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Glasses are typically characterized by time-dependent relaxation, leading to temporally changing properties. This inconsistency is a substantial issue in the development of new glasses, in particular optical glasses that require predictive responses to realize highly controlled and uniform optical responses. Here, we seek to expedite the relaxation rate using a novel thermo-ultrasonication process. As such, the As2S3 chalcogenide glass system is an ideal candidate due to its low glass-transition temperatures (Tg) and prevalent use as optical materials. The samples were subjected to ultrasonic vibration at an elevated temperature below Tg to accelerate their relaxation. We employ a combined theoretical–experimental approach to study glass relaxation via the evolution of refractive index and optical band edge. By understanding the effects of ultrasonication on glasses, we demonstrate new insights into the nature of relaxation while opening the possibility of developing ultra-stable glasses that can realize optical devices with increased lifespan. 

The functions of biomolecular condensates are thought to be influenced by their material properties, and these will be determined by the internal organization of molecules within condensates. However, structural characterizations of condensates are challenging, and rarely reported. Here, we deploy a combination of small angle neutron scattering, fluorescence recovery after photobleaching, and coarse-grained molecular dynamics simulations to provide structural descriptions of model condensates that are formed by macromolecules from nucleolar granular components (GCs). We show that these minimal facsimiles of GCs form condensates that are network fluids featuring spatial inhomogeneities across different length scales that reflect the contributions of distinct protein and peptide domains. The network-like inhomogeneous organization is characterized by a coexistence of liquid- and gas-like macromolecular densities that engenders bimodality of internal molecular dynamics. These insights suggest that condensates formed by multivalent proteins share features with network fluids formed by systems such as patchy or hairy colloids.