Ab initio Computationally Generated Nanoporous Carbon and its Comparison to Experiment

2008 ◽  
Vol 1145 ◽  
Author(s):  
Cristina Romero ◽  
Ariel A. Valladares ◽  
R. M. Valladares ◽  
Alexander Valladares ◽  
Alipio G. Calles
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Nanoporous Carbon ◽  
Group Iv ◽  
Distribution Functions ◽  
Graphene Sheets ◽  
Radial Distribution Functions ◽  
Carbon Chains ◽  
Potential Applications ◽  
Dynamics Process

AbstractNanoporous carbon is a widely studied material due to its potential applications in hydrogen storage or for filtering undesirable products. Most of the developments have been experimental although some simulation work has been carried out based on the use of graphene sheets and/or carbon chains and classical molecular dynamics. Here we present an application of our recently developed ab initio method [1] for the generation of group IV porous materials. The method consists in constructing a crystalline diamond supercell with 216 atoms of carbon and a density of 3.546 g/cm3, then lengthening the supercell edge to obtain a density of 1.38 g/cm3, yielding a porosity of 61.1 % in order to be able to compare with experimental results reported in the literature [2]. We then subject the resulting supercell to an ab initio molecular dynamics process at 1000 K during 295 steps. The radial distribution functions obtained are compared to experiment to discern coincidences and discrepancies.

Computer Modeling of Nanoporous Materials: An ab initio Novel Approach for Silicon and Carbon

2006 ◽  
Vol 988 ◽  
Author(s):  
Ariel A. Valladares ◽  
Alexander Valladares ◽  
R. M. Valladares
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Porous Materials ◽  
Porous Carbon ◽  
Nanoporous Materials ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Novel Approach ◽  
Real Value ◽  
Dynamics Process

AbstractCarbon and silicon have been consistently proposed as elements useful in the generation of porous materials. Carbon has been insistently postulated as a promising material to store hydrogen, and crystalline silicogermanate zeolites have recently been synthesized and are being considered in catalytic processes. In the present work we report an approach to generating porous materials, in particular porous carbon and silicon, which leads to the existence of nanopores within the bulk. The method consists in constructing a crystalline diamond-like supercell with 216 atoms with a density (volume) close to the real value, then halving the density by doubling the volume (50% porosity), and subjecting the resulting supercell to an ab initio molecular dynamics process at 300 K for Si, and 1000 K for carbon, followed by geometry relaxation. The resulting samples are essentially amorphous and display pores along some of the “crystallographic” directions. We report their radial distribution functions and the pore structure where prominent.

Molecular Dynamics Study of the Structural and Dynamical Properties of Liquid Tetrahydrofuran

1990 ◽  
Vol 45 (11-12) ◽  
pp. 1342-1344 ◽  
Author(s):  
W. Drabowicz
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Radial Distribution ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Radial Distribution Functions ◽  
Frequency Spectra ◽  
Autocorrelation Functions ◽  
Dynamical Properties

AbstractA molecular dynamics simulation has been performed to investigate the structural and dynamical properties of liquid tetrahydrofuran. In particular, we have calculated six radial distribution functions, translational and rotational autocorrelation functions and their associated frequency spectra.

Structure and Properties of the GeAsS Glasses from Ab initio Calculations

2014 ◽  
Vol 1035 ◽  
pp. 502-507
Author(s):  
Li An Chen
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Ab Initio ◽  
Bond Angle ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Angle Distribution ◽  
Structure And Properties ◽  
Bond Angle Distribution ◽  
Pair Distribution Functions

The structure and properties of the GexAsxS100-2x have been studied by ab initio molecular dynamics simulation. By calculating the pair distribution functions, bond angle distribution functions, we analyze the structure and properties of the alloys. Calculations show that Ge and As are all well combined with S atoms. When x is smaller than 25.0 the binding increases with x , when x is larger than 25.0 the binding decreases with increasing x . The intervention of As atom does not affect the GeS2 formation in Ge40As40S80

Molecular Dynamics Studies of Nanoparticles of Energetic Materials

2003 ◽  
Vol 800 ◽  
Author(s):  
Saman Alavi ◽  
Gustavo F. Velardez ◽  
Donald L. Thompson
Keyword(s):  
Molecular Dynamics ◽  
Correlation Function ◽  
Solid State ◽  
Molecular Dynamics Simulations ◽  
Energetic Materials ◽  
Center Of Mass ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Dynamics Simulations ◽  
Dipole Correlation

ABSTRACTThe structural properties of several nanoparticles of 2,4,6,8,10,12-hexanitrohexaazaiso-wurtzitane, HNIW or CL-20, are studied by using molecular dynamics simulations. The internal structure of the CL-20 molecule is held rigid and the intermolecular interactions in the nanoparticles are taken from a previously developed force field. [Sorescu et al., J. Phys. Chem. B, 102, 948 (1998)] Molecular dynamics simulations of solid-like and annealed nanoparticles with 48 and 88 CL-20 molecules have been carried out in the solid-state range of temperatures from 50 to 500 K. The center-of-mass to center-of-mass radial distribution functions, dipole-dipole correlation function, the orientations of the surface dipoles, and the density of the nanoparticles were calculated at fixed temperatures for the nanoparticles.

scholarly journals Molecular Dynamics Study of Stability and Diffusion of Graphene-Based Drug Delivery Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Xiunan Wang ◽  
Yi Liu ◽  
Jingcheng Xu ◽  
Shengjuan Li ◽  
Fada Zhang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Molecular Dynamics ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Graphene Sheets ◽  
Pristine Graphene ◽  
Drug Molecules ◽  
Potential Applications ◽  
The Stability ◽  
And Diffusion

Graphene, a two-dimensional nanomaterial with unique biomedical properties, has attracted great attention due to its potential applications in graphene-based drug delivery systems (DDS). In this work graphene sheets with various sizes and graphene oxide functionalized with polyethylene glycol (GO-PEG) are utilized as nanocarriers to load anticancer drug molecules including CE6, DOX, MTX, and SN38. We carried out molecular dynamics calculations to explore the energetic stabilities and diffusion behaviors of the complex systems with focuses on the effects of the sizes and functionalization of graphene sheets as well as the number and types of drug molecules. Our study shows that the binding of graphene-drug complex is favorable when the drug molecules and finite graphene sheets become comparable in sizes. The boundaries of finite sized graphene sheets restrict the movement of drug molecules. The double-side loading often slows down the diffusion of drug molecules compared with the single-side loading. The drug molecules bind more strongly with GO-PEG than with pristine graphene sheets, demonstrating the advantages of functionalization in improving the stability and biocompatibility of graphene-based DDS.

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