Sudha Anand, Rohde Martin
Radiation Science and Technology, Technische Universiteit Delft, Mekelweg 5, 2628 CD Delft, The Netherlands.
Microfluid Nanofluidics. 2025;29(8):53. doi: 10.1007/s10404-025-02828-1. Epub 2025 Jul 9.
Liquid-liquid Extraction has emerged as a major technique for radioisotope extraction in recent years. This technique is particularly advantageous in the microscale as the surface-volume ratio is much larger. Since some of these radioisotopes have short half-lives, parallel flow in the microscale is used to extract them as it eliminates the need for separating the two fluids. Though such a configuration has been experimentally studied, dimensionless numbers have not been employed to understand the mass transfer mechanisms. This study uses three dimensionless numbers-the Biot, Peclet and Damkohler numbers-to delve deeper into mass transfer with a chemical reaction at the interface. Mass transfer simulations are performed using a Finite Difference model to solve the 2D Convection-Diffusion Equation with a first-order reaction at the interface, and these numbers are varied. The Damkohler number was observed to have the maximal impact on the extraction efficiency, and this was confirmed to be the case when the extraction efficiency didn't change much as long as the Damkohler number was kept constant. In general, a higher Damkohler number results in a higher extraction efficiency and a correlation was proposed to quantify this influence.
液-液萃取近年来已成为放射性同位素萃取的一项主要技术。这项技术在微尺度下尤为有利，因为其表面体积比要大得多。由于其中一些放射性同位素半衰期较短，微尺度下的并流被用于萃取它们，因为这样无需分离两种流体。尽管这种配置已通过实验研究，但尚未采用无量纲数来理解传质机制。本研究使用三个无量纲数——毕奥数、佩克莱数和达姆科勒数——来更深入地研究界面处有化学反应时的传质情况。使用有限差分模型进行传质模拟，以求解二维对流扩散方程，且界面处有一级反应，同时改变这些数。观察到达姆科勒数对萃取效率的影响最大，并且当达姆科勒数保持恒定时萃取效率变化不大时，证实了这种情况。一般来说，较高的达姆科勒数会导致较高的萃取效率，并提出了一种相关性来量化这种影响。
