Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Str. 24/25, 14476, Potsdam, Germany.
Fraunhofer Institute for Applied Polymer Research IAP, Geiselbergstraße 69, 14476, Potsdam-Golm, Germany.
Adv Mater. 2023 Jun;35(25):e2300358. doi: 10.1002/adma.202300358. Epub 2023 Apr 29.
Separation of particles by size, morphology, or material identity is of paramount importance in fields such as filtration or bioanalytics. Up to now separation of particles distinguished solely by surface properties or bulk/surface morphology remains a very challenging process. Here a combination of pressure-driven microfluidic flow and local self-phoresis/osmosis are proposed via the light-induced chemical activity of a photoactive azobenzene-surfactant solution. This process induces a vertical displacement of the sedimented particles, which depends on their size and surface properties . Consequently, different colloidal components experience different regions of the ambient microfluidic shear flow. Accordingly, a simple, versatile method for the separation of such can be achieved by elution times in a sense of particle chromatography. The concepts are illustrated via experimental studies, complemented by theoretical analysis, which include the separation of bulk-porous from bulk-compact colloidal particles and the separation of particles distinguished solely by slight differences in their surface physico-chemical properties.
通过大小、形态或材料特性对颗粒进行分离在过滤或生物分析等领域至关重要。到目前为止，仅通过表面特性或体相/表面形态来分离颗粒仍然是一个极具挑战性的过程。在这里，通过光活性的偶氮苯表面活性剂溶液的光致化学活性，提出了一种结合压力驱动微流和局部自泳/渗透的方法。这个过程会引起沉降颗粒的垂直位移，这取决于它们的大小和表面特性。因此，不同的胶体成分会经历环境微流剪切流的不同区域。因此，可以通过粒子色谱法的洗脱时间来实现这种胶体的简单、通用的分离方法。通过实验研究和理论分析来验证这些概念，包括从体相多孔到体相致密胶体颗粒的分离，以及通过表面物理化学性质的微小差异来区分颗粒的分离。
