Water is the foundation of survival and the origin of civilization. It nourishes all living things and sustains endless life, yet it exhibits highly anomalous physical properties and remains one of the least understood substances. Professor Wang Biao and Professor Sun Changqing from the Center for Interdisciplinary Science Research, together with their collaborators, took the lead in verifying the existence of the polarized super-solid state and temperature-induced quasi-solid state of water through extensive spectroscopic experiments and theoretical calculations, and clarified their core characteristics and functions.
Based on the theory of hydrogen bond coupled excitation polarization and cooperative relaxation (HBCP) of O:H-O bonds, the research team proved that the cooperativity of segmented specific heat of hydrogen bonds uniquely defines the temperature-driven phase transition and density evolution of water under atmospheric pressure, as well as the existence of the quasi-solid state featured by cold expansion. This clarifies the essential mechanism of hydrogen bond relaxation behind the floating ice phenomenon.
The team also discovered that molecular undercoordination or electric field polarization can induce the formation of the super-solid state. This state possesses a series of extraordinary properties: low density, high elasticity, excellent lubricity, high toughness, low freezing point, high melting point, high thermal diffusivity, high reflectivity, high surface charge density, long-lived electron-phonon states, high chemical activity, and strong catalytic effect. The findings reveal the common physical mechanisms underlying various natural phenomena, including surface premelting and lubrication of ice, surface toughness and hydrophobicity of water, the Mpemba effect (hot water freezes faster), and the low-temperature superelasticity of ice fibers.
In-depth research has established the correlation among the physical properties of droplets — such as shell thickness, mass density, loaded charge, work function, local electric field intensity, vibration frequency, freezing point variation, and electron-phonon lifetime — as well as their scaling rules related to droplet size. It provides theoretical guidance for in-depth research and application development of droplet surface properties.
The discovery and validation of these new phases of water fundamentally resolve a series of long-standing puzzles regarding water. It also offers new perspectives for the understanding and regulation of material science and life processes, covering fields such as deep processing of water, hydration reactions, energy storage of explosives, dipolar atomic catalysis, hydrovoltaics, water-assisted catalysis, solid-liquid interfaces, chemical adsorption, and low-dimensional high-temperature superconductivity.
