Max-Born-Institut für nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2A, 12489 Berlin, Germany.
J Phys Chem B. 2013 Feb 28;117(8):2422-8. doi: 10.1021/jp304773n. Epub 2013 Feb 14.
Electrokinetic charging of aqueous microjets was characterized by measuring streaming currents as a function of sodium iodide salt concentration. Measured streaming currents at high salt concentrations (up to 0.5 M) varied nonmonotonically with the jet velocity and can be explained by a multipolar charge distribution at the nozzle-water interface. In the case of potassium fluoride no multipolar charge distribution is observed. Electrokinetic potentials were estimated from the streaming currents, under the assumption that all excess charges are confined within the liquid jet. Measured photoelectron spectra indicate much smaller streaming potentials. To resolve the apparent discrepancy, we propose that a significant fraction of excess charges evaporates in the form of ion-water clusters.
通过测量作为碘化钠盐浓度函数的射流电流来表征水微射流的电动充电。在高盐浓度（高达 0.5 M）下测量的射流电流随射流速度呈非单调变化，可以用喷嘴-水界面的多极电荷分布来解释。在氟化钾的情况下，没有观察到多极电荷分布。在假设所有过剩电荷都局限在液体射流中的情况下，从射流电流估算了电动电势。测量的光电子能谱表明，射流电势要小得多。为了解决明显的差异，我们提出，相当一部分过剩电荷以离子-水簇的形式蒸发。
