scholarly journals Assessing relative humidity dependent photoacoustics to retrieve mass accommodation coefficients of single optically trapped aerosol particles

2019 ◽  
Vol 21 (9) ◽  
pp. 4721-4731 ◽  
Author(s):  
Matus E. Diveky ◽  
Sandra Roy ◽  
Johannes W. Cremer ◽  
Grégory David ◽  
Ruth Signorell
Keyword(s):  
Relative Humidity ◽  
Atmospheric Aerosols ◽  
Photoacoustic Spectroscopy ◽  
Aerosol Particles ◽  
Accommodation Coefficients ◽  
Humidity Dependence ◽  
Optically Trapped ◽  
Evaporation Kinetics ◽  
Absorption Measurements

Photoacoustic spectroscopy is a standout technique widely used for absorption measurements of atmospheric aerosols. Here we investigate the relative humidity dependence of photoacoustics and its implication for evaporation kinetics.

scholarly journals Correction: Assessing relative humidity dependent photoacoustics to retrieve mass accommodation coefficients of single optically trapped aerosol particles

2020 ◽  
Vol 22 (27) ◽  
pp. 15770-15771
Author(s):  
Matus E. Diveky ◽  
Sandra Roy ◽  
Johannes W. Cremer ◽  
Grégory David ◽  
Ruth Signorell
Keyword(s):  
Relative Humidity ◽  
Aerosol Particles ◽  
Chem Phys ◽  
Accommodation Coefficients ◽  
Optically Trapped ◽  
Phys Chem Chem Phys

Correction for ‘Assessing relative humidity dependent photoacoustics to retrieve mass accommodation coefficients of single optically trapped aerosol particles’ by Matus E. Diveky et al., Phys. Chem. Chem. Phys., 2019, 21, 4721–4731, DOI: 10.1039/C8CP06980H.

scholarly journals Amorphous and crystalline aerosol particles interacting with water vapor: conceptual framework and experimental evidence for restructuring, phase transitions and kinetic limitations

2009 ◽  
Vol 9 (24) ◽  
pp. 9491-9522 ◽  
Author(s):  
E. Mikhailov ◽  
S. Vlasenko ◽  
S. T. Martin ◽  
T. Koop ◽  
U. Pöschl
Keyword(s):  
Phase Transitions ◽  
Water Vapor ◽  
Relative Humidity ◽  
Atmospheric Aerosols ◽  
Aerosol Particles ◽  
Organic Substances ◽  
Hygroscopic Growth ◽  
Amorphous Phases ◽  
Semi Solid ◽  
Hydration And Dehydration

Abstract. Interactions with water are crucial for the properties, transformation and climate effects of atmospheric aerosols. Here we present a conceptual framework for the interaction of amorphous aerosol particles with water vapor, outlining characteristic features and differences in comparison to crystalline particles. We used a hygroscopicity tandem differential mobility analyzer (H-TDMA) to characterize the hydration and dehydration of crystalline ammonium sulfate, amorphous oxalic acid and amorphous levoglucosan particles (diameter ~100 nm, relative humidity 5–95% at 298 K). The experimental data and accompanying Köhler model calculations provide new insights into particle microstructure, surface adsorption, bulk absorption, phase transitions and hygroscopic growth. The results of these and related investigations lead to the following conclusions: (1) Many organic substances, including carboxylic acids, carbohydrates and proteins, tend to form amorphous rather than crystalline phases upon drying of aqueous solution droplets. Depending on viscosity and microstructure, the amorphous phases can be classified as glasses, rubbers, gels or viscous liquids. (2) Amorphous organic substances tend to absorb water vapor and undergo gradual deliquescence and hygroscopic growth at lower relative humidity than their crystalline counterparts. (3) In the course of hydration and dehydration, certain organic substances can form rubber- or gel-like structures (supramolecular networks) and undergo transitions between swollen and collapsed network structures. (4) Organic gels or (semi-)solid amorphous shells (glassy, rubbery, ultra-viscous) with low molecular diffusivity can kinetically limit the uptake and release of water and may influence the hygroscopic growth and activation of aerosol particles as cloud condensation nuclei (CCN) and ice nuclei (IN). Moreover, (semi-)solid amorphous phases may influence the uptake of gaseous photo-oxidants and the chemical transformation and aging of atmospheric aerosols. (5) The shape and porosity of amorphous and crystalline particles formed upon dehydration of aqueous solution droplets depend on chemical composition and drying conditions. The apparent volume void fractions of particles with highly porous structures can range up to ~50% or more (xerogels, aerogels). (6) For efficient description of water uptake and phase transitions of aerosol particles, we propose not to limit the terms deliquescence and efflorescence to equilibrium phase transitions of crystalline substances. Instead we propose generalized definitions according to which amorphous and crystalline components can undergo gradual or prompt, partial or full deliquescence or efflorescence. We suggest that (semi-)solid amorphous phases may be important not only in the upper atmosphere as suggested in recent studies of glass formation at low temperatures. Depending on relative humidity, (semi-)solid phases and moisture-induced glass transitions may also play a role in gas-particle interactions at ambient temperatures in the lower atmosphere.

scholarly journals The evaporation kinetics of pure water droplets at varying drying rates and the use of evaporation rates to infer the gas phase relative humidity

2018 ◽  
Vol 20 (36) ◽  
pp. 23453-23466 ◽  
Author(s):  
Yong-yang Su ◽  
Rachael E. H. Miles ◽  
Zhi-ming Li ◽  
Jonathan P. Reid ◽  
Jiang Xu
Keyword(s):  
Relative Humidity ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Pure Water ◽  
Analytical Models ◽  
Volatile Components ◽  
Water Droplets ◽  
Drying Rates ◽  
Kinetics Of ◽  
Evaporation Kinetics

Numerous analytical models have been applied to describe the evaporation/condensation kinetics of volatile components from aerosol particles for use in many applications.

scholarly journals Measurements of Ice Nucleating Particles and Ice Residuals

2017 ◽  
Vol 58 ◽  
pp. 8.1-8.13 ◽  
Author(s):  
Daniel J. Cziczo ◽  
Luis Ladino ◽  
Yvonne Boose ◽  
Zamin A. Kanji ◽  
Piotr Kupiszewski ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Condensed Phase ◽  
Atmospheric Aerosols ◽  
Aerosol Particles ◽  
Ice Crystals ◽  
Ice Formation ◽  
Similar Amount ◽  
Residual Material ◽  
History Of ◽  
Phase Water

Abstract It has been known that aerosol particles act as nuclei for ice formation for over a century and a half (see Dufour). Initial attempts to understand the nature of these ice nucleating particles were optical and electron microscope inspection of inclusions at the center of a crystal (see Isono; Kumai). Only within the last few decades has instrumentation to extract ice crystals from clouds and analyze the residual material after sublimation of condensed-phase water been available (see Cziczo and Froyd). Techniques to ascertain the ice nucleating potential of atmospheric aerosols have only been in place for a similar amount of time (see DeMott et al.). In this chapter the history of measurements of ice nucleating particles, both in the field and complementary studies in the laboratory, are reviewed. Remaining uncertainties and artifacts associated with measurements are described and suggestions for future areas of improvement are made.

scholarly journals Characterisation of biofluorescent aerosol emissions over winter and summer periods in the United Kingdom

2018 ◽  
Author(s):  
Elizabeth Forde ◽  
Martin Gallagher ◽  
Virginia Foot ◽  
Roland Sarda-Esteve ◽  
Ian Crawford ◽  
...  
Keyword(s):  
United Kingdom ◽  
Relative Humidity ◽  
Aerosol Particles ◽  
Fungal Spores ◽  
Ultra Violet ◽  
Fungal Spore ◽  
Complete Analysis ◽  
Hierarchical Agglomerative Cluster ◽  
The United Kingdom ◽  
Fluorescent Particles

Abstract. Primary biological aerosol particles (PBAP) are an abundant subset of atmospheric aerosol particles which comprise viruses, bacteria, fungal spores, pollen, and fragments such as plant and animal debris. The abundance and diversity of these particles remain poorly constrained, causing significant uncertainties for modelling scenarios and for understanding the potential implications of these particles in different environments. PBAP concentrations were studied at four different sites in the United Kingdom (Weybourne, Davidstow, Capel Dewi, and Chilbolton) using an ultra-violet light induced fluorescence (UV-LIF) instrument, the Wideband Integrated Bioaerosol Spectrometer (WIBS), versions 3 and 4. Using hierarchical agglomerative cluster (HAC) analysis, particles were statistically discriminated between. Fluorescent particles and clusters were then analysed by assessing their diurnal variation and their relationship to the meteorological variables, temperature and relative humidity, and wind speed and direction. Using local land cover types, sources of the suspected fluorescent particles and clusters were then identified. Most sites exhibited a wet discharged fungal spore dominance, with the exception of one site, Davidstow, which had higher concentrations of bacteria, suggested to result from the presence of a local dairy factory. Differences were identified as to the sources of wet discharged fungal spores, with particles originating from arable and horticultural land at Chilbolton, and improved grassland areas at Weybourne. Total fluorescent particles at Capel Dewi were inferred to comprise two sources, with bacteria originating from the broadleaf and coniferous woodland and wet discharged fungal spores from nearby improved grassland areas, similar to Weybourne. The use of HAC and a higher fluorescence threshold (9SD) produced clusters which were considered to be biological following the complete analysis. More knowledge of the reaction of speciated biological particles to differences in meteorology, such as relative humidity and temperature would aid characterisation studies such as this.

A relative humidity processing method for the sampling of aerosol particles with low growth-ability

Tellus B ◽  
1992 ◽  
Vol 44 (5) ◽  
pp. 632-644 ◽  
Author(s):  
BENGT G. MARTINSSON ◽  
HANS-CHRISTEN HANSSON ◽  
LARS ASKING ◽  
SVEN-INGE CEDERFELT
Keyword(s):  
Relative Humidity ◽  
Aerosol Particles ◽  
Processing Method ◽  
Growth Ability
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