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Li X.-M.,Beijing University of Chemical Technology | Shen C.,Liming Research Institute of Chemical Industry | Li C.-X.,Beijing University of Chemical Technology
Journal of Chemical Thermodynamics | Year: 2012

Vapour pressures were measured using a quasi-static ebulliometer for the pseudo-binary mixtures of (water + ethanol), (water + methanol), and (methanol + ethanol) containing an alkanolammonium-based ionic liquid (IL), namely, mono-ethanolammonium formate ([HMEA][HCOO]) and di-ethanolammonium formate ([HDEA][HCOO]), respectively, with fixed IL mass fraction of 0.30 and over the temperature ranges of (292.12 to 371.13) K. The vapour pressures of the IL-containing ternary systems were favourably correlated using the NRTL model with an overall average absolute relative deviation (AARD) of 0.0082. Further, the salt effects of [HMEA][HCOO] and [HDEA][HCOO] on isobaric vapour liquid equilibria (VLE) of azeotrope and close boiling mixture, especially for the mixtures of (water + ethanol) and (methanol + ethanol), were investigated and compared with other ILs in terms of the x′-y phase diagrams predicted with the binary NRTL parameters. It is demonstrated that the relative volatilities of ethanol to water and ethanol to methanol are enhanced, and [HMEA][HCOO] might be used as a promising entrainer for the efficient separation of ethanol aqueous solution by special rectification. © 2012 Elsevier Ltd. All rights reserved. Source


Sakal S.A.,Beijing University of Chemical Technology | Shen C.,Beijing University of Chemical Technology | Shen C.,Liming Research Institute of Chemical Industry | Li C.-X.,Beijing University of Chemical Technology
Journal of Chemical Thermodynamics | Year: 2012

(Liquid + liquid) equilibrium data of the following ternary and quaternary systems at different temperatures and mass fractions of ionic liquids (ILs) were measured at atmospheric pressure, i.e., {cyclohexane + benzene + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])} at 298.2 K, {cyclohexane + benzene + 1-methylimidazolium tetrafluoroborate ([MIM][BF 4])} at 338.2 K, {cyclohexane + benzene + [MIM][BF 4] + [MMIM][DMP]} at (298.2 and 313.2) K, and {cyclohexane + benzene + 1-methylimidazolium perchlorate [MIM][ClO 4] + [MMIM][DMP]} at 298.2 K. The results indicate that both selectivity and distribution factor of the IL mixture for benzene are lower than that of pure IL [MMIM][DMP] at a specified condition, and decrease with the increase of the mass fraction of [MIM][BF 4] or [MIM][ClO 4] in its mixture of [MMIM][DMP] and the mole fraction of benzene. The extremely high selectivity of [MIM][BF 4] and [MIM][ClO 4] for aromatic compounds as predicted by the COSMOS-RS model is not justified by the present experimental results, and on the contrary, they show a relatively lower selectivity and extraction capacity for benzene than [MMIM][DMP]. © 2012 Elsevier Ltd. All rights reserved. Source


Gong Y.-H.,Beijing University of Chemical Technology | Shen C.,Beijing University of Chemical Technology | Shen C.,Liming Research Institute of Chemical Industry | Lu Y.-Z.,Beijing University of Chemical Technology | And 2 more authors.
Journal of Chemical and Engineering Data | Year: 2012

The experimental data of viscosity and density for six binary mixtures of water (methanol or ethanol) with an ionic liquid, 1-butyl-3-methylimidazolium dimethylphosphate ([BMIM][DMP]) or 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]), were measured in the temperature range of (293.15 to 333.15) K at atmospheric pressure using a viscometer and densimeter. The solution behavior of the mixtures is discussed in terms of the variation of the excess viscosity and excess volume with temperatures and compositions. It is found that both excess volume and viscosity of the mixtures studied show a negative deviation from the ideal solution behavior, and the viscosity of the mixtures decreases drastically with the increase of temperatures and mole fractions of solvents. The excess volume of the binary mixtures is quite low, in the range of (1.0 to 1.9) cm 3·mol -1; moreover, it shows a monotonic decrease with increasing temperature for the aqueous solution of ILs and a reverse trend for the IL solutions of methanol or ethanol at any concentrations. © 2011 American Chemical Society. Source


Liu J.,Henan University of Science and Technology | Fu M.,Liming Research Institute of Chemical Industry | Jing M.,Henan University of Science and Technology | Li Q.,Henan University of Science and Technology
Polymers for Advanced Technologies | Year: 2013

The fire performance of polystyrene-organic montmorillonite (OMMT) nanocomposite was investigated by limiting oxygen index (LOI) and cone calorimetry. Scanning electron microscopy, electron dispersive spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy were employed to study the charring process of the nanocomposite. The residue collected upon thermal degradation was analyzed by various means to determine its composition and to understand the flame-retardant mechanism of the nanocomposite. It has been shown that the introduction of OMMT does not have much influence on LOI of the nanocomposite, but can greatly decrease the heat release rate (HRR) and mass loss rate (MLR) and enhance the flame retardancy of the material. The flame-retardant mechanism is due to charring in the condensed phase. The intercalated nanostructure is destroyed, and the silicate nanolayers in the nanocomposite rearrange and accumulate on the material surface during pyrolysis. The charred residue has a honeycomb-like porous structure, which covers on the material surface and serves as a protection barrier against heat transfer and mass exchange, leading to enhanced flame retardancy. The charred residue is composed of pyrolyzed silicate layers and graphitic char. The char is highly stable in nitrogen even at 800°C, but thermo-oxidative decomposition is allowed, and it can be removed completely in the presence of air. Due to the porous structure of the charred residue, the protection from it is mainly to reduce the HRR and MLR and retard burning of the material. It is not enough to make the nanocomposite self-extinguish. © 2012 John Wiley & Sons, Ltd. Source


Zhu L.,CAS Changchun Institute of Applied Chemistry | Zhu L.,Liming Research Institute of Chemical Industry | Deng Y.,CAS Changchun Institute of Applied Chemistry | Zhang J.,CAS Changchun Institute of Applied Chemistry | Chen J.,CAS Changchun Institute of Applied Chemistry
Journal of Colloid and Interface Science | Year: 2011

N-butylimidazolium functionalized strongly basic anion exchange resin with Cl - anion (MCl) was prepared by anchoring N-butylimidazole onto chloromethylated macroporous styrene-divinylbenzene (St-DVB) copolymer. The adsorption performances of phenol on MCl were studied using the batch technique at acidic and alkaline pH. The studies showed that phenol can be effectively removed at both acidic and alkaline pH. The maximum adsorption was achieved at about pH 11. The maximum adsorption capacities of phenol on MCl at pH 6.6 and 11.2 were 80.2 and 92.9mg/g, respectively. The adsorption mechanism was mainly molecular adsorption at acidic pH and anion exchange at alkaline pH. The adsorption of phenol was hindered by the presence of Cl - and SO42- at alkaline pH due to the competitive anion exchange reaction. The adsorption of molecular phenol species on MCl at acidic pH was exothermic, and the anion exchange of phenolate species by MCl at alkaline pH was endothermic. Desorption of phenol from loaded adsorbent was achieved by using 0.5mol/L NaOH and 0.5mol/L NaCl mixed solution. MCl can simultaneously remove phenol and Cr(VI) from their mixtures, which would be of practical value in actual industrial wastewater treatment. © 2011 Elsevier Inc. Source

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