computational nanoenginering of polymer surface systems

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

-8

-6

-4

-2

0

2

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0 1 2 3 4 5 6 7 8-6

-4

-2

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

-7

-6

-5

-4

-3

-2

-1

0

1

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Using MATLAB to Generate “Off-Lattice” Polymer Chains

-1.5-1

-0.50

0.51

-0.5

00.5

11.5-1

-0.5

0

0.5

-0.5

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0.5

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0

1

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3-1.5

-1

-0.5

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0.5

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

5

10-20

-10

0

10

20

30

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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