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Calibration of optical counters, condensation particle counters, electrical impactors, filtration efficiency measurement, heterogeneous condensation (and many other laboratory applications in aerosol science and technology) are widely used with singly charged particles classified by a differential mobility analyzer with particles smaller than 1 μm. Nevertheless the method presents an ambiguity because of the presence of multi charged large particles of the same mobility than singly ones. This ambiguity results in uncertainty in the concentration regarded as a reference. The present paper reports a generation method of strictly singly (positive and negative) charged liquid and solid particles up to 1 μm. The generation-method is based on ion-induced nucleation of singly charged atmospheric ions. The method uses evaporation and controlled condensation of liquids or solid on seed ions. The ions grow and form wide continuum polydisperse distributions of positive or negative liquid/solid polydisperse particles up to 1 μm. The ions are produced with a corona or radioactive or soft X ray or UV source in filtered dry stream air. The final formed droplets or spheres around the ions keep the positive or negative initial charge of the ions. Vapors from low meting point solids or high boiling point and low vapor pressure liquids are used in this vaporizer-condenser generator. The paper focuses on particles with diameters up to 1 μm dedicated to classical differential mobility analyzers (DMA). The results with larger particles produced with the same generator design using heterogeneous condensation of vapors on sub 10 nm singly charged particles from melting NiCr (Kanthal) wires in air will be published in a second paper (manuscript in preparation). A companion paper on the saturation ratio profiles modeling with Comsol and comparison theory-experiments is in preparation.
Michel Attoui. Ion induced nucleation based-generator of strictly singly charged (solid - liquid) polydisperse particles up to 1 μm. Journal of Aerosol Science 2020, 153, 105732 .
AMA StyleMichel Attoui. Ion induced nucleation based-generator of strictly singly charged (solid - liquid) polydisperse particles up to 1 μm. Journal of Aerosol Science. 2020; 153 ():105732.
Chicago/Turabian StyleMichel Attoui. 2020. "Ion induced nucleation based-generator of strictly singly charged (solid - liquid) polydisperse particles up to 1 μm." Journal of Aerosol Science 153, no. : 105732.
Tetraheptylammonium bromide (THABr), tetrabutylammonium bromide (TBABr) and tetraethylammonium bromide (TEABr) dissolved in methanol or water methanol mixtures (~ 1mM) produce via positive electrospray atomization and high resolution classification electrical classification standard clean ions (monomer and dimer) which are singly charged. THABr is hydrophobic and insoluble in water, TBABr and TEABr are hygroscopic and water soluble (0.6 and 2.8 kg/l respectively). These ions are used to study the effect of hygroscopicity on the activation of aerosol particles in the sub 2 nm range via the detection efficiency measurement of a boosted ultrafine TSI condensation particle counter (3025A). Water solubility of particles seems to play a role in the activation and growth with butanol vapor in the CPC (condensation particle counter) independently of the size.
Michel Attoui; Juha Kangasluoma. Activation of sub 2 nm Water Soluble and Insoluble Standard Ions with Saturated Vapors of Butanol in a Boosted TSI Ultrafine CPC. Atmosphere 2019, 10, 665 .
AMA StyleMichel Attoui, Juha Kangasluoma. Activation of sub 2 nm Water Soluble and Insoluble Standard Ions with Saturated Vapors of Butanol in a Boosted TSI Ultrafine CPC. Atmosphere. 2019; 10 (11):665.
Chicago/Turabian StyleMichel Attoui; Juha Kangasluoma. 2019. "Activation of sub 2 nm Water Soluble and Insoluble Standard Ions with Saturated Vapors of Butanol in a Boosted TSI Ultrafine CPC." Atmosphere 10, no. 11: 665.
Classifying sub-3 nm particles effectively with relatively high penetration efficiencies and sizing resolutions is important for atmospheric new particle formation studies. A high-resolution supercritical differential mobility analyzer (half-mini DMA) was recently improved to classify aerosols at a sheath flow rate less than 100 L/min. In this study, we characterized the transfer functions, the penetration efficiencies, and the sizing resolution of the new half-mini DMA at the aerosol flow rate of 2.5–10 L/min and the sheath flow rate of 25–250 L/min using tetra-alkyl ammonium ions and tungsten oxide particles. The transfer functions of the new half-mini DMA at an aerosol flow rate lower than 5 L/min and a sheath flow rate lower than 150 L/min agree well with predictions using a theoretical diffusing transfer function. The penetration efficiencies can be approximated using an empirical formula. When classifying 1.48 nm molecular ions at an aerosol-to-sheath flow ratio of 5/50 L/min, the penetration efficiency, the sizing resolution, and the multiplicative broadening factor of the new half-mini DMA are 0.18, 6.8, and 1.11, respectively. Compared to other sub-3 nm DMAs applied in atmospheric measurements (e.g. the mini-cyDMA, the TSI DMA 3086, the TSI nanoDMA 3085, and the Grimm S-DMA), the new half-mini DMA characterized in this study is able to classify particles at higher aerosol and sheath flow rates, leading to a higher sizing resolution at the same aerosol-to-sheath flow ratio. Accordingly, the new half-mini DMA can reduce the uncertainties in atmospheric new particle formation measurement if coupled with an aerosol detector that could work at the corresponding high aerosol flow rate.
Runlong Cai; Michel Attoui; Jingkun Jiang; Frans Korhonen; Jiming Hao; Tuukka Petäjä; Juha Kangasluoma. Characterization of a high-resolution supercritical differential mobility analyzer at reduced flow rates. Aerosol Science and Technology 2018, 52, 1332 -1343.
AMA StyleRunlong Cai, Michel Attoui, Jingkun Jiang, Frans Korhonen, Jiming Hao, Tuukka Petäjä, Juha Kangasluoma. Characterization of a high-resolution supercritical differential mobility analyzer at reduced flow rates. Aerosol Science and Technology. 2018; 52 (11):1332-1343.
Chicago/Turabian StyleRunlong Cai; Michel Attoui; Jingkun Jiang; Frans Korhonen; Jiming Hao; Tuukka Petäjä; Juha Kangasluoma. 2018. "Characterization of a high-resolution supercritical differential mobility analyzer at reduced flow rates." Aerosol Science and Technology 52, no. 11: 1332-1343.
Measurement of atmospheric sub-10 nm nanoparticle number concentrations has been of substantial interest recently, which, however, is subject to considerable uncertainty. We report a laboratory characterization of a high flow differential mobility particle sizer (HFDMPS), which is based on the Half-mini type differential mobility analyzer (DMA) and nano condensation nuclei counter (A11), and show the first results from atmospheric observations. The HFDMPS utilizes the state-of-the-art aerosol technology, and is optimized for sub-10 nm particle size distribution measurements by a moderate resolution DMA, optimized and characterized low-loss particle sampling line and minimal dilution in the detector. We present an exhaustive laboratory calibration to the HFDMPS and compare the measured size data to the Hyytiälä long-term DMPS and Neutral cluster and ion spectrometer. The HFDMPS detects about two times higher 3–10 nm particle concentrations than the long-term DMPS, and the counting uncertainties are halved as compared to the long-term DMPS. The HFDMPS did not observe any sub-2.5 nm particles in Hyytiälä, and the reason for that was shown to be the inability of diethylene glycol to condense on such small biogenic particles. Last, we discuss the general implications of our results to the sub-10 nm DMPS based measurements.
Juha Kangasluoma; Lauri R. Ahonen; Tiia M. Laurila; Runlong Cai; Joonas Enroth; Stephany Buenrostro Mazon; Frans Korhonen; Pasi P. Aalto; Markku Kulmala; Michel Attoui; Tuukka Petäjä. Laboratory verification of a new high flow differential mobility particle sizer, and field measurements in Hyytiälä. Journal of Aerosol Science 2018, 124, 1 -9.
AMA StyleJuha Kangasluoma, Lauri R. Ahonen, Tiia M. Laurila, Runlong Cai, Joonas Enroth, Stephany Buenrostro Mazon, Frans Korhonen, Pasi P. Aalto, Markku Kulmala, Michel Attoui, Tuukka Petäjä. Laboratory verification of a new high flow differential mobility particle sizer, and field measurements in Hyytiälä. Journal of Aerosol Science. 2018; 124 ():1-9.
Chicago/Turabian StyleJuha Kangasluoma; Lauri R. Ahonen; Tiia M. Laurila; Runlong Cai; Joonas Enroth; Stephany Buenrostro Mazon; Frans Korhonen; Pasi P. Aalto; Markku Kulmala; Michel Attoui; Tuukka Petäjä. 2018. "Laboratory verification of a new high flow differential mobility particle sizer, and field measurements in Hyytiälä." Journal of Aerosol Science 124, no. : 1-9.
Ultrafine laminar TSI CPC based on the work of Stolzenburg and Mc Murry (1991) is widely used in aerosol science for the detection of particles down to 3 nm (D50 ~ 2.7 nm).This instrument uses butanol as working fluid. Di ethylene glycol (DEG) as working fluid has been introduced by Iida et al. 2011 for the activation and the growth of sub 3 nm particles without however giving detectable droplets with scattering light detectors. A second CPC is used as booster to count the DEG droplets. DEG presents on the other hand a high chemistry dependence to the activation and growth of particles. Butanol is known to present less chemistry dependence. This study focuses on the ability of butanol to activate and grow sub 3 nm positive particles in a commercial 3776 TSI CPC. The flowrate in the capillary is increased to minimize the losses. The temperature difference ΔT between the saturator and the condenser is increase to the limit of the homogeneous nucleation. The flowrate in the condenser and in the optical detector is kept constant and equal to 0.3 lpm. Tetra ethyl ammonium bromide positive monomer of 1.11 nm mobility diameter (0.81 nm mass diameter) is detected by the boosted instrument.
Michel Attoui. Activation of sub 2 nm singly charged particles with butanol vapors in a boosted 3776 TSI CPC. Journal of Aerosol Science 2018, 126, 47 -57.
AMA StyleMichel Attoui. Activation of sub 2 nm singly charged particles with butanol vapors in a boosted 3776 TSI CPC. Journal of Aerosol Science. 2018; 126 ():47-57.
Chicago/Turabian StyleMichel Attoui. 2018. "Activation of sub 2 nm singly charged particles with butanol vapors in a boosted 3776 TSI CPC." Journal of Aerosol Science 126, no. : 47-57.
Condensation particle counter (CPC) technology has continued to evolve, with the introduction of several new instruments over the last several years. An important aspect in the characterization of these instruments is the measurement of their time response. Yet there is no standardly accepted approach for this measurement. Here we evaluate different classically used methods for determining CPC time response, and present the potential pitfalls associated with these approaches. Further, we introduce a new simple definition for the term response time, ϵ, which is based on the first-order systems response, while providing a practical definition by corresponding to ∼95% change in concentration. We also present results for various commonly used CPCs, and for the Airmodus A11 nano Condensation Nucleus Counter (nCNC) system, the TSI 3777+3772 Nano Enhancer system, and Aerosol Dynamics Inc.'s (ADI) new versatile water condensation particle counter. Copyright © 2018 American Association for Aerosol Research
Joonas Enroth; Juha Kangasluoma; Frans Korhonen; Susanne Hering; David Picard; Greg Lewis; Michel Attoui; Tuukka Petäjä. On the time response determination of condensation particle counters. Aerosol Science and Technology 2018, 52, 778 -787.
AMA StyleJoonas Enroth, Juha Kangasluoma, Frans Korhonen, Susanne Hering, David Picard, Greg Lewis, Michel Attoui, Tuukka Petäjä. On the time response determination of condensation particle counters. Aerosol Science and Technology. 2018; 52 (7):778-787.
Chicago/Turabian StyleJoonas Enroth; Juha Kangasluoma; Frans Korhonen; Susanne Hering; David Picard; Greg Lewis; Michel Attoui; Tuukka Petäjä. 2018. "On the time response determination of condensation particle counters." Aerosol Science and Technology 52, no. 7: 778-787.
The ability to properly scale the synthesis of advanced materials through combustion synthesis routes is limited by our lack of knowledge regarding the initial stages of particle formation. In flame aerosol reactors, the high temperatures, fast reaction rates, and flame chemistry can all play a critical role in determining the properties of the resulting nanomaterials. In particular, multicomponent systems pose a unique challenge as most studies rely on empirical approaches toward designing advanced composite materials. The lack of predictive capabilities can be attributed to a lack of data on particle inception and growth below 2 nm. Measurements for the initial stages of particle formation during the combustion synthesis of SiO2 and composite SiO2/TiO2 using an atmospheric pressure inlet time-of-flight mass spectrometer are presented. Both positively and negatively charged clusters can be measured and results show the presence of silicic acid species which grow through dehydration, hydrogen abstraction, and interactions with hydroxyl radicals. In the case of composite SiO2/TiO2 particle formation, new molecular species containing Ti atoms emerge. Tandem differential mobility analysis-mass spectrometry (DMA-MS) provided further insight into the size-resolved chemistry of particle formation to reveal that at each cluster size, further hydroxyl-driven reactions take place. From this we can conclude that previous assumptions on collisional growth from simple monomer species of SiO2 and TiO2 do not sufficiently describe the collisional growth mechanisms for particle growth below 2 nm. Copyright © 2018 American Association for Aerosol Research
Jiaxi Fang; Yang Wang; Juha Kangasluoma; Michel Attoui; Heikki Junninen; Markku Kulmala; Tuukka Petäjä; Pratim Biswas. The initial stages of multicomponent particle formation during the gas phase combustion synthesis of mixed SiO2/TiO2. Aerosol Science and Technology 2017, 52, 277 -286.
AMA StyleJiaxi Fang, Yang Wang, Juha Kangasluoma, Michel Attoui, Heikki Junninen, Markku Kulmala, Tuukka Petäjä, Pratim Biswas. The initial stages of multicomponent particle formation during the gas phase combustion synthesis of mixed SiO2/TiO2. Aerosol Science and Technology. 2017; 52 (3):277-286.
Chicago/Turabian StyleJiaxi Fang; Yang Wang; Juha Kangasluoma; Michel Attoui; Heikki Junninen; Markku Kulmala; Tuukka Petäjä; Pratim Biswas. 2017. "The initial stages of multicomponent particle formation during the gas phase combustion synthesis of mixed SiO2/TiO2." Aerosol Science and Technology 52, no. 3: 277-286.
Jiaxi Fang; Yang Wang; Juha Kangasluoma; Michel Attoui; Heikki Junninen; Markku Kulmala; Tuukka Petäjä; Pratim Biswas. Cluster formation mechanisms of titanium dioxide during combustion synthesis: Observation with an APi-TOF. Aerosol Science and Technology 2017, 51, 1071 -1081.
AMA StyleJiaxi Fang, Yang Wang, Juha Kangasluoma, Michel Attoui, Heikki Junninen, Markku Kulmala, Tuukka Petäjä, Pratim Biswas. Cluster formation mechanisms of titanium dioxide during combustion synthesis: Observation with an APi-TOF. Aerosol Science and Technology. 2017; 51 (9):1071-1081.
Chicago/Turabian StyleJiaxi Fang; Yang Wang; Juha Kangasluoma; Michel Attoui; Heikki Junninen; Markku Kulmala; Tuukka Petäjä; Pratim Biswas. 2017. "Cluster formation mechanisms of titanium dioxide during combustion synthesis: Observation with an APi-TOF." Aerosol Science and Technology 51, no. 9: 1071-1081.
Aerosol instrument characterization and verification for nanometer-sized particles requires well-established generation and classification instruments. A precise size selection of sub-3-nm charged aerosol particles requires a differential mobility analyzer (DMA), specially designed for the sub-3-nm size range. In this study, a Herrmann-type high-resolution DMA developed at Yale University was characterized in various operation conditions. A relation between sheath flow rate and tetraheptylammonium ion (C28H60N+, THA+, 1.47 nm, mobility equivalent diameter) was established. The maximum particle size that the DMA was able to classify was 2.9 nm with the highest sheath flow rate of 1427 liters per minute (Lpm), and 6.5 nm with the lowest stable sheath flow rate of 215 Lpm, restricted by the maximum and minimum flow rates provided by our blower. Resolution and transmission of DMA are reported for tetrapropylammonium (C12H28N+, TPA+, 1.16 nm), THA+, and THA2Br+ (1.78 nm) ions measured with two different central electrodes and five different sheath flow rates. The transmission varied between 0.01 and 0.22, and the resolution varied between 10.8 and 51.9, depending on the operation conditions. Copyright © 2016 American Association for Aerosol Research
Juha Kangasluoma; M. Attoui; F. Korhonen; Lauri Ahonen; E. Siivola; T. Petäjä. Characterization of a Herrmann-type high-resolution differential mobility analyzer. Aerosol Science and Technology 2016, 50, 222 -229.
AMA StyleJuha Kangasluoma, M. Attoui, F. Korhonen, Lauri Ahonen, E. Siivola, T. Petäjä. Characterization of a Herrmann-type high-resolution differential mobility analyzer. Aerosol Science and Technology. 2016; 50 (3):222-229.
Chicago/Turabian StyleJuha Kangasluoma; M. Attoui; F. Korhonen; Lauri Ahonen; E. Siivola; T. Petäjä. 2016. "Characterization of a Herrmann-type high-resolution differential mobility analyzer." Aerosol Science and Technology 50, no. 3: 222-229.
A new method for generating metal clusters in the gas phase is described and characterized in this work. The method is based on material evaporation by spark ablation at atmospheric pressure. The characterization of atomic clusters was done by measuring their electrical mobility. The measured mobilities were compared with values found in literature in order to identify the cluster species. We show that silver clusters consisting from one up to 25 atoms can be produced in helium at atmospheric pressure. In addition, the effect of oxygen concentration on the resulting cluster mobility distribution was investigated. Results show that at higher oxygen level, the mobility distribution is dominated by the abundance of stable clusters (i.e., magic number clusters). This can be attributed to an oxidation etching effect. Copyright 2015 American Association for Aerosol Research
A. Maisser; K. Barmpounis; M. B. Attoui; George Biskos; A. Schmidt-Ott. Atomic Cluster Generation with an Atmospheric Pressure Spark Discharge Generator. Aerosol Science and Technology 2015, 49, 886 -894.
AMA StyleA. Maisser, K. Barmpounis, M. B. Attoui, George Biskos, A. Schmidt-Ott. Atomic Cluster Generation with an Atmospheric Pressure Spark Discharge Generator. Aerosol Science and Technology. 2015; 49 (10):886-894.
Chicago/Turabian StyleA. Maisser; K. Barmpounis; M. B. Attoui; George Biskos; A. Schmidt-Ott. 2015. "Atomic Cluster Generation with an Atmospheric Pressure Spark Discharge Generator." Aerosol Science and Technology 49, no. 10: 886-894.
Because of the rise of anthropogenic sources of NP human exposure to NP has dramatically increased in the recent years, in the general population as well as in workers (e.g., welders). This raises the question of the potential adverse effects of NP on human health, particularly at the respiratory level, since it represents the main route of exposure for air pollutants. Since inhalation exposure is the most relevant but yet under evaluated route of exposure for the evaluation of NP toxicity our study was aimed to design, build, and characterize a safe inhalation system dedicated to evaluate the respiratory effects of NP in mice. We chose to focus on the generation of iron (Fe) and manganese (Mn) oxide NP distributions centered on 20–25 nm diameters at concentrations of 107–108 NP/cm3 as it is representative of the occupational exposure of welders. Fe and Mn NP aerosols were generated with the spark discharge generator technique with air as a carrier gas conditio sine qua non for the mice. Indeed, the spark generator has been widely studied and used but in noble gases (N2, Ar, . . .) suggests the absence of oxidation. Aerosol particles are characterized in terms of size distribution, concentration, morphology, and chemical composition. Exposure of mice for 1 to 4 days (3 h a day) to these occupationally relevant aerosol concentrations induces inflammatory effects (increased lung total protein content). Moreover, clusters of particles were observed throughout the lungs. Copyright © 2015 American Association for Aerosol Research
M. Presume; M. Attoui; A. Maisser; G. Petit; S. Lanone. Design and Characterization of an Inhalation System of Iron and Manganese Oxide Nanoparticles for Rodent Exposure. Aerosol Science and Technology 2015, 49, 580 -588.
AMA StyleM. Presume, M. Attoui, A. Maisser, G. Petit, S. Lanone. Design and Characterization of an Inhalation System of Iron and Manganese Oxide Nanoparticles for Rodent Exposure. Aerosol Science and Technology. 2015; 49 (8):580-588.
Chicago/Turabian StyleM. Presume; M. Attoui; A. Maisser; G. Petit; S. Lanone. 2015. "Design and Characterization of an Inhalation System of Iron and Manganese Oxide Nanoparticles for Rodent Exposure." Aerosol Science and Technology 49, no. 8: 580-588.