AI Article Synopsis
- - Temperature significantly impacts the friction of solids, particularly leading to high friction at cryogenic temperatures where traditional thermal processes are suppressed, complicating lubrication in such environments.
- - The study presents findings on hydrogenated amorphous carbon (a-C:H) that exhibit a new sub-Arrhenius friction behavior at cryogenic temperatures, allowing for stable ultralow friction across a broad temperature range.
- - The observed friction mechanism is linked to hydrogen-induced structural transformations, explained through a modified quantum mechanical tunneling model, providing insights for better lubrication solutions in extreme conditions.
Article Abstract
Temperature is one of the governing factors affecting friction of solids. Undesired high friction state has been generally reported at cryogenic temperatures due to the prohibition of thermally activated processes, following conventional Arrhenius equation. This has brought huge difficulties to lubrication at extremely low temperatures in industry. Here, the study uncovers a hydrogen-correlated sub-Arrhenius friction behavior in hydrogenated amorphous carbon (a-C:H) film at cryogenic temperatures, and a stable ultralow-friction over a wide temperature range (103-348 K) is achieved. This is attributed to hydrogen-transfer-induced mild structural ordering transformation, confirmed by machine-learning-based molecular dynamics simulations. The anomalous sub-Arrhenius temperature dependence of structural ordering transformation rate is well-described by a quantum mechanical tunneling (QMT) modified Arrhenius model, which is correlated with quantum delocalization of hydrogen in tribochemical reactions. This work reveals a hydrogen-correlated friction mechanism overcoming the Arrhenius temperature dependence and provides a new pathway for achieving ultralow friction under cryogenic conditions.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/smll.202400083 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The nature of halogen bonding: insights from interacting quantum atoms and source function studies.
IUCrJ
March 2025
Department of Chemistry, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
A detailed study of the X...
View Article and Find Full Text PDFRationalizing protein-ligand interactions via the effective fragment potential method and structural data from classical molecular dynamics.
J Chem Phys
January 2025
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
The Effective Fragment Potential (EFP) method, a polarizable quantum mechanics-based force field for describing non-covalent interactions, is utilized to calculate protein-ligand interactions in seven inactive cyclin-dependent kinase 2-ligand complexes, employing structural data from molecular dynamics simulations to assess dynamic and solvent effects. Our results reveal high correlations between experimental binding affinities and EFP interaction energies across all the structural data considered. Using representative structures found by clustering analysis and excluding water molecules yields the highest correlation (R2 of 0.
View Article and Find Full Text PDFOptical properties and photobleaching of wildfire ashes aqueous extracts.
Environ Sci Process Impacts
January 2025
Department of Civil, Environmental and Architectural Engineering, University of Colorado at Boulder, Boulder, 80309, USA.
Wildfires can severely degrade soils and watersheds. Post-fire rain events can leach ashes and altered dissolved organic matter (DOM) into streams, impacting water quality and carbon biogeochemistry. The photochemical properties and persistence of DOM from wildfire ash leachates are not well understood.
View Article and Find Full Text PDFDual opposing quadrature-PT symmetry.
iScience
January 2025
Department of Electrical and Computering Engineering, Binghamton University, Binghamton, NY 13902, USA.
Our recent research on type-I quadrature parity-time (PT) symmetry, utilizing an open twin-beam system, not only enables observing genuine quantum photonic PT symmetry amid phase-sensitive amplification (PSA) and loss in the presence of Langevin noise but also reveals an additional classical-to-quantum (C2Q) transition in noise fluctuations. In contrast to the previous setup, our exploration of an alternative system assuming no loss involves a type-II PSA-only scheme. This scheme facilitates dual opposing quadrature-PT symmetry, offering a comprehensive and complementary comprehension of C2Q transitions and PT-enhanced quantum sensing with optimal performance in the symmetry unbroken region.
View Article and Find Full Text PDFQuantum Molecular Dynamics Approach to Understanding Interactions in Betaine Chloride and Amino Acid Natural Deep Eutectic Solvents.
ACS Phys Chem Au
January 2025
Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, 12247-014 São Paulo, Brazil.
The unique properties and versatile applications of natural deep eutectic solvents (NaDES) have sparked significant interest in the field of green chemistry. Comprised of natural components that form liquids at room temperature through strong noncovalent electrostatic interaction, these solvents are cost-effective, nontoxic, and versatile. Betaine chloride-based NaDES, in particular, have shown promise in biocatalysis and sugar extraction due to their excellent properties.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!