Karvar Masoumeh, Strubbe Filip, Beunis Filip, Kemp Roger, Smith Nathan, Goulding Mark, Neyts Kristiaan
Department of Electronics and Information Systems and ‡Center for Nano- and Biophotonics, Ghent University , B-9000 Ghent, Belgium.
Langmuir. 2014 Oct 21;30(41):12138-43. doi: 10.1021/la502287m. Epub 2014 Oct 9.
Transient current measurements are used to characterize a wide variety of charge carriers in nonpolar liquids. The transient current method allows us to obtain both the concentration and mobility of charge carriers and therefore also the hydrodynamic radius using Stokes' law. In this article, five different surfactants in dodecane are investigated: OLOA11K, Solsperse13940, Span80, Span85, and AOT. We show that different types of currents are observed depending on the size of the inverse micelles. For large inverse micelles such as for OLOA11K, Solsperse13940, and Span80, the measurement of the transient current is straightforward because of the low steady-state current level. However, for small inverse micelles such as AOT and Span85, the current from the generation of charges is much larger such that high voltages, a small distance between the electrodes, and dielectric coatings on the electrodes are required to measure the signal related to the initially present charged inverse micelles. The estimated hydrodynamic radii of AOT and Span85, the two smallest inverse micelles, are in good agreement with the values reported in the literature. The comparison of the transient currents with simulations indicates that the dynamics of the charge transport are well-understood.
瞬态电流测量用于表征非极性液体中各种各样的电荷载流子。瞬态电流法使我们能够获得电荷载流子的浓度和迁移率，因此也能利用斯托克斯定律得到流体动力学半径。在本文中，研究了十二烷中的五种不同表面活性剂：OLOA11K、Solsperse13940、Span80、Span85和AOT。我们表明，根据反胶束的大小会观察到不同类型的电流。对于大的反胶束，如OLOA11K、Solsperse13940和Span80，由于稳态电流水平较低，瞬态电流的测量很直接。然而，对于小的反胶束，如AOT和Span85，电荷产生的电流要大得多，因此需要高电压、电极之间的小距离以及电极上的介电涂层来测量与最初存在的带电反胶束相关的信号。两种最小的反胶束AOT和Span85的估计流体动力学半径与文献报道的值吻合良好。瞬态电流与模拟结果的比较表明，电荷传输的动力学已得到很好的理解。
