The vapor pressures and activities of dicarboxylic acids  reconsidered: the impact of the physical state of the aerosol

Soonsin, V.; Zardini, Alessandro; Marcolli, Claudia; Zuend, Andreas; Krieger, Ulrich K.

doi:10.5194/acp-10-11753-2010

Cited by 74 publications

(122 citation statements)

References 59 publications

(114 reference statements)

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“…As illustrated by Soonsin et al (2010), γ PEG can be determined in the gas-diffusion-limited regime, where D PEG is sufficiently high such that PEG-4 is distributed homogeneously throughout the particle, by measuring the radius change of evaporating particles. In contrast, it is impossible to further constrain D PEG in this regime.…”

Section: Diffusion Modelmentioning

confidence: 99%

Diffusivity measurements of volatile organics in levitated viscous aerosol particles

et al. 2017

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Abstract. Field measurements indicating that atmospheric secondary organic aerosol (SOA) particles can be present in a highly viscous, glassy state have spurred numerous studies addressing low diffusivities of water in glassy aerosols. The focus of these studies is on kinetic limitations of hygroscopic growth and the plasticizing effect of water. In contrast, much less is known about diffusion limitations of organic molecules and oxidants in viscous matrices. These may affect atmospheric chemistry and gas-particle partitioning of complex mixtures with constituents of different volatility. In this study, we quantify the diffusivity of a volatile organic in a viscous matrix. Evaporation of single particles generated from an aqueous solution of sucrose and small amounts of volatile tetraethylene glycol (PEG-4) is investigated in an electrodynamic balance at controlled relative humidity (RH) and temperature. The evaporative loss of PEG-4 as determined by Mie resonance spectroscopy is used in conjunction with a radially resolved diffusion model to retrieve translational diffusion coefficients of PEG-4. Comparison of the experimentally derived diffusivities with viscosity estimates for the ternary system reveals a breakdown of the Stokes-Einstein relationship, which has often been invoked to infer diffusivity from viscosity. The evaporation of PEG-4 shows pronounced RH and temperature dependencies and is severely depressed for RH 30 %, corresponding to diffusivities < 10 −14 cm 2 s −1 at temperatures < 15 • C. The temperature dependence is strong, suggesting a diffusion activation energy of about 300 kJ mol −1 . We conclude that atmospheric volatile organic compounds can be subject to severe diffusion limitations in viscous organic aerosol particles. This may enable an important long-range transport mechanism for organic material, including pollutant molecules such as polycyclic aromatic hydrocarbons (PAHs).

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Section: Diffusion Modelmentioning

confidence: 99%

Diffusivity measurements of volatile organics in levitated viscous aerosol particles

et al. 2017

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“…Tang and Munkelwitz, 1994;Choi and Chan, 2002;Li et al, 2005;Parsons et al, 2006;Pope et al, 2010a;Zobrist et al, 2011), measurement of vapour pressure (e.g. Pope et al, 2010b;Soonsin et al, 2010), oxidation chemistry (e.g. Lee and Chan, 2007;Pope et al, 2010c;Lee et al, 2012), and supercooled droplets and ice nucleation (e.g.…”

Section: H-j Tong Et Al: a New Electrodynamic Balance (Edb) Designmentioning

confidence: 99%

A new electrodynamic balance (EDB) design for low-temperature studies: application to immersion freezing of pollen extract bioaerosols

et al. 2015

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Abstract. In this paper we describe a newly designed cold electrodynamic balance (CEDB) system, built to study the evaporation kinetics and freezing properties of supercooled water droplets. The temperature of the CEDB chamber at the location of the levitated water droplet can be controlled in the range −40 to +40 • C, which is achieved using a combination of liquid nitrogen cooling and heating by positive temperature coefficient heaters. The measurement of liquid droplet radius is obtained by analysing the Mie elastic light scattering from a 532 nm laser. The Mie scattering signal was also used to characterise and distinguish droplet freezing events; liquid droplets produce a regular fringe pattern, whilst the pattern from frozen particles is irregular. The evaporation rate of singly levitated water droplets was calculated from time-resolved measurements of the radii of evaporating droplets and a clear trend of the evaporation rate on temperature was measured. The statistical freezing probabilities of aqueous pollen extracts (pollen washing water) are obtained in the temperature range −4.5 to −40 • C. It was found that that pollen washing water from water birch (Betula fontinalis occidentalis) pollen can act as ice nuclei in the immersion freezing mode at temperatures as warm as −22.45 (±0.65) • C. Furthermore it was found that the protein-rich component of the washing water was significantly more iceactive than the non-proteinaceous component.

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“…Another important aspect of the differences observed between different data sets was identified to be caused by the physical state of the compound studied (Soonsin et al, 2010;Bilde et al, 2015). As multicomponent aerosol particles are expected often to be liquid or amorphous (glassy) under atmospheric conditions (Marcolli et al, 2004), the reference state for atmospheric applications is in general the subcooled liquid.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, it is not always certain that a solid crystalline compound is purely crystalline without any amorphous content. Any amorphous material present can enhance the vapor pressure significantly (Soonsin et al, 2010), as the saturation vapor pressure over an amorphous solid resembles more that of the subcooled liquid than that of the crystalline solid. Therefore, a reference material for instrument testing should be preferable in liquid state at the temperatures at which the measurements are performed.…”

Section: Introductionmentioning

confidence: 99%

A reference data set for validating vapor pressure measurement techniques: homologous series of polyethylene glycols

Krieger¹,

Siegrist²,

Marcolli³

et al. 2018

Atmos. Meas. Tech.

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Abstract. To predict atmospheric partitioning of organic compounds between gas and aerosol particle phase based on explicit models for gas phase chemistry, saturation vapor pressures of the compounds need to be estimated. Estimation methods based on functional group contributions require training sets of compounds with well-established saturation vapor pressures. However, vapor pressures of semivolatile and low-volatility organic molecules at atmospheric temperatures reported in the literature often differ by several orders of magnitude between measurement techniques. These discrepancies exceed the stated uncertainty of each technique which is generally reported to be smaller than a factor of 2. At present, there is no general reference technique for measuring saturation vapor pressures of atmospherically relevant compounds with low vapor pressures at atmospheric temperatures. To address this problem, we measured vapor pressures with different techniques over a wide temperature range for intercomparison and to establish a reliable training set. We determined saturation vapor pressures for the homologous series of polyethylene glycols (H−(O−CH 2 −CH 2 ) n −OH) for n = 3 to n = 8 ranging in vapor pressure at 298 K from 10 −7 to 5 × 10 −2 Pa and compare them with quantum chemistry calculations. Such a homologous series provides a reference set that covers several orders of magnitude in saturation vapor pressure, allowing a critical assessment of the lower limits of detection of vapor pressures for the different techniques as well as permitting the identification of potential sources of systematic error. Also, internal consistency within the series allows outlying data to be rejected more easily. Most of the measured vapor pressures agreed within the stated uncertainty range. Deviations mostly occurred for vapor pressure values approaching the lower detection limit of a technique. The good agreement between the measurement techniques (some of which are sensitive to the mass accommodation coefficient and some not) suggests that the mass accommodation coefficients of the studied compounds are close to unity. The quantum chemistry calculations were about 1 order of magnitude higher than the measurements. We find that extrapolation of vapor pressures from elevated to atmospheric temperatures is permissible over a range of about 100 K for these compounds, suggesting that measurements should be performed best at temperatures yielding the highest-accuracy data, allowing subsequent extrapolation to atmospheric temperatures.

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The vapor pressures and activities of dicarboxylic acids reconsidered: the impact of the physical state of the aerosol

Cited by 74 publications

References 59 publications

Diffusivity measurements of volatile organics in levitated viscous aerosol particles

Diffusivity measurements of volatile organics in levitated viscous aerosol particles

A new electrodynamic balance (EDB) design for low-temperature studies: application to immersion freezing of pollen extract bioaerosols

A reference data set for validating vapor pressure measurement techniques: homologous series of polyethylene glycols

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