Solsona Miguel, Papadimitriou Vasileios A, Olthuis Wouter, van den Berg Albert, Eijkel Jan C T
BIOS-Lab on a chip group, MESA+ Institute for Nanotechnology , Max Planck-University of Twente Center for Complex Fluid Dynamics University of Twente , Drienerlolaan 5 , Enschede , The Netherlands.
Langmuir. 2019 Jul 30;35(30):9704-9712. doi: 10.1021/acs.langmuir.9b00802. Epub 2019 Jul 16.
Microparticle porosity is normally determined in bulk manner providing an ensemble average that hinders establishing the individual role of each microparticle. On the other hand, single particle characterization implies expensive technology. We propose to use ion concentration polarization to measure differences in mesoporosity at the single particle level. Ion concentration polarization occurs at the interface between an electrolyte and a porous particle when an electric field is applied. The extent of ion concentration polarization depends, among others, on the mesopore size and density. By using a fluorescence marker, we could measure differences in concentration polarization between particles with 3 and 13 nm average mesopore diameters. A qualitative model was developed in order to understand and interpret the phenomena. We believe that this inexpensive method could be used to measure differences in mesoporous particle materials such as catalysts.
微粒孔隙率通常以整体方式测定，给出的是总体平均值，这妨碍了确定每个微粒的个体作用。另一方面，单颗粒表征意味着使用昂贵的技术。我们建议利用离子浓度极化来测量单颗粒水平的介孔率差异。当施加电场时，离子浓度极化发生在电解质与多孔颗粒之间的界面处。离子浓度极化的程度尤其取决于介孔尺寸和密度。通过使用荧光标记物，我们能够测量平均介孔直径分别为3纳米和13纳米的颗粒之间的浓度极化差异。为了理解和解释这些现象，我们建立了一个定性模型。我们认为，这种低成本方法可用于测量诸如催化剂等介孔颗粒材料的差异。
