Computational Investigation of Point Defect Formation and Migration in Nuclear Fuels
08 Mar 2012 | Online Presentations | Contributor(s): Susan Sinnott
The stabilities of selected fission products are investigated as a function of stoichiometry in uranium oxide. The approach is density functional theory (DFT) that is used to calculate the incorporation and solution energies of solid and gaseous fission products at the anion and cation vacancy sites, at the divacancy, and at the bound Schottky defect...
26 Apr 2007 | Tools | Contributor(s): Xufeng Wang, Susan Sinnott, Jing Xu, SeongJun Heo, Wen-Dung Hsu
Second-generation reactive empirical bond order(REBO)potential energy expression for hydrocarbons
Atomistic Modeling of the Mechanical Properties of Nanostructured Materials
16 Apr 2007 | Online Presentations | Contributor(s): SeongJun Heo, Susan Sinnott
The mechanical properties of carbon nanotubes are studied by using classical molecular dynamics simulations. Especially, the effects of filling, temperature, and functionalization on CNT's tensional and twisting properties are considered in this study.
Fouling Mechanisms in Y-shaped Carbon Nanotubes
04 Apr 2007 | Online Presentations | Contributor(s): Jason Myers, SeongJun Heo, Susan Sinnott
In the modern pharmaceutical and chemical industries, solutions of extremely high purity are needed. Current filtration methods are reaching the limits of their abilities, so new filters must be developed. One possible filter is a Y-shaped carbon nanotube (Y-tube). By changing the sizes of the arms of the Y-tube, custom molecular filtration is theoretically possible. Through the use of REBO molecular dynamics simulations, this is tested.
Y-tubes of different size and chirality are used ...
24 Jul 2006 | Tools | Contributor(s): Wen-Dung Hsu, SeongJun Heo, Jing Xu, Susan Sinnott
Reactive Empirical Bond-Order (REBO) potential is a many-body expression optimized for modeling covalently bonded materials, such as carbon and silicon, in large-scale atomistic simulations
24 Jul 2006 | Tools | Contributor(s): Kunal Shah, Patrick Chiu, Jing Xu, Susan Sinnott
Parallel Molecular Dynamics (MD) code that models surfactant structures in water and at liquid/solid interfaces.
Molecular Dynamics Simulations with the Second-Generation Reactive Empirical Bond Order (REBO) Potential
02 Apr 2006 | Online Presentations | Contributor(s): Wen-Dung Hsu, Susan Sinnott
In this presentation, the molecular dynamics (MD) simulation will be introduced first. The applications of MD simulation, the procedure of MD simulation and some speed-up methods in MD simulation will be talked. Then the bond order potentials which are capable to predict bond breaking and new bond formation will be talked and also how they be improved to the newer versions will be included. At last the input files, output files and some solutions for the error messages in REBO code will be mentioned.
Molecular Dynamics Studies of Gaseous Transport
05 Apr 2006 | Online Presentations | Contributor(s): Ki-Ho Lee, Jason Myers, Susan Sinnott
Carbon nanotubes (CNTs) have generated a great deal of interest due to their unique properties. In this study, we examine the transport properties of various nanotubes using REBO-MD to determine the effects of diameter and chirality on transport mode. Both oxygen and methane were diffused through different CNTs. It was determined that non-equlibrium transport through CNTs results in anomalous diffusion. As nanotube diameter increases, transport becomes more normal.
Tutorial on Using Micelle-MD
05 Apr 2006 | Online Presentations | Contributor(s): Patrick Chiu, Kunal Shah, Susan Sinnott
This is a tutorial using Micelle-MD. This includes the main
capabilities, computation procedure, with format of files
generated, and the simulation setup, which includes the material
Mechanical Properties of Surfactant Aggregates at Water-Solid Interfaces
05 Apr 2006 | Online Presentations | Contributor(s): Patrick Chiu, Kunal Shah, Susan Sinnott
This is a talk on the mechanical properties of surfactant
aggregates at water-solid interfaces using Micelle-MD. This
includes silica indentations of micelles with comparison to
experimental data and graphite indentation of Micelle.
Tribological Properties of Carbon Nanotube Bundles
03 Apr 2006 | Online Presentations | Contributor(s): SeongJun Heo, Susan Sinnott
The tribological properties of carbon nanotube(CNT) bundles are investigated in this research using classical molecular dynamics(MD) simulations. Bundle of hollow single walled CNT or CNT filled with C60 is placed between two hydrogen-terminated amorphous diamond-like carbon(DLC) substrates. The topmost diamond substrate moves to compress the nanotubes and then slides relative to the lower diamond surface in order to shear the nanotube bundle. The forces on the atoms at the topmost diamond substrate are calculated.
The Effect of Temperature Control on the Mechanical Behavior of Carbon Nanotubes
29 Mar 2006 | Online Presentations | Contributor(s): SeongJun Heo, Susan Sinnott
The effect of thermostat configurations on the mechanical behavior of empty and butane (n-C4H10) filled (10,10) carbon nanotubes (CNTs) is examined using classical, atomistic, molecular dynamics (MD) simulations. In particular, the influence of different types of thermostats, relative numbers of thermostat atoms, and rates of deformation are considered. The compressive forces on the atoms are calculated using the second generation reactive bond-order (REBO) potential.
Irradiation and Nanomechanics of Multi-Walled Carbon Nanotubes
23 Mar 2006 | Online Presentations | Contributor(s): Sharon K. Pregler, Susan Sinnott
Irradiation of nanotube structures with electron and ion beams has been used to produce functionalized nanotubes and fundamentally new structures, including junctions. Here, we build on previous studies to investigate the low-energy electron and ion (Ar and CF3) beam irradiation of triple walled carbon nanotubes that consist entirely of either chiral or armchair tubes. Effective incident energies of 50 eV/ion and 50 keV/electron are considered.
Engineering the Fiber-Matrix Interface in Carbon Nanotube Composites
23 Mar 2006 | Online Presentations | Contributor(s): Sharon K. Pregler, Yanhong Hu, Susan Sinnott
Particle depositions on polymer and carbon substrates to induce surface chemical
modification are a growing research topic in particle-surface interactions due to
localized deposition energy and the high density of molecules impacting the surface.
Previous simulations have shown that particle beam deposition can induce crosslinking
between unfunctionalized carbon nanotubes and polymer chains resulting in increased
mechanical strength and improvements of thin-film growth of the composite.
Simulating irradiation can determine if the numbers of crosslinking and/or
functionalized groups are increased in a polymer-carbon nanotube composite. These
simulations include the irradiation of fluorocarbon particles and Ar on polymer-carbon
nanotube composite substrates. Molecular dynamic simulations are used to investigate
the irradiation of multiwalled carbon nanotubes and carbon nanotube composites using
reactive empirical bond-order (REBO) potential for hydrocarbons and fluorocarbons to
calculate the forces between the atoms at equilibrium. Variables include particle type
and composite structure. This study will determine if a substrate subjected to irradiation
can affect the shear modulus, tensile modulus, and other mechanical properties of the
Bending Properties of Carbon Nanotubes
21 Mar 2006 | Online Presentations | Contributor(s): SeongJun Heo, Susan Sinnott
The effect of filling carbon nanotubes on the mechanical, especially bending, behavior of empty and filled (10,10) carbon nanotubes (CNTs) is examined using classical, atomistic, molecular dynamics (MD) simulations. In particular, influences of different filling materials like C60 or other CNT and different temperature are considered. The bending force and the deflection are investigated using the second generation reactive bond-order (REBO) potential.
Introduction to Carbon Nanotube Electronics
12 Oct 2005 | Learning Modules | Contributor(s): Susan Sinnott
Carbon nanotubes (CNT) have interesting, structure-dependent electronic properties. In particular, CNTs can be a metallic or semiconducting depending on the way in which the carbon atoms are arranged in the CNT walls. The purpose of this learning module is to familiarize students with the basic concepts associated with CNT electronic properties. It begins with a pre-test to assess initial student knowledge of the topic, followed by a presentation and reading material on the electronic properties of CNTs. This is followed by some exercises that utilize the CNTbands tool on the nanoHUB for computing key electronic properties of CNTs. Finally, a post-test is administered to determine the degree to which the module assisted in student learning of the fundamental concepts associated with the electronic properties of CNTs.
15 Jun 2004 | Online Presentations | Contributor(s): Susan Sinnott
Introduction to Nanofluidics
26 May 2005 | Learning Modules | Contributor(s): Susan Sinnott
The purpose of this learning module is to introduce students to some fundamental concepts in Nanofluidics. The module includes a pretest (without keys), a presentation, reading materials on Nanofluidics, links to the REBO simulation tool on the nanoHUB along with necessary instructions for running the simulation, and a quiz that includes keys and feedback.
Computational Studies of Confined & Externally Flowing Gases on the Mechanical Properties of Carbon
08 Apr 2005 | Presentation Materials | Contributor(s): Susan Sinnott
Historically, molecular dynamics simulations have played an important role in elucidating the mechanical responses of carbon nanotubes to external forces. Here, they are used to explore the interactions of carbon nanotubes with gases that are either confined to the nanotube interiors or are external to the nanotubes.
REBO Nanofluidics Exercise
10 May 2006 | Teaching Materials | Contributor(s): Susan Sinnott, Hetal Patel
Nanofluidics exercise showing the variation of energy and position
of methane and butane molecules flowing through an opened carbon
nanotube as the system temperature and the length of the nanotube