scholarly journals Prompt deliquescence and efflorescence of aerosol nanoparticles

2006 ◽  
Vol 6 (12) ◽  
pp. 4633-4642 ◽  
Author(s):  
G. Biskos ◽  
D. Paulsen ◽  
L. M. Russell ◽  
P. R. Buseck ◽  
S. T. Martin
Keyword(s):  
Relative Humidity ◽  
Ammonium Sulfate ◽  
Size Range ◽  
Hygroscopic Growth ◽  
Differential Mobility ◽  
Aerosol Nanoparticles ◽  
Experimental Apparatus ◽  
Kelvin Effect ◽  
Nonspherical Shape ◽  
Individual Particles

Abstract. Literature reports have differed on the possibilities of discontinuous and continuous (i.e., prompt and nonprompt) deliquescence and efflorescence of aerosol particles in the nanosize regime. Experiments reported herein using a hygroscopic tandem nano-differential mobility analyzer demonstrate prompt deliquescence and efflorescence of ammonium sulfate particles having diameters from 6 to 60 nm. Apparent nonpromptness can be induced both by operation of the experimental apparatus and by interpretation of the measurements, even though the underlying phase transitions of individual particles remain prompt. No nanosize effect on the relative humidity values of deliquescence or efflorescence is observed for the studied size range. Smaller hygroscopic growth factors are, however, observed for the nanoparticles, in agreement with thermodynamic calculations that include the Kelvin effect. A slightly nonspherical shape for dry ammonium sulfate particles is inferred from their hygroscopically induced reconstruction between 5 and 30% relative humidity. Our results provide a further understanding of nanoparticle behavior, especially relevant to the growth rates of atmospheric nanoparticles.

scholarly journals Prompt deliquescence and efflorescence of aerosol nanoparticles

2006 ◽  
Vol 6 (4) ◽  
pp. 7051-7073
Author(s):  
G. Biskos ◽  
D. Paulsen ◽  
L. M. Russell ◽  
P. R. Buseck ◽  
S. T. Martin
Keyword(s):  
Relative Humidity ◽  
Ammonium Sulfate ◽  
Size Range ◽  
Hygroscopic Growth ◽  
Differential Mobility ◽  
Aerosol Nanoparticles ◽  
Experimental Apparatus ◽  
Kelvin Effect ◽  
Nonspherical Shape ◽  
Individual Particles

Abstract. Literature reports have differed on the possibilities of discontinuous and continuous (i.e., prompt and nonprompt) deliquescence and efflorescence of aerosol particles in the nanosize regime. Experiments reported herein using a hygroscopic tandem nano-differential mobility analyzer demonstrate prompt deliquescence and efflorescence of ammonium sulfate particles having diameters from 6 to 60 nm. Apparent nonpromptness can be induced both by operation of the experimental apparatus and by interpretation of the measurements, even though the underlying phase transitions of individual particles remain prompt. No nanosize effect on the relative humidity values of deliquescence or efflorescence is observed for the studied size range. Smaller hygroscopic growth factors are, however, observed for the nanoparticles, in agreement with thermodynamic calculations that include the Kelvin effect. A slightly nonspherical shape for dry ammonium sulfate particles is inferred from their hygroscopically induced reconstruction between 5 and 30% relative humidity. Our results provide a further understanding of nanoparticle behavior, especially relevant to the growth rates of atmospheric nanoparticles.

scholarly journals Effect of mixing structure on the water uptake of mixtures of ammonium sulfate and phthalic acid particles

2020 ◽  
Author(s):  
Weigang Wang ◽  
Ting Lei ◽  
Andreas Zuend ◽  
Hang Su ◽  
Yafang Cheng ◽  
...  
Keyword(s):  
Growth Factor ◽  
Relative Humidity ◽  
Ammonium Sulfate ◽  
Water Uptake ◽  
Phthalic Acid ◽  
Core Shell ◽  
Hygroscopic Growth ◽  
The Core ◽  
Mass Fractions ◽  
Shell Particles

Abstract. Aerosol mixing state regulates the interactions between water molecules and particles and thus controls the aerosol activation and hygroscopic growth, which thereby influences the visibility degradation, cloud formation, and its radiative forcing. Current studies on the mixing structure effects on aerosol hygroscopicity, however, is few reported. Here we investigated the effect of phthalic acid (PA) coatings on the hygroscopic behavior of the core-shell mixtures of ammonium sulfate (AS) with PA using a coating-hygroscopicity tandem differential mobility analyzer (coating-HTDMA). The slow increase in the hygroscopic growth factor of core-shell particles is observed with increasing thickness of coating PA prior to the DRH of AS. At RH above 80 %, a decrease in hygroscopic growth factor of particles occurs as the thickness of PA shell increases, which indicates that the increase of PA mass fractions leads to a reduction of the overall core-shell particle hygroscopicity. In addition, the use of the ZSR relation leads to the underestimation for the measured growth factors of core-shell particles without consideration of the morphological effect of core-shell particles. For the AS/PA well mixed particles, a shift of deliquescence relative humidity (DRH) of AS to lower relative humidity (RH) is observed due to the presence of PA in the well-mixed particles. The predicted hygroscopic growth factor using the ZSR relation is consistent with the measured hygroscopic growth factor of the well-mixed particles. Moreover, we compared and discussed the influence of mixing states on the water uptake of AS/PA aerosol particles. It is found that the hygroscopic growth factor of the core-shell particles is slightly higher than that of the well-mixed particles with the same mass fractions of PA at RH above 80 %. For our observation of AS/PA particles may contribute to a growing field of knowledge regarding the influence of coating properties and mixing structure on water uptake.

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 Hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their influence on the water uptake of ammonium sulfate

2011 ◽  
Vol 11 (24) ◽  
pp. 12617-12626 ◽  
Author(s):  
Z. J. Wu ◽  
A. Nowak ◽  
L. Poulain ◽  
H. Herrmann ◽  
A. Wiedensohler
Keyword(s):  
Relative Humidity ◽  
Ammonium Sulfate ◽  
Water Uptake ◽  
Ammonium Oxalate ◽  
Water Soluble ◽  
Hygroscopic Growth ◽  
Organic Salts ◽  
Deliquescence Relative Humidity ◽  
Hygroscopic Behavior ◽  
Atmospherically Relevant

Abstract. The hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their effects on ammonium sulfate were investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA). No hygroscopic growth is observed for disodium oxalate, while ammonium oxalate shows slight growth (growth factor = 1.05 at 90%). The growth factors at 90% RH for sodium acetate, disodium malonate, disodium succinate, disodium tartrate, diammonium tartrate, sodium pyruvate, disodium maleate, and humic acid sodium salt are 1.79, 1.78, 1.69, 1.54, 1.29, 1.70, 1.78, and 1.19, respectively. The hygroscopic growth of mixtures of organic salts with ammonium sulfate, which are prepared as surrogates of atmospheric aerosols, was determined. A clear shift in deliquescence relative humidity to lower RH with increasing organic mass fraction was observed for these mixtures. Above 80% RH, the contribution to water uptake by the organic salts was close to that of ammonium sulfate for the majority of investigated compounds. The observed hygroscopic growth of the mixed particles at RH above the deliquescence relative humidity of ammonium sulfate agreed well with that predicted using the Zdanovskii-Stokes-Robinson (ZSR) mixing rule. Mixtures of ammonium sulfate with organic salts are more hygroscopic than mixtures with organic acids, indicating that neutralization by gas-phase ammonia and/or association with cations of dicarbonxylic acids may enhance the hygroscopicity of the atmospheric particles.

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.

scholarly journals Linking variations in sea spray aerosol particle hygroscopicity to composition during two microcosm experiments

2016 ◽  
Author(s):  
Sara D. Forestieri ◽  
Gavin C. Cornwell ◽  
Taylor M. Helgestad ◽  
Kathryn A. Moore ◽  
Christopher Lee ◽  
...  
Keyword(s):  
Light Scattering ◽  
Relative Humidity ◽  
Salt Content ◽  
Sea Salt ◽  
Sea Spray ◽  
Hygroscopic Growth ◽  
Phytoplankton Blooms ◽  
Aerosol Composition ◽  
Sea Spray Aerosol ◽  
Indoor And Outdoor

Abstract. The extent to which water uptake influences the light scattering ability of marine sea spray aerosol (SSA) particles depends critically on SSA chemical composition. The organic fraction of SSA can increase during phytoplankton blooms, decreasing the salt content and therefore the hygroscopicity of the particles. In this study, subsaturated hygroscopic growth factors at 85 % relative humidity (GF(85 %)) of SSA particles were quantified during two induced phytoplankton blooms in marine aerosol reference tanks (MARTs). One MART was illuminated with fluorescent lights and the other was illuminated with sunlight, referred to as the "indoor" and "outdoor" MARTs, respectively. GF(85 %) values for SSA particles were derived from measurements of light scattering and particle size distributions, concurrently with online single particle and bulk aerosol composition measurements. During both microcosm experiments, the observed bulk average GF(85 %) values were depressed substantially relative to pure, inorganic sea salt, by 10 to 19 %, with a one (indoor MART) and six (outdoor MART) day lag between GF(85 %) depression and the peak chlorophyll-a concentrations. The fraction of organiccontaining SSA particles generally increased after the peak of the phytoplankton blooms. The GF(85 %) values were inversely correlated with the fraction of particles containing organic or other biological markers. This indicates these particles were less hygroscopic than the particles identified as predominately sea salt containing and demonstrates a clear relationship between SSA particle composition and the sensitivity of light scattering to variations in relative humidity. The implications of these observations to the direct climate effects of SSA particles are discussed.

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