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h l d hNanotechnology and the Energy Industrye gy dust y
Evan L. FloydDoctoral Candidate, University of Alabama at Birmingham
US NanoMetro Mapphttp://www.nanotechproject.org/inventories/map/
Why are Nanomaterials so Popular?Why are Nanomaterials so Popular?
Spun Carbon Nanotubes (left)p ( )Natural Cotton Fiber (below)
50‐100 um
4 um
2 um
Nanotechnology and the dEnergy Industry
Nano sized vs. Nanomaterial
Nanomaterial Uses
Concerns about Nanomaterials
The good newsThe good news
Nano Sized vs NanomaterialNano Sized vs. Nanomaterial
Nanomaterials are technically defined(ISO/ TS 27687:2008)
At least 1 dimension < 100 nmAt least 1 dimension < 100 nm
Intentionally produced
Nanoplate ‐ 1 dimensions <100 nm (graphene)Nanoplate 1 dimensions <100 nm (graphene)
Nanofiber – 2 dimensions <100nm (carbon nanotubes, Si nanowires, nano trees), )
Nanoparticles – 3 dimensions <100nm (quantum dots)
IIOSH Approaches to Safe Nanotechnology
Nano Sized vs NanomaterialNano Sized vs. Nanomaterial
Nano sized matter has existed for eonsVolcanic ash, smoke, sea spray, virus aerosols, lightning strike…lightning strike…
Man made nano sized matter is not necessarily nanomaterialy
Diesel particulate, stack emissions, welding fume
Nano sized materials (<100nm) are referred to as Ultrafine particles
Nano Sized Welding FumesNano Sized Welding Fumes
Mild Steel welding fume at successive stages of a cascade impactorcascade impactor
NeuroToxicology ‐gyVolume 30, Issue 6November 2009Pages 915–925Pages 915 925
Toxicity Trends of Ultrafine MaterialsToxicity Trends of Ultrafine Materials
As size decreases, toxicity increases (LD50 gets lower)
“…research suggests that, among different particle gg g psizes, Ultrafine particles are potentially the most dangerous owing to their”
Small SizeSmall Size
Deep penetration
Large surface area / volume ratio
High content of redox cycling organics
High rates of retention in the lungs
Xia, Li, Nel, Public Health Reviews, Potential Health Impacts of Nanoparticles (2009), p.138
Ultrafine Toxicity Applied to lNanoparticles
While certain differences exist between ultrafines and engineered nanomaterials, many similarities remain
Both are expected to exhibit increased toxicity due to large surface area / volume ratios
d d d f l f d bToxicity paradigms derived from ultrafine studies can be applied to nano
Oxidative Stress Paradigm
Oxidative Stress Paradigmg
Limitations Applying Ultrafine h lresearch to Nanoparticle exposure
Nanoparticles may differ from Ultrafine particles in:Nanoparticles may differ from Ultrafine particles in:
Nanomaterial UsesNanomaterial Uses
Medical / Health Related
Electronics and Technology
l dMaterials and Engineering
Nanomaterials in Medicine/ HealthNanomaterials in Medicine/ Health
Quantum dots ‐ band gap proportional to sizeUnique optical properties improve imaging (CT scans) and can be targeted to tumorsbe targeted to tumors
Used in microchip arrays
Nano Silver (nAg) –Nano Silver (nAg) antimicrobial properties
Used to prevent disease transmission from surfaces, sanitize laundry claimed to cure malaria and HIV (non‐clinical trials)
http://www.nanocotechnologies.com
laundry, claimed to cure malaria and HIV (non clinical trials)
Nano Zinc Oxide –UV absorption in sunscreen and cosmetics
Nanomaterials in l d h lElectronics and Technology
Quantum Dots – transistors and photovoltaic cells
Carbon nanobutes – electron microscope tips, photovoltaic cells, touch screen technology, cloaking/ camoflauge, super conductors
l lSilicon nanowires – electronics, transistors
http://www.nanohedron.com/Pan_octopus_small.jpg
Nanomaterials in l dMaterials and Engineering
Carbon nanotubes –Adsorption of CO2 and organic vapors, charge storage, enhancing photovoltaic efficiency, additive to conventional materials for tensile strengthg
TiO2 –UV absorption, catalysis, enhancing photovoltaic efficiency
Nanodiamond thin films – coatings on high wear surfaces to improve longevity and performance
Ex: engine cylinder walls and piston rings, bearing surfaces, etc.
Coating and growth techniques to improve drill bits and cutting tools
Nanomaterials in the Power IndustryNanomaterials in the Power Industry
Applications of Nanomaterials in the Energy SectorCreated by Dr. Wolfgang Luther for
Hessain Ministry of Economic Transportation and Urban and Hessain Ministry of Economic, Transportation and Urban and Regional Development
Published August 2008
Concerns about NanomaterialsConcerns about Nanomaterials
CdSeQuantum Dots dissociate under UV light and can lead CdSeQuantum Dots dissociate under UV light and can lead to an exposure of Cadmium and Selenium in vivo
Nano Silver is not harmful to humans but extremely toxic to many aquatic species
Carbon Nanotubes are asbestos‐like and suspected of being carcinogenic especially multi walled carbon nanotubescarcinogenic, especially multi walled carbon nanotubes
Concerns about NanotechnologyConcerns about Nanotechnology
Highly interdisciplinary field(s), unclear regulatory body/ rules
Fast time to market; <5 yrs from discovery to product
Exercising caution before we “discover” the toxicities of nanomaterials is good Industrial Hygiene practice and good bbusiness
Concerns About NanomaterialsConcerns About Nanomaterials
Nanoaerosols do not remain nano‐sized and monodispersedforever
Through agglomeration they tend to GSD of 1.34
Through nucleated condensation nanoparticles may grow to b d lsub‐micron size (0.1‐0.3 um) and larger
Aerosol Technology; Hinds 1999
Concerns About NanoparticlesConcerns About Nanoparticles
Single Fiber Filtration theory
Aerosol Technology; Hinds 1999
The Good NewsThe Good News
While single fiber filtration theory tells us 0.2 ‐0.3 um is the most penetrating particle size
HEPA filters and P‐100 respirator cartridges are 99.97% efficient at the most penetrating particle size (0.2 ‐0.3 um)
l ll bl h l dNanoparticles are especially susceptible to Thermal and Electrostatic precipitation techniques
The Good NewsThe Good News
Our standard approach is a good starting pointAnticipate – know your products and what is contained therein
Recognize if you use a product that has the potential for Recognize – if you use a product that has the potential for nanomaterial release then you can be ready to evaluate exposure
Evaluate classic sampling techniques are effective in Evaluate – classic sampling techniques are effective in capturing/ measuring nanosizedmaterial in air, water and on surfaces
Control Nanoaerosols behave much like gasses conventional Control – Nanoaerosols behave much like gasses, conventional engineering controls can be effective
More Good NewsMore Good News
We have many new tools that really help with Nano assessments
Field portable counting and sizing devices have aboundedCondensation Nuclei Counters – particle count only
Scanning Mobility Particle Sizers – Size selection and countScanning Mobility Particle Sizers Size selection and count
Wide Range Aerosol Spectrometers – Size selection and count
Analytical Methods specifically adapted for NanomaterialsAnalytical Methods specifically adapted for Nanomaterials
6 hr battery life, 10nm – 10um, 1x106 particles/cm3
Useful ResourcesUseful Resources
Approaches to Safe Nanotechnology: 2009, NIOSH
Aerosol Technology: Properties, Behavior and Measurement of Airborne Particles, Hinds, 2nd edition 1999, Wiley Interscience
l f h l hApplication of Nanotechnologies in the Energy Sector, Luther, 2008; Hessain Ministry of Economy, Transport and Urban and Regional Development