visualizing the critical dynamic events of carbon...

Visualizing the Critical Dynamic Events of Carbon Nanocomposites

using Low Cost Wearable Virtual Reality Tools

Chad Brewer, Taylor Kuttenkuler, Brittany Porter, and Chris Klenke

Missouri State University

Advisors: Dr. Razib Iqbal and Dr. Ridwan Sakidja

Abstract

Purpose of the study is to construct Virtual Reality tools that can be used for materials

science education to educate topics related to the dynamics in nanomaterials. Researchers

used the Unity Game Engine to visualize the reactions between Carbon Nanocomposites

and Oxygen molecules. After the development of the atomistic models and the initial

development in Unity, the application is able to be installed on mobile devices that meet

the API level for Google Daydream.

Modeling Development

Our project concentrates on evaluating the effect of aggressive environments onto the structural

stability of carbon nanomaterials. As a model system, we specifically looked at the stability of

Carbon Nanotubes (CNTs) against oxidative environments at elevated temperatures. The range

of temperature that we examined was set from 1000K to 3000K. We used the molecular

dynamics simulation code developed by Sandia National Laboratory called “LAMMPS” which

stands for Large-Scale Atomic/Molecular Massively Parallel Simulator. Each time step is set to

be ¼ of a femtosecond (10-15

s). We allowed the CNT to be surrounded by oxygen molecules and

we maintained each simulation under a constant average temperature. One of the challenge in

simulating the chemical reaction is the need to have a ready reactive potential that can depict

accurately the formation and breakage of chemical bonds during chemical reactions. For Carbon

and Oxygen, REAX-FF (Reactive Force Field) developed by materials scientists Adri van Duin,

William A. Goddard, III, and co- workers at the California Institute of Technology[1-2]. We

used 10,288 atoms for each molecular dynamics (MD) simulation.

As expected, the reaction rate depends quite heavily on the temperatures. At 1000-1500K, we did

not see any disintegration of the CNTs at least with the simulation time that we used. Figure 1-4

show the atomic trajectories at the start and end of the simulations at 1500K. Figure 5-8 show the

similar trajectories but at 2500K. The disintegration at 2500K initiates at the edge of the CNS

and this is expected because of the dangling carbon bonds at the edge of each CNTs. The oxygen

molecules would create C-O bonds and over time starts to weaken the stability of the edges

before the whole CNT becomes disintegrated. During the disintegration process, CO and CO2

molecules form.

Figure 1: 1500K Time Step 1


Application Development

The chemical reactions associated with the oxidation of carbon nanocomposites as shown above

and the trajectory of atoms involved in such reactions as well as the trajectories of carbon

nanocomposites under various forms of stress is often a hard concept to intuitively visualize. For

this reason, and due to the growing prevalence of nanocomposites within the sciences, a method

for visualizing these atomic processes becomes a very beneficial tool. As such, this project set

out with the notion to make visualizing various simulated atomic reactions in real-time a

possibility, utilizing new virtual reality technology and enhanced user control to allow for

researchers to gain a better idea as to the nature of such events.

We utilized the Unity Game Engine to create a visualization of the chemical reactions involving

Carbon nanocomposites. The project is a continuation of a previous project that used Google

Cardboard to view the molecular structure of statically modeled Buckminsterfullerene chemical

structures. The project was expanded to be developed for the Google Daydream device and

corresponding functionality. The upgrade from Google Cardboard to Daydream allows for more

user accessibility and interaction than the project had previously been able to achieve.

The development team was given data by their physics counterparts in the form of a text file to

be parsed by Unity and assigned to individual atoms for a virtual reality simulation. The original

data was created utilizing software available to the physics department and edited into the correct

format for the file parser. This data was intended to model the trajectories of the various atoms

involved, and had to be parsed in such a way that it were separated by frame and then by

individual atom. Each atom was then assigned a list of its overall trajectory path that would be

used to simulate the movement of the atom over the course of the entire simulation data set. The

atoms were also distinguished by their type via color so that users would be aware of the various

atoms properties.

We designed the user interface of the application to allow for frame manipulation capabilities,

such as rewinding and fast forwarding, and to allow the user to halt the simulation and go back

and forth between frames as desired. This allows for users to easily study the simulated chemical

interactions. Due to the bluetooth controller that comes partnered with the Daydream, the user is

able to manipulate the scene which they are viewing in a much more impactful way, and is now

able to move about the scene to get a better view of the chemical reactions taking place. Given

the enhanced user controls, the user is able to utilize the program to study a given simulation in a

much more productive manner, both due to addition of movement, and due to the ability to

manipulate the playback of the simulation as desired.

A method was also implemented that allows the user to choose which data set to visualize. This

is accomplished by retrieving the text files, containing the trajectory data to be visualized, from a

website hosted by Missouri State University. The user interface displays a list of the simulations

that can be ran, then loads the chosen data, from the website, into the application for

visualization. More data can be added to the website so that it can be used by the application for

future simulation purposes, and so that all of the data may be consolidated within a single

location.

Summary

We have developed visualization tools to help understand the dynamics in nanomaterials under

aggressive environments. This technology can potentially be used as an effective tool for

physics/materials science courses.

Acknowledgements

We would like to thank NASA and MOSGC for funding the project.

Biographies

Chad Brewer is originally from Charleston, Arkansas. He is a Senior Computer Science major at

Missouri State University and also holds a BA in Sociology and an AA in Criminal Justice. Chad

is currently involved with one independent research project: Visualizing the Critical Dynamic

Events of Carbon Nanocomposites Using Low Cost Wearable Virtual Reality Tools. This project

will end with an IEEE published paper that will hopefully land him a career either involving

Virtual Reality applications or software development.

Taylor Kuttenkuler is originally from California, Missouri. He is currently a Junior Computer

Science major at Missouri State University and may possibly pursue a minor in Cybersecurity.

Taylor is currently involved with one independent research project: Visualizing the Critical

Dynamic Events of Carbon Nanocomposites Using Low Cost Wearable Virtual Reality Tools.

While not attending school, Taylor works as intern in the Information Technology Department of

the the Missouri Department of Employment Security. He is hoping to use the experience gained

from this project to further widen his knowledge of software development and his future career.

Chris Klenke is from Pacific, Missouri. He is a senior majoring in both Physics and General

Mathematics and minoring in both astronomy and computer science. Chris researches the

stability of carbon nanomaterials against aggressive environments with Dr. Ridwan Sakidja and

theoretical exoplanet atmosphere components with Dr. David Cornelison, both in the Physics,

Astronomy, and Materials Science Department at Missouri State University. Chris hopes to carry

his research forward into a doctoral program researching astrophysics after his undergraduate

studies are over.

Brittany Porter is from Kansas City, Missouri. She is a senior Sociology major with a

Mathematics minor at Missouri State University. Brittany’s current research projects include

working with Dr. Ridwan Sakidja studying the stability of carbon nanomaterials. She also studies

the intersection of Catholicism and politics with Dr. Catherine Hoegeman. Brittany is hoping to

continue her education in the social sciences in the future.

References

1. van Duin, Adri C. T.; Dasgupta, Siddharth; Lorant, Francois; Goddard, William A. (2001).

"ReaxFF: A Reactive Force Field for Hydrocarbons" (PDF). The Journal of Physical

Chemistry A. 105 (41): 9396–9409

2. Nielson, Kevin D.; van Duin, Adri C. T.; Oxgaard, Jonas; Deng, Wei-Qiao; Goddard, William

A. (2005). "Development of the ReaxFF Reactive Force Field for Describing Transition Metal

Catalyzed Reactions, with Application to the Initial Stages of the Catalytic Formation of

Carbon Nanotubes" (PDF). The Journal of Physical Chemistry A. 109 (3): 493–499

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