CO2在醚酯溶剂中的溶解度测定及热力学计算

采用恒定容积法,在温度353.15、363.15、373.15 K下,测定了CO₂在丙二醇甲醚醋酸酯(PMA)、二丙二醇甲醚醋酸酯(DPMA)、乙二醇丁醚醋酸酯(BAC)以及乙二醇苯醚醋酸酯(EPA)中的溶解度数据,压力最高可达11.73 MPa。结果表明CO₂在醚酯体系中溶解度受温度、压强的影响较大,压强一定时,CO₂在醚酯中溶解度随温度升高而减小;温度一定时,随着压强增大而增大;相同条件下,CO₂在四种醚酯中溶解度大小为PMA＜ EPA＜BAC＜DPMA。通过变形Clausius - Clapeyron方程,计算得到CO₂在醚酯溶剂中的Gibbs自由能Δ_sol G,溶解焓变Δ_sol H和熵变 Δ_sol S等热力学性质,从宏观热运动角度进一步解释了CO₂的溶解机理,为开发新型CO₂物理吸收剂提供理论支撑。     

胆酸在5种溶剂中的溶解度测定及关联

采用重量法测定了胆酸在甲醇、乙醇、乙酸乙酯、冰醋酸和正丙醇中的溶解度数据，并采用Modified Apelblat模型、λh模型、二次多项式模型和三参数van’tHoff模型对溶解度数据进行了拟合。通过修正的van’tHoff方程分析溶解过程的热力学参数(吉布斯自由能变Δ_mixG、焓变Δ_mixH和熵变Δ_mixS)，并计算了焓相对贡献ζH和熵相对贡献ζ_TS。结果表明，二次多项式模型对溶解度的关联效果最好。在研究所采用的溶剂体系中，Δ_mixH>0，Δ_mixS>0，Δ_mixG>0，说明胆酸的溶解是非自发、不可逆的吸热过程。焓的相对贡献ζ_H远大于熵的相对贡献ζ_TS，说明胆酸在所选的溶剂的溶解过程中，溶解焓变Δ_solH对溶解吉布斯能变Δ_solG的贡献大于溶解熵变Δ_solS。这些溶解度和热力学性质可为胆酸结晶工艺提供重要...     

阿奇霉素二水合物在水-有机溶剂中溶解度及三元相图测定

采用静态法测定了293.15～323.15 K范围内，阿奇霉素二水合物在丙酮-水和异丙醇-水混合溶剂中的溶解度，并研究阿奇霉素在293.15、298.15、303.15及308.15 K温度下丙酮-水混合溶剂中转晶水活度，根据溶解度特性绘制丙酮-阿奇霉素-水三元相图，溶解度数据用Apelblat方程、λh方程和van’t Hoff方程进行关联。结果表明，阿奇霉素溶解度随着有机溶剂体积分数和温度的升高而增加，转晶水活度随温度的升高增大，阿奇霉素一水二水共存区域随温度的升高减小，Apelblat方程拟合效果更好，R²≥0.988。     

地高辛在不同溶剂中的溶解度测定及关联

在278. 15～323. 15 K下采用静态平衡法测定了地高辛在乙醇、甲醇、异丙醇、甲醇-水体系(甲醇体积分数为80%)及乙醇-水体系(乙醇体积分数为80%、60%、40%、20%)中的溶解度数据,采用Apelblat方程、多项式经验方程和λh方程对地高辛的溶解度进行关联。实验结果表明,8种溶剂中,地高辛的溶解度均随温度的升高而增加,在80%乙醇水混合溶剂中溶解度最大,在20%乙醇水中溶解度最小,几种热力学模型对地高辛的关联效果也很好。经热力学理论分析,计算溶解焓与溶解熵可知地高辛的溶解过程为吸热过程。地高辛溶解度的测定及关联为其工业化纯化溶剂的选择提供重要理论依据。     

离子液体[Bmim][NTf2]对CO2在碳酸二乙酯中溶解性能的强化

采用恒定容积法在温度范围308.15~328.15 K、压力范围0~3 MPa条件下测定了CO₂在碳酸二乙酯（DEC）、离子液体[Bmim][NTf₂]以及二者不同质量分数配比混合溶剂中的溶解度,并用COSMO-RS模型研究了离子液体的加入对DEC蒸气分压的影响。实验表明,在相同实验条件下CO₂在[Bmim][NTf₂]中的溶解度大于在DEC中的溶解度。[Bmim][NTf₂]的加入可强化CO₂在DEC中的溶解性能,在相同温度下CO₂在混合溶剂中的溶解度随[Bmim][NTf₂]质量分数增加而增大,在相同浓度的混合溶剂中CO₂的溶解度随温度升高而降低。COSMO-RS模型计算表明,DEC的蒸气分压下降的分数随混合溶剂中离子液体质量分数增加而增大,而对于相同质量分数配比的混合溶剂温度对DEC的蒸气分压影响较小。     

普瑞巴林晶型Ⅰ在纯溶剂及丙酮-水混合溶剂中的溶解度测定与关联

通过平衡法测定了283.15~328.15 K温度下普瑞巴林晶型I在水、甲醇、乙醇、丙酮、四氢呋喃、N,N-二甲基甲酰胺、乙酸乙酯及丙酮-水混合溶剂中的溶解度,实验结果表明:普瑞巴林晶型I在所测定的所有纯溶剂及丙酮-水混合溶剂中的溶解度均随温度的升高而增大;在丙酮-水混合溶剂中,溶解度随着丙酮的摩尔分数的增加而降低,在丙酮的摩尔分数达到0.83附近时溶解度最小,接近0。采用修订的Apelblat经验方程和(CNIBS)/Redlich-Kister方程对溶解度数据进行关联,结果令人满意。所得实验数据和拟合模型为普瑞巴林在工业结晶及药物多晶型等方面的研究提供了重要的依据。     

超重力精馏回收果胶沉淀溶剂的应用

同时应用超重力精馏连续与间歇操作分离回收果胶沉淀溶剂中的乙醇,并以不锈钢波纹丝网为填料,在原料乙醇质量分数x_f=55%、回流比R=4、超重力因子β=63.16～252.67、原料流量F=15～50L/h、1.01×10⁵Pa和室温进料下操作,研究了四级超重机在连续精馏过程中的传质性能;并在β=161.71、R=2.5～7及1.01×10⁵Pa操作条件下,考察了间歇精馏过程中不同回流比R对塔顶和塔底乙醇浓度x_d和x_w的影响.结果表明,在连续精馏过程中,理论塔板数N_T随β和F的增大而增加,设备的等板高度HETP为41.12～58.21mm,x_d=93%,x_w=35%;在间歇精馏过程中,x_d随着R的增大先增高后降低,x_w随着R和t的增大而下降,所得产品x_d为92.5%,x_w为1.05%;乙醇分离回收效果良好,回收率为91.28%,单位回收乙醇产品成本为0.644元/L,充分表现出超重力精馏工艺应用于果胶沉淀溶剂的回收再利用的优势.     

雄烯二酮在含大豆油的有机溶剂体系中溶解度的测定与关联

测定了雄烯二酮在不同有机溶剂及含大豆油的有机溶剂体系中的溶解度,旨在为工业生产工艺优化提供基础数据和理论支持。采用平衡法测定了253.15K~313.15K,雄烯二酮在甲醇、乙腈、丙酮、异丙醇、乙酸乙酯和乙醇这六种有机溶剂和分别含有大豆油的这六种有机溶剂体系中的溶解度,结果表明:雄烯二酮在乙腈中的溶解度最大,有机溶剂对雄烯二酮溶解能力的大小依次为:乙腈丙酮乙酸乙酯甲醇乙醇异丙醇。且雄烯二酮在所有溶剂体系中溶解度随着温度的升高而增加。在含大豆油的有机溶剂体系中的溶解度均大于在相应纯溶剂中的溶解度。采用多项式经验方程、半经验关联模型和Apelblat方程模型对实验测定溶解度数据进行关联,相关系数都在98%以上,结果满意。     

甲醇-水溶剂中L-苯丙氨酸结晶热力学

在293.15~322.15 K温度范围内，研究L-苯丙氨酸无水物在甲醇-水混合溶剂中溶解度和超溶解度特性，得到L-苯丙氨酸无水物结晶介稳区，计算了成核级数及成核速率，考察了不同初始温度和降温速率对介稳区宽度的影响，并通过研究L-苯丙氨酸297.15 K和302.15 K的转晶水活度，依据溶解度特性绘制L-苯丙氨酸-甲醇-水在该温度下的三元相图。溶解度数据用Apelblat方程、λh方程关联、van t Hoff方程拟合。结果表明，L-苯丙氨酸无水物溶解度随温度的升高而增大，随甲醇体积分数的增加而减小；L-苯丙氨酸无水物结晶介稳区宽度在相同条件下，随初始温度的升高，降温速率的降低变窄；L-苯丙氨酸转晶水活度随温度的升高而增大。     

喜树碱在二甲亚砜和甲醇(或乙醇)混合溶剂中溶解度的测定和关联

采用重量法测定了喜树碱(camptothecine,CPT)在二甲亚砜(dimethylsulfoxide,DMSO)+甲醇(或乙醇)混合溶剂中的溶解度,温度范围是274.50~326.00 K。在混合溶剂中CPT的溶解度随温度的升高而增大,随混合溶剂中DMSO摩尔分数含量的增大而增大。分别用修正Apelblat方程、λh方程和理想状态方程进行关联,关联效果令人满意,获得了相关模型参数。相对而言,λh方程关联的效果较好。根据溶解度数据和修正的Apelblat方程计算出溶解焓、溶解熵和吉布斯自由能。     

Solubility of CO2 in Methanol, 1-Octyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide, and Their Mixtures

Solubility data of carbon dioxide (CO₂) (1) in methanol (2), 1-octyl-3-methylimidazolium bis(trifluoro- methylsulfonyl)imide ([omim]⁺[Tf₂N]^-) (3), and their mixtures (w₃ 0.2, 0.5, and 0.8) at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO₂ in methanol (w₃=0), [omim]⁺[Tf₂N]^- (w₃=1.0) and their mixtures follows the order of (w₃=0)<(w₃=0.2)< (w₃=0.5)<(w₃=0.8)<(w₃=1.0) at the same temperature and pressure, while the magnitude of Henry's constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS (conductor-like screening for real solvents) calculation. The solubility data of CO₂ in methanol and [omim]⁺[Tf₂N]^- are correlated with the Peng-Robinson equation of state, and the solubility of CO₂ in the mixtures of methanol and [omim]⁺[Tf₂N]^- can be well predicted based on the mole fraction average of methanol and [omim]⁺[Tf₂N]^- over the solubility of CO₂ in pure methanol and [omim]⁺[Tf₂N]^-. The mixtures of methanol and [omim]⁺[Tf2N]^- may be used as physical solvents for capturing CO₂ with high partial pressures since they combine the advantages of organic solvents and ionic liquids.     

Thermodynamic properties of metamizol monohydrate in pure and binary solvents at temperatures from (283.15 to 313.15)K

The thermodynamic properties of metamizol monohydrate in pure solvents (methanol,ethanol,n-propanol and isopropanol) and two binary mixed solvent systems including (methanol + ethanol) and (methanol +isopropanol) were measured from 283.15 K to 313.15 K by gravimetric method under atmospheric pressure thought as 0.1 MPa.The modified Apelblat equation,the CNIBS/R-K equation,the Hybrid model and the NRTL model were used to correlate the solubility of metamizol monohydrate,respectively.The results show that the solubility of metamizol monohydrate in all the tested solvents increases with the rising temperature which means that it has temperature dependence.What's more,the effects of solvent components of the binary solvent mixtures on solubility were discussed,it illustrates that the increasing of the molar fraction of methanol gives the system a greater dissolving power.Furthermore,according to the NRTL model,the enthalpy,the Gibbs energy and the entropy of the mixing process were also obtained and discussed.     

Determination and correlation solubility of 4-nitroimidazole in twelve pure solvents from 278.15 K to 323.15 K

In this paper, the solubility of 4-nitroimidazole in twelve pure solvents (toluene, benzene, 1,4-dioxane, acetonitrile, ethyl acetate, acetone, GBL, ethanol, methanol, n-butanol, DMF and NMP) were determined by using the laser monitoring system from 278.15 K to 323.15 K under 101.1 kPa, which are 0.00018-0.00070, 0.00021-0.00073, 0.00034-0.00092, 0.00038-0.00142, 0.00047-0.00120, 0.00126-0.00303, 0.00225-0.00517, 0.00310-0.00724, 0.00467-0.00982, 0.00453-0.01940, 0.01947-0.04652, and 0.04670-0.07452, respectively. At constant temperature, the mole fraction solubility of 4-nitroimidazole were increased as the following order: toluene < benzene < 1,4-dioxane < (ethyl acetate or acetonitrile) < acetone < GBL < ethanol < (methanol or nbutanol) < DMF < NMP, and the solubility of 4-nitroimidazole in (ethyl acetate, acetonitrile) and (methanol, n-butanol) had an intersection point at 297.55 K and 281.85 K, respectively. The solubility of 4-nitroimidazole could be increased with increasing temperature in twelve pure solvents. The ideal model, modified Apelblat equation, polynomial empirical equation, and λh equation were used to correlate the experimental values. The experimental solubility values were employed to calculate the standard dissolution enthalpy, standard dissolution entropy and Gibbs energy. The dissolution of 4-nitroimidazole could be an endothermic process in twelve pure solvents. The determination and fitting solubility of 4-nitroimidazole have important guiding significance for the purification and crystallization of its preparation process.     

溴化1-乙烯基-3-烷基咪唑离子液体的电化学性能

合成了溴化1-乙烯基-3-烷基咪唑([VAIM]Br)离子液体,采用FTIR、¹H NMR、TG及DSC进行了表征,并系统研究了[VAIM]Br的电化学性能。结果表明:在298.15～323.15 K内,[VAIM]Br的电导率(σ)与温度符合Arrhenius方程,电导活化能随[VAIM]⁺上烷基链的增长而降低。分别以水、甲醇和乙醇为溶剂的[VAIM]Br溶液的电导率均随浓度的增大而显著增大,且σ(水)>σ(甲醇)>σ(乙醇)。通过电导法确定了[VAIM]Br在水、甲醇、乙醇中的临界胶束浓度,分别约为6.8×10^-6、1.5×10^-5、2.0×10^-5 mol·L^-1,表面活性优异。[VAIM]Br的电化学窗口在1.6～2.5 V,其电化学稳定性随[VAIM]⁺上烷基链的增长而逐渐降低。     

Thermodynamic studies of zinc chloride in mixed aqueous solvents from electromotive force measurments I. methanol-water mixtures

From the emf measurements of the cell Pt/Zn(Hg)/ZnCl₂, CH₃OH, H₂O/AgCl/Ag the standard emf of the cell have been determined for mass fractions of methanol of 10, 20, 30, 50 and 70% at 298 K, 303 K, 308 K and 313 K in the molality range for zinc chloride from 0.004 to 0.1 mol kg⁻¹. These data were used in calculations of: (a) the mean activity coefficient of zinc chloride, (b) the primary medium effect, (c) the standard thermodynamic quantities for the cell reaction and the transfer of zinc chloride from water to mixed solvents.     

温度对氨基酸同系物在盐酸二甲双胍水溶液中体积和黏度特性的影响(英文)

Density(ρ)and viscosity(η)are measured for glycine,DL-α-alanine DL-α-valine,and DL-α-leucine in 0.05,0.10,0.15 and 0.20 mol·L-1aqueous metformin hydrochloride at 308.15,313.15 and 318.15 K.The measured values are used to estimate some important parameters,such as partial molal volume Vφ,standard partial molal volume0Vφ,transfer volume 0 ΔVφ,hydration number nH,the second derivative of infinite dilution of partial molal volume with respect to temperature,viz.,2 0 2 Vφ /T,viscosity B-coefficient,variation of B with temperature,viz., dB/dT,free energy of activation per mole of solvent0 * 1 Δμand solute 0* 2 Δμof the amino acids.These parameters are interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.In addition,0Vφ, 0 ΔVφ,viscosity B-coefficient,ΔB and 0* 2 Δμare split into group contributions(3NH COO +-)and CH2 of the amino acids using their linear correlation and their behavior is discussed.     

Determination and Correlation of Solubility of Nonivamide in Different Solvents☆

The solubility of nonivamide in dimethyl sulfoxide, methanol, acetone, ethyl acetate, methyl tert-butyl ether, ace-tonitrile, n-hexane and water over the temperature range of 293.2 K to 323.2 K was mea...     

异烟肼在有机溶剂中溶解度测定及晶习研究

在283.15~323.25 K范围内，利用在线浊度法测定了异烟肼在甲醇、乙醇、正丙醇、异丙醇、正丁醇、异丁醇、丙酮、乙腈、乙酸甲酯与乙酸丁酯中的溶解度。数据表明，异烟肼在不同溶剂中的溶解度均随着温度升高而增加。在同一温度下，异烟肼的溶解度与溶剂关系符合如下顺序：甲醇 > 丙酮 > 乙醇 > 正丙醇 > 异丙醇 > 乙酸甲酯 > 异丁醇 > 正丁醇 > 乙腈 > 乙酸丁酯。采用改进的Apelblat、Wilson与NRTL方程对溶解度数据进行了拟合，结果与实验数据有较高的吻合。基于溶解度数据，对异烟肼溶解焓、溶解熵与溶解吉布斯能进行了计算，发现异烟肼溶解过程是吸热熵增过程。分析了甲醇、乙醇、正丙醇与丙酮对异烟肼冷却结晶过程所获产品晶习的影响，确定乙醇为合适的结晶溶剂。     

改性超细煤粉对甲基橙的吸附行为研究

The adsorption of methyl orange onto ultrafine coal powder (UCP) and modified ultrafine coal powder (MUCP) from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated. The adsorption kinetics of methyl orange by UCP and MUCP can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively. The adsorption isotherms of methyl orange onto MUCP at 303, 313 and 323 K follow the Freundlich and Langmuir isotherm equation. Values of &#61508;G0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ&#8226;mol－1 at 303, 313, and 323 K, respectively. The values of ΔH0 and ΔS0 are -3.74 kJ&#8226;mol－1 and 61.99 J&#8226;mol－1, respectively. The adsorption process is spontaneous and exothermic.