Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany.
Soft Matter. 2018 Oct 17;14(40):8191-8204. doi: 10.1039/c8sm00934a.
We characterize the electro-phoretic motion of charged sphere suspensions in the presence of substantial electro-osmotic flow using a recently introduced small angle super-heterodyne dynamic light scattering instrument (ISASH-LDV). Operation in integral mode gives access to the particle velocity distribution over the complete cell cross-section. Obtained Doppler spectra are evaluated for electro-phoretic mobility, wall electro-osmotic mobility and particle diffusion coefficient. Simultaneous measurements of differing electro-osmotic mobilities leading to asymmetric solvent flow are demonstrated in a custom made electro-kinetic cell fitting standard microscopy slides as exchangeable sidewalls. The scope and range of our approach are discussed demonstrating the possibility of an internal calibration standard and using the simultaneously measured electro-kinetic mobilities in the interpretation of a microfluidic pumping experiment involving an inhomogeneous electric field and a complex solvent flow pattern.
我们使用最近引入的小角度超外差动态光散射仪（ISASH-LDV）来描述存在大量电动渗透流时带电球体悬浮液的电泳运动。积分模式的操作可获得整个细胞横截面的颗粒速度分布。评估获得的多普勒光谱以获得电泳迁移率、壁电动渗透迁移率和颗粒扩散系数。在一个定制的电动流动池中，通过同时测量导致不对称溶剂流动的不同电动渗透迁移率，证明了这种方法的范围和应用。我们讨论了这种方法的范围和应用，展示了内部校准标准的可能性，并在解释涉及非均匀电场和复杂溶剂流动模式的微流泵送实验时，使用同时测量的电动动力学迁移率。
