Electronics and Information Systems, Ghent University, Technologiepark Zwijnaarde 15, 9052 Gent, Belgium.
Soft Matter. 2017 Aug 23;13(33):5604-5612. doi: 10.1039/c7sm00559h.
The electrokinetics and charging of nonpolar colloidal dispersions subjected to a voltage are investigated by electric current and optical measurements. From electric current measurements in response to an alternating triangular voltage with a peak value of a few hundred volts, we find that polystyrene toner particles are compacted near the electrodes and their charge increases by more than a factor of 20. The important increase of charge is interpreted by a mechanism in which counter charges, which are originally at the particle surface, are desorbed. Optical measurements performed under a dc voltage of the order of a few hundred volts demonstrate that the charge of the particles can again decrease or even be inverted. These phenomena are attributed to the movement of counter charged species from the interface layers onto the surface of the particles. The findings of this study are relevant for electrophoretic displays and liquid toner printing.
通过电流和光学测量研究了在电压下的非极性胶体分散体的电动现象和带电情况。通过对峰值为几百伏特的交流电三角波电压的电流响应测量，我们发现，带正电的聚苯乙烯调色剂粒子在电极附近被压缩，其电荷量增加了 20 多倍。电荷的重要增加可以通过一种机制来解释，在这种机制中，最初位于粒子表面的反电荷被解吸。在几百伏特直流电压下进行的光学测量表明，粒子的电荷可以再次减小甚至反转。这些现象归因于反电荷物种从界面层向粒子表面的迁移。本研究的结果与电泳显示器和液体调色剂打印有关。
