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Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture
Published on: May 13, 2018
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Driven Dynamics of Long-Time Bond-Breaking Events
1Department of Mechanical and Aerospace Engineering , The George Washington University , Washington , District of Columbia 20052 , United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|November 21, 2019
Summary
We developed a new simulation method, predict-correct trajectory propagation (PCTP), to study long-time bond breaking in atomic force microscopy (AFM). This method accurately captures bond rupture dynamics in driven systems, overcoming limitations of existing techniques.
Area of Science:
- * Computational Physics and Chemistry
- * Materials Science and Engineering
Background:
- * Simulating long-timescale, infrequent events in driven systems, like bond breaking, presents a significant challenge for traditional molecular dynamics (MD).
- * Existing methods like parallel replica do not fully address the time scale issues in slow-driven systems, specifically the unphysically high attempt frequency.
- * Atomic Force Microscopy (AFM) experiments probe material properties at the nanoscale, requiring accurate simulation of dynamic processes like bond rupture.
Purpose of the Study:
- * To introduce and validate a novel simulation technique, predict-correct trajectory propagation (PCTP), for nonequilibrium driven dynamics.
- * To address the limitations of current MD methods in simulating slow-driven, infrequent bond-breaking events.
- * To investigate bond rupture mechanisms in gold nanojunctions under AFM-like pulling conditions.
Main Methods:
- * Development of the predict-correct trajectory propagation (PCTP) algorithm.
- * PCTP involves three key steps: trajectory prediction, atomic structural relaxation, and trajectory correction.
- * Simulation of a gold nanojunction under mechanical pulling, mimicking AFM experiments.
Main Results:
- * PCTP successfully captures key transition dynamics of bond breaking in the activationless regime, matching accurate MD simulations.
- * Simulations at AFM experimental pulling rates reveal distinct rupture mechanisms influenced by temperature and nanojunction structure.
- * The findings are consistent with recent experimental observations in AFM bond-breaking studies.
Conclusions:
- * The PCTP method offers a viable approach for simulating long-time, nonequilibrium driven dynamics, particularly bond breaking in AFM.
- * PCTP overcomes critical time-scale limitations inherent in traditional MD simulations for slow-driven systems.
- * The study highlights the influence of temperature and structural variations on bond rupture mechanisms, providing insights for AFM applications.
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