Does the church glass flow like a liquid at room temperature? This is not just an urban legend but a serious scientific question. Modern glass science believes that although the structure of glass is very similar to that of a supercooled liquid, it is in a deeply dynamics-arrested state at low temperatures (such as room temperature), which makes its properties more like those of a solid than a liquid. However, the latest observation results, showing abnormally occurred relaxation behavior of both oxide glasses and metallic glasses at very low temperatures, have cast doubles on the well-established consensus.
In the RELAX project, we aimed at investigating this irregular relaxation process in glasses and to decipher the underlying atomic-scale structural mechanisms. Specifically, the relaxation parameters, including relaxation time τ and Kohlrausch exponent β, were firstly be derived from fitting of the enthalpy or volume changes within low-temperature relaxation. Then, the relaxation behaviors depicted by different macroscopic state parameters (excess enthalpy vs. volume) or measured at different temperatures were compared to explore underlying decorrelation or crossover features of these relaxation modes. Finally, leveraging advanced experimental and modelling techniques, we strived to decode the atomic-scale details of structure reorganization behind such low-temperature relaxation.
We focused on uncovering these mechanisms in mixed-alkali bioactive (MAB) glasses and metal-organic framework (MOF) glasses, two families of materials with distinct structural and compositional features. MAB glasses, with their bioactive properties, are critical for applications in bone regeneration and drug delivery. MOF glasses, which combine inorganic nodes with organic linkers, have potential in energy storage and catalysis. By studying how these glasses undergo relaxation at low-temperature, the project sought to correlate their structural rearrangement with relaxation behaviors. This understanding is key to improving the stability, reliability, and performance of these glasses in practical applications, particularly in medical devices, energy storage systems, and other advanced technologies.
