Nanopatterns – Understanding Emergence of Properties at Scale

1. Nanopatterns – Understanding Emergence of Properties at Scale Robert D. Cormia / Jill N. Johnsen Foothill College

2. Overview • Nanoscience => the big ideas • Emergence => the missing idea • Nanopatterns => a new rubric • Examples => nanopatterns in use • Future directions and practice

3. Nanoscience – Big Ideas • 2006 workshops • NCLT and SRI • University of Michigan and Northwestern University • Eight big ideas • A textbook guide

4. The Big Ideas • Size and scale • Matter • Dominant Forces • Properties are size dependent • Models • Tools • Technology and society • Self assembly

5. The Missing Idea • Emergence of properties at scale • We talk about it all the time • But no one ever explains it • Because…… Emergence is a very difficult topic to talk about

6. Emergence Model Properties System behaviors System Properties Emergent Properties Class properties Archetype Behaviors Process evolution System System Archetype System process System Constituents Actor Interactions Archetype process Archetype Process Primitive interactions

7. Nanopatterns • Network archetypes • Memorizing patterns, vs. structures • Patterns of atoms in structural networks • Atoms as nodes, each with atomic orbitals => focus on bonding networks • Network archetypes => nanosystems • Smaller motifs, that expand into systems

8. Nanopatterns Rubric • Networks of atoms • Systems of physics • Emergence of properties at scale • Draw network of atoms for a structural system • Sketch out chemical bonding network • Look at the extended structure as a system

9. Size Dependent Properties “Molecular Dynamics (MD) simulations of heat transfer based on classical statistical mechanics allow the atom to have thermal heat capacity through kT energy. Here k is Boltzmann’s constant and T absolute temperature. The above picture shows melting temperatures applied on the left with the right maintained at freezing. The simulation is discreted and submicron. But lacking periodicity, MD solutions of discrete nanostructures are invalid by QM. Here QM stands for quantum mechanics. Unlike statistical mechanics, QM forbids atoms in discrete submicron nanostructures to have heat capacity, and therefore the nanostructure cannot conserve EM energy by an increase in temperature. Without temperature changes, thermal conduction is precluded at the nanoscale.” Melting point is an emergent property Validity of Heat Transfer by Molecular Dynamics - http://www.nanoqed.org/

10. Phonon Network http://en.wikipedia.org/wiki/Phonon Images Wikipedia commons

11. Size Dependent Properties:Ni nanoparticles => Nanomagnetism http://www.grin.com/en/doc/231229/size-dependent-magnetic-properties- http://www.flickr.com/photos/brookhavenlab/3191719900/in/photostream

12. Graphene as a System

13. Graphene Nanostructure Extended sp2 hybridized carbon and p-p* network

14. Nanostructures and Nanosystems from carbon nano-motifs

15. Allotropes of carbon A - diamond B - graphite C - lonsdaleite D - C60 Buckminsterfullerene E - Amorphous carbon F - C70 G - C540 H - single-walled carbon nanotube  http://en.wikipedia.org/wiki/Allotropes_of_carbon

16. Nano-Onion

18. Borazine Nanomesh • Borazine decomposition • Forms ordered surface network • One layer thick (like graphene) • Extended structure • Emergent properties http://en.wikipedia.org/wiki/Nanomesh

19. Borazine Nanomesh

20. Networks of atoms in novel nanoscale structures Dancing Triangles' are formed by sulfur atoms on a layer of copper, which in turn rests upon a base, or 'substrate' of ruthenium. Scientists at Brookhaven Lab will study this type of configuration to understand how metal behaves on top of another. Layered metals are often used as catalysts, such as those that clean pollutants from automobile exhaust in catalytic converters. Flickr Brookhaven Laboratory Stream http://www.flickr.com/photos/brookhavenlab/3191719710/in/photostream/

21. Nanostructures • Small networks of atoms • Liposomes • Dendrimers • Carbon nanotubes • Self Assembled Monolayers • Unit cells of extended nanostructured materials • Graphene • Nanomesh

22. Each phospholipid is a structural motif, a structure in itself, and a building block in a larger system http://en.wikipedia.org/wiki/Phospholipid A system of phospholipids that is an emergent structure itself. Liposomes and cellular vessicles http://en.wikipedia.org/wiki/Exosome_(vesicle)

23. Nanosystems

24. Summary / References • Nanopatterns rubric • Networks of atoms • Systems of physics • Emergence of properties at scale • Nanostructures to nanosystems • The Big Ideas in Nanoscale Science and Engineering Stevens, S. Y., Sutherland, L., Schank, P., & Krajcik, J. (2007). • http://www.mcrel.org/Nanoteach/pdfs/big_ideas.pdf