【作者】 纪俊荣；

【导师】 刘润静；

【作者基本信息】 河北科技大学 ， 工业催化， 2010， 硕士

【摘要】 离子液体是一类在室温或近于室温情况下呈液态的,由有机阳离子和无机或有机阴离子构成的有机盐,也叫室温离子液体。离子液体具有液态温度范围宽;蒸汽压几乎为零,几乎不挥发;对很多无机和有机物质都具有良好的溶解能力,且具有溶剂和催化剂的双重功效;可设计性强等优点,这些优异的特性是离子液体特有的、传统的有机溶剂无法比拟的。由于离子液体的这些特殊性质和表现,近年来离子液体的研究受到各国科技工作者的重视和关注。表面张力是液体(包括固体)表面的基本物理化学性质之一。了解离子液体的表面界面性质(包括界面张力)对于进一步深入研究和揭示离子液体在各个领域相互作用的内在本质,对认识界面结构、界面分子的相互作用是非常必要的,对各种与离子液体有关的工业过程的开发、设计和模拟以及工业生产都具有重要意义。本文对系列N-烷基-N-烷基-咪唑类离子液体的表面张力、混合离子液体的表面张力以及离子液体与烷烃的界面张力进行了研究。将硬球模型理论应用于离子液体表面张力的计算,主要研究内容如下:1.采用表面张力测定仪对28个纯离子液体体系的表面张力进行了研究,研究结果表明,纯离子液体的表面张力随温度的升高呈下降趋势;将Reiss的分子硬球模型应用于纯离子液体表面张力的计算,得到相应的关联参数,其模型值与实验测试值表面张力的平均偏差为0.51%。2.对混合离子液体的表面张力进行了研究,结果表明,混合离子液体的表面张力变化情况随温度的上升呈下降的趋势。在相同的温度下,固定两种物质中的一种,另一种为含有相同阴离子系列离子液体随着阳离子咪唑环1位氮上取代基碳链的增加,混合物的表面张力减小。这与纯离子液体的变化趋势是一致的,并在纯离子液体模型内引入混合规则,建立了混合离子液体的体系表面张力的计算模型,对16种离子液体体系进行了预测和关联,计算结果非常成功,说明此模型是成功的。3.对离子液体与正烷烃的界面张力进行了研究,结果表明:随着温度的升高,离子液体与正烷烃的界面张力呈现下降趋势,其表面能、表面熵随1为氮上取代基碳链的增长而增长。将离子液体与有机溶液的界面张力看成是纯离子液体与有机溶剂表面张力的函数,引入了校正参数,其结果符合非极性/极性体系校正参数φ值小于1的规律。更多还原

【Abstract】 Ionic liquids or room temperature ionic liquids (RTILs)are a class of organic salts that remain liquid at room temperature or near room temperature, usually composed of organic cations and organic or inorganic anions. Compared with traditional organic solvents, RTILs have tremendous advantages, such as negligible vapor pressure, good solvation ability for organic or inorganic materials, and have the function of both solvent and catalyst. Furthermore, through different combinations of cations and anions, there is a tremendous variety of "designer" solvents. Their status as "green" or "designer" solvents explains the large amount of studies concerning their possible industrial use as reaction or extraction media. These special properties of ILs are in close connection with their microscopic structures, but how the microscopic structures affect their properties has not yet been understood completely.Surface tension is one of the basic physical and chemical properties of a liquid (including solid). It is very important to study the property of ionic liquid surface and interface (including the interfacial tension), because it is useful to further study and reveal the interaction of ionic liquids in various fields, and it is helpful to study the interaction between interface structure and interface elements. And it is necessary to study the process development, design, simulation, as well as industrial production about the ionic liquid.In this paper, the surface tensions of N-alkyl-N-alkyl -imidazolium ionic liquid and mixture of ionic liquid, the interface tension between ionic liquids and Alkanes were experimentally studued. The hard-sphere model theory is proposed to calculate the surface tension of ionic liquid. The following results were obtained.The first, with the temperature increasing, the surface tension of pure ionic liquid decreased. Reiss molecular hard-sphere model was applied to calculate the surface tension of 28 pure ionic liquids, the corresponding correlation parameters were obtained, and the average deviation of surface tension between calculation value and experimental one is 0.51%.The second, surface tensions of two mixture of ionic liquids were also studied, and the results showed that with the temperature increasing, the surface tension of ionic liquids mixture decreased. At the same temperature, fixed in one of two substances, another to contain the same anion series of ionic liquids with cations of nitrogen on the imidazole ring a substituent carbon chain increases, the surface tension of the mixture decreased. It is same with the trend of pure ionic liquids . After introducing the mixing rule into the model of pure ionic liquid, the calculation surface tension of ionic liquid mixture was established. Then 16 pairs of ionic liquid systems were predicted, and the calculation results are very successful.The third, interface tensions between ionic liquids and n-alkanes were studied. The results showed that, with the temperature increasing, the interface tension between ionic liquids and n-alkanes decreased, and with the growth of a nitrogen substituent carbon chain,its surface energy and surface entropy increased. If we consider the interface tension of pure ionic liquids and organic solvents as a function of the surface tension of pure ionic liquids and organic solvents, a correction parameter is given,and the results inosculate with the rule that correction parameter of non-polar / polar systems is lower than one.更多还原