Nanomaterials ReviewNanomaterials Review

Last Time on Last Time on The Wide World of NanoThe Wide World of Nano … … What are nanoparticles, nanomaterials, and what’s out there?What are nanoparticles, nanomaterials, and what’s out there? How do we analyze and control production of such small things?How do we analyze and control production of such small things? What detection methods do we have and how good are they?What detection methods do we have and how good are they? Where does your company fit in? => in most cases, it’s on the Where does your company fit in? => in most cases, it’s on the

Integration side; not Production.Integration side; not Production.

(image taken from http://www.nature.com/nnano/journal/v4/n1/fig_tab/nnano.2008.364_F1.html)

(image taken from http://www.laboratoryequipment.com/news/2013/05/method-improves-carbon-fiber-composites-airplanes)

(image taken from http://newatlas.com/battelle-heatcoat-aircraft-icing/36201/)

Long Chain Fibers: Nothing NewLong Chain Fibers: Nothing New

Historical Structural Basics of Fibers:Historical Structural Basics of Fibers:Woven Fabrics (polyethylene, polyester, nylon, most commercial Woven Fabrics (polyethylene, polyester, nylon, most commercial textiles)textiles)

Some unrefined crystalline regions, broken up by amorphous regionsSome unrefined crystalline regions, broken up by amorphous regionsExtended Chain Fibers (refined polyethylene, Kevlar, Spectra, Extended Chain Fibers (refined polyethylene, Kevlar, Spectra, Xylon)Xylon)

Introduced a new level of straight, long-chain crystalline regions, but still Introduced a new level of straight, long-chain crystalline regions, but still contained impurities and air pockets, limiting strengthcontained impurities and air pockets, limiting strength

Nano-Composites (Carbon Nanofibers, Carbon Nanotubes)Nano-Composites (Carbon Nanofibers, Carbon Nanotubes) Offer a new level of refinement (polymer-like chains wrapped into a Offer a new level of refinement (polymer-like chains wrapped into a

strong 3D tube), but also many new levels of complexity and challengestrong 3D tube), but also many new levels of complexity and challenge

(image of (a) single-walled carbon nanotubes, (b) few-walled carbon nanotubes, and (c) multi-walled carbon nanotubes taken from http://www.intechopen.com/books/carbon-nanotubes-polymer-nanocomposites/functionalization-of-carbon-nanotubes)

(image taken from http://www.ccm.udel.edu/research_summaries/structural-hierarchy-of-ultra-high-molecular-weight-polyethylene-uhmwpe-fibers-studied-by-atomic-force-microscopy/)

(image taken from http://pslc.ws/macrog/kidsmac/polyeth.htm)

Carbon NanotubesCarbon Nanotubes

Structural Structural SpecificsSpecifics of Carbon Nanotubes of Carbon NanotubesA batch of nanotubes can have the following configurations:A batch of nanotubes can have the following configurations:

Armchair (always metallic and conductive)Armchair (always metallic and conductive) Zigzag (often semi-conductive; seldom metallic)Zigzag (often semi-conductive; seldom metallic) Chiral (often semi-conductive; seldom metallic)Chiral (often semi-conductive; seldom metallic) The dream was to have a full batch of Armchair buckytubes; hasn’t happened The dream was to have a full batch of Armchair buckytubes; hasn’t happened

yet.yet.Nanotubes can be single-walled or multi-walledNanotubes can be single-walled or multi-walled

Single-Wall Advantages: disperse better; usually longer and provide greater Single-Wall Advantages: disperse better; usually longer and provide greater strength propertiesstrength properties

Multi-Wall Advantages: More resistant to chemical damage; good potential for a Multi-Wall Advantages: More resistant to chemical damage; good potential for a variety of properties single-walled samples don’t providevariety of properties single-walled samples don’t provide

(image taken from http://physicsworld.com/cws/article/news/2013/feb/19/scientists-delve-deeper-into-carbon-nanotubes)(image taken from

http://nanophys.seas.upenn.edu/nanotube4.html)

So You Want to Make a Carbon Nanotube So You Want to Make a Carbon Nanotube Enabled Material?Enabled Material?

SynthesisSynthesis Most common method: Chemical Vapor DepositionMost common method: Chemical Vapor Deposition

Involves passing heated hydrocarbon gas over metal catalyst nanoparticlesInvolves passing heated hydrocarbon gas over metal catalyst nanoparticles Can also be made from Laser Ablation and Arc Discharge (similar to above, but the heating Can also be made from Laser Ablation and Arc Discharge (similar to above, but the heating

process is different)process is different) Plasma Enhanced CVD can produce Plasma Enhanced CVD can produce alignedaligned nanotubes nanotubes Mysteries and “Magic!”Mysteries and “Magic!”

Purification (need to remove leftover catalyst, amorphous “junk” carbon, etc., usually Purification (need to remove leftover catalyst, amorphous “junk” carbon, etc., usually by oxidizing the catalyst w/ strong acids and heating; can lead to defects, but could by oxidizing the catalyst w/ strong acids and heating; can lead to defects, but could this be a this be a goodgood thing?) thing?)Functionalization (need buffer chemicals to separate tubes from each other)Functionalization (need buffer chemicals to separate tubes from each other)

Covalent functionalization (hydrocarbons bond at tube ends and defect sites)Covalent functionalization (hydrocarbons bond at tube ends and defect sites) Noncovalent functionalization (hydrocarbon surfactants or polymers that are 1 part Noncovalent functionalization (hydrocarbon surfactants or polymers that are 1 part

hydrophobic; 1 part hydrophilic, like soap!)hydrophobic; 1 part hydrophilic, like soap!)

Functionalization

Synthesis

(image taken from http://www.intechopen.com/books/carbon-nanotubes-from-research-to-applications/syntheses-of-carbon-nanotube-metal-oxides-composites-adsorption-and-photo-degradation)

(image taken from http://what-is-nanotechnology.com/5CNTs-dispersions-carbon-nanotubes-CNTs.htm)

Purification

(image taken from http://sti.srs.gov/fulltext/ms2001443/ms2001443.html)

(image taken from http://www.goalfinder.com/product.asp?productid=113)

Carbon Nanotube Enabled MaterialsCarbon Nanotube Enabled Materials

Potential UsesPotential Uses Energy Conduction (best thermally conductive material known already; Energy Conduction (best thermally conductive material known already;

electrical conductivity 60 times WORSE than copper, but can be made electrical conductivity 60 times WORSE than copper, but can be made into conductive polymers) into conductive polymers)

Energy Storage (batteries, capacitors, hydrogen fuel cell containment all Energy Storage (batteries, capacitors, hydrogen fuel cell containment all in the works)in the works)

Further possibilities in new Composites, Fibers, and Fabrics Further possibilities in new Composites, Fibers, and Fabrics Current Real-Life UsesCurrent Real-Life Uses

High-Strength Composites being tested now (Nanotubes High-Strength Composites being tested now (Nanotubes alonealone have have demonstrated an Fdemonstrated an Ftutu of 5366 ksi, though currently in composites they of 5366 ksi, though currently in composites they offer only some improvements over carbon fiber)offer only some improvements over carbon fiber)

James Kunda: Flight deck protection for terrorist threatsJames Kunda: Flight deck protection for terrorist threats Greg Waugh: isolation and electrical spark protection for fuel transfer Greg Waugh: isolation and electrical spark protection for fuel transfer

systems on the 787 Dreamlinersystems on the 787 Dreamliner

(image taken from http://news.softpedia.com/news/Carbon-Nanotube-Wires-Are-Now-Capable-of-Electrical-Conductivity-220674.shtml)

(images taken from http://puccini.che.pitt.edu/index2.html)

(images taken from http://mechanosynthesis.mit.edu/2008/04/joining-prepreg-composite-interfaces-with-aligned-carbon-nanotubes/)