Definitions. Dimensions

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1 : Benefits and Risks A Challenge for Occupational Safety Definitions the ability to measure, see, manipulate and manufacture things between 1 and 100 nanometers (1 billionth of a meter) is seen as the driver of a new industrial revolution emerging with the development of materials that exhibit new properties and potential new risks and benefits at this tiny scale. Andrew Maynard Pictures that may be subject to third party rights have been deleted. Dr. Brock, BG, Heidelberg, 1 Dr. Brock, BG, Heidelberg, 2 Typology of Nanomaterials Nanoobjects Nanoplates (1 dimension 1 nm < l < 100 nm) Nanorods (2 dimensions 1 nm < l < 100 nm) Nanoparticles (3 dimensionens 1 nm < l < 100 nm) Materials with nanostructures Nanoparticels in matrices Nanostructures in macroscopic materials Nanostructures on surfaces Dimensions l = m Deposition in the alveoles Penetration of cell membranes Dislocation Dr. Brock, BG, Heidelberg, 3 Dr. Brock, BG, Heidelberg, 4 Nanoscaled Structures Structures on surfaces Structures inside of macroscopic objects Free nanoobjects Nanoobjects in matices Nanoparticles in the Environment Fires Volcanoes Biogenetic Nanomagnetites Viruses Dr. Brock, BG, Heidelberg, 5 Dr. Brock, BG, Heidelberg, 6

2 Anthropogenic Sources of Nanoparticels I Unintentionally formed Byproducts Anthropogenic Sources of Nanoparticels II Intentionally formed Products Formation unrealised Designed nanomaterials Dr. Brock, BG, Heidelberg, 7 Dr. Brock, BG, Heidelberg, 8 What s happening Key Technology for the Future NANO GOES BIG TIME New York and other states dole out BIG BUCKS to boost nanotechnology ACS: C&EN, 2007 New Patents worldwide Prosperity Environmental protection Improvement of the quality of life and health Private life Health care Workplace t Dr. Brock, BG, Heidelberg, 9 Dr. Brock, BG, Heidelberg, 10 Prospectives 1st Generation: Passive nanostructures (2001) Dr. Brock, BG, Heidelberg, 11 coatings, nanoparticles, nanostructured metals, polymers, ceramics 2nd Generation: Active nanostructures (2005) transistors, amplifiers, targeted drugs, actuators, adaptive structures 3rd Generation: Systems of nanosystems (2010) guided molecular assembling; 3D networking and new system architectures, robotics, supramolecular 4th Generation: Molecular nanosystems (2020) molecules as devices/components by design, based on atomic design, hierarchical emerging functions, evolutionary systems Increased integration, system approach M. C. Roco, AIChE Journal, 2004, Vol. 50 (5) Chair of the U.S. National Science and Technology Council's subcommittee on Nanoscale Science, Engineering and Technology. Strategies to Designed Nanoobejcts Top-down -Strategy X-ray lithography Nanolab on a chip Bottom-up -Strategy Aggregation of single molecules Fixation of the structures Dr. Brock, BG, Heidelberg, 12

3 Synthesis of Nanoobjects Properties Mechanical processes plastical forming, ball milling, electrospinning Thermal processes Thermal decomposition (oven, plasma, laser), Recrystallisation of amorphous alloys, vaporisation and condensation, lyophilisation, spray drying Physical processes Noble gas condensation, elektrodeposition Chemical processes Precipitiation, sol-gel process, electrochemical deposition, etching (porous Si, Raney nickel), crystallisation of amorphous solids, oxidation of precursor molecules Dr. Brock, BG, Heidelberg, 13 High surface activities Large specific surfaces Chemically active centers Catalysis Dr. Brock, BG, Heidelberg, 14 Formation of radicals Chemical modifications Quantum effects Adsorption of large quantities of other substances Agglomeration Aggregation Agglomerates & Aggregates Rapid Agglomeration or Aggregation Dustiness? Cosmetics, pharmaceutics Skin cream with fullerenes oder particles reflecting UV radiation Dental care Cancer treatment Nanocapsules as carriers Quantum dots Markers Dr. Brock, BG, Heidelberg, 15 Dr. Brock, BG, Heidelberg, 16 Textiles, ceramics, glas, coatings UV protective clothing (ZnO) Catalysis, explosives Antibacterial clothing Kleidung (Ag) Ceramic paper in recharable batteries Low reflection photovoltaic systems Stain-resistant windows, clothing, shoes Colour effects in lacquers Scratch-resistant coatings Self-cleaning coatings Catalytical oxidation of dirt on coatings Hgher degrees of efficiency of chemical processes Higher reaction rates in explosives Compounds and blends Stabitily Fire retardant Lower viscosities Reversible adhesives Dr. Brock, BG, Heidelberg, 17 Dr. Brock, BG, Heidelberg, 18

4 Questions Electronics Pt Au 55 (PPh 3 ) 12 Cl 6 CNT for Dies OLED CNT as conductors Pd(lig) x What do we know? Single-electron switches Batteries, fuel cells, H 2 storage systems, detectors Where are we going? What has to be done? Dr. Brock, BG, Heidelberg, 19 Dr. Brock, BG, Heidelberg, 20 Particle Concentrations Exposure at the Workplace Indoor measurements (1) Up to 10 4 m 3 Nanomaterial Inhalation Dermal Exposure Concentration at industrial workplaces (1) Up to 10 5 m 3 Nanodusts Yes Yes Bakery (oven) (2) 6, m 3 Cigarette smoke (1) 10 6 m 3 Welding (1) Up to 10 7 m 3 Particles, rods, plates Nanoobjects in solid matices Only if released form the matrix Only if released form the matrix Diesel exhausts (3) Up to m 3 Nanoobjects in suspensions Yes for aerosols Possible Taken from BASF 1, BGIA 2, Grimm 3 Dr. Brock, BG, Heidelberg, 21 Dr. Brock, BG, Heidelberg, 22 Potential Hazards Factors Expositon Dusts, Aerosols Toxic effects? Fires and explosions Environmental effects Dermal exposure Oral Exposure Very broad range of properties Properites determinded by Intrinsic properties of the materisal itself Geometry and surface properties Properties of coatings (for coated nanoobjects) Properties of embedded molecules Dr. Brock, BG, Heidelberg, 23 Dr. Brock, BG, Heidelberg, 24

5 Free Nanoparticels and Nanorods Exposure Data Exposition determined by Concentration Time Distance Agglomerates, Aggregates Kinetics of formation Stability of structures Mass concentration m/v Number concentration 1/V Surface concentration a/v Chemical & physical properties of the material Background concentrations Much more data needed Dr. Brock, BG, Heidelberg, 25 Dr. Brock, BG, Heidelberg, 26 Toxic Effects of Nanoobjects Requirements for the near Future Intrinsic toxicity of the substance itself Low solulibility in body fluids Permeation of membranes, dislocation Inflammatory processes, other adverse effects Data are still inconsistent Better interdisciplinary research Physics, chemistry, material science, toxicology Improved toxicological research Systematical research on well-characterized modell particles New approach on a moleclar mechanistic basis Physicochemical research Development of better measurement techniques Systematic gathering of exposure data Dr. Brock, BG, Heidelberg, 27 Dr. Brock, BG, Heidelberg, 28 In the Meantime Prudent Practices Assumption: Nanoobjects are probably more dangerous than the bulk material (if not known better) Avoid exposure Inhalation of dusts, aerosols Minimize the formation of airborne nanoobjects Use closed systems Use effective ventilation Wear respiratory protection Dermal exposure Bestow great care on cleanliness Wear protective gloves Explosion protection Dr. Brock, BG, Heidelberg, 29