Water expands approximately 9% in volume upon freezing due to the hexagonal crystalline structure of ice Ih, an intrinsic property confirmed by standard physical chemistry and thermodynamics. The density of liquid water at 0°C is about 999.8 kg/m³, while ice is about 916.8 kg/m³, resulting in volumetric expansion under negligible confining stress. Experiments with plastic containers showed anomalous volume shrinkage during freezing, explained by the container’s elasticity, semipermeability, and air pressure reduction inside the container, not by changes in water’s intrinsic properties. High confining stress, such as in metal pipes or under ice skate blades, alters ice volume expansion and can induce melting due to pressure-dependent phase equilibrium shifts.
Physical chemists, materials scientists, thermodynamics researchers, and engineers studying phase transitions, container design for freezing liquids, and the mechanical effects of ice formation in confined environments.
And with that, the thread will remain closed. Thanks to all who provided responses.PeterDonis said:This is why we don't discuss personal research here at PF.