Sharma Anjali, Rohne Fabian, Vasquez-Muñoz Daniela, Jung Se-Hyeong, Lomadze Nino, Pich Andrij, Santer Svetlana, Bekir Marek
Institute of Physics and Astronomy, University of Potsdam, 14476, Potsdam, Germany.
DWI-Leibniz Institute for Interactive Materials e.V., 52074, Aachen, Germany.
Small Methods. 2024 Dec;8(12):e2400226. doi: 10.1002/smtd.202400226. Epub 2024 Aug 1.
Separation of equally sized particles distinguished solely by material properties remains still a very challenging task. Here a simple separation of differently charged, thermo-responsive polymeric particles (for example microgels) but equal in size, via the combination of pressure-driven microfluidic flow and precise temperature control is proposed. The separation principle relies on forcing thermo-responsive microgels to undergo the volume phase transition during heating and therefore changing its size and correspondingly the change in drift along a pressure driven shear flow. Different thermo-responsive particle types such as different grades of ionizable groups inside the polymer matrix have different temperature regions of volume phase transition temperature (VPTT). This enables selective control of collapsed versus swollen microgels, and accordingly, this physical principle provides a simple method for fractioning a binary mixture with at least one thermo-responsive particle, which is achieved by elution times in the sense of particle chromatography. The concepts are visualized in experimental studies, with an intend to improve the purification strategy of the broad distribution of charged microgels into fractioning to more narrow distribution microgels distinguished solely by slight differences in net charge.
仅通过材料特性来分离尺寸相同的颗粒仍然是一项极具挑战性的任务。本文提出了一种简单的方法，通过压力驱动的微流体流动和精确的温度控制，来分离电荷不同但尺寸相同的热响应性聚合物颗粒（例如微凝胶）。分离原理基于迫使热响应性微凝胶在加热过程中发生体积相变，从而改变其尺寸，并相应地改变其在压力驱动的剪切流中的漂移。不同类型的热响应性颗粒，例如聚合物基质中不同等级的可电离基团，具有不同的体积相变温度（VPTT）区域。这使得能够选择性地控制微凝胶的收缩与膨胀状态，因此，这一物理原理提供了一种简单的方法，用于分离含有至少一种热响应性颗粒的二元混合物，这是通过颗粒色谱意义上的洗脱时间来实现的。这些概念在实验研究中得到了验证，旨在改进将电荷分布广泛的微凝胶纯化成分离为仅由净电荷微小差异区分的更窄分布微凝胶的策略。
