altered surface substrate chemistry on critical adsorption from a binary liquid mixture.

We have demonstrated the importance of the surface chemical character of the substrate in the phenomenon of critical adsorption---the long-range perturbation of chemical concentration in a critical binary liquid mixture by a boundary. By measuring the reflectivity of the solid/liquid interface between borosilicate glass and a mixture of carbon disulfide and nitromethane near its critical demixing point, we find that the substitution of methyl for hydroxyl groups on the glass surface inverts the sign of the long-range order-parameter perturbation.

Spectral characteristics and nature of the emission from explosions in a closed volume II. Explosions of CS2/O2=1/4 mixtures

The paper describes experiments undertaken to secure additional spectral and energy measurements of the emission from explosions of mixtures of carbon disulfide with oxygen at atmospheric pressure and with the composition CS/sub 2//O/sub 2/ = 1/4. The true emission spectrum in the case of these explosions was obtained. It was found that the principal contribution to the observed emission is made by SO/sub 2/ molecules. It is possible that the emission of the SO radical is also present in the spectrum. Previous conclusions concerning superequilibrium intensity of the emission and the attribution of the luminosity exclusively to the radiative recombination reaction SO+O--SO/sub 2/+hv, are erroneous. The luminosity observed in the case of these explosions in a closed volume has a thermal equilibrium nature. The absorption cross-section of the SO/sub 2/ molecule, from which the emission of SO/sub 2/ in gases heated to 3500-3700 K can be calculated, for a wavelength of 380nm amounts to a value of about 3 X 10/sup -20/ cm/sup 2/.

Self-ignition in mixtures of carbon disulfide with oxygen

Self-ignition in mixtures of carbon disulfide with oxygen

Molecular orientational relaxation times in liquids

We have used picosecond light pulses from a mode-locked Nd:glass laser to observe the kinetics of the optical Kerr effect in several liquids. From these data we determined the molecular orientational relaxation times for carbon disulfide, bromobenzene, nitrobenzene, toluene, iodomethane and mixtures of carbon disulfide and carbon tetrachloride. Our results are in good agreement with the Debye relation between orientational relaxation time and the macroscopic viscosity.