Tuning ice nucleation with pH-modulated Fe³⁺ cross-linked hydrogel surfaces

Ice nucleation plays a vital function in various fields. In this study, we prepared hydrogel surfaces with different cross-linkages by pH-modulating the coordination pattern of Fe³⁺ and catechol. We found that the ice nucleation temperature decreases with increasing cross-linkages. Further analysis shows that the hydrogel surfaces with different cross-linking degrees could achieve the regulation of ice nucleation by modulating the interfacial water. Our study elucidates the mechanism of ice nucleation regulated by interfacial water in soft matter and proposes a new method for preparing ice nucleation-regulated material.