Freezing Purification by Obstacle-Guided Suppression of Mullins-Sekerka Instability

Description

Interfacial instability limits solidification‑based purification by trapping solute. Using a multiphysics model with a solute exclusion potential, we show that separating low and high concentration regions expands the pure ice layer. Fixed obstacles create upstream solute retention and downstream sheltering zones, reorganizing heat and solute transport and stabilize the freezing front. Mullins-Sekerka analysis confirms the stable shift, while obstacle‑guided convection governs whether brine drains continuously or fragments into trapped pockets. Staggered arrays form more connected channels and outperform single-layer structures, offering a passive geometric route to stable the freezing interface.

Institutions

• Tsinghua University

  Beijing, Beijing

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