Virtually all liquids can be maintained for some time in a supercooled state, that is, at temperatures below their equilibrium melting temperatures, before eventually crystallizing. If cooled sufficiently quickly, some of these liquids will solidify into an amorphous solid, upon passing their glass transition temperature. Studies of these supercooled liquids reveal a considerable diversity in behaviour in their dynamical properties, particularly the viscosity. Angell characterized this in terms of their kinetic fragility. Previous synchrotron X-ray scattering studies have shown an increasing degree of short- and medium-range order that develops with increased supercooling. Here we demonstrate from a study of several metallic glass-forming liquids that the rate of this structural ordering as a function of temperature correlates with the kinetic fragility of the liquid, demonstrating a structural basis for fragility.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1038/ncomms5616 | DOI Listing |
J Phys Chem Lett
January 2025
Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
The behavior of supercooled glass-forming metals depends on the cooperative atomic fluctuations caused by dynamic heterogeneities in the melt. These spatial and temporal heterogeneities form dynamic clusters, which are regions of cooperative rearrangement (CRR). In this study, the macroscopic kinetics and the correlation length , of the CRR, are derived for PtCuNiP and PdCuNiP metallic glass-formers by fast differential scanning calorimetry near the glass transition.
View Article and Find Full Text PDFRSC Adv
October 2024
Department of Chemical Engineering, Tsinghua University Beijing 100084 People's Republic of China
Peroxymonosulfate (PMS) activation by solid catalysts for ciprofloxacin (CIP) removal is a promising method for decontaminating wastewater. However, mainstream catalysts suffer from efficiency and durability issues due to mechanical fragility and structural instability. Here, we have developed a durable calcium alginate hydrogel encapsulating fluorinated cobalt oxyhydroxide (FCO/CAH), fabricated by a simple hydrogen-bond-assisted cross-linking reaction, to enhance PMS activation for complete CIP removal.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2023
State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China. Electronic address:
ACS Appl Bio Mater
October 2024
Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi, Kerala 682022, India.
Cellulose nanofiber-based aerogels (CNFAs) hold immense promise across diverse fields, but their innate hydrophilicity and structural fragility in water have constrained their utility in water purification. This study introduces a green approach to induce hydrophobicity into CNFAs via thermally induced phase separation (TIPS) of beeswax, which was adhered to the nanofiber by hydrogen bonding and hydrophobic-hydrophobic interactions. The fabricated aerogel was characterized by using FTIR, SEM, XRD, TGA, contact angle, BET, and compression test.
View Article and Find Full Text PDFJ Phys Condens Matter
September 2024
Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus, 8000, DENMARK.
The Boson peak is a universal phenomenon in amorphous solids. It can be observed as an anomalous contribution to the low-temperature heat capacity over the Debye model. Amorphous phase-change materials (PCMs) such as Ge-Sb-Te are a family of poor glass formers with fast crystallization kinetics, being of interest for phase-change memory applications.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!