A molecular dynamics study of grain boundary free energies, migration mechanisms and mobilities in a bcc Fe–20Cr alloy

2012 ◽  
Vol 60 (3) ◽  
pp. 1116-1128 ◽  
Author(s):  
I. Toda-Caraballo ◽  
P.D. Bristowe ◽  
C. Capdevila
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Free Energies

scholarly journals Doxorubicin Encapsulation in Carbon Nanotubes Having Haeckelite or Stone–Wales Defects as Drug Carriers: A Molecular Dynamics Approach

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1586
Author(s):  
Leonor Contreras ◽  
Ignacio Villarroel ◽  
Camila Torres ◽  
Roberto Rozas
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Drug Delivery Systems ◽  
Nitrogen Doping ◽  
Drug Carriers ◽  
Acidic Ph ◽  
Free Energies ◽  
Interaction Forces ◽  
Chiral Nanotubes ◽  
Binding Free Energies

Doxorubicin (DOX), a recognized anticancer drug, forms stable associations with carbon nanotubes (CNTs). CNTs when properly functionalized have the ability to anchor directly in cancerous tumors where the release of the drug occurs thanks to the tumor slightly acidic pH. Herein, we study the armchair and zigzag CNTs with Stone–Wales (SW) defects to rank their ability to encapsulate DOX by determining the DOX-CNT binding free energies using the MM/PBSA and MM/GBSA methods implemented in AMBER16. We investigate also the chiral CNTs with haeckelite defects. Each haeckelite defect consists of a pair of square and octagonal rings. The armchair and zigzag CNT with SW defects and chiral nanotubes with haeckelite defects predict DOX-CNT interactions that depend on the length of the nanotube, the number of present defects and nitrogen doping. Chiral nanotubes having two haeckelite defects reveal a clear dependence on the nitrogen content with DOX-CNT interaction forces decreasing in the order 0N > 4N > 8N. These results contribute to a further understanding of drug-nanotube interactions and to the design of new drug delivery systems based on CNTs.

Atomic Mechanisms of Grain Boundary Motion

2005 ◽  
Vol 502 ◽  
pp. 157-162 ◽  
Author(s):  
A. Suzuki ◽  
Yuri M. Mishin
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Geometric Model ◽  
Lattice Rotation ◽  
Shear Stresses ◽  
Translation Rate ◽  
Embedded Atom ◽  
Local Lattice ◽  
Symmetrical Tilt ◽  
Grain Boundary Motion

We present results of atomistic computer simulations of spontaneous and stress-induced grain boundary (GB) migration in copper. Several symmetrical tilt GBs have been studied using the embedded-atom method and molecular dynamics. The GBs are observed to spontaneously migrate in a random manner. This spontaneous GB motion is always accompanied by relative translations of the grains parallel to the GB plane. Furthermore, external shear stresses applied parallel to the GB and normal to the tilt axis induce GB migration. Strong coupling is observed between the normal GB velocity vn and the grain translation rate v||. The mechanism of GB motion is established to be local lattice rotation within the GB core that does not involve any GB diffusion or sliding. The coupling constant between vn and v|| predicted within a simple geometric model accurately matches the molecular dynamics observations.

Molecular dynamics simulation of crack propagation behaviors at the Ni/Ni3Al grain boundary

RSC Advances ◽  
2014 ◽  
Vol 4 (62) ◽  
pp. 32749 ◽  
Author(s):  
Jingui Yu ◽  
Qiaoxin Zhang ◽  
Rong Liu ◽  
Zhufeng Yue ◽  
Mingkai Tang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Grain Boundary ◽  
Crack Propagation ◽  
Dynamics Simulation
Sign in / Sign up

Export Citation Format

Share Document