Fast charge transport processes in dielectric liquids under high pressure

高压下介电液体中的快速电荷传输过程

• 批准号: 06044048
• 负责人: NISHIKAWA Masaru
• 金额: $ 6.27万
• 依托单位: Kanagawa Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06044048/
• 关键词: Electron mobility; Electron transport process; Partial molar volume; Dielectric liquid; Liquid hydrocarbon; Nonpolar liquid; Charge transfer; Electron capture reaction; Excess electron; 電荷移動

The behavior of excess electrons in dielectric liquids was studied both experimentally and theoretically. Experiments include mobility an d reaction rate measurements as a function of pressure (1-3,000 bar) and temperature (0-120ﾟC). Mobility values were measured in : 1.mixtures of 2,2-dimethylbutane (DMB) and n-hexane, 2.m-and o-xylene, 3.hexamethyldisoloxane (HMDS) and bistrimethylsiylmethane (BTMSM), 4.tri-, tetramethylethylene and 1-pentene. 5.Electron attachment and detachment rates, and equilibrium constants with CO_2 were measured in HMDS and BTMSM.6.The pressure dependence of conducting state energy V_0 in several dielectric liquids were analyzed by means of thermodynamics. Results and Discussion 1.Above 75% DMB electrons are essentially quasifree, and below 75% localization becomes predominant. 2.Pressure dependence of mu in xylenes (0.01-0.2cm^2/Vs) is of hitherto unknown type, namely it goes through a maximum at an intermediate pressure which shifts toward higher values with … More temperature. 3.Although HMDS is an ether-like compound, electrons are not solvated throughout the pressure range (mu*20). mu are still higher (*60) in BTMSM.These higher values are attributed to the highly symmetrical molecular shape. 4.1-pentene is a typical low mu liquid olefin (0.01-0.2). Whereas tri and tetramethylethylene are intermediate mu-liquids (2-5 and 8-12, respectively). 1 through 4, the partial molar volumes of electrons Ve were estimated from the pressuredependence of mu for respective liquids in terms of a 2-state model. 5.From the electron attachment/detachment equilibrium constants with CO_2 in HMDS and BTMSM,the ground-state energy for electrons in these liquids were estimated by means of the Born-Haber cycle. 6.Thermodynamic treatment of V_0 values revealed that Ve of the quasifree electrons are positive (40 for tetramethylsilane-200cm^3/mole for n-pentane).Conclusion The most important finding of this study is that the behavior of electrons in dielectric liquids are governed by the partial molar volume of electrons in the respective liquids : When the compressibility chi is large, Ve is negative and electron localization (into cavities) becomes predominant, while for liquids with smaller chi, electrons tend to stay quasifree. The importantce of chi is due to the fact that the electrostriction volume and hence Ve are determined by the magnitude of chi. Less

从实验和理论两方面研究了介质液体中过剩电子的行为。实验包括迁移率和反应速率测量作为压力（1- 3，000巴）和温度（0-120摄氏度）的函数。测定了2，2-二甲基丁烷（DMB）与正己烷、间二甲苯和邻二甲苯、六甲基二硅氧烷（HMDS）与双三甲基硅烷（BTMSM）、三甲基乙烯和四甲基乙烯与1-戊烯的混合物的迁移率。5. 6.从热力学角度分析了几种介质液体的导电态能量V_0与压力的关系。结果与讨论1.75%以上的DMB电子基本上是准自由电子，75%以下的DMB电子成为主要的局域电子。2.二甲苯中μ的压力依赖性（0.01-0.2cm^2/Vs）是迄今未知的类型，即它在中间压力下经历最大值，随着压力的升高， ...更多信息 温度3.虽然HMDS是一种醚类化合物，但在整个压力范围内（mu*20），电子不会被溶剂化。在BTMSM中，μ仍然更高（*60）。这些更高的值归因于高度对称的分子形状。4.1-戊烯是典型的低μ液体烯烃（0.01-0.2）。而三甲基乙烯和四甲基乙烯是中间μ液体（分别为2-5和8-12）。在图1至图4中，电子的偏摩尔体积Ve是根据2态模型从各个液体的μ的压力依赖性估计的。5.根据HMDS和BTMSM中电子与CO_2的吸附/脱附平衡常数，用Born-Haber循环估算了电子在这两种液体中的基态能量。6.对V_0值的热力学处理表明，准自由电子的Ve为正值（对于四甲基硅烷为40-对于正戊烷为200cm^3/mole）。结论本研究最重要的发现是电介质液体中电子的行为受相应液体中电子的偏摩尔体积控制：当可压缩性chi大时，Ve为负，电子局域化（进入空腔）成为主导，而对于具有较小chi的液体，电子倾向于保持准自由。chi的重要性是由于电致伸缩体积和Ve是由chi的大小决定的。少

项目成果

Holroyd・ Stradowska・伊藤 西川: "Volume and entropy changes in electron attachment reactions : butadiene in 2,2-dimethylbutane" Radiat. Phys. Chem.47. 39-42 (1996)

Holroyd、Stradowska、Nishikawa Ito：“电子附着反应中的体积和熵变化：2,2-二甲基丁烷中的丁二烯”《Radiat》Phys.47（1996）。

Schiller・Holroyd・西川: "Some thermodynamic considerations on the quasifree state of excess electrons in hydrocarbons" NATO ASI Ser.B,Physics. 326. 121-125 (1994)

Schiller、Holroyd 和 Nishikawa：“关于碳氢化合物中多余电子的准自由态的一些热力学考虑”NATO ASI Ser.B，物理学。326. 121-125 (1994)

K.Itoh, M.Nishikawa, R.A.Holroyd: "Electron transport in liquid o-and m-xylene under high pressure" in preparation.

K.Itoh、M.Nishikawa、R.A.Holroyd：“高压下液体邻二甲苯和间二甲苯中的电子传输”正在准备中。

K.Itoh, M.Nishikawa, R.A.Holroyd: "Electron mobility and energy level in hexamethyl-disiloxane and bistrimethylmethane as a function of pressure and temperature" in preparation.

K.Itoh、M.Nishikawa、R.A.Holroyd：“六甲基二硅氧烷和双三甲基甲烷中的电子迁移率和能级作为压力和温度的函数”正在准备中。

伊藤・西川・Holroyd: "Electron mobility and energy level in hexamethyldisiloxane and bistrimethyl-methane as a function of pressure and temperature" (in preparation).

Ito、Nishikawa 和 Holroyd：“六甲基二硅氧烷和双三甲基甲烷中的电子迁移率和能级作为压力和温度的函数”（准备中）。