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Detection of nanoparticles

Detection of nanoparticles. Maja Remškar 1 , Ivan Iskra 1 , Janja Vaupotič 1 , Griša Močnik 2 1 Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia 2 Aerosol d.o.o., Kamniska 41, Ljubljana, Slovenia. Special properties of nanoparticles Direct observation of nanoparticles (microscopy)

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Detection of nanoparticles

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  1. Detection of nanoparticles Maja Remškar1, Ivan Iskra1, Janja Vaupotič1, Griša Močnik2 1Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia 2Aerosol d.o.o., Kamniska 41, Ljubljana, Slovenia

  2. Special properties of nanoparticles Direct observation of nanoparticles (microscopy) Indirect observation (scattering) Detection of nanoparticles Demonstration of nanoparticle detectors (Ivan Iskra, Grisa Mocnik)

  3. Number of NPs in cm3: • Office: 1.104- 4.104 • Welding (varjenje): 4.106 • Grinding (brušenje): 2.105 • Smoking >1.108 exahalation Eye: resolution - 0.1 mm Optical microscope: 300 nm (3000 x) Transmission electron microscope: 0.12 nm – 1.5.106 x Unvisible Airborn Fast NANOPARTICLE Brownian motion velocity  m-1/2  r – 3/2 mCarbon (10 nm) = 3.10-22 kg v (RT) = 11 m/s Reactive • Large surface area/mass ratio • Quantum effects

  4. Agglomeration of nanoparticles - Self-assembly of MoxSyIznanotubes 50 m - Agglomeration of TiO2 during the production process 2 nm Agglomeration of WOx nanowires during evaporation of solvent • NO data on agglomeration and recrystallization in: • bio-compatible solvents • during the transition through the cell membrane • inside the cell and its nucleus

  5. Chemical activity of nanoparticles Strongly depends on the ration of surface atoms to volume atoms Diameter NS / NV atoms 8 nm 7 % 1 nm 58 % Physical and Chemical properties of nanoparticles could influence theirpotential risk. • Composition • Size • Shape • Surface properties (possibility of adsorbed spieces) • Bulk properties- chemistry

  6. Origin of nanoparticles and where we meet them: • intentionally produced - engineered: cosmetics, food, detergents, textile, water protective films • non intentionally produced: • a side product in industrial production (grinding, soldering, milling) • combustion of bio-mass • emission from diesel engines • natural: erosion, desert powder, viruses

  7. FROM EVER Nanoparticles have always been present in the environment Combustion processes in the last 200 years have added to the amount of manmade nanoparticles entering the environment • How can we determine and measure this? • Is the overall amount of nanoparticles inthe environment set to increase?

  8. Workplace exposure Large concentrations of nanoparticles may be present in occupational environments, which deserve particular attention from the standpoint of exposure. Limited data and guidelines are available for handling nanoparticles in occupational settings as well as research laboratories. For example, guidelines for the selection of respiratory protection for specific types of nanoparticles are lacking.

  9. A number of organisations including CEN, ISO orOECD are working to develop and standardizeinstruments and test methods for the support ofappropriate health, safety and environmentlegislation and regulations of nanomaterials. Itincludes work on the development andstandardisation of: · Instruments and test methods for measurementand identification of airborne nanoparticle in theworkplace and the environment; · Test methods to characterize nanomaterials; · Protocols for toxicity and eco toxicity testing; · Protocols for whole life cycle assessment ofnanomaterials, devices and products; · Risk assessment tools relevant to the field of nanotechnologies; · Test methods to assess the performanceefficiency of engineered and personal controlmeasures; · Occupational health protocols relevant to nanotechnologies. Powered blouse respirator www.nanosafe.org

  10. STM-Scanning tunneling microscope -for studying surfaces at atomic level. -for good resolution is considered to be 0.1 nm lateral resolution and 0.01 nm depth resolution www.iap.tuwien.ac.at www.ijs.si

  11. Atomic Force Microscopy Carbon nanotubes- non-contact AFM http://mrsec.wisc.edu

  12. 15 nm TiO2 Sigma-Aldrich Interdepartmental Center for Electron Microscopy, IJS: JEM-2010F, 200 keV

  13. Light scattering Large particles: small angle of scattering Small particles: large angle of scattering Dynamic light scattering By knowing the incident light frequency and measuring the scattered light frequency to determine the shift, we can calculate particle size

  14. Detection principles Detection Condensation Electrometers Number concentration Number of particles Net charge 15-500 nm Max 105 NPs/cm3 Prize: 7.000 Eur Dekati ETaPS sensor for diesel exhaust

  15. Current Monitoring Method • Condensation Particle Counter (CPC) • • Old technology--based on cloud chamber effect • • Grow nm particles in saturated alcohol or water atmosphere • • Then use optical counter to determine number concentration • • First widespread application was in clean rooms • • Needed to count very low levels • CPCs are now common in air pollution researchstudies and to monitor industrial processes • • CPCs in routine air monitoring are novel-currently no widespread use in routine monitoring • • Results are model specific! • • No explicit upper size cut • • Performance in smallest sizes is model specific

  16. Size distribution Impactors Cascade impactors are designed for a particle size related sampling of ambient and industrial aerosols. Weight or mass size distributions of nanoparticles are obtained. Air inlet www.dekati.com www.ki.si

  17. Size distribution of nanoparticles TSI model Particle Size Range: 10 to 487nm Differential mobility analyzer Condensation particle chamber Concentrations: up to 1.107 NPs / cm3 Price: cca. 50.000 Eur

  18. Electrostatic Low Pressure Impactor 6 nm – 10.000 nm Max: 10 8 NPs / cm3 Prize: 75.000 Eur

  19. GRIMM SMPS (dr. Janja Vaupotič, JSI) Measurements of aerosol concentration and their size distribution in the range 10 – 1100 nm were carried out at different locations. Scanning mobility particle sizer (SMPS+C; GRIMM Aerosol Technik) was used. The system consisted of the condensation particle counter (CPC) and electrostatic classifier (L-DMA), without the neutraliser.

  20. Laboratory 1 cleaning open window

  21. Laboratory 2/Office –next to workroom open window

  22. Workshop (metallurgy) end of working hours start of working hours

  23. Parking place end of working day evening morning

  24. Monitoring results in IonBond, UK Background sample before vacuum system opened Vacuum chamber door opened – first 6 minutes Vacuum chamber door opened – after 9 minutes Vacuum chamber door opened – after 30 minutes

  25. Monitoring at workplace • Personal sampling: Exposure integration or alarm for personal use. Daily to monthy analysis. • Mobile device: New operations, maintenance. Response time: 5 min. • Work places: Monitoring tool for data collection and alarm. Response time: 5-30 min. • Efficiency of collective protective equipments. Qualification after new filter installation. • 5-6: Drain: Environmental protection in the liquid drain. • 7-8: Extraction: Environmental protection in the air. • 9: External: 2 different needs: • Monthly survey of the impact of the factory on the environment (routine and accidental situations) • Real time determination of the fluctuation of the external background noise in order to correct inside measurements

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