DIFFUSION IN PARAFFIN HYDROCARBONS
DIFFUSION IN PARAFFIN HYDROCARBONS
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DOI：
10.1021/j150567a020
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发表时间：
1958-01-01
影响因子：
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通讯作者：
MCCALL, DW
中科院分区：
文献类型：
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作者：
DOUGLASS, DC;MCCALL, DW
Carr-Purcell自旋回波法已用于测量正链烷烃C3 H12、C1 H14、C7 H16、C8 H18、C19、H20、C10 H22、C18 H38和C32 H66的自扩散系数。在一定的温度范围内进行测量，以获得活化能。在实验误差范围内，log D与1/T的曲线呈线性。正如所预期的，扩散系数随着分子量的增加而降低。活化能随分子量的增加而增加。提出了基本扩散过程涉及平行于其链轴的延伸分子的平移。一个降低的温度图的扩散系数集群的数据在一个有趣的方式和所有thehydrocarbons外推到各自的临界点的扩散系数是近似相等的。
The Carr-Purcell spin-echo method has been used to measure the self-diffusion coefficients of the normal paraffins C3Hi2, C «Hi4, C7H16, CsHis, Cí, H2o, Ci0H22, Ci8H38 and C32H66. The measurements were made over a temperature range in order to obtain activation energies. Within experimental error the plots of log D vs. 1/T are linear. As expected the diffusion coefficients decrease with increasing molecular weight. The activation energies increase with increasing molecular weight. It is proposed that the elementary diffusion process involves the translation of an extended molecule parallel to its chain axis. A reduced temperature plot of the diffusion coefficient clusters the data in an interesting manner and the diffusion coefficients for all thehydrocarbons extrapolated to their respective critical points are approximately equal.