scholarly journals Nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) for investigating hygroscopic properties of sub-10 nm aerosol nanoparticles

2020 ◽  
Author(s):  
Ting Lei ◽  
Nan Ma ◽  
Juan Hong ◽  
Thomas Tuch ◽  
Xin Wang ◽  
...  
Keyword(s):  
Materials Science ◽  
Current Knowledge ◽  
Measurement Techniques ◽  
Chemical Properties ◽  
High Accuracy ◽  
Hygroscopic Growth ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Aerosol Nanoparticles ◽  
Hygroscopic Properties

Abstract. Interactions between water and nanoparticles are relevant for atmospheric multiphase processes, physical chemistry, and materials science. Current knowledge of the hygroscopic and related physico-chemical properties of nanoparticles, however, is restricted by limitations of the available measurement techniques. Here, we present the design and performance of a nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) apparatus that enables high accuracy and precision in hygroscopic growth measurements of aerosol nanoparticles with diameters less than 10 nm. Detailed methods of calibration and validation are provided. Beside maintaining accurate and stable sheath/aerosol flow rates (± 1 %), high accuracy of DMA voltage (± 0.1 %) in the range of ~0–50 V is crucial to achieve accurate sizing and small sizing offsets between the two DMAs (

scholarly journals Nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) for investigating hygroscopic properties of sub-10 nm aerosol nanoparticles

2020 ◽  
Vol 13 (10) ◽  
pp. 5551-5567
Author(s):  
Ting Lei ◽  
Nan Ma ◽  
Juan Hong ◽  
Thomas Tuch ◽  
Xin Wang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Materials Science ◽  
Current Knowledge ◽  
Measurement Techniques ◽  
High Accuracy ◽  
Air Conditioner ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Aerosol Nanoparticles ◽  
Hygroscopic Properties

Abstract. Interactions between water and nanoparticles are relevant for atmospheric multiphase processes, physical chemistry, and materials science. Current knowledge of the hygroscopic and related physicochemical properties of nanoparticles, however, is restricted by the limitations of the available measurement techniques. Here, we present the design and performance of a nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) apparatus that enables high accuracy and precision in hygroscopic growth measurements of aerosol nanoparticles with diameters less than 10 nm. Detailed methods of calibration and validation are provided. Besides maintaining accurate and stable sheath and aerosol flow rates (±1 %), high accuracy of the differential mobility analyzer (DMA) voltage (±0.1 %) in the range of ∼0–50 V is crucial for achieving accurate sizing and small sizing offsets between the two DMAs (<1.4 %). To maintain a stable relative humidity (RH), the humidification system and the second DMA are placed in a well-insulated and air conditioner housing (±0.1 K). We also tested and discussed different ways of preventing predeliquescence in the second DMA. Our measurement results for ammonium sulfate nanoparticles are in good agreement with Biskos et al. (2006b), with no significant size effect on the deliquescence and efflorescence relative humidity (DRH and ERH, respectively) at diameters down to 6 nm. For sodium sulfate nanoparticles, however, we find a pronounced size dependence of DRH and ERH between 20 and 6 nm nanoparticles.

Nano-HTDMA for investigating hygroscopic properties of sub-10 nm aerosol nanoparticles

2021 ◽  
Author(s):  
Ting Lei ◽  
Nan Ma ◽  
Juan Hong ◽  
Thomas Tuch ◽  
Xin Wang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Ammonium Sulfate ◽  
Sodium Sulfate ◽  
Size Dependence ◽  
Current Knowledge ◽  
Measurement Techniques ◽  
Aerosol Flow ◽  
Aerosol Nanoparticles ◽  
Hygroscopic Properties ◽  
Inorganic Substances

&lt;p&gt;Interactions between water and nanoparticles are of great significance for atmospheric multiphase processes, physical chemistry, and materials science. Current knowledge of the hygroscopic and related physicochemical properties of nanoparticles, however, is insufficient due to limitations of the available measurement techniques. Here, we present the design and performance of a nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) apparatus. To enable high accuracy and precision in hygroscopicity measurements of sub-10 nm aerosol nanoparticles, systematic and comprehensive calibration criteria of nano-HTDMA have been developed and applied, including sheath/aerosol flow rates, DMA voltage, relative humidity (RH) sensor, temperature sensor, and particle sizing. After calibration, the nano-HTDMA system has been shown to have an accurate sizing and a small sizing offsets between the two DMAs (&lt;1.4%) for aerosol nanoparticles with diameters down to 6 nm. Moreover, to maintain the RH-uniformities that prevent the pre-deliquescence and non-prompt phase transition of nanoparticles within DMA2, the RH of sheath flow is kept as same as that of aerosol flow at inlet of DMA2, and the humidification system and the DMA2 system are placed in a well-insulated and air conditioner housing (&amp;#177;0.1K). Using nano-HTDMA system. We investigate the hygroscopic behavior of aerosol nanoparticles of two inorganic substances (e.g., ammonium sulfate and sodium sulfate). A strong size dependence of the hygroscopic growth factor is observed for ammonium sulfate and sodium sulfate nanoparticles with diameters down to 6 nm, respectively. For size dependence of phase transition, we find a weak size dependence of DRH and ERH of ammonium sulfate nanoparticles with diameters from 6 to 100 nm but a pronounced size dependence of DRH and ERH between 20 and&amp;#160; 6 nm for sodium sulfate nanoparticles.&lt;/p&gt;

scholarly journals Design and Application of an Unattended Multifunctional H-TDMA System

2013 ◽  
Vol 30 (6) ◽  
pp. 1136-1148 ◽  
Author(s):  
Haobo Tan ◽  
Hanbing Xu ◽  
Qilin Wan ◽  
Fei Li ◽  
Xuejiao Deng ◽  
...  
Keyword(s):  
Particle Size ◽  
Growth Factor ◽  
Cloud Condensation Nuclei ◽  
Polystyrene Latex ◽  
Hygroscopic Growth ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
China Meteorological Administration ◽  
Hygroscopic Properties ◽  
Calibration Methods

Abstract The hygroscopic properties of aerosols have a significant impact on aerosol particle number size distributions (PNSD), formation of cloud condensation nuclei, climate forcing, and atmospheric visibility, as well as human health. To allow for the observation of the hygroscopic growth of aerosols with long-term accuracy, an unattended multifunctional hygroscopicity-tandem differential mobility analyzer (H-TDMA) system was designed and built by the Institute of Tropical and Marine Meteorology (ITMM), China Meteorological Administration (CMA), in Guangzhou, China. The system is capable of measuring dry and wet PNSD, hygroscopic growth factor by particle size, and mixing states. This article describes in detail the working principles, components, and calibration methods of the system. Standard polystyrene latex (PSL) spheres with five different diameters were chosen to test the system’s precision and accuracy of particle size measurement. Ammonium sulfate was used to test the hygroscopic response of the system for accurate growth factor measurement. The test results show that the deviation of the growth factor measured by the system is within a scope of −0.01 to −0.03 compared to Köhler theoretical curves. Results of temperature and humidity control performance tests indicate that the system is robust. An internal temperature gradient of less than 0.2 K for a second differential mobility analyzer (DMA2) makes it possible to reach a set-point relative humidity (RH) value of 90% and with a standard deviation of ±0.44%, sufficient for unattended field observation.

scholarly journals Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

2014 ◽  
Vol 14 (2) ◽  
pp. 737-749 ◽  
Author(s):  
K. A. Kamilli ◽  
L. Poulain ◽  
A. Held ◽  
A. Nowak ◽  
W. Birmili ◽  
...  
Keyword(s):  
Growth Factors ◽  
Chemical Composition ◽  
Chemical Properties ◽  
Temporal Variations ◽  
Summation Method ◽  
Urban Site ◽  
Hygroscopic Growth ◽  
Differential Mobility ◽  
Hygroscopic Properties ◽  
Particle Sizer

Abstract. Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site Laboratoire d'Hygiène de la Ville de Paris (LHVP) in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m−3, e.g., during winter.

scholarly journals Hygroscopicity of organic compounds as a function of organic functionality, water solubility, molecular weight and oxidation level

2021 ◽  
Author(s):  
Shuang Han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Organic Compounds ◽  
Water Solubility ◽  
Chemical Properties ◽  
Molecular Formula ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Hygroscopic Properties ◽  
Physico Chemical

Abstract. Hygroscopic properties of 23 organics including carboxylic acids, amino acids, sugars and alcohols were characterized using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We show that hygroscopicity of organics varies widely with different functional groups and organics with additional functional groups are more hygroscopic. However, some compounds sharing the same molecular formula or functionality show quite different hygroscopicity, demonstrating that other physico-chemical properties may contribute to their hygroscopicity as well. If the organics are fully dissolved in water (solubility > 7× 10−1 g/ml), we found that their hygroscopicity is mainly controlled by their molecular weight. For the organics that are not fully dissolved in water (slightly soluble: 5 × 10−4 g/ml < solubility < 7 × 10−1 g/ml), we observed that some of them show no obvious water uptake, which probably due to that they may not deliquesce under our studied conditions up to 90 % RH. The other type of slightly soluble organics is moderate hygroscopic and the larger their solubility the higher their hygroscopicity. Moreover, the hygroscopicity of organics generally increased with O : C ratios, although this relationship is not linear. Hygroscopicity of organic compounds were also predicted by two thermodynamic models using the Extended Aerosol Inorganics Model (E-AIM) and UManSysProp. Both models do not consider phase transition and intermolecular interactions in the simulations and show poor representation of the hygroscopicity for most of the organics.

scholarly journals Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

2013 ◽  
Vol 13 (5) ◽  
pp. 14297-14330
Author(s):  
K. A. Kamilli ◽  
L. Poulain ◽  
A. Held ◽  
A. Nowak ◽  
W. Birmili ◽  
...  
Keyword(s):  
Growth Factors ◽  
Chemical Composition ◽  
Chemical Properties ◽  
Temporal Variations ◽  
Summation Method ◽  
Urban Site ◽  
Hygroscopic Growth ◽  
Differential Mobility ◽  
Hygroscopic Properties ◽  
Particle Sizer

Abstract. Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site LHVP in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m3, e.g. during winter.

scholarly journals Tandem configuration of differential mobility and centrifugal particle mass analysers for investigating aerosol hygroscopic properties

2017 ◽  
Vol 10 (3) ◽  
pp. 1269-1280 ◽  
Author(s):  
Sergey S. Vlasenko ◽  
Hang Su ◽  
Ulrich Pöschl ◽  
Meinrat O. Andreae ◽  
Eugene F. Mikhailov
Keyword(s):  
Water Uptake ◽  
Aerosol Particles ◽  
Interaction Model ◽  
Growth Curves ◽  
Particle Mass ◽  
Submicron Particles ◽  
Hygroscopic Growth ◽  
Differential Mobility ◽  
Hygroscopic Properties ◽  
Modal Mass

Abstract. A tandem arrangement of Differential Mobility Analyser and Humidified Centrifugal Particle Mass Analyser (DMA-HCPMA) was developed to measure the deliquescence and efflorescence thresholds and the water uptake of submicron particles over the relative humidity (RH) range from 10 to 95 %. The hygroscopic growth curves obtained for ammonium sulfate and sodium chloride test aerosols are consistent with thermodynamic model predictions and literature data. The DMA-HCPMA system was applied to measure the hygroscopic properties of urban aerosol particles, and the kappa mass interaction model (KIM) was used to characterize and parameterize the concentration-dependent water uptake observed in the 50–95 % RH range. For DMA-selected 160 nm dry particles (modal mass of 3.5 fg), we obtained a volume-based hygroscopicity parameter, κv ≈  0.2, which is consistent with literature data for freshly emitted urban aerosols.Overall, our results show that the DMA-HCPMA system can be used to measure size-resolved mass growth factors of atmospheric aerosol particles upon hydration and dehydration up to 95 % RH. Direct measurements of particle mass avoid the typical complications associated with the commonly used mobility-diameter-based HTDMA technique (mainly due to poorly defined or unknown morphology and density).

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