The Influence of Contact States on the Freezing Behavior of Soap Bubbles on Superwetting Surfaces

Bubbles are ubiquitous in nature and play vital roles in industrial processes such as cleaning and catalysis. However, the influence of contact states on bubble freezing remains underexplored. This study investigates the freezing behavior of soap bubbles on superwetting surfaces under different contact and thermal conditions, including dry and liquid film‐covered superwetting surfaces, as well as isothermal and supercooled environments. On dry surfaces, soap bubbles exhibited bowl‐shaped freezing under supercooling. In the isothermal state, small‐volume bubbles were prone to the “roof collapse” between −25 °C and −15 °C, while larger ones experienced the “pocket rupture”. On liquid film‐covered surfaces, soap bubbles didn't freeze under supercooling. In the isothermal state, freezing occurred below −20 °C, preserving the shape. Between −20 °C and −12.5 °C, bubbles underwent “progressive collapse”. Above −12.5 °C, “rupture dissolution” appeared. The Marangoni effect and upward airflow were identified as key factors in shaping the freezing morphology. These findings provide insights for applications in food, bubble freeze casting, and related fields.