Improving airborne nanoparticle and cluster detection with the butanol based laminar flow condensation nuclei counters Grimm and

Transcription

1 Improving airborne nanoparticle and cluster detection with the butanol based laminar flow condensation nuclei counters Grimm and Gerhard Steiner 1,2,3,M. Orzan 1, I.Nagler 1, E. Petrakakis 1, M. Selimovic 1, C. Tauber 1, F. Tettich 3 1. University of Vienna Aerosolphysicsand Environmental Physics Boltzmanngasse 5, 1090 Wien, Austria g.steiner@univie.ac.at 2. University of Innsbruck Institute of Ion Physics and Applied Physics Technikerstrasse 25, 6020 Innsbruck, Austria gerhard.steiner@uibk.ac.at 3. GRIMM Aerosol Technik GmbH & Co. KG Ainring Dorfstraße 9, Ainring, Germany gerhard.steiner@grimm.durag.com

2 sub 3 nm nanoclusters, where to find them? nucleation particle formation condensational growth - + primary ions or molecular clusters larger particles neutral molecules e.g. cloud condensation nuclei ~ 0.5 nm 1-2 nm nm trace gases; VOCs scavenging by pre-existing aerosol (loss) particles

3 where else to find sub 3nm particles? traffic related aerosols Rönkkö et al., 2017, PNAS major fraction of particles emitted by road transportation are in size range of nm in semiurbanroadside environment: 20-54% of total particle concentration in ambient air Nosko et al., 2017, AST emissions from vehicle brakes: a significantnumber of nm airborne particles theseparticlesshould not be neglected in environmental and tribological studies.

4 detection of sub 3 nm particles? 1) Aerosol Electrometers already possible since end of 19 th century (as reviewed e.g. by Flagan, 1998, Aerosol Sci. Technol, 28: 4, ) need to be charged virtually no size dependent detection efficiency detection limit rather high 1 fa@ 2 L/min => 187 particles /cm³ 0.3 fa@ 2 L/min => 56 particles/cm³ 2) Condensation Particle Counters single particle detection possible detection of neutrals possible size dependent detection efficiency detection efficiency dependent on working fluid chemical composition of particles

5 overview of nano-cpcs adiabatic expansion CPCs Pinterich et al. (2016) The versatile analyzing nuclei counter (vsanc). Aerosol Sci. Technol. 50: mixing type CPCs Sgro & Fernández de la Mora (2004) A Simple Turbulent Mixing CNC for Charged Particle Detection Down to 1.2 nm, Aerosol Sci. Technol., 38:1, 1 11 Vanhanen et al. (2011) Particle Size Magnifier for Nano-CN Detection, Aerosol Sci. Technol., 45:4, thermally diffusive laminar flow CPCs Stolzenburg and McMurry (1991) An Ultrafine Aerosol Condensation Nucleus Counter. Aerosol Sci. Technol., 14: 1, Hering et al. (2005)A Laminar-Flow, Water-BasedCondensation Particle Counter (WCPC). Aerosol Sci. Technol., 39:7, Iida et al. (2009) Effect of Working Fluid on Sub-2 nm Particle Detection with a Laminar Flow Ultrafine Condensation Particle Counter. Aerosol Sci. Technol., 43:1, Hering et al. (2017) Detection near 1-nm with a laminar-flow, water-based condensation particle counter. Aerosol Sci. Technol., 51:3,

6 what if none of those super sophisticated instruments is available? tune your standard lab CPC

7 GRIMM 5412 GRIMM 5403

8 GRIMM 5412 GRIMM 5403 CPC counting efficiency, eta (-) WOx Ag NaCl D 50 = 4.0nm D 50 = 5.0nm D 50 = 5.4nm CPC counting efficiency, eta (-) WOx Ag NaCl D 50 = 4.0nm D 50 = 6.2nm D 50 = 7.3nm mobility diameter, D (nm) mobility diameter, D (nm)

9 GRIMM 5412 GRIMM C 10 C 36 C 1.2 L/min 35 C

10 GRIMM 5412 GRIMM

11 GRIMM 5412 GRIMM 5403 standard tuned 40-7 standard tuned 40-7 Anne Maißer & Christian Tauber, University of Vienna: onset saturation ratio for THA+ (1.43nm) : S = 4.138

12 counting efficiency measurements 1 Vienna type UDMA Steiner et al., 2010, Aerosol Sci. Technol. 44: 4, , running in closed-loop channellength& width= 6.50 mm Q a = 6-20 L/min UDMA 1 & 2 Q sh = L/min R = 1 cm²/vs (~1.4 nm) UDMA 4 Q sh = L/min R = 1 cm²/vs (~1.4 nm) UDMA 4 (2016)

13 counting efficiency measurements 1 SEADM bipolar electrospray source Fernándezde la Mora & Barrios-Collado(2017) A bipolar electrospray source of singly charged salt clusters of precisely controlled composition. Aerosol Sci. Technol.51:6,

14 counting efficiency measurements L/min 1.5 L/min GRIMM 5403 zero air bipolar electrospray 15 L/min UDMA L/min VIE- FCE excess flow

15 SEADM bipolar electrospray source ion concentrationx 10 4 (cm -3 ) cluster diameter, D [nm] dat THABr + n=2 ~ 2.6nm n= inv. electrical mobility, 1/Z [Vs/cm²]

16 SEADM bipolar electrospray source ion concentrationx 10 4 (cm -3 ) dat n=1 2 3 cluster diameter, D [nm] ~ 2.6nm THABr inv. electrical mobility, 1/Z [Vs/cm²]

17 tuned GRIMM 5403 results CPC counting efficiency, eta (-) WOx + (standard settings) THABr + (tuned) TBAI + (tuned) D 50 = 4.0nm D 50 = 2.6nm mobility diameter, D (nm)

18 counting efficiency measurements 2 3 L/min 24 L/min 1.5 L/min GRIMM 5403 zero air tube furnace 241 Am NDMA 1.5 L/min TSI 3068B

19 tuned GRIMM 5403 results CPC counting efficiency, eta (-) WOx + (standard settings) THABr + (tuned) TBAI + (tuned) Ag + (tuned) Ag - (tuned) NaCl + (tuned) NaCl - (tuned) D 50 = 4.0nm D 50 = 2.6nm D 50 = 2.1nm D 50 = 1.9nm D 50 = 1.6nm mobility diameter, D (nm)

20 conclusions sub 3 nm (neutral) particle detection only few commercial instruments tuning of GRIMM 5403 CPC bipolar electrospray + high res. DMA tube furnace + nano DMA CPC counting efficiency, eta (-) WOx + (standard settings) THABr + (tuned) TBAI + (tuned) Ag + (tuned) Ag - (tuned) NaCl + (tuned) NaCl - (tuned) D 50 = 4.0nm D 50 = 2.6nm D 50 = 2.1nm D 50 = 1.9nm D 50 = 1.6nm mobility diameter, D (nm)

21 Acknowledgments Funding University of Vienna Aerosol Group S. Brilke, P. Wlasits and C. Tauber Austrian Science Fund, FWF project P27295-N20 Chemical Composition of Atmospheric Clusters University of Innsbruck promotion grant for young researchers project Cluster Calibration Unit, CCU Science Fund of the federal state Tirol, Tiroler Wissenschaftsfonds, project nanotof ICE