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

4. Agglomeration of nanoparticles
- Self-assembly of MoxSyIz nanotubes
50 m
- Agglomeration of TiO2 during the production process
Agglomeration of WOx nanowires during evaporation of solvent
2 nm
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 %
1 nm %
Physical and Chemical properties of
nanoparticles could influence their potential 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 in the 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 or OECD are working to develop and standardize instruments and test methods for the support of appropriate health, safety and environment legislation and regulations of nanomaterials. It includes work on the development and standardisation of:
· Instruments and test methods for measurement and identification of airborne nanoparticle in the workplace and the environment;
· Test methods to characterize nanomaterials;
· Protocols for toxicity and eco toxicity testing;
· Protocols for whole life cycle assessment of nanomaterials, devices and products;
· Risk assessment tools relevant to the field of
nanotechnologies;
· Test methods to assess the performance efficiency of engineered and personal control measures;
· Occupational health protocols relevant to
nanotechnologies.
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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

11. Atomic Force Microscopy
Carbon nanotubes- non-contact AFM

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

13. Dynamic 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 nm
Max 105 NPs/cm3
Prize: 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 research studies 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

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

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