Size Distribution of TiO2 Nanoparticles Generated by a Commercial Aerosol Generator for Different Solution Concentrations and Air Flow Rates

2012 ◽  
Vol 727-728 ◽  
pp. 861-866
Author(s):  
João Victor Marques Zoccal ◽  
Fábio de Oliveira Arouca ◽  
José Renato Coury ◽  
José Antônio Silveira Gonçalves
Keyword(s):  
Size Distribution ◽  
Particle Concentration ◽  
Air Flow ◽  
Industrial Applications ◽  
Scanning Mobility Particle Sizer ◽  
Flow Rates ◽  
Nanoscale Particles ◽  
Aerosol Generator ◽  
Particle Sizer ◽  
Number Of Particles

Advances in scientific research in the field of nanotechnology sparked an increase in technological and industrial applications involving nanoparticles, Moreover, there was increasing concern about the control of nanoscale particles released to the atmosphere, driven by concerns over air quality and human health. In this context, this study aims to determine the size distribution of TiO2nanoparticles generated by the commercial TSI Atomizer Aerosol Generator model 3079 for different solution concentrations and air flow rates. The concentrations of the TiO2solutions used in the generator were 0.0125, 0.025 and 0.05 g.L-1, while the aerosol flow rates were 1.27, 2.55 and 3.82 L.min-1. The size distribution was measured with the TSI Scanning Mobility Particle Sizer (SMPS) equipment, which provides the number of particles per size range. The results showed that even changing the concentration of TiO2in solution, peak concentrations of nanoparticles remained in the same range between 15 to 45 nm. Moreover, it was observed that particle concentration in the gas stream decreased with increasing flow rate.

Laboratory Measurements of the Size Distribution and Activation Ratio of Synthetic Ice Nuclei

2020 ◽  
Author(s):  
David Delene ◽  
Eli Peske ◽  
Mascha Rauscher ◽  
Werner Lubitz
Keyword(s):  
Size Distribution ◽  
Cloud Condensation Nuclei ◽  
Scanning Mobility Particle Sizer ◽  
Condensation Particle Counter ◽  
Ice Nuclei ◽  
Aerosol Generator ◽  
Condensation Nucleation ◽  
Activation Ratio ◽  
Particle Sizer ◽  
Measured Size Distribution

<p>Laboratory measurement of the particle size distribution and cloud condensation nucleation activation ratio are conducted using two types of synthetic ice nuclei (IN). New Engineered Organic Nuclei (NEON) are fabricated by fermentation and so-called E-lysis of Gram-negative bacteria, which are havested via centrifugation and resuspended in a NaHCO<sub>3</sub> buffer (pH of ~7.8) for final inactivation of lysis escape muntants. NEON is inactivated using 1.25 % (final concentration) glutaraldehyde (GA) and stored in a deep freezer. The NEON with GA solution is atomized using a Sparging Liquid Aerosol Generator (SLAG), which does not sheer or impact the aerosols. The measured size distribution is compared to aerosols produced by the TSI Atmomizer (Model 3076), which impacts generated droplets. The size distribution is measured using a TSI Scanning Mobility Particle Sizer Spectrometer (SMPS) and a TSI Aerodynamic Particle Sizer. A DMT Cloud Condensation Nuclei Counter (CCNC) operated at 0.6 % supersaturation and a TSI Condensation Particle Counter (CPC) is used to measure the activation ratio, which is important to determine effectiveness of the NEON as an immersion ice nuclei. The NEON results are compared to IN produced by burning silver iodine cloud seeding flares.</p>

scholarly journals Measurement of nonvolatile particle number size distribution

2016 ◽  
Vol 9 (1) ◽  
pp. 103-114 ◽  
Author(s):  
G. I. Gkatzelis ◽  
D. K. Papanastasiou ◽  
K. Florou ◽  
C. Kaltsonoudis ◽  
E. Louvaris ◽  
...  
Keyword(s):  
Size Distribution ◽  
Black Carbon ◽  
Biomass Burning ◽  
Particle Number ◽  
Number Concentration ◽  
Experimental Methodology ◽  
Particle Number Concentration ◽  
Scanning Mobility Particle Sizer ◽  
Number Size Distribution ◽  
Particle Sizer

Abstract. An experimental methodology was developed to measure the nonvolatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a nonvolatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol (OA; 40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50–60 % of the particles had a nonvolatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon with an 80 % contribution, while OA was responsible for another 15–20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA is of extremely low volatility.

scholarly journals Quantifying aerosol size distributions and their temporal variability in the Southern Great Plains, USA

2019 ◽  
Vol 19 (18) ◽  
pp. 11985-12006 ◽  
Author(s):  
Peter J. Marinescu ◽  
Ezra J. T. Levin ◽  
Don Collins ◽  
Sonia M. Kreidenweis ◽  
Susan C. van den Heever
Keyword(s):  
Size Distribution ◽  
Great Plains ◽  
Diurnal Cycle ◽  
Particle Formation ◽  
Aerosol Size Distribution ◽  
Size Distributions ◽  
New Particle Formation ◽  
Scanning Mobility Particle Sizer ◽  
Southern Great Plains ◽  
Particle Sizer

Abstract. A quality-controlled, 5-year dataset of aerosol number size distributions (particles with diameters (Dp) from 7 nm through 14 µm) was developed using observations from a scanning mobility particle sizer, aerodynamic particle sizer, and a condensation particle counter at the Department of Energy's Southern Great Plains (SGP) site. This dataset was used for two purposes. First, typical characteristics of the aerosol size distribution (number, surface area, and volume) were calculated for the SGP site, both for the entire dataset and on a seasonal basis, and size distribution lognormal fit parameters are provided. While the median size distributions generally had similar shapes (four lognormal modes) in all the seasons, there were some significant differences between seasons. These differences were most significant in the smallest particles (Dp<30 nm) and largest particles (Dp>800 nm). Second, power spectral analysis was conducted on this long-term dataset to determine key temporal cycles of total aerosol concentrations, as well as aerosol concentrations in specified size ranges. The strongest cyclic signal was associated with a diurnal cycle in total aerosol number concentrations that was driven by the number concentrations of the smallest particles (Dp<30 nm). This diurnal cycle in the smallest particles occurred in all seasons in ∼50 % of the observations, suggesting a persistent influence of new particle formation events on the number concentrations observed at the SGP site. This finding is in contrast with earlier studies that suggest new particle formation is observed primarily in the springtime at this site. The timing of peak concentrations associated with this diurnal cycle was shifted by several hours depending on the season, which was consistent with seasonal differences in insolation and boundary layer processes. Significant diurnal cycles in number concentrations were also found for particles with Dp between 140 and 800 nm, with peak concentrations occurring in the overnight hours, which were primarily associated with both nitrate and organic aerosol cycles. Weaker cyclic signals were observed for longer timescales (days to weeks) and are hypothesized to be related to the timescales of synoptic weather variability. The strongest periodic signals (3.5–5 and 7 d cycles) for these longer timescales varied depending on the season, with no cyclic signals and the lowest variability in the summer.

Validation of TiO2Particle-Size Distribution Measured by Scanning Mobility Particle Sizer

2007 ◽  
Vol 46 (19) ◽  
pp. 6269-6272 ◽  
Author(s):  
Meng-Dawn Cheng ◽  
Emory A. Ford ◽  
David W. DePaoli ◽  
Edward A. Kenik ◽  
Peter Angelini
Keyword(s):  
Size Distribution ◽  
Scanning Mobility Particle Sizer ◽  
Particle Sizer

Deposition of Controllable Nanoparticles by Hybrid Aerodynamic and Electrostatic Spray

NANO ◽  
2017 ◽  
Vol 12 (02) ◽  
pp. 1750023 ◽  
Author(s):  
Baekhoon Seong ◽  
Soohyun Ha ◽  
Hyeong-U Kim ◽  
Cheolmin Shin ◽  
Taesung Kim ◽  
...  
Keyword(s):  
Electric Field ◽  
Aerodynamic Force ◽  
Industrial Applications ◽  
Scanning Mobility Particle Sizer ◽  
Sem Images ◽  
Spray System ◽  
Particle Sizer ◽  
Secondary Breakup ◽  
Electrostatic Spray ◽  
Controllable Particle Size

Generating uniform and size controllable nanoparticles are important for various analytical and industrial applications. Here, we propose the hybrid aerodynamic and electrostatic spray system with a large amount of size-controlled nanoparticles. The aerodynamic force easily produces a large amount of sprayed droplets and the electric field assists in secondary breakup of sprayed droplets. The charge of droplets was evaluated to understand the mechanism of controllable particle size because the size and uniformity of particles are determined by the distributions of droplets after evaporation. The distributions of particles are evaluated with a scanning mobility particle sizer (SMPS) technique and a field emission scanning electron microscope (FE-SEM) images. The size and aggregation of the particles are reduced and controlled by electric field strengths.

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