Reaction and Transport Process of Charged Species in Supercritical Fluids

超临界流体中带电物质的反应和输运过程

• 批准号: 10044097
• 负责人: NISHIKAWA Masaru
• 金额: $ 4.35万
• 依托单位: Kanagawa Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10044097/
• 关键词: Supercritical fluids; Electron mobility; Electron attachment reaction; Attachment; detachment equilibria; Reaction volume change; Electrostriction; ion mobility; Cluster size; 電子付着・脱離平衝定数; 反応体積

Electron mobility μ in supercritical fluidsμ-values were measured in upercritical ethane as a function of temperature and pressure over the range 33-47℃ and 40-120 bar. At all temperatures measured, μ decreases exponentially with increasing pressure, but passes through a minimum in the pressure region where x goes through a maximum. Since excess electrons are quasifree in the region of μ minima (μ=50-100 cmィイD12ィエD1/Vs), it is obvious that the scattering of electrons by the maxima in the deformation potential due to density fluctuations are the cause for the minima. Measurement of μ in SC Xe was initiated.Rate of electron attachment and attachment/detachment equilibriaElectron attachment rate to COィイD22ィエD2 pyrimidine, pyrazine, styrene and NO, was measured in supercritical ethane. By using 10 psec pulse from the laser-electron-accelerator, both attachment and detachment rate were measured for COィイD22ィエD2, pyrimidine and pyrazine. Styrene even at high concentrations are unreactive towa … More rds electrons. For NO, however, only attachment was observed even with 10 psec pulse. Attachment-detachment equilibrium constants KィイD2eqィエD2 were determined for COィイD22ィエD2, pyrimidine and pyrazine as a function of temperature and pressure. The Gibbs energy change △GィイD2rィエD2 and the reaction volume change △VィイD2rィエD2 were estimated from KィイD2eqィエD2. The comparison of △VィイD2rィエD2 with a compressible continum model led to the conclusion that these volume changes were essentially due to the electrostriction of media by negative ions. The model also shows that the trend in △ィイD2rィエD2 with respect to pressure or additives are largely accounted for by the magnitude of polarization energy due to irons.Ion mobility in supercritical fluidsThe mobility of positive ions in ethane and of both positive and negative ions in COィイD22ィエD2 were measured. Cluster radii were estimated by means of (1) Stokes' equation and by (2) a compressible continuum model. Radii go through a maximum at the pressure where compressibility reached its peak. For ethane, both methods give largest values 15-16 nm at 33℃ and ρ/ρィイD2cィエD2-0.8. In COィイD22ィエD2 the radius for the slower ion was 12 nm at 33℃ and ρ/ρィイD2cィエD2=0.8. Preliminary measurements of positive ion mobility μ in Sc Xe indicated that μ is lower that in SC ethane and the cluster radius at the maximum is ca. 1.2nm(293K). Less

在33-47℃和40-120巴范围内，测量了超临界乙烷中电子迁移率μ值随温度和压力的变化。在测量的所有温度下，μ随压力增加呈指数下降，但在x经历最大值的压力区域中经历最小值。由于过剩电子在μ极小值区域（μ=50-100 cm ² D 12 ² D 1/Vs）是准自由的，很明显，密度涨落引起的形变势极大值对电子的散射是极小值的原因。在超临界乙烷中，测定了电子与CO、D22、D2、嘧啶、吡嗪、苯乙烯和NO的吸附速率和吸附/脱附平衡。利用激光电子加速器产生的10皮秒脉冲，测量了CO双金属D22、嘧啶和吡嗪的吸附和脱附速率。即使在高浓度下，苯乙烯也不会与a反应。 ...更多信息 rds电子然而，对于NO，即使使用10皮秒脉冲也仅观察到附着。本文测定了CO_（22）O吉布斯自由能变化△G Δ D2 r Δ D2和反应体积变化△V Δ D2 r Δ D2由K Δ D2 eq Δ D2估算。通过与可压缩连续介质模型的比较，得出这样的结论：这些体积变化主要是由于负离子引起的介质的电致伸缩。超临界流体中的离子迁移率测量了正离子在乙烷中的迁移率和正、负离子在CO中的迁移率。团簇半径分别用Stokes方程和可压缩连续介质模型估算。半径在压缩性达到峰值的压力处经历最大值。对于乙烷，这两种方法在33℃下给出的最大值为15-16 nm，ρ/ρ ε D2c ε D2-0.8。在33℃时，CO_（22）_（22）_（22）中慢离子的半径为12 nm，ρ/ρ_（22）_（22）_（22）=0.8。正离子迁移率μ的初步测量结果表明，Sc_（12）中的μ低于Sc_（12）中的μ，最大团簇半径约为100 nm。1.2nm（293K）。少

项目成果

M.Nishikawa, K.Itoh, R.A.Holroyd: "Behavior of excess electrons in supercritical fluids"Proc.13th Int.Conf.on Diel.Liquids. 9-12 (1999)

M.Nishikawa、K.Itoh、R.A.Holroyd：“超临界流体中过量电子的行为”Proc.13th Int.Conf.on Diel.Liquids。

R.A.Holroyd,M.Nishikawa,K.Itoh: "Behavior of Charged Species in Nonpolar Supercritical Fluids-Electron Attachment and Ionic Transport"Proceedings of 5th International Symposium on Supercritical Fluids. 予定. (2000)

R.A.Holroyd、M.Nishikawa、K.Itoh：“非极性超临界流体中带电物质的行为 - 电子附着和离子传输”预定的第五届国际超临界流体研讨会论文集。

R.A.Holroyd, M.Nishikawa, K.Itoh: "Thermodynamics of clectron attachment to pyrimidine and styrene in supercritical ehtane"J.Phys.Chme.B. 103/43. 9205-9210 (1999)

R.A.Holroyd、M.Nishikawa、K.Itoh：“超临界乙烷中电子附着于嘧啶和苯乙烯的热力学”J.Phys.Chme.B。

R.A.Holroyd,M.Nishikawa,K.Itoh: "Charged Species in Supercritical Fluids-Properties and Reactions-"Proceedings of Int.Symposium for Appl. Of Radiation towards 21st Century. 予定 (2000)

R.A.Holroyd、M.Nishikawa、K.Itoh：“超临界流体中的带电物质 - 性质和反应 -”21 世纪辐射应用国际研讨会论文集（2000 年）。