A molecular dynamics study on force between solidification front and nanoparticle at atomic scale

Author(s):  
Kunio Fujiwara ◽  
Tomoya Miyamoto ◽  
Shota Uchida ◽  
Masahiko Shibahara
Author(s):  
Mohammad Moulod ◽  
Gisuk Hwang

Fundamental understanding of the water in graphene is crucial to optimally design and operate the sustainable energy, water desalination, and bio-medical systems. A numerous atomic-scale studies have been reported, primarily articulating the surface interactions (interatomic potentials) between the water and graphene. However, a systematic comparative study among the various interatomic potentials is rare, especially for the water transport confined in the graphene nanostructure. In this study, the effects of different interatomic potentials and gap sizes on water self-diffusivity are investigated using the molecular dynamics simulation at T = 300 K. The water is confined in the rigid graphene nanogap with the various gap sizes Lz = 0.7 to 4.17 nm, using SPC/E and TIP3P water models. The water self-diffusivity is calculated using the mean squared displacement approach. It is found that the water self-diffusivity in the confined region is lower than that of the bulk water, and it decreases as the gap size decreases and the surface energy increases. Also, the water self-diffusivity nearly linearly decreases with the increasing surface energy to reach the bulk water self-diffusivity at zero surface energy. The obtained results provide a roadmap to fundamentally understand the water transport properties in the graphene geometries and surface interactions.


2021 ◽  
Author(s):  
Nadire Nayir ◽  
Mert Y. Sengul ◽  
Anna L. Costine ◽  
Petra Reinke ◽  
Siavash Rajabpour ◽  
...  

2019 ◽  
Vol 21 (24) ◽  
pp. 13099-13108 ◽  
Author(s):  
Susanna Monti ◽  
Jiya Jose ◽  
Athira Sahajan ◽  
Nandakumar Kalarikkal ◽  
Sabu Thomas

Functionalized gold nanoparticles for antibiotic drug delivery: from the nanoscale to the atomic scale.


Author(s):  
Pengfei Ji ◽  
Mengzhe He ◽  
Yiming Rong ◽  
Yuwen Zhang ◽  
Yong Tang

A multiscale modeling that integrates electronic scale ab initio quantum mechanical calculation, atomic scale molecular dynamics simulation, and continuum scale two-temperature model description of the femtosecond laser processing of nickel film at different thicknesses is carried out in this paper. The electron thermophysical parameters (heat capacity, thermal conductivity, and electron-phonon coupling factor) are calculated from first principles modeling, which are further substituted into molecular dynamics and two-temperature model coupled energy equations of electrons and phonons. The melting thresholds for nickel films of different thicknesses are determined from multiscale simulation. Excellent agreement between results from simulation and experiment is achieved, which demonstrates the validity of modeled multiscale framework and its promising potential to predict more complicate cases of femtosecond laser material processing. When it comes to process nickel film via femtosecond laser, the quantitatively calculated maximum thermal diffusion length provides helpful information on choosing the film thickness.


2019 ◽  
Vol 33 (11) ◽  
pp. 10941-10952 ◽  
Author(s):  
Kejiang Li ◽  
Hongtao Li ◽  
Minmin Sun ◽  
Jianliang Zhang ◽  
Hang Zhang ◽  
...  

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1660
Author(s):  
Ziqi Cui ◽  
Xianglin Zhou ◽  
Qingbo Meng

This article deals with a Ti-Al alloy system. Molecular dynamics simulation was used to simulate and explore the mass transfer behavior during the laser fabrication process at atomic scale. The research goal is to investigate the mass transfer mechanism at atomic scale and the movement of solute atoms during the laser fabrication process. The mean square displacement (MSD), radial distribution function (RDF), atomic number density, and atomic displacement vector were calculated to characterize it. The results show that the TiAl alloy is completely melted when heated up to 2400 K, and increasing the temperature past 2400 K has little effect on mass transfer. As the heating time increases, the diffusion coefficient gradually decreases, the diffusion weakens, and the mass transfer process gradually stabilizes. In Ti-Al binary alloys, the diffusion coefficients of different solute atoms are related to the atomic fraction. During the melting process, the alloy particle system has a greater diffusion coefficient than the elemental particle system.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2339 ◽  
Author(s):  
Wentian Cui ◽  
Wenke Huang ◽  
Bei Hu ◽  
Jiawen Xie ◽  
Zhicheng Xiao ◽  
...  

The purpose of this study was to investigate the effect of aggregate surface adsorbed water on the adhesive capacity and nanostructure of asphalt-aggregate interfaces at the atomic scale. Molecular dynamics (MD) simulation was performed to measure and analyze the molecular interactions of asphalt binder with calcite and silica. Radial distribution function (RDF) and relative concentration (RC) were applied to characterizing the concentrations and distributions of asphalt components on aggregate surfaces. In addition, debonding energy and adhesion energy were employed to calculate the variations of interface adhesion energy of the asphalt-aggregate system under different conditions. The obtained results illustrated that the water molecules adsorbed onto the surface of weakly alkaline aggregates inhibited the concentration and distribution of asphalt components near the aggregate surface, decreased adhesion energy between asphalt and aggregates, and changed asphalt nanostructure. Especially, when external free water intruded into the interface of the asphalt-calcite system, the adsorbed water interacted with free water and seriously declined the water damage resistance of the asphalt mixture with limestone as an aggregate and decreased the durability of the mixtures. The water adsorbed onto the surface of the acid aggregate negatively affected the asphalt-silica interface system and slightly reduced the water damage resistance of the asphalt mixture.


Sign in / Sign up

Export Citation Format

Share Document