气液色谱法测量醇类在惰性溶剂中的无限稀热力学函数

用气液色谱法测量了在不同温度下C_1～C_4醇类的各种异构物在C_(16)～C_(23)正构烷烃、角鲨烷,和角鲨烯中的无限稀活度系数γ_i,偏摩尔过量焓、偏摩尔过量熵。在各种溶剂中γ_i、均大于1,在同一溶剂中γ_i依下列次序减小: 甲醇>乙醇>正丙醇>正丁醇; 正丙醇>异丙醇; 正丙醇>异丁醇>仲丁醇>叔丁醇同一种醇在角鲨烯中的γ_i较在角鲨烷中为低。异构醇类的低于正构醇类。所测的有随的增加而增加的趋势。     

醇类在惰性溶剂中的缔合溶液热力学

用Kretschmer-Wiebe模型结合Hildebrand-Scatchard公式处理含醇体系的活度系γ_i,得到醇类的自身缔合平衡常数K_A和氢键生成焓h_A。在烷烃溶剂中,K_A与烷烃的碳原子数关系不显著。在同一溶剂中,K_A依下列顺序减小: 甲醇>乙醇>正丙醇>正丁醇; 正丙醇>异丙醇; 正丁醇>异丁醇>仲丁醇>叔丁醇。所测醇类的h_A的平均值为:k_A=-24.3±0.6kJmol~(-1),与醇类的碳原子数及异构关系不显著计算出醇类-角鲨烯体系偏离Hildebrand-Scatchard公式的相互作用常数l_(AB),l_(AB)均为负值,|l_(AB)|依下列顺序减小: 甲醇>乙醇>正丙醇>正丁醇; 正丙醇>异丙醇; 正丁醇>异丁醇>仲丁醇>叔丁醇     

某些单体-单体、单体-二聚体体系的活度系数

用气液色谱法测定了苯在二苯醚、联苄、二苄醚、二苯甲烷、二苯乙炔、二苯甲酮、联苯、二苯胺、α-甲基萘、α-氯萘、α-溴萘、氮萘、α-硝基萘、α-萘胺等十四种溶剂中的无限稀活度系数;用单体-二聚体的溶液模型对以上体系进行活度系数的计算,计算值与实验值接近。 用气液色谱法测定了甲苯、乙苯、邻二甲苯、对二甲苯、间二甲苯等五种溶质在环丁砜、二甲基环丁砜、N-甲基吡咯烷酮,5,N-二甲基吡咯烷酮等四种溶剂中的无限稀活度系数;用单体-单体的溶液模型计算溶剂的“溶解度参数”,计算得各溶剂的“溶解度参数”分别为一常数。     

气液色谱法研究醇类在芳烃中的缔合溶液热力学

用气液色谱法测量了不同温度下C~1-C~4醇类的各异构物在二苯甲烷、联苄、二苯乙炔、二苯甲酮及二苯亚砜中的无限稀活度系数γ~i、偏摩尔过量焓H^E~i及偏摩尔过量熵S^E~i。用Kretschmer-Wiebe 模型计算各醇类在二苯甲烷、联苄、二苯乙炔中的自身缔合常数K~A, 得到在同一溶剂中, C~1-C~4醇类, K~A减小次序。用同一模型计算各醇类在二苯甲酮、二苯亚砜中的交叉缔合常数K~A~B, 得到在同一溶剂中, K~A~B减小次序。     

酚类在芳烃溶剂中的缔合溶液热力学

用凝固点降低法测量了对甲酚、间甲酚、邻甲酚、2,4-二甲酚、2,6-二甲酚以及对甲酚+间甲酚、对甲酚+邻甲酚、间甲酚+邻甲酚、2,4-二甲酚+2,6-二甲酚的1:1摩尔比混合物等为溶质, 溶剂为苯或对二甲苯的活度系数, 用Wiehe-Bagley型的连续缔合模型对数据进行了处理, 得到了各种酚的自缔合常效K_A. 在同一溶剂中, K_A依下列顺序减小: 对甲酚>间甲酚>邻甲酚; 2,4-二甲酚>2,6-二甲酚. 各混合酚的表观K_A 介于两种纯酚的K_A之间.     

磷酸三丁酯与醇二元混合体系的热力学性质

用量热法测定了298.15 K时, 磷酸三丁酯(TBP)+甲醇/乙醇/正丁醇/正丙醇四个二元混合体系的超额混合焓及293.15 K和303.15 K时部分组成下的超额混合焓, 其值均在−0.3 − 0.3 kJ•mol−1之间, 且基本不受温度的影响. 用无热溶液模型计算了各体系的超额熵、超额Gibbs自由能及各组分的活度系数. 热力学分析表明, TBP+甲醇/乙醇/正丙醇二元体系能较好地符合无热溶液模型, 而TBP+正丁醇体系则不符合无热溶液模型.     

萃取体系的热力学研究(Ⅳ)——磷-32标记TBP分配法测定TBP的活度系数

在前文^[1],我们提出用磷-32标记TBP分配法测定它在苯、正己烷、四氯化碳和氯仿中的活度系数。该法简便、可靠。为了研究TBP活度系数的变化规律和溶剂的影响,本文继续测定它在另外几类溶剂中的活度系数,并用公式来表示。     

甲醇-苯混合溶剂中NaI活度系数的测定与计算

测定了甲醇-苯-NaI体系在恒压条件下的汽液平衡数据,采用双标准检验法对数据进行检验,检验结果全部合格.应用P itzer强电解质在水溶液中的活度系数模型,采用全部合格的汽液平衡数据拟合出方程中的维利系数,从而获得在双液比固定条件下盐在甲醇-苯混合溶剂中的活度系数.计算结果表明,正常泡点温度下在具有固定双液比的甲醇-苯混合溶剂中,NaI的平均活度系数随盐浓度的增加先减小,经过一个极小值后又增加.     

醇类的缔合作用与热压力系数

测定了甲醇、正丙醇、正丁醇和正癸醇在25-85℃温度范围的热压力系数, 并为正构醇液体建立了一个热压力系数与密度间的通式。这个通式可用来预测正构醇在各种温度下的内压值。用同形物近似法, 本文还获得了正构醇缔合作用的若干重要信息和估计其缔合度的近似方法。     

冰点下降法测定正十六烷中TBP的活度系数

磷酸三正丁酯(TBP)是核燃料及多种稀有金属水冶过程中使用的重要萃取剂,Healy 等人用蒸气压法、Alcock 用溶解度法先后测定过它在一些溶剂中的活度系数,不同作者的数据分歧很大,测定的浓度范围一般也较小.高宏成等人用磷-32标记TBP 分配法在较大浓度范围内测定过TBP 在氯仿、四氯化碳、苯、正已烷等8～9种溶剂中的活度系数,     

一种无膜的自呼吸式直接醇燃料电池

采用液相化学还原法制备出多壁碳纳米管（MWCNT）负载的双金属PdNi纳米颗粒（PdNi／MWCNT）;采用水热法,在乙醇为溶剂和还原剂的体系中,制备出MWCNT负载的双金属AgCo纳米颗粒（AgCo／MWCNT）．碱性溶液中,PdNi／MWCNT对甲醇、乙醇、丙醇和丁醇的氧化具有稳定而强的电催化活性;AgCo／MWCNT对氧还原反应也表现出强的电活性,且对上述高浓度的醇具有较强的耐受力．以PdNi／MWCNT催化剂为阳极,同时将AgCo／MWCNT催化剂制备成气体扩散电极,组装成无离子交换膜的自呼吸式直接醇燃料电池．分别以甲醇、乙醇、丙醇和丁醇为燃料时,这种无膜的燃料电池均能稳定放电,且具有较高的功率密度及较大的输出电压．     

合成介质对稀土铽-邻苯二甲酸有机配合物荧光强度的影响

在不同介质(依次为甲醇、乙醇、正丙醇、正丁醇)中合成了邻苯二甲酸Tb3+稀土二元配合物. 利用元素分析和红外光谱分析等对配合物的组成和结构进行了表征. 荧光光谱结果表明, 直链醇作为合成介质时配合物的荧光强度大小顺序依次为: 甲醇>乙醇>正丙醇>正丁醇. 同时该配合物在2~300 K范围内测定的变温磁化率说明该配合物具有反铁磁性.     

Studies on the electrode reaction of Cr(III)CyDTA/Cr(II)CyDTA by the coulostatic method in various alcohol + water mixtures

Standard rate constants (k_s)_ms and cathodic transfer coefficients (α_c)_ms of the electrode reaction of Cr(III)CyDTA/Cr(II)CyDTA have been obtained by the coulostatic method in methanol + water, ethanol + water, n-propanol + water and n-butanol + water mixtures, where CyDTA means trans-1,2-cyclohexanediaminetetraacetate. The values of (k_s)_ms obtained at low concentrations of the alcohols are nearly equal to that obtained in aqueous solutions. With increasing concentrations of alcohols, they decrease, in the cases of methanol and n-butanol, in the concentration ranges in which the measurements were made, while, in the cases of ethanol and n-propanol, they decrease to reach minima at certain concentrations and then increase again. The values of (α_c)_ms obtained at high concentrations of n-propanol and n-butanol are much larger than those obtained in aqueous solutions.     

Ion-exchange resins in non-aqueous solvents-I Sorption rates of p-nitroaniline and the effects of small amounts of water

The rates of sorption of p-nitroaniline onto three hydrogenform resins in methanol, ethanol, n-propanol, isopropanol, n-butanol, acetonitrile, benzene, acetic acid and dioxan are reported. Two of the resins are typical gel-type, microreticular, sulphonated resins and the third is a new, highly porous and rigid, macroreticular, sulphonated resin, Amberlyst 15. There appears to be a correlation between viscosity or dielectric constant and the time for maximum sorption or maximum distribution coefficient when the alcohols are used, but no correlation for all the solvents is apparent. The macroreticular resin still functions when dry, even in the presence of non-polar solvents, but the microreticular resin does not. Small amounts of water present in the solvent or resin aid the sorption of the amine onto both types of resin. The effect of mesh size and cross-linkage are examined.     

凝固点降低法研究某些脂肪胺的自缔合作用

本工作利用计算机技术改进加热式凝固点测量装置的数据采集系统. 改进后装置的混合物凝固点测量再现性为±0.001 K; 溶剂偏摩尔过量自由能测量再现性为±0.1 J.mol~(-1). 用凝固点降低法测量正丙胺、异丙胺、正丁胺, 异丁胺、正戊胺、异戊胺、二乙胺、二异丙胺、三乙胺、三正丁胺分别与苯和对二甲苯构成二元混合物的溶剂活度系数. 并使用一个包含物理相互作用的三参数连续缔合模型拟合实验数据. 结果表明该模型能较好地刻画所研究的二元缔合混合物。     

Some Factors Affecting the Photosensitized Polymerization of Methyl Methacrylate

The effects of sensitizer, alcohol, and reaction temperature on the photosensitized polymerization of methyl methacrylate in cyclohexane-alcohol mixtures were investigated. A maximum conversion was indicated at a certain concentration of alcohol in the mixture for the systems sensitized with quinones such as anthraquinone, 2-tert-butylanthraquinone, and α-naphthoquinone, while it was not observed for the benzophenone-sensitized system. The concentration of alcohol corresponding to the maximum conversion increased in the order methanol < ethanol < n-propanol < n-butanol, and shifted to the lower side by raising the reaction temperature from 20 to 40°C. Based on the absorption and ESR spectra of irradiated solution of quinones, reasons for maximum conversion at an optimum concentration of alcohol are discussed.     

Distribution coefficients of Rb(+) on zirconium phosphate in mixed aqueous-organic media

The distribution coefficients have been determined for Rb(+) distributed between zirconium phosphate and 0.85M hydrochloric acid in aqueous solutions of methanol, ethanol, n-propanol, isopropyl alcohol, t-butyl alcohol, dimethylsulphoxide, dimethylformamide, tetrahydrofuran, acetone, dioxane, "Methylcellusolve", "Propylcellosolve" acetic acid and sulpholane, in 0-88% concentration.     

Effects of solvent on TEOS hydrolysis kinetics and silica particle size under basic conditions

In-situ liquid-state ²⁹Si nuclear magnetic resonance was used to investigate the temporal concentration changes during ammonia-catalyzed initial hydrolysis of tetraethyl orthosilicate in different solvents (methanol, ethanol, n-propanol, iso-propanol and n-butanol). Dynamic light scattering was employed to monitor simultaneous changes in the average diameter of silica particles and atomic force microscopy was used to image the particles within this time frame. Solvent effects on initial hydrolysis kinetics, size and polydispersity of silica particles were discussed in terms of polarity and hydrogen-bonding characteristics of the solvents. Initial hydrolysis rate and average particle size increased with molecular weight of the primary alcohols. In comparison, lower hydrolysis rate and larger particle size were obtained in the secondary alcohol. Exceptionally, reactions in methanol exhibited the highest hydrolysis rate and the smallest particle size. Ultimately, our investigation elaborated, and hence confirmed, the influences of chemical structure and nature of the solvent on the formation and growth of the silica particles under applied conditions.     

Heats of immersion of titanium dioxide pigments in alcohol—water mixtures

The heats of immersion of partially dried anatase and rutile pigments in mixtures of water with methanol, ethanol, and n-propanol were measured by a differential calorimetric method. The anatase heats of immersion could best be explained by assuming preferential adsorption of the alcohols, the effect being greatest for n-propanol The rutile pigment, however, appeared to adsorb water preferentially in methanol—water and ethanol—water mixtures over the whole concentration range. In propanol—water mixtures the rutile pigment preferentially adsorbed water below an alcohol mol fraction of 0.25, and preferentially adsorbed propanol at mol fractions of alcohol greater than 0.25. The differences in behaviour between the two pigments may be explained qualitatively from the point of view of their surface morphology.