nano technology & nano materials

Ray Fernando PhDRay Fernando, PhD22 June 2009

California Polytechnic State UniversityPolymers and Coatings Program

Department of Chemistry and BiochemistrySan Luis Obispo, CAp ,

www.polymerscoatings.calpoly.edu

Nanotechnology Overview

Nanomaterials Properties

Potential Benefits

Commercial ApplicationsCommercial Applications

ChallengesChallenges

Nanotechnology is the understanding and Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications…. ……………encompassing nano-scale science,

i i d t h l t h l engineering and technology; nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scalemanipulating matter at this length scale.

(www.nano.gov)

U.S. National Nanotechnology Initiative (NNI)Initial phase funded by Federal Government in late 1990’sFormal NNI proposal on March 11, 1999Funded in 2001 with a$489 millionFunded in 2001 with a$489 million“…….a ‘new industrial revolution’ powered by systematic control of matter at the nanoscale….”yNNI is largest nanotechnology investor

over last 7 years ($7 billion)l d d $Now NNI involves 26 independent agencies $1.5

billion (2008)

“Top ten advances in materials Science”, J. Wood, Materials Today, 1(12), 40

Global InitiativesOver 65 countries have national research focus projects Over 65 countries have national research focus projects on nanotechnology2007 global nanotechnology related R&D budget was g gy gin excess of $12 billionIndustry investment surpassed governments’ in recent yearsyears.

“Top ten advances in materials Science”, J. Wood, Materials Today, 1(12), 40

http://www.nano.gov/html/facts/The_scale_of_things.html

C-C bond – 1.5 angstromsg

C-H bond – 1.1 angstroms

Ethanol: CH3-CH2OH

10-4 10-2 100 102 104 106 108 1010

Nanometer

Size and refractive index of particles are important

Nanoparticles are smaller than the wavelength of visible light; reduces chance of light scattering

Polymer latex particle size 50 - 500 nmPolymer latex particle size 50 - 500 nm

Hidi d TiO ti l 200 250Hiding grade TiO2 particle size

200 - 250 nm

Polyurethane Dispersion particle size

50 - 100 nm

Polymer molecular size in solution

2 - 100 nm

A = 4Πr2A = 4Πr2

Volume = 4/3*π*r3 Surface area = 4*π*r2

1 gram of TiO2 Volume = 0.25 cm3

P ti l P ti l S f S fParticle diameter

(nm)

Particles per gram

Surface area per

gram (m2)

Surface Area /

Volume

200 6 x 1013 7.5 1.8 x 1012

20 6 1016 75 1 8 101620 6 x 1016 75 1.8 x 1016

2 6 x 1019 750 1.8 x 1020

Bulk properties are not scalable to nanoscale

A particle of 10nm diameterA particle of 10nm diameter has 20% surface atomsA particle of 2nm diameter hasA particle of 2nm diameter has 80% surface atomsA ti l f 1 di t hA particle of 1nm diameter has 100% surface atoms

Single wall Carbon nanotube

A capped single-wall carbon nanotube with a slight bend. http://www.thomas-swan.co.uk/pages/nano_images.html

Particle Diameter ( ) 300 250 200 150 100 50(nm) 300 250 200 150 100 50

Interfacial Volume Fraction

0.03 0.04 0.05 0.06 0.10 0.22Volume Fraction

10 nm Interfacial Layer

Dispersed particle volume fraction is 0.3 in all cases

Extensive interfacial area103 to 104 m2/ml

Large number density of particles106 to 108 particles/μm3

Low percollation threshold~0.1 – 2 volume%

Sh d b lShort distance between particles~0.1 – 2 volume%

B lk t i l ti t l blBulk material properties not scalable

Optical clarity

P l l l t i t f S f t t t t / i i t fPolymer molecules at interface Surfactants at water/air interface

“Thermo-mechanical properties of LLDPE/SiO2 nanocomposites”, E. K t d M Ni iki P l 47 1267 2006 T Kontou and M. Niaounsikis, Polymer, 47, 1267, 2006 - Tg increases of 25 to 30oC observed with up to 10% nano silica

“Glass-Transition Temperature Behavior of Alumina/PMMA Glass Transition Temperature Behavior of Alumina/PMMA Nanocomposites”, B. J. Ash, R. W. Siegel, and L. S. Schadler, J. Polym. Sci.: Part B: Polym. Phys., 42, 4371, 2004. – Nano alumina / PMMA composites. 25oC drop in Tg with less / p p gthan 1% 38nm and 0.5% 17 nm. Up to 10% further addition did not lead to additional Tg reductions

“Glass Transition of the Polymer Microphase”, Bares, J., Macromolecules, 8, 244, 1975 - Tg of finely dispersed phases (~12 nm) was 20oC lower than the analogous bulk phase; proposed the first equation (modified Fox-Flory) relating the proposed the first equation (modified Fox Flory) relating the Tg to the enhanced surface to volume ratio

“Nanofiller effect on the glass transition of a polyurethane”, J. G.-I. Rodriguez et al J Thermal Anal Calorimetry 87(1) 45 2007Rodriguez, et al., J. Thermal Anal. Calorimetry, 87(1), 45, 2007 -DSC study on polyester PU with “nano” silica. Silica particle sizes are 175, 395, 730 nm, and levels are up to 10 wt.%; PU Tg (-10oC) did not change with the nanoparticles; g ( ) g p

“Dynamic and viscoelastic behavior of natural yrubber/layered silicate nanocompositesobtained by melt blending”, Ramorino, et al., Polym Eng Sci 2007Polym. Eng. Sci., 2007“Natural rubber nanocomposite reinforced with nano silica”, Chen, et al., Polym. Eng. Sci., with nano silica , Chen, et al., Polym. Eng. Sci., 2008“Sol-gel process of alkyltriethoxysilane in latex for alkylated silica formation in natural rubber”, Siramanont, et al., Polym. Eng. Sci., 20092009

Dispersion of layered inorganics in polymerIn-situ generation of nano-phasesIncorporation of nano-particles

Nylon/Clay Nylon/Clay Nanocomposites (Toyota/Ube, 1980’ )1980’s)

70% higher tensile modulus125% higher flexural modulusH t di t ti Heat distortion temperature increased from 65 oC t 152 oC

Epoxy / Layered Silicate (Vaia –to 152 oC Materials Today, 2004)

X-ray diffraction pattern

Dispersed Intercalated ExfoliatedDispersed Intercalated Exfoliated

•Pinnavaia, T.J., and Beall and G.W. (Ed.), “Polymer-Clay Nanocomposites”, Wiley (2000)•Gao F Materials Today November 2004•Gao F., Materials Today, November 2004•Vaia, R.A. and Wagner, H.D., Materials Today, November 2004

BarrierGas Water etcGas, Water, etc.

Anti-CorrosionFire RetardancyFire RetardancyMechanical Properties

MicrocompositeAspect Ratio

25:1

NanocompositeNanocompositeAspect Ratio

250:1

Nano-Clay SuppliersElementisNanocorNanocorSouthern ClayOthers

P d M fProduct ManufacturersInmat, Inc.

2001 Wilson double core tennis ballsRecent efforts on PET, PP film barrier coatings

Others

TEOS Hydrolysis/condensation

SolSol--Gel Hybrid NanoGel Hybrid Nano--Composite Composite CoatingsCoatings

Si

OCH3

TEOS Cyclo-aliphatic Epoxy

CoatingsCoatings

OCH2CH2CHCH2H3COOCH3 O

OC2H5 H2O

TEOS Cyclo-aliphatic Epoxy

+ +Si

2 5

OC2H5C2H5OOC2H5

O

CO

H2C

O

GPTMOS

OC2H5

Inorganic / Organic Nanocompositeg g p

Aluminum OxideAntimony Tin OxideBarium Sulfate

Copper OxideIndium Tin OxideIron OxideBarium Sulfate

Bismuth OxideBoehmiteCalcium Cabonate

Iron OxideNano-ClaysPOSSSilicon DioxideCalcium Cabonate

Carbon NanotubesCerium Oxide

Silicon DioxideTitanium DioxideZinc Oxide

Cobalt Aluminate ...……

Anti-microbialAntistatic

Optical PropertiesPhotocatalysis

Gas/Stain BarrierCorrosionFire Retardant

PhotocatalysisSurface Energy

ModificationUV StabilityFire Retardant

IR-AbsorptionMagnetic

UV StabilityX-Ray Shield………..

Mechanical

100

80

90

ntio

n (2

0o )

60

70

Glo

ss R

ete

Alumina C

Alumina D

40

50

0 0 5 1 1 5 2 2 5 3 3 5

%G

Silica A

0 0.5 1 1.5 2 2.5 3 3.5

Nanoparticle Content (Wt.%)

Transformation of a Simple Plastic into a Superhydrophobic SurfaceErbil, Demirel, Avci, and Mert, Science, Vol 299, Issue 5611, 1377-1380 , 28 February 2

Figure 1. (A) The profile of a water drop on a smooth i-PP surface that has a t t l f 104° 2° Th i PP fil d b lti t 200°Ccontact angle of 104° ± 2°. The i-PP film was prepared by melting at 200°C

between two glass slides and crystallizing at 100°C. (B) The profile of a water drop on a superhydrophobic i-PP coating on a glass slide that has a contact angle of 160°. The i-PP was dissolved in a 60% p-xylene/40% MEK mixture by volume at an initial concentration of 20 mg/ml at 100°C. The solvent mixture was evaporated at 70°C in a vacuum oven The morphology of the i-PP coatingwas evaporated at 70 C in a vacuum oven. The morphology of the i-PP coating is shown in Fig. 4.

Fig. 4. SEM picture of an i-PP coating obtained using the nonsolvent MEK as described in Fig. 1B

θ

θ - Contact Angle

Zero Contact Angle

Spontaneous WettingSpontaneous Wetting& Spreading

Rainwater cleans lotus leaves because of their bumpy surface.

Abramzon, et al., Chemistry & Life (1982)y ( )Barthlott et al., Annals of Botany (1997)

Nano-Structuring Methods

Nun, Oles, & Schleich, Macromol. Symp., 187, 677-682 (2002)

“Nanostructured superhydrophobic surfaces”, H. M. Shang, Y. Wang, K. Takahashi, G. Z. Cao, D. Li, and Y. N. Xia, J. Mater. Sci., 40, 3587, 2005

1.0 Wt. % Alumina D ~25nm Avg. particle size, 10 micron scan area

0.67 Wt. % Alumina C ~25 nm Avg. particle size, 10 micron scan area

Self-cleaning surfacegAntibacterial Activity

Super hydrophilicityAnti-fogging activityAnti fogging activity

1.2

IRVisible RegionUV0 8

1

ce

0.6

0.8

Ref

lect

anc

Rutile

Anatase0.2

0.4

R

0360 400 440 480 520 560 600 640 680 720

W l th ( )Wavelength (nm)

TiO2 + UV light ⎯→ e- + hole+

e- + hole+ ⎯→ TiO2 + heat

hole+ + OH- ⎯→ OH•

2

e- + O2 ⎯→ O2-

O2- + OH• + (-CH2-) ⎯→ intermediates•

•

•

O2- + OH• + intermediates ⎯→ CO2 + H2O•

UV light + O + (-CH -) → intermediatesUV light + O2 + (-CH2-) ⎯→ intermediatesUV light + intermediates ⎯→ CO2 + H2O

Self-Cleaning Surfaces

Chalking: loose pigment particles form on the surface from the erosion of the binder as a result of photodegradation

Type I Type II Type III Type IV

erosion of the binder as a result of photodegradation.

Anatase Rutile Rutile Rutile

Product Name TiO min %

LW 94

R-900 92

R-900, R-90180

R-960 80TiO2 min.%

Chalking Surface treatment

94free none

92medium resistant Al2O3

80medium resistant SiO2 +Al2O3

80medium resistant SiO2 +Al2O3Surface treatment none Al2O3 SiO2 +Al2O3 SiO2 +Al2O3

Complete encapsulation to protect TiO2 from UV free radical reaction

www.nanotechproject.orgwww.nanotechproject.orgwww.nanoshop.com

Umicore – transparent Cerium Oxide and Zinc Oxide in Waterborne and solvent-based PU coatings for wood.

Nanovations - Lignol® Wood Coating with nanoscale UV absorber; Nano-Silver, antimicrobial and energy saving façade paint from Bioni Paints

“Bioni Paints are the only chemical free coatings in the world that can preventBioni Paints are the only chemical free coatings in the world that can prevent the growth of moss, algae and mildew permanently”

Teak Guard® Marine with Nanotechnology UV protection

Nanotec Ultra® Coating UV protection

Nanolinx™ “First wood floors finishing system to use a network of crosslinked g ynanoparticles”

Nanoseal® Wood by Nanotec “…is not a sealer; nano particles adhere directly to substrate molecules hydrophobic surface”; Nanoprotect® AntiG is ato substrate molecules……hydrophobic surface ; Nanoprotect® AntiG is a water based nanotechnology treatment that provides a layer against Graffiti on concrete and natural stone surfaces

•Nichiha Fiber Cement “Nichiha uses Nanotechnology to create self•Nichiha Fiber Cement - Nichiha uses Nanotechnology to create self-cleaning fiber cement panels”

•Markilux – Awning fabric SNC (Swela Nano Clean); dirt and water repellant•STO Lotusan® Self Cleaning Paint – water repellant surface

•AVM Industries – E-85 Nano 2000™ Self cleaning and deodorizing Titanium Dioxide coatings – water basedTitanium Dioxide coatings – water based.

•Akzo Nobel – Herbol® brand for professional architectural paints and coatings has introduced Symbiotec based on BASF’s COL.9 technology for façade coatings. Water based, water-thinnable, easy to handle, less thermoplastic, low dirt pick-up

•Behr – NanoguardBehr Nanoguard

•Nanoclean - supplier of ultrathin glass treatments

•NanoSafeguard - supplies photocatalytic self-cleaning hydrophilicNanoSafeguard supplies photocatalytic self cleaning hydrophilic coatings for outdoor.

•Saint-Gobain Glass supplies BIOCLEAN for window glasses (UV ti t d)activated)

•Pilkington Activ™ Self Cleaning glass – nano thin layer

•Nanoprotect® Glass Coating by Nanotec – easy to clean; self-cleaning; hydrophobic

•nanoCotz™ Eco Refresh and nanoCotz™•nanoCotz™ Eco-Refresh, and nanoCotz™

•Eco-Clean by Inspiraz, “The best self-cleaning clay roof in the world” by Erlus, Germany

•n-tec, Germany – Photocatalytic Self-Cleaning Coatings – titania

•Centrosolar supplies glasses with or without nano-coated anti-reflective properties

•Bioni Roof by Bioni – Heat reflecting roof coating with unique nano effects•Bioni Roof by Bioni,– Heat reflecting roof coating with unique nano effects

•Delphi Labs– “Asgard™ is comprised of a strong, ultra-thin, transparent silica binder that holds tin-oxide and other functional ingredients in place

•NaturalNano – supply cell phone blocking paint based on nanotechnology

•Halloysite nanotubes 100nm X 500nm; claim that the tubes are insertedHalloysite nanotubes 100nm X 500nm; claim that the tubes are inserted with copper particles to reflect radio signel; other applications claimed as well.

Nanoparticle SuppliersAltair NanoBYK-ChemieClariantDegussagFuso Chemical Co.Hybrid PlasticsIshiharaNanophaseNanoscale Corp.Sachtleben ChemieSachtleben ChemieSolveySukgyung A.-T.Sumitomo Osaka Cement CoSumitomo Osaka Cement Co.…..& many more

Carbon Nanotubes (CNTs)Multiwalled

Sumio Iigima Nature 354 56 1991Sumio Iigima, Nature 354, 56, 1991Radushkevich and Lukyanovich, Zurn. Fisic. Chim., 26, 88, 1952

First direct observation reportedpOberlin et al.. J. Cryst. Growth, 32, 335, 1976

First image publishedSingle-walled

Ii i d I hih hi N t 363 603 1993Iigima and Ichihashi, Nature 363, 603, 1993Bethune et al., Nature 363, 605, 1993

Nano-buds; Bucky-ballGraphene

Calling all Chemists, Nanure Nanotechnology, 3, 10 January 2008 by Rod Ruoff UTexasR t t b P d’h F ti li d G h NRecent report by Prud’homme – Functionalized Graphene Nano-Sheets. Tg of PMMA increased to 118C from 95C at 0.25 wt.% level

Mechanical PropertiesLight WeightLight WeightConductivity

Metallic to Semiconductor

More than 50 companies worldwidepAerospace Corp.Applied Carbon NanotechnologiesArkemaBayer MaterialsNanoledgeCanatuN lNanocylZYVEX Performance MaterialsHyperionIlgin NanotechIlgin NanotechShenzhen NanotechMitsui-Hodogaya

Dispersion and Dispersant DemandSurface Functionalization• Application Specific

RheologyAggregation & Flocculation

CharacterizationCost/Performance BalanceHealth-Safety ConcernsHealth Safety Concerns

BASF COL.9 Nano-binder (Example)BASF COL.9 Nano binder (Example)Herbol (Germany) Façade coatingMajor US Paint ManufacturerjLow dirt pick-up and better durability claimedComposition: Nano-silica embedded in polymer l i l d i h ilatex particle during synthesis

Avoids dispersion by formulatorMinimum interference with polymer particle Minimum interference with polymer particle coalescence

Characterization TechniquesCharacterization Techniques

Nano- Micro- Macro-(Meso-)For Bulk/Surface Morphology, Microstructure and Dispersion

mmμmnm

Nano

AFMAFMOptical MicroscopyTEM - SEM

Laser Scanning Confocal Microscopy

Light Scattering

SANSNeutron Scattering

USANS Scatteringmetrology

SAXS/WAXS USAXSX-ray Scattering

metrology

Courtesy of LiPiin Sung - NIS

•Nanoscale Materials Stewardship Program – launched by EPA January 28, 2008. TSCA Inventory Status of Nanoscale Substances Jeneral Approach 2008 pdf available at websiteSubstances – Jeneral Approach 2008 pdf available at website,•Epa.gov/oppt/nano/stewardship.stm

•“The potential risks of nanomaterials: a review carried out for pECETOC”, P. J. A. Borm and 10 other authors, Particle and Fibre Toxicology, 3(11), 2006. Open Access at Journal website.ECETOC – European Centre for Ecotoxicology and Toxicology of Chemicals 35 page review with 172 referencesChemicals - 35 page review with 172 references

•Nanosafe2.org

Volume / Mass:Gravity Vol me d3y

Surface:F i ti

Volume d3

FrictionSurface EnergyVan der Waals S f d2Van der WaalsCharge capacity

Surface d2

10-9 10-8 10-510-610-7 10-4 10-110-210-3 101100

meters

d dDispersion and Dispersant DemandRheologyCharacterizationMaterial Safety/Health EffectsCost/Performance Balance

*FSCT Virtual Learning Conference -- 2004

DLVO ThDLVO Theory(Two Particles)

S

Inter-Particle Forcesa - Van der Waals, Long-range (Attractive)b - Electrostatic, Long-range (Attractive orR l i )

Inter Particle Forces

Repulsive)c - Steric, Short-range (Repulsive)d - Solvation, Short-range (Attractive or

64

g (Repulsive)e - Born, Atomic-range (Repulsive)

Repulsiveal

Ene

rgy

S

Repulsive

bc

Pot

entia S

Att ti

ade

Attractive

ergy

Repulsive

oten

tial E

ne

SFlocculation/

65

Po

AttractiveAggregation Agglomeration