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Published on: April 24, 2014
Kinetics of surface enrichment: A molecular dynamics study
Prabhat K Jaiswal1, Sanjay Puri, Subir K Das
1School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
The Journal of Chemical Physics
|October 26, 2010
Summary
Surface enrichment (SE) in mixtures is studied using molecular dynamics. Hydrodynamic effects cause a crossover in SE layer growth, changing the exponent from 0.5 to 1.0.
Area of Science:
- Physical Chemistry
- Materials Science
- Computational Physics
Background:
- Surface enrichment (SE) is crucial in multicomponent systems.
- Understanding SE kinetics informs material design and stability.
- Homogeneous mixtures (AB) interacting with selective surfaces present complex behaviors.
Purpose of the Study:
- To investigate the kinetics of surface enrichment in a binary mixture.
- To analyze the role of preferential surface attraction on SE.
- To elucidate the influence of hydrodynamic effects on SE dynamics.
Main Methods:
- Molecular dynamics simulations were employed.
- A stable homogeneous mixture (AB) was modeled.
- The system was brought into contact with a surface favoring component A.
Main Results:
- Surface enrichment profiles exhibited double-exponential behavior.
- Two distinct length scales, ξ(-) and ξ(+), were identified.
- Hydrodynamic effects induced a crossover in the growth exponent (θ) from ~0.5 to ~1.0.
- A corresponding crossover in SE layer thickness growth dynamics was observed.
Conclusions:
- The kinetics of SE are characterized by multiple time and length scales.
- Hydrodynamic interactions significantly alter the power-law growth of SE.
- The findings provide insights into the dynamic behavior of enriched surfaces.
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