超临界流体化学热力学

本文简要介绍了超临界流体的基本概念和性质，评述了化学热力学在超临界萃取、超临界态化学反应、超临界流体制备材料等方面的作用和研究进展，讨论了二氧化碳-离子液体两相体系的热力学行为。     

超临界二氧化碳介质中过渡金融催化反应研究进展

超临界介质中的化学反应研究是目前热点研究领域之一，对超临界CO2介质中 过渡金属催化反应研究进行了总结和述评，同时讨论了有关提高过渡金属催化剂在 超临界CO2中溶液度的方法。     

超临界流体技术制备超细粒子

超临界流体用于制备超细粒子是一项新技术，本文综述了两种形成微粒的方法；超临界快速膨胀法和超临界反溶剂法，并着重介绍了其在研究和应用方面的进展。     

超临界流体的共溶剂效应和混合流体研究进展

共溶剂的出现极大地拓展了超临界流体的应用范围，推动了超临界流体科学与技术的发展。本文从相行为和分子间相互作用热力学的角度，对相行为测定、量热技术、光谱技术和分子模拟等在超临界流体中共溶剂效应的研究作了综述，主要介绍超临界流体中共溶剂的作用机理和混合流体在临界点附近热力学性质研究，并对其未来发展方向进行了展望。     

超临界水的性质及其在化学反应中的应用

介绍了水的热物理性质、结构性质、离子积、扩散系数和粘度等在超临界区域的特殊性，以及超临界水溶液在介电常数、偏摩尔体积、溶解性和极性等方面的特殊性质，并阐述了超临界水的这种特殊性在化学反应和环境治理中的应用。     

超临界二氧化碳-高分子化学中的绿色介质

介绍了超临界二氧化碳的特点，综述了近期以超临界二氧化碳为溶剂的高分子聚合和高分子化学反应及其应用前景。指出超临界CO2在聚合反应中能作为传统有机溶剂的替代溶剂。     

超临界化学反应的研究进展

超临界流体具有许多独特的性质使其成为有吸引力的化学反应介质，本文综述了近年来超临界流体对化学反应影响的基础理论研究以及超临界化学反应在应用方面的研究进展。     

超临界流体色谱仪在天然产物研究中的应用

超临界流体可以用做色谱的流动相，使混合物质在色谱柱上得到分离，这种分离方法被称为超临界流体色谱(Supercdtical Fluid Chromatography,简称SFC)。作为色谱流动相的超临界流体，其作用与超临界流体萃取(Supercritical Fluid Extraction，简称SFE)类似。超临界流体对物质的溶解能力远比一般气体大的多，     

超临界萃取装置的研制及其应用

超临界流体萃取是近的上来兴起的一种新的分离技术，报道了将超临界萃取原理与回流技术相结合研制的二氧化碳回流中低压超临界流体萃取设备，解决了关键实验手段，通过应用证明设备可靠，费用低廉，有实用价值。     

超临界流体在有机合成中的应用

超临界化学反应是一种新型的反应体系，本文对超临界流体在有机合成反应中应用的最新进展进行了综述。     

Thermodynamic and acoustic properties of (heptane + dodecane) mixtures under elevated pressures

The speed of sound in (heptane + dodecane) mixtures was measured over the whole concentration range at pressures up to 101 MPa and within the temperature range from (293 to 318) K. The density of (heptane + dodecane) was measured in the whole composition range under atmospheric pressure and at temperatures from (293 to 318) K. The densities and heat capacities of these binaries at the same temperatures were calculated for pressures up to 100 MPa from the speeds of sound under elevated pressures together with the densities and heat capacities at atmospheric pressure. The effects of pressure and temperature on the excess molar volume and the excess molar heat capacity are discussed.     

Solubility and density measurements of palmitic acid in supercritical carbon dioxide + alcohol mixtures

Solubility data of palmitic acid (hexadecanoic acid) in supercritical carbon dioxide were measured in the pressure range from 10 to 25 MPa at temperatures of 313 and 318 K. Densities for this binary mixture in the homogeneous phase and at saturation conditions were measured in the same range of temperature. The influence of 3 and 6 mol% ethanol and 2-propanol as co-solvent on the solubility and density data for the CO₂ + palmitic acid mixture was also determined at 313 K. Measurements were carried out in a static-synthetic sapphire cell coupled to a vibrating-tube densitometer. The self-consistency of the data was tested according to the density-based models proposed by Mendez-Santiago and Teja.     

The Effect of Pressure on the Thermodynamic Properties of Propan-1-ol + n-Heptane Mixtures

The densities of propan-1-ol + n-heptane have been measured over the whole composition range at atmospheric pressure and at temperatures from 293 to 318 K using a vibrating tube densimeter. The densities and heat capacities for propan-1-ol + n-heptane mixtures at pressures up to 120 MPa and for temperatures ranging from 293 to 318 K were calculated using the speeds of sound measured under elevated pressures, together with the densities and heat capacities at atmospheric pressure. A modified method, based on the suggestion of Davis and Gordon J. Chem. Phys. 46 (1967), has been applied. The effect of pressure and temperature on the isentropic compressibility, the excess volume, and the excess heat capacity are discussed.     

Surface tension and its temperature coefficient of molten tin determined with the sessile drop method at different oxygen partial pressures

The surface tension of molten tin has been determined by the sessile drop method at temperatures ranging from 523 to 1033 K and in the oxygen partial pressure (P(O(2))) range from 2.85 x 10(-19) to 8.56 x 10(-6) MPa, and its dependence on temperature and oxygen partial pressure has been analyzed. At P(O(2))=2.85 x 10(-19) and 1.06 x 10(-15) MPa, the surface tension decreases linearly with the increase of temperature and its temperature coefficients are -0.151 and -0.094 mN m(-1) K(-1), respectively. However, at high P(O(2)) (3.17 x 10(-10), 8.56 x 10(-6) MPa), the surface tension increases with the temperature near the melting point (505 K) and decreases above 723 K. The surface tension decrease with increasing P(O(2)) is much larger near the melting point than at temperatures above 823 K. The contact angle between the molten tin and the alumina substrate is 158-173 degrees, and the wettability is poor.     

Solubility of tetrafluoromethane in the ionic liquid [hmim][Tf2N

Experimental results for the solubility of tetrafluoromethane (CF4, R14) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]) are presented for temperatures between 293.3 and 413.3 K, at pressures (gas molalities) up to 9.6 MPa (0.22 mol kg-1). The experimental results were determined with a high-pressure view-cell technique operating on the synthetic method. The experimental data were used to determine Henry's constant of tetrafluoromethane in [hmim][Tf2N]. The results for the Henry's constant (at zero pressure) are correlated (on the molality scale) within the experimental uncertainty (i.e., about 1.1%) by ln(k(0)(H,CF4)/MPa) = 7.537 - 893.8/(T/K) - 0.003977(T/K). Henry's law was also extended to describe the gas solubility at higher pressures. Furthermore, a cubic equation of state was used to correlate the gas solubility over the entire range of experimentally investigated temperature and pressure. Both methods proved suited for a reliable correlation of the new experimental data.     

Solubility of titanocene dichloride in supercritical propane

The solubilities of titanocene dichloride in supercritical propane had been investigated under the pressure range from 10 to 35 MPa using a flow phase equilibrium apparatus at temperatures of 383.15, 388.15, 393.15, 398.15, 403.15, and 408.15 K, respectively. The measured solubilities exhibited a clear dependence on temperature and pressure and could be correlated with the Peng–Robinson equation of state in the fugacity coefficient expression with fairly good accuracy.     

The effect of temperature and pressure on acoustic and thermodynamic properties of 1,4-butanediol. The comparison with 1,2-, and 1,3-butanediols

The speeds of sound in 1,4-butanediol have been measured in the temperature range from (298 to 318) K at pressures up to 101 MPa by the pulse-echo-overlap method. The densities have been measured in the temperature range from (293.15 to 353.15) K under atmospheric pressure with a vibrating tube densimeter. Based on the experimental results, the densities, isobaric heat capacities, isobaric coefficients of thermal expansion, isentropic and isothermal compressibilities, as well as the internal pressure as function of temperature and pressure have been calculated. The effects of pressure and temperature are discussed and compared with the previous results for 1,2- and 1,3-butanediols.     

Pressure-tuning of magnetism and linkage isomerism in iron(II) hexacyanochromate

A pressure-induced linkage isomerization of the cyanide anion has been observed in single crystals of a chromium(III)-iron(II) Prussian blue analogue of formula K0.4Fe4[Cr(CN)6]2.8 square1.2.16H2O (1). Upon application of pressure in the 0-1200 MPa range, the cyanide ligand rotates and becomes C-bonded to the iron(II) cations, leading to a stabilization of their diamagnetic low-spin states. The result is a decrease of magnetization and magnetic ordering temperatures from TC = 19 K at ambient pressure to 13 K at 1200 MPa. The initial magnetic properties can be restored on pressure release. The reversible movement of cyanide in the solid state can be exploited as a switch of the magnetic interaction at the molecular level.     

Adsorption of hydrogen on nanoporous carbon adsorbents

Four samples of active carbons with specific micropore volumes of 0.4—1.33 cm³g^-1 at 77 K and pressures up to 5 MPa were used to study hydrogen adsorption. The highest amount of of hydrogen adsorbed on these active carbons at the boiling point 20.38 K and pressure 0.101 MPa was calculated by methods derived from the theory of volumetric filling of micropores (TVFM). The adsorbent FAS-1-05 prepared by the liquid-phase polymerization of furfurol was shown to have the highest adsorption capacity. The amounts of hydrogen adsorbed on FAS-1-05 at temperatures 77, 196, and 300 K and pressures 7 and 20 MPa were calculated using the TVFM methods with allowance for linearity of the isosters. The results were compared with the experimental values obtained at 77 K and pressure below 5.1 MPa and at 293 K and pressures up to 16.1 MPa. The highest amounts of hydrogen adsorbed (6.2 wt.% for the adsorbent FAS-1-05) were obtained under pressures below 5.1 MPa and at 77 K.     

Deformation of AUK microporous carbon adsorbent induced by methane adsorption

The dependence of the relative linear deformation of AUK microporous carbon adsorbent on pressure is studied upon the adsorption of methane in the pressure range of 1 Pa to 6 MPa at 177.65, 216.2, 243.3, 273.15, 313, 333, and 393 K. It is found that the curves of adsorption-induced deformation show similar behavior; except for in the initial pressure range (p < 0.2 MPa), the adsorption-induced deformation increases with pressure and drops as the temperature rises. At low temperatures, a shrinkage region is observed in the initial part of the deformation curves that narrows with a rise in temperature. At temperatures above 350 K, the initial shrinkage is absent and the adsorbent expands with an increase in methane pressure. In the pressure and temperature ranges under investigation, the contribution of deformation to the differential isosteric heat of adsorption of AUK carbon adsorbent does not exceed 2%. It is shown that, upon the adsorption of CO₂, N₂, Ar, and CH₄ at 273 K and pressures below 6 MPa, the maximum deformation of AUK adsorbent varies cymbately with variations in the Lennard-Jones (6–12) potential constants for the pair interaction of gas molecules.