This paper presents the vapor–liquid equilibrium(VLE) data of acetonitrile–water system containing ionic liquids(ILs) at atmospheric pressure(101.3 k Pa). Since ionic liquids dissociate into anions and cations, the ...This paper presents the vapor–liquid equilibrium(VLE) data of acetonitrile–water system containing ionic liquids(ILs) at atmospheric pressure(101.3 k Pa). Since ionic liquids dissociate into anions and cations, the VLE data for the acetonitrile + water + ILs systems are correlated by salt effect models, Furter model and improved Furter model. The overall average relative deviation of Furter model and improved Furter model is 5.43% and 4.68%, respectively. Thus the salt effect models are applicable for the correlation of IL containing systems. The salting-out effect theory can be used to explain the change of relative volatility of acetonitrile–water system.展开更多
TiClx （x=2.17） was prepared by using titanium sponge to reduce the concentration of TiCl4 in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiClx melt was employed as the electrolyte, and two para...TiClx （x=2.17） was prepared by using titanium sponge to reduce the concentration of TiCl4 in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiClx melt was employed as the electrolyte, and two parallel crude titanium plates and one high-purity titanium plate were used as the anode and cathode, respectively. A series of electrochemical tests were performed to investigate the influence of electrolytic parameters on the current efficiency and quality of cathodic products. The results indicated that the quality of cathodic products was related to the current efficiency, which is significantly dependent on the current density and the initial concentration of titanium ions. The significance of this study is the attainment of high-purity titanium with a low oxygen content of 30× 10^-6.展开更多
In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concent...In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concentration of BF_3 is less than 0.1 mol/L.Two ionic equilibrium models were proposed to simulate the hydrolysis equilibrium of BF_3 and tested by special acid-base titration technique.The most accurate ion equilibrium constants were determined.The model,which was assumed to have no HF,was proved to be more representative for the real system and used to simulate the hydrolysis equilibrium of BF_3.The simulation suggested that H^+,BF_4^-,BF_3OH^- and H_3BO_3 were the main species in the dilute hydrolysis solution,while BF_2(OH)_2^- and F^- were insignificant species whose concentrations were both in the order of 10^(-4) mol/L magnitude,and BF(OH)_3^- could be omitted because its concentration almost equaled zero.Meanwhile,the equilibrium constant of the overall ionic reaction at 25℃ was obtained as 161.6.展开更多
L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purificati...L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography. In this work, the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimentally and theoretically. A modified Donnan ion-exchange （DIX） model, which takes the activiW into account, was established to predict the uptake of L-phenylalanine at various solution pH values. The model parameters including selectivity and mean activity coefficient in the resin phase are presented. The modified DIX model is in good agreement with the experimental data. The optimum operating pH value of 2.0, with the highest t-phenylalanine uptake on the resin, is predicted by the model. This basic information combined with the general mass transfer model will lay the foundation for the prediction of dynamic behavior of fixed bed separation process.展开更多
Both ionic solutions under an external applied static electric field E and glassy-forming liquids under undercooled state are in non-equilibrium state.In this work,molecular dynamics(MD)simulations with three aqueous ...Both ionic solutions under an external applied static electric field E and glassy-forming liquids under undercooled state are in non-equilibrium state.In this work,molecular dynamics(MD)simulations with three aqueous alkali ion chloride(NaCl,KCl,and RbCl)ionic solutions are performed to exploit whether the glass-forming liquid analogous fractional variant of the Stokes–Einstein relation also exists in ionic solutions under E.Our results indicate that the diffusion constant decouples from the structural relaxation time under E,and a fractional variant of the Stokes–Einstein relation is observed as well as a crossover analogous to the glass-forming liquids under cooling.The fractional variant of the Stokes–Einstein relation is attributed to the E introduced deviations from Gaussian and the nonlinear effect.展开更多
文中采用平衡釜法测定在常压下温度为303.15 K时{[BMIM][TFA](一丁基三甲基咪唑三氟乙酸盐)、[BMIM][DCA](一丁基三甲基咪唑双氰胺盐)和[BMIM][SCN](一丁基三甲基咪唑硫氰酸盐)}+乙醇+庚烷三元体系的液液相平衡数据,使用Bachman方程和Ot...文中采用平衡釜法测定在常压下温度为303.15 K时{[BMIM][TFA](一丁基三甲基咪唑三氟乙酸盐)、[BMIM][DCA](一丁基三甲基咪唑双氰胺盐)和[BMIM][SCN](一丁基三甲基咪唑硫氰酸盐)}+乙醇+庚烷三元体系的液液相平衡数据,使用Bachman方程和Othmer-Tobias方程对实验数据的热力学一致性进行检验,其线性相关系数均大于0.99。通过实验数据计算的分配系数和选择性比较了3种离子液体的分离性能,利用Aspen Plus v11模拟软件对实验数据回归得到二元相互作用参数,对比实验值得到的E_(RMSD)均小于4%。综上所述,使用离子液体萃取分离乙醇-庚烷体系是可行的,其中双氰胺根离子液体具有更好的探究价值。展开更多
基金Supported by the National Natural Science Foundation of China(21306036)the Youth Scholars of Educational Commission of Hebei Province of China(Y2012040)the Joint Specialized Research Fund for the Doctoral Program of Higher Education(20131317120014)
文摘This paper presents the vapor–liquid equilibrium(VLE) data of acetonitrile–water system containing ionic liquids(ILs) at atmospheric pressure(101.3 k Pa). Since ionic liquids dissociate into anions and cations, the VLE data for the acetonitrile + water + ILs systems are correlated by salt effect models, Furter model and improved Furter model. The overall average relative deviation of Furter model and improved Furter model is 5.43% and 4.68%, respectively. Thus the salt effect models are applicable for the correlation of IL containing systems. The salting-out effect theory can be used to explain the change of relative volatility of acetonitrile–water system.
基金the National Science Foundation of China(Nos.50934001 and 51322402)the National High-Tech Research and Development Program of China (No.2012AA062302)+2 种基金the Program of the Co-construction with Beijing Municipal Commission of Education of China (Nos.00012047 and 00012085)the Program for New Century Excellent Talents in Universities(NCET-11-0577)the Fundamental Research Funds for the Central Universities(No.FRF-AS-11-003A)
文摘TiClx （x=2.17） was prepared by using titanium sponge to reduce the concentration of TiCl4 in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiClx melt was employed as the electrolyte, and two parallel crude titanium plates and one high-purity titanium plate were used as the anode and cathode, respectively. A series of electrochemical tests were performed to investigate the influence of electrolytic parameters on the current efficiency and quality of cathodic products. The results indicated that the quality of cathodic products was related to the current efficiency, which is significantly dependent on the current density and the initial concentration of titanium ions. The significance of this study is the attainment of high-purity titanium with a low oxygen content of 30× 10^-6.
文摘通过COSMO-RS模型筛选出1-乙基-3-甲基咪唑三氟乙酸盐([EMIM][TFA])、1-乙基-3-甲基咪唑二氰胺盐([EMIM][DCA])、1-乙基-3-甲基咪唑磷酸二乙酯([EMIM][DEP])三种离子液体作为萃取剂分离正己烷-异丙醇体系。在303.15 K、101.3 kPa下,测定正己烷+异丙醇+[EMIM][DCA]/[EMIM][TFA]/[EMIM][DEP]的三元液液相平衡实验数据,通过计算得出选择性与分配系数,分析离子液体各自的分离性能。通过Othmer-Tobias,Bachman,Hand方程对实验数据进行一致性检验。采用Aspen Plus v11流程模拟软件中NRTL模型进行数据关联拟合,获得均方根偏差(RMSD)和二元交互作用参数。模拟结果表明,选择性与分配系数均大于1,说明三种离子液体均可作为萃取剂;方程的回归系数均大于0.95,说明实验数据可靠;得到RMSD均小于3%,说明模拟计算数据能较好地关联实验数据。
基金Supported by the Independent Innovation Fund of Tianjin University(No.1307)
文摘In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concentration of BF_3 is less than 0.1 mol/L.Two ionic equilibrium models were proposed to simulate the hydrolysis equilibrium of BF_3 and tested by special acid-base titration technique.The most accurate ion equilibrium constants were determined.The model,which was assumed to have no HF,was proved to be more representative for the real system and used to simulate the hydrolysis equilibrium of BF_3.The simulation suggested that H^+,BF_4^-,BF_3OH^- and H_3BO_3 were the main species in the dilute hydrolysis solution,while BF_2(OH)_2^- and F^- were insignificant species whose concentrations were both in the order of 10^(-4) mol/L magnitude,and BF(OH)_3^- could be omitted because its concentration almost equaled zero.Meanwhile,the equilibrium constant of the overall ionic reaction at 25℃ was obtained as 161.6.
基金Supported by the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1066)National Natural Science Foundation of China(No.21306086)Applied Basic Research Programs of Science and Technology Commission Foundation of Jiangsu Province(No.BK20151452)
文摘L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography. In this work, the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimentally and theoretically. A modified Donnan ion-exchange （DIX） model, which takes the activiW into account, was established to predict the uptake of L-phenylalanine at various solution pH values. The model parameters including selectivity and mean activity coefficient in the resin phase are presented. The modified DIX model is in good agreement with the experimental data. The optimum operating pH value of 2.0, with the highest t-phenylalanine uptake on the resin, is predicted by the model. This basic information combined with the general mass transfer model will lay the foundation for the prediction of dynamic behavior of fixed bed separation process.
基金Project supported by the Science Foundation of Civil Aviation Flight University of China(Grant Nos.J2019-059 and JG2019-19)。
文摘Both ionic solutions under an external applied static electric field E and glassy-forming liquids under undercooled state are in non-equilibrium state.In this work,molecular dynamics(MD)simulations with three aqueous alkali ion chloride(NaCl,KCl,and RbCl)ionic solutions are performed to exploit whether the glass-forming liquid analogous fractional variant of the Stokes–Einstein relation also exists in ionic solutions under E.Our results indicate that the diffusion constant decouples from the structural relaxation time under E,and a fractional variant of the Stokes–Einstein relation is observed as well as a crossover analogous to the glass-forming liquids under cooling.The fractional variant of the Stokes–Einstein relation is attributed to the E introduced deviations from Gaussian and the nonlinear effect.
文摘文中采用平衡釜法测定在常压下温度为303.15 K时{[BMIM][TFA](一丁基三甲基咪唑三氟乙酸盐)、[BMIM][DCA](一丁基三甲基咪唑双氰胺盐)和[BMIM][SCN](一丁基三甲基咪唑硫氰酸盐)}+乙醇+庚烷三元体系的液液相平衡数据,使用Bachman方程和Othmer-Tobias方程对实验数据的热力学一致性进行检验,其线性相关系数均大于0.99。通过实验数据计算的分配系数和选择性比较了3种离子液体的分离性能,利用Aspen Plus v11模拟软件对实验数据回归得到二元相互作用参数,对比实验值得到的E_(RMSD)均小于4%。综上所述,使用离子液体萃取分离乙醇-庚烷体系是可行的,其中双氰胺根离子液体具有更好的探究价值。
