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

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

Unvisible Airborn NANOPARTICLE 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 NANOPARTICLE Fast 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

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

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 their potential risk. • Composition • Size • Shape • Surface properties (possibility of adsorbed spieces) • Bulk properties- chemistry

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

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?

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.

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. Powered blouse respirator www.nanosafe.org

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

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

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

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

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

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

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

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

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

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.

Laboratory 1 cleaning open window

Laboratory 2/Office – next to workroom open window

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

Parking place end of working day evening morning

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

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