Tailoring Emulsification-Functional SnO2–Metal Composite Membranes with Robust Blade-Shaped Pore Walls for Uniform and Size-Controlled Metal Microspheres

Abstract

Liquid metal microspheres are pivotal in biomedicine, catalysis, and microfluidics, yet their synthesis via membrane emulsification remains hindered by high surface tension and poorly controlled pore sizes in conventional metal membranes, leading to nonuniform microspheres. Addressing this, we developed a ceramic–metal composite membrane using 2D SnO₂ with blade-shaped pore walls and tunable pores (0.68–7.92 μm) via in situ hydrothermal synthesis. The blade-shaped pore walls reduce liquid metal surface tension, enabling smooth extrusion through pores while suppressing aggregation. This design leverages the membrane’s large metal contact angle and structural robustness to enhance emulsification under harsh conditions. The resultant microspheres exhibit precise size control (average particle size: 8.79–35.89 μm) and narrow distribution (Span: 0.41–0.84), outperforming traditional methods. By integrating adjustable pore engineering with ceramic–metal interfaces, this work establishes a scalable strategy for fabricating functional membranes tailored to high-surface-tension systems.