Excess volume of mixing of some polar and nonpolar liquids with propylene carbonate

The excess volume of mixing as a function of composition has been measured at 30°C and 40°C for mixtures of propylene carbonate with nitrobenzene, chlorobenzene, benzene, toluene, cyclohexane, dioxane, carbon tetrachloride, and chloroform. The highly polar nitrobenzene forms an ideal mixture with propylene carbonate. Chloroform, carbon tetrachloride, dioxane, chlorobenzene, benzene, and toluene give negative volume changes on mixing. In mixtures with cyclohexane,V _m ^E is positive at lower mole fractions of cyclohexane but becomes negative as the mole fraction of cyclohexane increases.     

The effect of polymer side chains on vapor sorption in polyacrylate and polymethacrylate solutions

The segment fraction Ψ₁ activity coefficients, a₁/Ψ₁, of solvents have been determined by the piezoelectric sorption method for 0.1 ≤ Ψ₁ ≤ 0.5 in binary solutions of chlorinated methanes [carbon tetrachloride (CCl₄), chloroform (CHCl₃), and dichloromethane (CH₂Cl₂)] with aromatic hydrocarbons (benzene and toluene) in poly(methyl methacrylate), poly(methyl acrylate), poly(ethyl methacrylate), and poly(n-butyl acrylate) at 23.5°C. The present results for toluene in PMMA agree with previously published values obtained by gas-liquid chromatography. For CCl₄ and the aromatic hydrocarbons, the polymer–solvent interaction parameter χ is positive and constant, while for the polar solvents (CHCl₃ and CH₂Cl₂), χ is negative and increases with increasing Ψ₁. The effect of the polymer side chains on vapor sorption in nonpolar and polar solvent systems is discussed in terms of the χ parameter.     

Selective polymeric effects on solvent NMR relaxations

Measurements of the spin-lattice relaxation times (T₁) of solvent protons have been performed on systems containing mixed solvents with and without polymer. It has been found that the motion of solvent is selectively affected by polymers present in the system. Polyisobutylene (10%) in mixed solvents of carbon tetrachloride (or cyclohexane) and dichloromethane at various proportions produces little effect on T₁ values of dichloromethane, but it affects significantly the T₁ values of cyclohexane; whereas poly(methyl methacrylate) (10%) in carbon tetrachloride and dichloromethane (or acetone) selectively associates with dichloromethane (or acetone), resulting in an approximate 50% reduction of the T₁ values for dichloromethane (or acetone). In systems of poly(methyl methacrylate) and three mixed solvents of carbon tetrachloride, dichloromethane, and cyclohexane, the polymer (10%) has a negligible effect on the T₁ values of cyclohexane, but brings about a 50% reduction of the T₁ values of dichloromethane. These phenomena are discussed in terms of local selective interactions between the solvent molecules and the polymeric chain segments.     

Vapor-liquid equilibria for polybutadiene and polyisoprene solutions

Vapor-liquid equilibria in binary solutions of hydrocarbons (n-hexane, benzene, toluene, cyclohexane) and chlorinated methanes [carbon tetrachloride (CCl₄), chloroform (CHCl₃), and dichloromethane (CH₂Cl₂)] in polybutadiene (PBD) and polyisoprene have been determined at 23.5°C by using the piezoelectric sorption method. The weight-fraction activity coefficient of solvent (a₁/w₁) in cis-PBD (98% cis-1,4 addition) and random cis-trans-PBD (r-PBD, 34.3% cis-1,4 addition; 54.3% trans-1,4 addition; 11.4% vinyl-1,2 addition) are almost equal for CCI₄, CHCI₃, CH₂CI₂, benzene, and toluene solutions, while the values of a₁/w₁ in n-hexane and cyclohexane solutions in cis-PBD are larger than those in r-PBD solutions. The values of a₁/w₁ for solutions of hydrocarbons and chlorinated methanes in cis-1,4 polyisoprene (95% cis-1,4 addition) have been compared with those for cis-PBD.     

Influence of the solvent on the extraction of copper(II) from nitrate medium using salicylideneaniline

Different solvents including cyclohexane, dichloromethane, chloroform, toluene, 1-octanol, and methyl isobutyl ketone (MIBK) have been evaluated in extracting copper(II) from nitrate medium by salicylideneaniline. Extracted species differs from solvent to solvent: CuL₂ in cyclohexane, toluene, 1-octanol, and methyl isobutyl ketone. However, in dichloromethane or chloroform, there are two complexes of the type CuL₂ and CuL₂(HL). The extraction constants and percentage of extraction (%E) are calculated for different solvents. Solvent played an important role in recovering copper(II) from the aqueous solution, thus affecting the extraction equilibrium and extraction efficiency. The nonpolar solvent showed better performance than the polar solvent. The maximum extraction efficiency was 85.75% at pH?=?4.5, which was from cyclohexane.     

Effect of solvent upon competitive liquid-liquid extraction of alkali metal cations by isomeric dibenzo-16-crown-5-oxyacetic acids

The selectivity and efficiency of competitive liquid-liquid extraction of alkali metal cations into organic solvents containingsym-(octyl)dibenzo-16-crown-5-oxyacetic acid (2) andsym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic acid (3) have been determined. Solvents examined include: dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, benzene, toluene,p-xylene, chlorobenzene, 1,2-dichlorobenzene, and 1,2,3,4-tetrahydronaphthalene. The Na⁺/K⁺ and Na⁺/Li⁺ extraction ratios are highest in chloroform. The extraction selectivity is found to correlate with the diluent parameter (DP) of the organic solvent.This paper is dedicated to the memory of the late Dr C. J. Pedersen.     

Proton spin-lattice relaxation study of polymer solutions

Proton spin-lattice relaxation times of solvent molecules were measured on ternary mixtures of a polymer and two solvents by the adiabatic rapid-passage method. The selective adsorption of a good solvent was verified by this experimental technique for the systems benzene—cyclohexane—polystyrene(PS), benzene—carbon tetrachloride—poly(methyl methacrylate)(PMMA), and chloroform—carbon tetrachloride—PMMA. The number of molecules of adsorbed benzene per monomeric unit of PS was estimated to be about four, which is almost identical with that determined previously by thermodynamic measurements. The number of molecules of benzene and chloroform adsorbed on PMMA were also determined to be about five and four, respectively. It was found that the interaction between chloroform and PMMA has the greatest effect on the molecular motion of the solvent, whereas the benzene—PS interaction is weak.     

Adsorption of radioisotopes from their organic solutions on filter papers the Sb(III)-nonpolar solvents-system

The extraction of Sb(III) chloride by nonpolar solvents from 0.15M HCl was studied as a function of sulphuric acid concentrations in the aqueous phase. The distribution of Sb(III) chloride between the nonpolar solvents benzene, toluene, xylene, nitrobenzene, cyclohexane, chloroform and carbon tetrachloride and filter paper is reported. In case of benzene the Sb(III) activity (given in counts·s^–1·ml^–1) decreases from 1500 to 200 after 24 hours. The corresponding values are about 1200 and 540 for toluene, 1330 and 50 for xylene, 1050 and 700 for nitrobezene, 1080 and 22 for cyclohexane, 330 and 30 for chloroform and 130 and 40 for carbon tetrachloride. More than 95% of the adsorbed Sb(III) is desorbed by 1M HNO₃, 1M HCl or 0.5M H₂SO₄ by contacting the loaded filter paper with any of these acids for 27 hours.     

Solvent effect on pyridine derivatives. Molecular iodine donor-acceptor equilibria. The isoquinoline-I2-organic solvent system and the 2,4-lutidine-I2-organic solvent system

The absorption spectra of isoquinoline-iodine or 2,4-lutidine-iodine solutions in organic solventsn-hexane,n-heptane, cyclohexane, carbon tetrachloride, benzene, toluene, chlorobenzene, ando-dichlorobenzene have been measured and interpreted in terms of the D+I₂=DI₂ equilibrium, where D is isoquinoline or 2,4-lutidine. Values ofK (288–320°K), ΔH^o, and ΔS^o for the reaction were calculated. A correlation between theK values and the solubility parameter of the solvent (Buchowski's relation) has been found.     

The effect of diluents on extraction of uranium(VI) with petroleum-sulfoxides (PSO)

The effect of diluents on the extraction of uranium(VI) with petroleum sulfoxides (PSO) was studied. The decreasing order of extraction ability of PSO is as follows: benzene, toluene, cyclohexane, heptane, kerosene, carbon tetrachloride and chloroform. The effect of temperature on the extraction equilibrium was also investigated and enthalpy of the extraction was obtained. The relationship between the extraction equilibrium constantsK _ex and the physical parameters of diluents can be derived.     

Thermochemical investigations of nearly idial binary solvents. 6. Solubilities of iodine and benzil in systems of nonspecific interactions

Solubilities have been determined at 25°C for iodine in binary mixtures of carbon tetrachloride with cyclohexane, n-hexane, n-heptane, and octamethylcyclotetrasiloxane (OMCTS) and in mixtures of cyclohexane with n-hexane and OMCTS; and for benzil in binary mixtures of carbon tetrachloride with cyclohexane, n-hexane, and n-heptane, mixtures of n-hexane with cyclohexane and n-heptane, and mixtures of benzene with cyclohexane and toluene. With the exception of the benzene+cyclohexane system, the nearly ideal binary solvent model predicts these solubilities with a maximum deviation of 6% and an overall standard deviation of 2.4%. The model correctly predicts minima for solubility (mole fraction) of iodine in the OMCTS systems, and predicts solubilities within 4% for benzil in the carbon tetrachloride+n-hexane system, in which the solubility changes by a factor of 14. The failure of the model for predicting solubilities of benzil in mixtures of benzene and cyclohexane (maximum error of 25% for and 18-fold range of solubilities) is possibly due to specific interactions between benzil and benzene.     

挥发性有机物的气相光解及光催化降解研究

研究了三氯乙烯、丙酮、苯、甲苯、二氯甲烷、三氯甲烷、四氯化碳的气相光解及光催化反应,对反应过程中反应物及CO2的浓度进行了定量监测。结果表明,在253.7nm的紫外灯光照射下,三氯乙烯可迅速被光解,反应产生CO2;甲苯和丙酮蒸气也可以被光解,但不产生CO2;在空气介质中,除CCl4外,其它几种有机物均可被光催化降解。     

Polymerization of 4-phenyl-1-butyne catalyzed by metathesis and Ziegler–Natta catalysts

The polymerization of 4-phenyl-1-butyne was carried out using metathesis and Ziegler-Natta catalysts. Especially, the Fe(acac)₃-AlEt₃ catalyst with toluene as a solvent produced an extremely high molecular weight polymer of M_w ≈ 10⁶. Solubility of the polymers at room temperature in organic solvents such as benzene, toluene, dichloromethane, chloroform, and THF was excellent despite their high molecular weights. It has been indicated that the polymer prepared by the Fe(acac)₃-AlEt₃ catalyst is of cis form with a high stereoregularity. © 1993 John Wiley & Sons, Inc.     

反气相色谱法测定离子液体1-己基-3-甲基咪唑三氟甲磺酸盐的热力学参数

采用反气相色谱法研究了343.15~373.15 K温度范围内离子液体1-己基-3-甲基咪唑三氟甲磺酸盐([HMIM]OTF)的热力学参数。根据18种探针溶剂的保留时间计算出探针溶剂与[HMIM]OTF之间的摩尔吸附焓、无限稀释的摩尔混合焓、摩尔蒸发焓、质量部分活度系数、Flory-Huggins相互作用参数及[HMIM]OTF的溶解度参数。结果表明,所选溶剂中正构烷烃、四氢呋喃、乙醚、环己烷和苯为[HMIM]OTF的不良溶剂;二氯甲烷、丙酮、氯仿、乙酸乙酯、四氯化碳、乙酸甲酯、甲苯和甲醇为[HMIM]OTF的良溶剂;运用外推法得到了室温(298.15 K)时[HMIM]OTF的溶解度参数为20.74 (J/cm³)^0.5。本研究为离子液体的应用及相关工作提供了参考。     

Oxidation of polystyrene in solution

Polystyrene (PS) has been oxidized in carbon tetrachloride, chloroform, methylene chloride and cyclohexane under O₂ at atmospheric pressure using γ-initiation. Benzaldehyde, acetophenone and reductions in molecular weight were observed in all solvents. Yields of benzaldehyde and acetophenone were used to show that attack in chlorinated solvents is essentially random along the polymer chains and is predominantly by Cl^? radicals. Intramolecular propagation is much faster for attack on tertiary carbons than on secondary carbons. There are more neighboring hydroperoxide groups in PS oxidized in carbon tetrachloride and methylene chloride than in PS oxidized in chloroform, because, in chloroform, the solvent hydrogen is abstracted by polymer-based peroxyl radicals. For one set of conditions, about six intramolecular propagation steps took place in carbon tetrachloride and one in chloroform. At lower rates of initiation, the kinetic oxidation chains are longer and more intramolecular propagation occurs. HCl added in excess of that formed in these experiments decomposes hydroperoxide groups to give an autoaccelerating effect.Rates of scission were proportional to $\text{G}{}_{\mathrm{Cl?}}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, where G_Cl? is proportional to the rate of production of Cl? radicals. The alkoxyl radicals on polystyrene, produced in bimolecular interactions of peroxyl radicals, did not abstract hydrogen from the solvents, and thus appear to be very short-lived.The amount of oxidation of polystyrene in cyclohexane is much smaller than in chlorinated solvents. The analytical techniques used were too imprecise to allow meaningful comparison with the oxidations in chlorinated solvents.     

Relation between preferential solvation and intrinsic viscosity of polymers in solvent mixtures

Preferential solvation and intrinsic viscosity measurements are reported for three systems: polystyrene + benzene + methanol, polystyrene + carbon tetrachloride + methanol, and poly(2-vinylpyridine) + ethanol + cyclohexane. Plots of the coefficient of preferential solvation λ′ as a function of variation of the segment density Δ_ρ for a given ternary system, give a single curve for a large range of molecular weight and solvent mixture composition. This correlation between λ′ and Δ_ρ is verified in previously published data.     

The absorption of organic liquids in poly(aryl-ether-ether-ketone) [PEEK]

The absorption and subsequent desorption of benzene, toluene, carbon disulfide, and chloroform in amorphous and 27% crystalline poly (aryl-ether-ether-ketone) (PEEK) were determined. At 35°C, the equilibrium weight gain (solubility) of benzene, toluene, chloroform, and CS₂ are 23.5, 19.8, 51.2, and 21.2 wt%, respectively. The initial weight gain is linear with root-time and pseudodiffusion constants for absorption into amorphous PEEK ranging from 0.35 to 9.85 x 10^-12m²/s were calculated. The desorption processes are two-step and are controlled by the T_g of the penetrant-resin mixture. The rate of diffussion into the crystalline material is extremely slow; crystalline PEEK reaches saturation (12.5 wt%) after immersion in CS₂ (35°C) for several hundred hours but, even after 1300 h immersion, the other fluids do not reach saturation.     

Determination of dipole moment in the ground and excited state by experimental and theoretical methods of N-nonyl acridine orange

The absorption and fluorescence spectra of N-nonyl acridine orange are determined at room temperature (298 K) in cyclohexane, benzene, carbon tetrachloride, chloroform, chlorobenzene and dichloromethane. The ground state of dipole moment was obtained by impedance measurements using Guggenheim-Debeye's method. The experimental excited state dipole moment of N-nonyl acridine orange was determined using Bakhshiev's and Kawski-Chamma-Viallet's formulae and solvent polarity parameter proposed by Reichardt. These experimental results were completed with theoretical results using quantum chemical methods. The experimental (muexp=10.76 D) and theoretical (mucal=9.9 D) dipole moments in the ground and excited state (muexp*=14.56 D) were compared.     

Mutual solubilities of selected solvents and 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate

1-(2-Hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([HYDEMIM][BF₄]) ionic liquid was characterised by infrared spectroscopy, nuclear magnetic resonance, ultraviolet-visible spectra and thermogravimetric analysis. Mutual mass fraction solubilities of the 12 selected solvents (ethanol, 1-propanol, 1-butanol, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, dichloromethane, chloroform and carbon tetrachloride) and [HYDEMIM][BF₄] in the temperature range from 283.16 to 353.61?K were measured using a cloud-point method. Measured solubility value S was correlated as a function of temperature by a second-order polynomial.     

二-(2-乙基己基)磷酸在不同稀释剂中对钙、钴(Ⅱ)的萃取

本文测定了25±1℃时二-(2-乙基己基)磷酸在不同稀释剂中从硫酸盐水溶液里对钙、钴(Ⅱ)的萃取,计算得到了萃取络合物中结合的自由萃取剂分子数和萃取平衡的表观常数,并讨论了溶剂对萃取的影响。