Self-diffusion in molecular liquids: medium-chain n-alkanes and coenzyme Q10 studied by quasielastic neutron scattering.
Self-diffusion in molecular liquids: medium-chain n-alkanes and coenzyme Q10 studied by quasielastic neutron scattering.
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分子液体中的自扩散：通过准弹性中子散射研究中链正构烷烃和辅酶 Q10。
DOI：
10.1063/1.2943673
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
T. Unruh
中科院分区：
文献类型：
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作者：
C. Smuda;S. Busch;G. Gemmecker;T. Unruh
首次采用飞行时间准弹性中子散射（TOF-QENS）方法对正构烷烃在熔体中的扩散进行了系统研究。作为中链分子的另一个例子，以相同的方式研究辅酶Q（10）。在频域和时域中评估数据。TOF-QENS数据可以令人满意地描述不同的模型，它证明了，所确定的扩散系数在很大程度上是独立的应用模型。导出的扩散系数与脉冲场梯度核磁共振（PFG-NMR）测量值进行比较。随着链长的增加，TOF-QENS扩散系数和PFG-NMR扩散系数之间的差异越来越大。这种差异的扩散系数是最有可能的，由于在纳米长度尺度上的分子的中链长度的扩散机制的变化。
A systematic time-of-flight quasielastic neutron scattering (TOF-QENS) study on diffusion of n-alkanes in a melt is presented for the first time. As another example of a medium-chain molecule, coenzyme Q(10) is investigated in the same way. The data were evaluated both in the frequency and in the time domain. TOF-QENS data can be satisfactorily described by different models, and it turned out that the determined diffusion coefficients are largely independent of the applied model. The derived diffusion coefficients are compared with values measured by pulsed-field gradient nuclear magnetic resonance (PFG-NMR). With increasing chain length, an increasing difference between the TOF-QENS diffusion coefficient and the PFG-NMR diffusion coefficient is observed. This discrepancy in the diffusion coefficients is most likely due to a change of the diffusion mechanism on a nanometer length scale for molecules of medium-chain length.