An Alternative Hypothesis on Enhanced Deep Supercooling of Water: Nucleator Inhibition via Bicarbonate Adsorption

Supercooling allows for retarding water crystallization toward negative Celsius temperatures. Previous findings of CO₂ molecules shifting into bicarbonate species upon freezing, the latter which naturally adsorb on hydrophobic interfaces, are put in perspective here to interpret earlier published data. Since it has been shown that ice nucleation is unlikely on negatively charged surfaces, I propose that bicarbonates adsorb on most solid particles present in water that act as nucleators, thus retarding freezing and enhancing supercooling. This hypothesis can now explain the deep supercooling observed for sealed and boiled water samples and oil-topped water samples, promoting both more bicarbonate generation and adsorption. Such an explanation opens new directions for access to cryopreservation.