Experimental study on the stability and supercooling behavior of liquid metal nanofluids

Research on water-based Ga-In-Sn nanofluids remains scarce despite their promising properties. This study utilizes the exceptional thermal conductivity, stability, and fluidity of gallium-indium-tin (Ga-In-Sn) alloy to develop nanofluids with deionized water as the base fluid and low-melting-point Ga-In-Sn alloy as the dispersed phase. We systematically investigate factors influencing their stability and supercooling behavior. The nanofluids were prepared using a two-step method combined with ultrasonic treatment. Stability was evaluated through sedimentation observation, dynamic light scattering (DLS) particle size analysis, and zeta potential measurements, while supercooling was assessed using temperature-time curves. Findings show that stability depends on Ga-In-Sn concentration, ultrasonic duration, and dispersant type, with optimal stability achieved at a 0.2% concentration and 80-min ultrasonication, particularly with the cationic dispersant CTAB. Supercooling is influenced by nanoparticle concentration and ultrasonic duration, with a 59.05% reduction compared to water at a 0.25% concentration and 80-min ultrasonication. However, dispersants slightly increase supercooling due to changes in interfacial tension. Theoretical calculations reveal that these nanofluids have significantly higher heterogeneous nucleation rates than deionized water, reaching 3.57 × 10³³ cm⁻³·s⁻¹ at 10 °C supercooling—1.14 × 10²⁰⁶ times greater than that of water.