Concurrent Formation of Ice Network within Mineral Colloids with Suppressed Volume Expansion.

The freezing behaviors of water are one of the most critical factors that define the formats of life and the landscapes on Earth. The current methods for regulating the freezing behaviors mainly rely on ice-structuring proteins or nanomaterials to hinder the conversion of water into crystalline ice (Ih) under low temperatures. Here we report that the presence of minuscule mineral particles can significantly suppress the volume expansion of water upon freezing into ice. In particular, colloidal precipitates of calcite, a primary mineral accounting for ∼4 wt % of the Earth's crust and the most abundant biomineral on Earth, are able to reduce water expansion by 69% (from 8.4% to 2.6%) at 243 K. The mechanism of expansion suppression involves the formation of a continuous network of fairly ordered "ice-like" hydration waters that are bound to the surface of the mineral colloids at room temperature, and their concurrent crystallization through heterogeneous nucleation upon freezing, which confines the interstitial free water and refrains its volume expansion. These findings reveal the remarkable ability of common minerals to suppress a most ubiquitous phenomenon, water volume expansion upon freezing, and offer fresh insights into various fields such as biomineralization, hydrology, soil science, and lithology.