practical use of nanomaterials in plastics
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Practical Use ofNanomaterials in Plastics
Innovative TechnologiesSymposium for Plastics
July 31, 2007
Joseph J. Schwab
www.hybridplastics.com
Hybrid™Plastics
What is Nanotechnology?
Nanotechnology is the understanding and controlof matter at dimensions of roughly 1 to 100nanometers.
Nanotechnology involves imaging, measuring,modeling, and manipulating matter at this lengthscale.
At the nano-scale, the physical, chemical, andbiological properties of materials differ from theproperties of individual atoms and molecules orbulk matter, creating improved materials,devices, and systems that exploit these newproperties.
What is Nanotechnology?
“A hundred years ago, or even fifty,nanotechnology would have just beencalled chemistry”
Economist, 5 July 2001
What is Nanotechnology? Nanotechnology
NanodevicesMolecular
Electronics
Mems &BioMems
Lab on Chip
Sensors &Detectors
DeviceMiniaturization
NanotoolsFabricationTechniques
InstrumentationMetrology &
Analysis
Software ComputationSimulation
NanostructuredMaterials
Nanoparticles
SupramolecularAssemblies
Nanocomposites
Representative Types of Nanoparticles
Nanoparticles
Carbon Tubes-Single Walled-Multi Walled
Fullerenes
Clays-Montmorillonite-Halloysite-Vermiculite
Metal & Metal Oxides
Silica
POSS®
-Molecular Silicas-Monomers-Silanols-Polymers
Nanofibers
DendrimersGraphenes
1 mm
0.1 nm
1.0 nm
10 nm
100 nm
1 µm
100 µm
10 µm
• Sewing Needle• Razor Blade Thickness
• Human Hair
• Most Cells & Fibers
• Bacteria, Fillers &
Polymer Morphology
• Viruses & Nanofillers
• Macromolecules• POSS® Building Blocks
• Atoms / Small Molecules
0.1-10 nmDefectNucleation1-10 nmCritical Nucleus Size1-10 nmSurface Corrugation
0.5-50 nmChain MotionTherm-Mech.
1-1000 nmDislocation InteractionMechanics1-100 nmCrack Tip Radius10-50 nmEntanglement Rad.
0.1-10 nmPrimary StructurePolymers10-1000 nmSecondary Structure
1-100 nmQuantum WellOptical10-1000 nmWave Decay
1-100 nmTunnelingElectronics
0.1-5 nmPorosity ControlMembranes1-100 nmCell WallsBiology1-10 nmSurface TopologyCatalysis
Critical LengthPropertyField
Why is Nano Important in Materials?
Nanomaterials Are Really Not New
What has been, that will be; what has been done, that will be done.Nothing is new under the sun. Even the thing which we say, “See, thisis new!” has already existed in the ages that proceeded us.
Ecclesiastes 1, 9-10
Source: University of Dayton NEST Lab
Carbon Nanotubes
Source:Wikimedia Commons
Source:Peter Harris
Source:Peter Harris
Multi-walled Nanotubes
Source:Hyperion Catalysis
Source:Hyperion Catalysis
Source:Hyperion Catalysis
Carbon Nanotubes
Carbon Nanotubes (CNTs) typically have diameters 1000times smaller than traditional carbon fibers.
Single-walled CNTs (SWCNTs) consist of a single tubulargraphene sheet and have diameters of 1-2nm.
Multi-walled CNTs (MWCNTs) typically consist of 5-15tubular graphene layers and have diameters of 10-12nm.
CNTs can be up to 50 times stronger than steel and haveexcellent thermal and electrical conductivity.
Fullerenes
RO OR
O O
C60Fullerene
Chemically Modified C60Fullerene
EndohedralC60Fullerene
Timeline for Fullerenes(A Cautionary Tale)
In 1985 C60 is discovered. By 1990 a process for making gram quantities is developed and acceleratesresearch efforts.
At the end of 2001 Mitsubishi Chemical Corporation and Mitsubishi Corporation establish a joint venturecalled the Frontier Carbon Corporation (FCC) with the goal of becoming the world leader in thecommercial production of nano-scale carbon products.
In 2002 FCC claims mass production of 400kg/yr of fullerenes.
By 2003 FCC claims to be operating a 40 tons/year commercial-scale, low-cost plant to producefullerenes. FCC claims delivery of fullerene samples at prices ten times lower than 2002 prices. FCCalso claims first commercial product, a bowling ball.
In 2004 FCC claims 400 Japanese companies have purchased samples. Claims that commercialproducts in Japan include fiber reinforced composites for badminton rackets, tennis rackets, golf clubshafts, snow boards, ski and snow board wax, lubricants for car air conditioners, and coatings for glass.
In December 2004 FCC establishes Frontier Carbon Corporation of America (FCCA) “To meet thegrowing commercial demand for nano-scale products in the United States and Europe”. FCCA is tobegin production of fullerene materials in the U.S.
In 2005 FCCA announces an agreement with TDA Research to offer a range of fullerene products underthe Nanom product line.
Although many claims about mass production, costs remain high.
Nanoclay
Source:Wikimedia Commons
Source:Southern Clay
Source:Natural Nano
Nanoclay
Almost all nanoclays used in the plastics industryare minerals which are mined from naturallyoccurring deposits.
Montmorillonite is the most widely used clay. Ithas a plate-like anisotropic structure and is nanoin only one dimension.
Halloysite is a tube shaped clay having a typicaldiameter of 40-200nm and a length of 0.5-10um.
Metal & Metal Oxide Nanoparticles
Source:Nanophase Technologies
Source:Nanophase Technologies
Source:Nanophase Technologies
Metal oxide nanoparticles are actually isolated asagglomerates, typically over 1,000 nanometers insize, and behave similarly to conventional powders.
POSS® NanostructuresOne or more reactive groups for grafting or
polymerization.
Thermally and chemically robust hybrid
(organic-inorganic) framework.
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Nanoscopic sizeSi-Si distance = 0.5 nmR-R distance = 1.5 nm.
Precise three-dimensional structure for molecular level reinforcement of polymer
segments and coils.
Unreactive organic (R)groups for solubilizationand compatibilization.
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Stable Silanols
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Metal Containing
Why Should We Expect Improvements?
A unique aspect of nanotechnology is the vastly increased ratio of surfacearea to volume present in many nano-scale materials.
Nanoparticles in particular have a very high surface area to volume ratio.
For example, montmorillonite nanoclay platelets have a surface area of750 m2/g. This means that ~7g of platelets could cover an area the sizeof a football field.
This enormous surface means that in a nanocomposite almost all of thematrix (polymer) will be in contact with the nanoparticle.
Since the physical properties of the nanoparticles themselves aregenerally superior to the polymer matrix this suggests that the propertiesof the nanocomposite will trend toward those of the nanoparticle.
Keys to Nanocomposite Polymers
– Compatibility: Nanoparticle must have compatibility with matrix.
– Dispersion: If good compatibility is achieved, complete dispersion at themolecular/nano level should occur.
– Properties: If dispersion at the molecular/nano level is achieved, improvedoptical, physical and mechanical properties should result.
Compatibility Dispersion Improved Properties
Unfortunately nanoparticles are rarely compatible with polymer matricesand a tremendous amount of time, money, and effort has gone into tryingto overcome this problem. If the nanoparticle is not acting act thenanometer level we really should not expect results any different fromthose obtained with ordinary macroscopic fillers.
Dispersion of NanotubesPoor compatibility between the CNT surface and the matrix lead to difficulty inexfoliating and debundling CNTs. Poor adhesion of the matrix causes poordispersion, phase separation and aggregation of the CNTs making incorporation ofuntreated CNTs into polymers difficult.
Several companies have now begun to address these issues by developingproprietary compatibilizers:
Polymer compatible functionality
CNT Surface compatible functionality
Dispersion of Nanoclay
Clay Particle Clay PlateletsClay particles consist of groups of stacked platelets. The challenge is to process theclay nanocomposite so as to achieve complete dispersion of individual platelets.
Dispersion of NanoclayNanoclay must be organically modified in order to achieve compatibility with apolymer matrix. Long chain alkyl ammonium cations are typically used
N
HO
OH+
Source: Southern Clay Source: Southern Clay
Dispersion of Nanoclay
Source: Southern Clay
Source: Southern Clay
Source: Southern Clay
Good Dispersion,considered complete
Partial Dispersion,considered incomplete
Poor Dispersion
Dispersion with POSS®
50 wt% loadingand transparent!
phase inversion
Blended into 2 million MW Polystyrene
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R = cyclopentyl
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R = cyclopentyl
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R = styrenyl
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R = Phenethyl
partial compatibilitydomain formation
Dispersion with POSS®
Imaging studies on Nanoreinforced® PP fibersMolecular Silica™ dispersion confirmed at molecular level.
* Each black dot represents a 1.5 nm POSS® cage.
Source: Viers - US Air Force Research Laboratory
*scale = 50nm.
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Representative Suppliers of Nanoparticles
Raw materialsSWCNTs-HiPco and CNI X GradesCarbon Nanotechnologies, Inc
Raw MaterialMetal oxides-NanoArc, NanoDur, NanoGardNanophase
ConcentratesCNTs-KenteraZyvex
ConcentratesCNT-NanoinNanoledge
Raw Material, MasterbatchCNTsNanocyl
Raw Material, MasterbatchMWCNTs-GraphistrengthArkema
Raw MaterialMWCNTs-BaytubesBayer MaterialScience
MasterbatchMWCNTs-FibrilHyperion
Compounded productsNanoclay-nanoSEALNycoa
Compounded, ConcentratesNanoclay-NanoblendPolyone
Compounded productsNanoclay, NanotubeRTP Company
Compounded polyolefinNanoclay-HyfaxBasell
Compounded nylonNanoclay-NanomedFoster Corp.
Raw MaterialNanoclay-ClositeSothern Clay
Raw Material & MasterbatchNanoclay-Nanomer, ImpermNanocor
Raw Material & MasterbatchPOSSHybrid Plastics
How suppliedMaterial suppliedCompany
Representative Applications of Nanotubes
For the most part, the plastics industry has focused on the use of MWCNTs,primarily because they are lower cost and the difference in property enhancementsrelative to SWCNTs is slight.
Largest use of CNTs is for electrostatic dissipation. Also targeted are improvedmechanical and thermal properties.
In the area of electrostatic dissipation the two largest applications are in automotiveand electronics handling equipment.
In automotive applications CNTs are used in body parts to provide a Class Asurface for electrostatic painting. Another automotive application is fuel linecomponents such as pumps, lines and housings.
In electronics applications CNTs are used in trays for wafer manufacturing and inhousings for disk drives.
Many applications are in sporting goods to improve mechanical properties ofcomposites.
Competes with carbon black and carbon fiber.
Representative Applications of Nanoclay
Applications in plastics principally revolve around improving barrierproperties, flame resistance, thermal and structural properties.
Early commercial targets were in automotive and packaging applications.
For automotive applications the target has mainly been weight savings, aslower loadings of nanoclay can be used to reinforce polymers vs. othermineral fillers. Clay nanocomposites also provide better surfaces, reducedCTE and are potentially amenable to recycling.
In packaging the target has been barrier properties. Mainly in the area ofbeverages. Other barrier applications have focused on tires and sportinggoods (balls).
Applications for improving fire resistance of plastics also vigorouslypursued.
Competes with traditional inorganic fillers.
Representative Applications ofMetal & Metal Oxides
Primary applications in plastics include antimicrobial, fungal and moldresistant materials.
Other applications include protection from visible and UV light andabrasion resistant coatings.
Representative Applications of POSS ®
Major focus on aerospace and defense applications.
Radiation hardening and shielding.
Food Packaging.
Electronic materials.
Space Resistant materials.
POSS® Barrier in Food Packaging
POSS® incorporation provides longer product shelf life.Improves color printing.
POSS® Oxidation Resistance
MISSE 1 POSS Polyimide Samples: Erosion Depth (µm)
POSS® Oxidation Resistance
LER 6.0 nm
Etch Capabilities in Bilayer Resist DesignSLR Resist Si-based Resist
Befo
re S
trip
Aft
er S
trip
LER 5.0 nm LER 6.6 nm
LER 12.9 nm
Much Improved LER after Pattern Transfer due toExcellent Etch Characteristics of Silicon-based Resist
POSS® Oxidation Resistance
No Pattern Collapse after Etch Transfer(75 nm line/150nm Pitch)
S i l i c o n b a s e d r e s i s t c a n s u p p o r thigh aspect ratio due to excellent etch selectivity
75nm L/S after drydevelopment of UL
POSS® Tooth Restoration Products
Examples of Commercial Nanocomposites
Source: Southern Clay
Source: GM
While reports on the use of nanocomposites inautomotive applications were quite frequent asrecently as 2005, there has been a significantreduction since. Some sources reported thatNanocomposites would be used in 2006 models,but it is unclear how much is currently beingused.
Examples of Successful Nanocomposites
Source: Oceanit Nanotube-containing surfboardis tested near San Francisco.
Source: Montreal Hockey
Source: Nanoledge
Additional examples includegolf clubs, tennis rackets,sail boat masts, and skis.
Triton Systems, Inc. - Converse All Star He:01 using ORMLAS polymernanocomposite discontinued after initial launch.
InMat, Inc. - Wilson discontinues development of Double Core tennisball after initial launch.
Commercial Success can be Short Lived
Honeywell Aegis NC - no longer manufactured. Aegis OX no longercontains nanocompoite.
Eastman Chemical’s Nanocomposites - after significant effort in the area,intellectual property portfolio for polymer nanocomposites was donated tothe University of South Carolina.
Truths about Nanotechnology
For a successful technology, reality must take precedenceover public relations, for Nature cannot be fooled.
Richard FeynmanUS educator & physicist (1918 - 1988)
Truths about Nanomaterials
“Nano” is not as important as the solution it provides.
Nano has no intrinsic merit other than what it does!
The entry and market capture for “nanosolutions” requires vastly more time, capital, and support
than anyone is willing to admit.
Each nanosolution must earn a right to survivevia the application of hard science and economics
rather than reliance on slick marketing.
Trouble Brewing?Earlier this year DuPont and Environmental Defense combined to launcha Nano Risk Framework. The framework is designed to provide asystematic and disciplined process to evaluate and address the potentialrisks of nano-scale materials.
In 2005 the EPA announced that it was reclassifying nanosilver as apesticide.
In 2005 the Berkeley, CA City Council approved an amendment to theirhazardous materials law to include nano-sized particles which requiresresearchers and manufacturers to report what materials they are workingwith and how they are handling them. Earlier this year the Cambridge,MA City Council announced that it is considering a similar law.
Several studies have indicated that carbon nanoparticles might act ascytotoxins while others have shown that CNTs can have an asbestos likeeffect on lung cells. Other studies have found no links between carbonnanoparticles and cytotoxic effects.
Thank You
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