Nanomaterials / NanoParticles Characterization and metrology E. Gaffet NanoMaterials Research Group (Belfort) Membre de l’European Academy of Sciences
Président des Groupes d’Experts / AFSSET « NanoMatériaux : Effets sur la santé de l’homme & sur l’environnement » - 2006 « NanoMatériaux et Sécurité au Travail » - 2008
Membre du Comité d’Experts Spécialisés CES / AFSSET « Evaluation des risques liés aux Agents Physiques »
Membre du GT / OMNT (Observatoire Micro-Nano-Technologies) « Nanoparticules, Nanomatériaux : Effets sur la Santé et l’Environnement » Membre du GVISN / Haut Conseil à la Santé Publique (HCSP) « Nanomatériaux »
Représentant Français - OCDE / Nanomatériaux Manufacturés « Base de données - Stratégies de recherche Sureté Sanitaire & Environnementale »
Agence Nationale de la Recherche (ANR) Membre du Comite Pilotage Pnano (2007 – 2008) Membre du Comite Scientifique Sectoriel NanoSciences – Nanotechnologies (2009 - 2012)
[email protected]
2 October 2009
France Nanomatériaux: Industries et Laboratoires en France Rapport « Nanomatériaux et sécurité au travail » Afsset - 2008
Dioxyde de titane
2 Millions* Tonnes
Silice (485.000 t)
Terres rares et Argiles
(250.000 t)
270p.
2 Millions* Tonnes
1330p. ?
Carbonate de calcium (300.000 t)
(faible quantités) (380p.)
1000p. Alumine (469.000 t)
290p. Carbone (240.000 t)
10 Millions* Tonnes
• Estimation du personnel de production potentiellement exposé dans les entreprises: 3.300 • Estimation du personnel potentiellement exposé dans les laboratoires: 7.000
* Worlwide Production
Italie R&D in nanotechnologies 1.337 Existing ultrafine manufacturing processes 9.916
Powder handling processes 341.197 Total : 352.450
The table concerns traditional industrial processes in which nanomaterials are intentionally produced or applied, together with nanotechnology R&D. The fourth column indicates the numbers of employees based on ISTAT data [18] corresponding to the ATECO category [17].
F. Boccuni et al. / Journal of Cleaner Production 16 (2008) 949e956
TiO2
nClay
ZnO TiO2
nClay
Ag nTC
nClay
nClay nClay
TiO2
TiO2
nTC
Ag
nTC
i) Nanoparticles (Specificities) ii) Nanoparticle Exposition iii) EHS Research, not yet achieved iv) A minima Nanoparticle Parameter v) Conclusions - Remarks
Nombre de particules = fonction de la dimension
1gramme d’oxyde de Titane Bulk Scale Dimension millimétrique Ø = 1mm 54 particules
1 gramme de nanoparticules d’oxyde de Titane – 100 m2
Micrometer Scale Dimension micronique Ø = 1 micromètre 10.000.000.000 particules (10 milliards) Nanometer Scale Dimension nanométrique Ø = 10 nanomètre 1016 particules (10 Quadrillions ou 10 Millions de Milliards) If only 2 grams of 100 nm diameter NPs were to be evenly distributed there would be enough to provide every human worldwide with 300,000 particles each (Hardman 2006). Source : K. Ausman Center for Biological and Environmental Nanotechnology
Source : Degussa (Evonik) / Sipernat 500 LS
F < 4 nm
????
mm
4 nm
The computer model of an AEROSIL® aggregate clearly shows the remarkable structure of the fumed silicon dioxide particles
5 mm
i)
Nanoparticles (Specificities)
ii) Nanoparticle Exposition iii) iv)
EHS Research, not yet achieved A minima Nanoparticle Parameter v) Conclusions - Remarks
A new study published in inhalation toxicology is the first published attempt to measure exposure to CNT using methods similar to those used to measure asbestos. The study “Monitoring Multiwalled Carbon Nanotube Exposure in a Carbon Nanotube Research Facility “ from a team led by Prof Il Je Yu measured exposures in the post production recovery of MWCNT and in a blending activity, part of a composite formulation process. The authors use real-time systems (SMPS, APS) to measure airborne concentrations (number and mass) and size distributions, but measured the concentration of fibre-like structures by collecting samples onto cellulose acetate filters and analysing using a transmission electron microscope. All objects, identified as MWCNT with an aspect ratio greater than 3 were counted and measured (length and diameter). High airborne concentrations of fibres were found in the blending activity (maximum 194 fibres/cc) well over the current fibre TLVs (asbestos 0.1/cc). However, the authors also report that the MWCNT lengths that were shorter than 5 μm, (1760.2 ± 1198.3 nm) and so if conventional fibre counting protocols were followed, all would have been excluded from the count. Clearly then all of the fibres measured in this case would fall into the short category as described by Poland and therefore would not be expected to exhibit the same pathogenicity as long CNT or long asbestos. However, the study does demonstrate that in a relatively simple industrial process, mixing and blending, it is possible to generate high levels of airborne MWCNT. This is extremely significant given the widely held view that generation of an aerosol of this material is almost impossible. Just because in this case, all of the fibres generated were short, there is no guarantee that a different batch of material or a different process would not produce longer fibres The study provides a very clear warning about the need for effective exposure control in facilities where MWCNT are being processed. I can only echo Andrews earlier comments, “action is also needed now to ensure carbon nanotube exposures to workers and users are kept as low as possible. This means developing appropriate exposure measurement methods, applying effective control and containment protocols, and agreeing on benchmark exposure levels to use in the absence of more formal exposure limits.”
http://community.safenano.org/blogs/rob_aitken/archive/2008/06/09/are-we-finally-getting-somewhere-withnanoparticle-risk-research.aspx
Study of Nanoparticle Emission from Production of Multi Walled Carbon Nanotubes Su-Jung (Candace) Tsai, Mario Hofmann, Marilyn Hallock , Earl Ada , Jing Kong , Michael Ellenbecker
NanoManufacturing Series – May 2009 Emissions were measured for the production of multi-walled carbon nanotubes under varying operating condiThe study was designed to investigate nanoparticle emissions from the production of carbon nanotube at a university laboratory. The furnace was located in a laboratory fume hood, and the emissions were measured at the furnace exhaust and at the researcher’s breathing zone..tions. Significant nanoparticle release was found under all conditions, and under certain operating conditions carbon nanotubes were found in the exhaust as well. Due to the excellent performance of the fume hood, no particles were found in the researcher’s breathing zone. In January 2009 the state of California asked all manufacturers of CNTs to submit information on CNT operations and release from their facilities, including fate and transport in the environment. Emissions from CNT furnaces have not been extensively characterized. The laboratory production of multi-walled carbon nanotubes by chemical vapor deposition was studied to evaluate and characterize the nanoparticle emission. Particle number concentrations for diameters from 5 nm to 20 µm were measured using the Fast Mobility Particle Sizer and the Aerodynamic Particle Sizer; the particles released from the furnace were found to be less than 500 nm in diameter. The morphology and elemental composition of the released nanoparticles were characterized by scanning and transmission electron microscopy and energy dispersive spectroscopy. Different operating conditions were studied to evaluate their effects on the number and morphology of aerosol particles, and the number of particles released. High concentration of nanoparticle aerosols were measured in the exhaust and CNT filaments and carbon particles in clusters were found.
The increase in concentration compared to the background exceeded 106 particle/cm3 and mostly the particle diameters were generally less than 100 nm. Different operating conditions changed the morphology of aerosol particles formed during production of multi-walled carbon nanotubes. The operating condition of using a lower injector temperature during production results in the mutual benefits of enhanced production yield and reduced filament formation during production. This study demonstrated that large quantities of spherical carbon nanoparticles can be found in the exhaust from carbon nanotube furnaces. That results in the potential for significant exposure to production personnel and the general public. It is essential that steps be taken to control these exposures. http://www.internano.org/ocs/index.php/NMS/NMS2009/paper/view/23/55
Co Présentation Chine / Japon – NanoSafe II – Grenoble Nov. 2008
NanoEco – Mars 2008 – Suisse
NanoEco – Mars 2008 – Suisse
Traffic-generated emissions of ultrafine particles from pavement–tire interface The mean particle number diameters were between 15–50 nm, similar to those found in LDV tail-pipe exhaust. Particle number size distributions of the aerosol generated at 30, 50 and 70km/h with non-studded tires on quartzite pavement, at 50 and 70km/h with the studded tires on quartzite pavement and at 70km/h with studded tires on granite pavement. The distributions are shown at steadystate concentrations.
1011 – 1012 particles / km (et par véhicule)
Andreas Dahl, Arash Gharibi, Erik Swietlicki, Anders Gudmundsson, Mats Bohgard, Anders Ljungman, Goran Blomqvist, Mats Gustafsson Atmospheric Environment 40 (2006) 1314–1323
Evaluation of nanoparticle emission for TiO2 nanopowder coating mater
Li-Yeh Hsu and Hung-Min Chein J. Nanoparticle Research (2007) 9:157–163
Among the three selected substrates (wood plate, polymer film, and tile plate) , tile coated with TiO2 nanopowder was found to have the highest particle emission (22 #/cm3 at 55 nm) due to nanopowder separation during the simulation process. The UV light was shown to increase the release of particle below 200 nm from TiO2 nanopowder coating materials. The results show that, under the conditions of UV lamps, a fan and scraping motion, particle number concentration or average emission rate decreases significantly after 60 and 90 min for TiO2/polymer and TiO2/wood, respectively. However, the emission rate continued to increase after 2 h of testing for TiO2/tile. It is suggested that nanoparticle emission evaluation is necessary for products with nanopowder coating.
i)
Nanoparticles (Specificities) ii) Nanoparticle Exposition
iii) EHS Research, not yet achieved iv)
A minima Nanoparticle Parameter v) Conclusions - Remarks
EHS Research Not yet achieved!!
Source : Future Techonologies Divison of VDI Technologiezentrum GmbH
Un article de revue récent (Hansen S et al., 2007 ) a ainsi recensé près de 428 études publiées ayant étudié la toxicité de 965 nanoparticules. Cet article indique que peu d’informations sont disponibles dans la littérature pour ce qui concerne l’écotoxicité. (Source : Categorization framework to aid hazard identification of nanomaterials S. F. HANSEN, B. Il H. souligne LARSEN, S.I. OLSEN, BAUN – Nanotoxicology 2007, 18) que surA.428 études,
120 indiquent une toxicité spécifique chez les mammifères et 270 une cytotoxicité « in vitro ». (> 85 % des 428 études : Toxicité spécifique Nano) Cependant, cet article met en exergue la variabilité des nanomatériaux à considérer (Figure 14) et le peu d’informations réellement disponibles sur la nature des nanoparticules étudiées.
Nanomatériaux et Sécurité au Travail AFSSET – Juillet 2008
Les effets sur la santé reliés aux nanoparticules Montréal, le
1er
mai 2008 – L’Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) vient de publier sa deuxième revue de littérature sur les risques pour la santé liés aux nanoparticules (NP) ….
de constater aussi que les effets toxiques des NP sur l’humain et sur l’animal ne sont que partiellement connus. Il est tout de même clairement établi que certaines nanoparticules insolubles peuvent franchir les différentes barrières de protection de l’humain, se distribuer dans l’organisme et s’accumuler dans certains organes et à l’intérieur des cellules. Des effets toxiques ont déjà été documentés aux niveaux pulmonaire, cardiaque, reproducteur, rénal, cutané et cellulaire. Alors que la revue de littérature publiée en 2006 concluait que la toxicité était liée à la surface des particules et non à leur masse, on sait aujourd’hui que de nombreux autres facteurs peuvent influencer la toxicité de ces produits dont leur taille, leur nombre, leur forme et leur structure cristalline, leur tendance à l’agrégation, leur réactivité de surface, leur composition chimique et leur solubilité. (…..) Quoique de grandes tendances se dessinent et démontrent de nombreux effets toxiques reliés aux NP, il ressort que chaque
produit pourrait avoir une toxicité qui lui est propre. Le responsable de cette revue de littérature, le chimiste Claude Ostiguy, croit que « Les effets toxiques documentés sur des animaux de même que les caractéristiques physico-chimiques des NP justifient de prendre dès à présent toutes les mesures nécessaires pour limiter l’exposition et protéger la santé des personnes potentiellement exposées. » Préoccupation d’avenir
L’instauration de procédures strictes de prévention demeure, selon lui, la seule façon de prévenir l’exposition professionnelle et le risque de développement de maladies professionnelles autant pour les chercheurs et les étudiants qui font le développement que pour les travailleurs qui oeuvrent à la synthèse, à la transformation ou à l’utilisation de NP. Il recommande que les efforts de recherche soient axés sur le développement de stratégies et d’outils d’évaluation de l’exposition de même que sur le développement et la mesure de l’efficacité de moyens de contrôle de l’exposition professionnelle aux NP. (….) La revue de littérature est disponible et téléchargeable gratuitement à : http://www.irsst.qc.ca/files/documents/PubIRSST/R-558.pdf
http://pubs.acs.org/journals/esthag/promo/top_papers/top2007/science1.html
http://www.nrc-cnrc.gc.ca/obj/inms-ienm/doc/nanomaterials-toxicity.pdf
Researchers Pinpoint Neural Nanoblockers in Carbon Nanotubes (1/2) A team of Brown University scientists has pinpointed why carbon nanotubes tend to block a critical signaling pathway in neurons. It’s not the tubes, the team finds, but the metal catalysts used to form the tubes. The discovery means carbon nanotubes without metal catalysts may be useful in treating human neurological disorders. Results appear in Biomaterials. PROVIDENCE, R.I. [Brown University] — Carbon nanotubes hold many exciting possibilities, some of them in the realm of the human nervous system. Recent research has shown that carbon nanotubes may help regrow nerve tissue or ferry drugs used to repair damaged neurons associated with disorders such as epilepsy, Parkinson’s disease and perhaps even paralysis. Yet some studies have shown that carbon nanotubes appear to interfere with a critical signaling transaction in neurons, throwing doubt on the tubes’ value in treating neurological disorders. No one knew why the tubes were causing a problem.
Now a team of Brown University researchers has found that it’s not the tubes that are to blame. Writing in the journal Biomaterials, the scientists report that the metal catalysts used to form the tubes are the culprits, and that minute amounts of one metal — yttrium — could impede neuronal activity. The findings mean that carbon nanotubes without metal catalysts may be able to treat human neurological disorders, although other possible biological effects still need to be studied. Lorin Jakubek “It’s a problem we can fix.” “We can purify the nanotubes by removing the metals,” said Lorin Jakubek, a Ph.D. candidate in biomedical engineering and lead author of the paper, “so, it's a problem we can fix.” Neural Nanoblocker Metal catalysts — nickel and particularly yttrium — used to create carbon nanotubes can block a key signalling pathway in neurons. Experiments show the metal particles tend to plug cellular pores normally reserved for calcium ions
http://news.brown.edu/pressreleases/2009/08/nanoblockers
i)
Nanoparticles (Specificities) ii) Nanoparticle Exposition iii) EHS Research, not yet achieved
iv) « A minima » Nanoparticle Parameter v)
Conclusions - Remarks
Nano Characterisation : « A Minima » Parameters to be determined Adopted by ISO TC 229 Shangai Conference (2008)
(a) Particle size and size distribution; (b) Agglomeration state and aggregation; (c) Shape; (d) Composition including chemical composition, crystal structure, purity/impurity; (e) Surface area; (f) Surface chemistry including catalytic activity, chirality, special considerations where particle is all surface such as dendrimers; (g) Surface charge; (h) Solubility/Dispersibility;
http://www.unece.org/trans/doc/2009/ac10c4/ST-SG-AC10-C4-2009-03e.doc
Source : Degussa (Evonik) / Sipernat 500 LS
F < 4 nm
????
mm
4 nm
The computer model of an AEROSIL® aggregate clearly shows the remarkable structure of the fumed silicon dioxide particles
5 mm
Tools for NanoCharacterisations
• Structural analyses: SEM, TEM, XRD, SAM, SPM, PEEM, LEEM
• Chemical analysis: AES, XPS, SIMS, EDS, SPM
• Electronic, optical analysis: UV/VIS, UPS, SPM
• Magnetic analysis: SQUID, MOKE, SEMPA, SPM
• Vibrational analysis: IR, HREELS, Raman, SPM
• Local physico-chemical probe: SPM
GENNESYS 2009
Elemental analysis techn. – detection range, sensitivity and lateral resolution
Electron Microscopy
d’après http://www.its.caltech.edu/~ae244/Lecture7_102307.pdf
http://www.microbeamanalysis.org/topicalconferences/particles-2009/PTC2009_Bunker.pdf
►
Scanning Probe Microscopy
http://mesonpi.cat.cbpf.br/e2008/G6-aula02.pdf
STM image (Fe / Cu)
The Quantum Corral This STM image shows the direct of standing-wave patterns in the local density of states of the Cu(111) surface. These spatial oscillations are quantum-mechanical interference patterns caused by scattering of the two-dimensional electron gas off the Fe adatoms and point defects.
http://www.nanoscience.com/education/STM.html
Atomic Manipulation by STM
Iron on Copper (111):
Circular corral radius= 71.3 A 48 Fe atoms
Quantum-mechanical interference patterns
M.F. Crommie, C.P. Lutz, D.M. Eigler. Science 262, 218-220 (1993).
Atomic Force Microscopy (AFM) • AFM is performed by scanning a sharp tip on the end of a flexible cantilever across the sample while maintaining a small force. • Typical tip radii are on the order of 1nm to 10nm. • AFM has two modes, tapping mode and contact mode. • In scanning mode, constant cantilever deflection is maintained. • In tapping mode, the cantilever is oscillated at its resonance frequency.
http://www.nanoscience.com/education/AFM.html
i)
Nanoparticles (Specificities) ii) Nanoparticle Exposition iii) EHS Research, not yet achieved iv) A minima Nanoparticle Parameter
v) Concluding Remarks
Nano Characterisation Challenge : Adaptation of Pertinent Surface Characterisation to Nanomaterials Studies
2007
http://www.nanonics.co.il/agent_files/Presentations/NSOM%2007.pdf
NanoCharacterization Statistical Point of View The Problems With TEM Technology for Measuring Colloidal Silver http://www.silver-colloids.com/Pubs/TEM.html While it is common for producers of ionic solutions to use TEM images in their promotional literature, those images are misleading in the extreme. There are three main problems with using transmission electron microscopes for analyzing colloidal silver: 1.The U.S. National Bureau of Standards (now N.I.S.T) has determined that it would require at least 10,000 digital TEM images undergoing computer analysis in order to make a statistically valid measurement of particle size distribution of colloidal particles in a liquid dispersant. Because the cost of producing such a high number of images in digital format is exorbitant, the TEM is not considered viable for measuring particle size distribution. In any case, such measurements would only be applicable to pure colloids that contain no ionic metals (cations), and since almost all colloidal silver solutions contain some silver ions, the measurements and the TEM images are not valid. The particles depicted in such images do not represent the particles in the solutions. The silver oxide particles shown on the images are not present in the actual solution, but are created during the sample preparation.
An Environmentally Sensitive Phase of Titania Nanocrystals
The calculated phase map indicates that the equilibrium boundary between anatase and rutile nanocrystals is surface charge chemistry dependent (fct Acidity), which relates to both their formation and postsynthesis environments. Anatase
Figure 2. The (D,T) phase map of titania, based on first principles calculations and Co-Existence melting enthalpies form experiment: (a) the solid-solid phase transition lines for Rutile nanocrystals with OH2- and OH-terminated surfaces and the coexistence region where PH Acide (high HCl concentration) : pure rutilethe nanocrystals (ex. : Estomac) relative stability depends on the type of PH intermédiaire (low HCl concentration), both rutile & anatase nanocrystals : Colon) adsorbed groups,(ex. and (b) the low PH basique (low acidity and pure watersolutions) : anatase nanocrystal temperature and size regime with the size range of experimental observations at 180 °C and 0,2 MHCl marked (anatase in blue, and rutile in red). Identification of individual anatase and rutile nanocrystals Co-Existence Rutile Anatase are base on their periodicities of lattice fringes in HRTEM images. The diameter refers to the anatase phase.
A.S. Barnard, H. Xu -ACS Nano, 2(11) (2008) 2237 - 2242
Hydration and Dispersion of C60 in Aqueous Systems: The Nature of Water-Fullerene Interactions
Hydrophobic → Hydrophilic character after exposure to water
The nature of fullerene-water interactions and the role that they play in the fate of C60 in aqueous systems is poorly understood. This work provides spectroscopic evidence for the surface hydroxylation of the initially hydrophobic C60 molecule when immersed in water. This mechanism appears to be the basis for stabilizing the hydrophilic nC60 aggregates in suspension. It is remarkable that such a chemical transformation and dispersion are achieved under mild conditions that are readily produced in an aquatic environment.
This acquired affinity for water is likely to play asubsequent role in the reactivity, mobility, and bioavailability of fullerenes in aqueous media Jerome Labille,Armand Masion,Fabio Ziarelli, Jerome Rose,Jonathan Brant,Frederic Villieras, Manuel Pelletier, Daniel Borschneck,Mark R. Wiesner, and Jean-Yves Bottero – Langmuir Letter - DOI: 10.1021/la9022807
Roadmap of synchrotron radiation and neutron probes for nanomaterials research.
GENNESYS 2009
Conclusions / Remarks Nano Characterisation : « A Minima » Parameters (a) Particle size and size distribution; (b) Agglomeration state and aggregation; (c) Shape; (d) Composition including chemical composition, crystal structure, purity/impurity; (e) Surface area; (f) Surface chemistry including catalytic activity, chirality, special considerations where particle is all surface such as dendrimers; (g) Surface charge; (h) Solubility/Dispersibility;
BUT !!! Statistical point of view ?? in vitro / in vivo Tests : Representative of real world ?? Parameter Stability = Fct (Environment, Life Cycle) ?? Contamination (laboratory ??)
[email protected]
Questions Discussion
Tin Whisker (Peter Bush, SUNY at Buffalo)
