Computational NanoEnginering of Polymer Surface Systems

Aquil Frost, Environmental Engineering, Central State UniversityJohn Lewnard, Mechanical Engineering, University of CincinnatiAnne Shim, Biomedical Engineering, The Ohio State University

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Polymers in the Real World

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[10] [11]

[12] [13]

Why Simulations?“Because they provide the

freedom to fail!”• Cost• Time

“Assess real-world processes too complex to analyze via spreadsheets or flowcharts”

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[1]

[2]

What can we see?

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Sub-atomi

c

Nano

Meso

Macro

Size

Tim

e

TimelineWeek

1Week

2Week

3Week

4Week

5Week

6Week

7Week

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Training

Literature Review

Create Surfaces

Create Polymers

Run Simulations

Analyze Simulations

Work on Deliverables

Finish Research Paper

Finish Final Presentation

Finish Research Poster

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Programs Used

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Large-scale Atomic/Molecular Massively Parallel Simulator

Visual Molecular Dynamics

POLYMER GENERATION

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What Are Polymers? Consist of repeating

units called “monomers”

Polymer industry is larger than the aluminum, copper, and steel industries combined [4]

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Polymer Adsorption

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Using MATLAB to Generate “On-Lattice” Polymer Chains

-12 -10 -8 -6 -4 -2 0-10

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0 1 2 3 4 5 6 7 8-6

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-8 -7 -6 -5 -4 -3 -2 -1 0 1-8

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Using MATLAB to Generate “Off-Lattice” Polymer Chains

-1.5-1

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11.5-1

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CREATE SURFACES

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Surfaces

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1. Regular, Rough

Oscillations in the x direction: 1Oscillations in the y direction: 1Amplitude: 0.5

Oscillations in the x direction: 2Oscillations in the y direction: 2Amplitude: 0.1

Surfaces

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2. Random, Rough

Roughness Factor: 0.9Roughness Factor: 0.1

Testing Surfaces

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www-ee.ccny.cuny.edu 

Face Centered Cubic with MATLAB

3 rows, 3 columns, Depth of 1 16

Face Centered Cubic with MATLAB

3 rows, 3 columns, Depth of 1 17

Problems?It’s not that simple!

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Brownian FieldsCreated Using FractalsFractals are a mathematical

concept:◦Self similar with a change of scale

(magnification)

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Brownian Field Uses FractalsSince Brownian Field has holes or

gaps we have simulated a FCC structure using fractals:

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Surface AreaUsing axb = IaIIbIsin(Ø) (Area)

we find area between those two vectors.

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RUN SIMULATIONS

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LAAMPS File

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Polymer Adsorbing onto Surface

0 2 4 6 8 10

0

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10-20

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Polymer is randomly placed around surface while data is taken

http://www.technewsworld.com/story/71829.html

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Polymers are Constantly Moving

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Surface

RUN ANALYSIS

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AnalysisIn order to receive usable data – all

variables must be controlled except oneIndependent Variable:

◦RoughnessDependent Variables:

◦Entropy◦Energy

Controlled Variables:◦Surface Area◦Polymer make-up◦Surface make-up

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EntropyEntropy – How

many options does the polymer have?◦ At bottom of

trough – the polymer is compact - order Not many options

◦ At top of trough – the polymer is free to move - chaos A lot of options

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Energy vs. Distance Analysis – “The Sweet Spot”

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Lennard Jones Potential Equation

[2]

Energy (v) is a function of distance (r).Interactive Force (Epsilon)Diameter of atom (sigma)

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Lennard Jones Potential Equation

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EnergyDistance

What does this analysis tell us?

The extent at which a polymer exists at a certain entropy level◦Depends on roughness

The distance that leads to the lowest energy potential◦Where is that “sweet spot?”

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Example:

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http://www.naturalcosmeticnews.com/recent-news/pg-introduces-pantene-plant-based-plastic-bottles/

Conditioner!

How does this information help us?In the development of

conditioner:◦What is the total change in entropy

of the conditioner when adsorbing onto hair?

◦What is the distance from conditioner to hair that achieves the lowest energy level?

If P&G knew these things they could make better conditioner!

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What will this save?

Time

Effort

Money

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[7]

[8]

[9]

Works Cited[1] (2010). “Polymers”, Chemical of the Week, <

http://scifun.chem.wisc.edu/chemweek/polymers/polymers.html>(May 31, 2013).

[2] (2010). “Lennard-Jones Potential”,UCDavisChemWiki, <http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics/Atomic_Theory/Intermolecular_Forces/Lennard-Jones_Potential>(May 31, 2013).

[3] (2012). “Solutions: Simulation Software Overview.” Imagine That!, <http://www.extendsim.com/sols_simoverview.html#monteCarlo>(May 29, 2013).

[4] (2012). “What are Polymers? , MAST, <http://matse1.matse.illinois.edu/polymers/ware.html>(May 31, 2013).

[5] (2013). “Why Simulations?” TATA Interactive Systems, <http://blog.tatainteractive.com/2013/01/why-simulations.html>(May 29,2013).

[6] Landau D. P. Binder K. (2000). “Introduction,” “Simple Sampling Monte Carlo Methods ,“Monte Carlo Simulations in Statistical Physics, Press Syndicate of the University of Cambridge, Cambridge, United Kingdom, 1-6, 48-67

[7] http://www.empowernetwork.com/teameaglefreedom/blog/the-clock-is-ticking-tic-toc-tic-toc/

[8] http://emotibot.net/?i=504

[9] http://www.merchantcircle.com/business/National.Lawsuit.Funding.302-792-1400/picture/view/3137972

[10] www.idahofamilyvision.com

[11] www.plasticstoday.com 

[12] carterpaintingboulder.com

[13] www.pennysimkin.com36