ADSORPTION AND DIFFUSION PROCESSES OF POLYETHYLENE ON SILICON (111) SURFACE STUDIED BY MOLECULAR DYNAMICS SIMULATION

2011 ◽  
Vol 10 (04) ◽  
pp. 411-421 ◽  
Author(s):  
DAN MU ◽  
YI-HAN ZHOU
Keyword(s):  
Molecular Dynamics ◽  
Adsorption Energy ◽  
Diffusion Processes ◽  
Dynamic Properties ◽  
Relative Dielectric Constant ◽  
Hydrophobic Surface ◽  
Degree Of Polymerization ◽  
Dynamics Simulation ◽  
Chain Lengths ◽  
And Diffusion

The adsorption of polyethylene with different chain lengths on a silicon (111) surface is studied via molecular dynamics simulations. The relative dielectric constant is selected to be 1 and 78.0 to mimic in vacuum and in solution environment, respectively. Different configurations and dynamic properties are found in the two absolutely different environments, showing that the solvent condition plays an obvious role in the process of chain adsorption and diffusion on the hydrophobic surface. The chain all present as two-dimensional (2D) adsorption configuration on the surface. The adsorption energy of different chain lengths follows a linear function, and the average adsorption energy per segment is -1.58 kcal/mol. In addition, the diffusion coefficient (D) of such chains scales with the degree of polymerization (N) as N-3/2.

scholarly journals A Study of the Adsorption and Diffusion Behavior of a Single Polydimethylsiloxane Chain on a Silicon Surface by Molecular Dynamics Simulation

2011 ◽  
Vol 391-392 ◽  
pp. 998-1002
Author(s):  
Jian Quan Li ◽  
Dan Mu
Keyword(s):  
Molecular Dynamics ◽  
Adsorption Energy ◽  
Dynamic Properties ◽  
Relative Dielectric Constant ◽  
Degree Of Polymerization ◽  
Dynamics Simulation ◽  
Dynamics Simulations ◽  
Chain Lengths ◽  
The Relationship ◽  
And Diffusion

The adsorption and diffusion of polydimethylsiloxane (PDMS) with different chain lengths on a silicon (111) surface were studied by molecular dynamics simulations. The relative dielectric constant was selected to be 1 to mimic a vacuum. The chains were all present as two dimensional (2D) adsorption conformation on the surface but different conformations and dynamic properties were found in the two absolutely different environments. The relationship between the adsorption energy of the different chain lengths and the degree of polymerization follows a linear function and the average adsorption energy per segment is -0.42 kcal/mol. In addition, the diffusion coefficient (D) of these chains scales with the degree of polymerization (N) as N-3/2.

MOLECULAR DYNAMICS SIMULATION OF THE ADSORPTION AND DIFFUSION OF A SINGLE POLYDIMETHYLSILOXANE POLYMER CHAIN ON A SILICON (111) SURFACE

2012 ◽  
Vol 11 (04) ◽  
pp. 697-708 ◽  
Author(s):  
DAN MU ◽  
JIAN-QUAN LI ◽  
SONG WANG ◽  
JIAN-FENG WANG
Keyword(s):  
Molecular Dynamics ◽  
Adsorption Energy ◽  
Dynamic Properties ◽  
Relative Dielectric Constant ◽  
Degree Of Polymerization ◽  
Dynamics Simulation ◽  
Single Chain ◽  
Dynamics Simulations ◽  
Chain Lengths ◽  
The Relationship

The adsorption of polydimethylsiloxane (PDMS) single chain with different chain lengths on a silicon (111) surface were studied by molecular dynamics simulations. The relative dielectric constant was selected to be 1 and 78.0 to mimic in vacuum and in solution environment, respectively. The chains were all present as two-dimensional (2D) adsorption conformation on the surface but different conformations and dynamic properties were found in the two absolutely different environments. The relationship between the adsorption energy of the different chain lengths and the degree of polymerization follows a linear function and the average adsorption energy per segment is -0.42 kcal/mol. In addition, the diffusion coefficient (D) of such chains scales with the degree of polymerization (N) as N-3/2.

Molecular dynamics simulation of carbon dioxide diffusion in NaA zeolite: assessment of surface effects and evaluation of bulk-like properties

2020 ◽  
Vol 22 (39) ◽  
pp. 22529-22536
Author(s):  
Sofia O. Slavova ◽  
Anastasia A. Sizova ◽  
Vladimir V. Sizov
Keyword(s):  
Carbon Dioxide ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Simulation Study ◽  
Surface Effects ◽  
Dynamics Simulation ◽  
Naa Zeolite ◽  
Lta Zeolite ◽  
And Diffusion ◽  
Diffusion Activation

Simulation study of surface effects and diffusion in CO2-loaded cationic LTA zeolite produced CO2 and Na+ diffusion activation energies.

Explosive Boiling of Water on a Hot Copper Plate: A Molecular Dynamics Simulation Study

2020 ◽  
Vol 35 ◽  
pp. 18-28
Author(s):  
Muhammad Rubayat Bin Shahadat ◽  
A.K.M.M. Morshed
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Liquid Water ◽  
Hydrophobic Surface ◽  
Copper Plate ◽  
Dynamics Simulation ◽  
Hydrophilic Surface ◽  
Explosive Boiling ◽  
Different Temperatures ◽  
Simulation Results

Non-equilibrium molecular dynamics simulations have been employed to study the explosive boiling phenomena of water over a hot copper plate. The molecular system was comprised of three sections: solid copper wall, liquid water, and water vapor. A few layers of the liquid water were placed on the solid Cu surface. The rest of the simulation box was filled with water vapor. Initially, the water molecules were equilibrated by using Berendsen thermostat at 298 K. Then heat was given to the copper plate at different temperatures so that explosive boiling occurs. After achieving the equilibrium by performing the previous two steps, the liquid water at 298 K is suddenly dropped on the hot plate. NVE ensemble was used in the simulation and the temperature of the copper plate was controlled to different temperatures with phantom atom thermostat. Four temperatures (400K, 500K, 650 K and 1000K) were taken to study the explosive boiling. The simulation results show that, the explosive boiling temperature of water on Cu plate is 500 K temperature. At this point, the energy flux was found 1.79x108 J/m3 which is very promising with the experimental results. Moreover, if the temperature of the surface was increased the explosive boiling occurred at a faster rate. The simulation results also show that explosive boiling occurs earlier for the hydrophilic surface than hydrophobic surface as for the hydrophilic surface the water attracted the Cu plate more than the hydrophobic surface and so the amount of energy transfer is more for the hydrophilic surface.

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