Kinetically controlled glass transition measurement of organic aerosol thin films using broadband dielectric spectroscopy

Zhang, Yue; Katira, Shachi; Lee, Andrew; Lambe, Andrew T.; Onasch, T. B.; Xu, Wen; Brooks, W. Abdullah; Canagaratna, Manjula R.; Freedman, Andrew; Jayne, John T.; Worsnop, D. R.; Davidovits, P.; Chandler, David; Kolb, C. E.

doi:10.5194/amt-11-3479-2018

Cited by 13 publications

(42 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7) of toluene-derived SOA when compared with the other two types of SOA may enhance the hygroscopicity of the particle (Lambe et al, 2011b;Liu et al, 2018;Zhao et al, 2016) and thus may reduce the deposition IN ability of BC particles. On the other hand, Hinks et al (2018) shows that toluene-derived SOA also contains a significant amount of oligomers under dry laboratory conditions, similar to what we conducted in the PAM chamber in this study, potentially reducing the hygroscopicity and altering the phase state of the SOA to be semi-solid or solid (Li et al, 2020;Zhang et al, 2018b), under which the SOA can still nucleate ice (Zhang et al, 2019c). Overall, these two competing factors make our toluene SOA coating IN onset move towards but not fully in the homogeneous freezing regime, agreeing with the results of Kulkarni et al (2016).…”

Section: Ice Nucleation On Bc Coated With Soa Materialssupporting

confidence: 75%

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

Zhang¹,

Zhang²,

Wolf³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. There is evidence that black carbon (BC) particles may affect cirrus formation and hence global climate by acting as potential ice nucleating particles (INPs) in the troposphere. Nevertheless, the ice nucleation (IN) ability of bare BC and BC coated with secondary organic aerosol (SOA) material remains uncertain. We have systematically examined the IN ability of 100–400 nm size-selected BC particles with different morphologies and different SOA coatings representative of anthropogenic (toluene and n-dodecane) and biogenic (β-caryophyllene) sources in the cirrus regime (−46 to −38 °C). Several aerosolized BC proxies were selected to represent different particle morphologies and oxidation levels. Atmospheric aging was further replicated with exposure of SOA-coated BC to OH. The results demonstrate that the 400 nm hydrophobic BC types nucleate ice only at or near the homogeneous freezing threshold (−42 to −46 ˚C). Deposition IN, as opposed to purely homogeneous freezing, was observed to occur for some BC types between 100–200 nm within the investigated temperature range. More fractal BC particles did not consistently act as superior deposition INPs over more spherical ones. SOA coating generated by oxidizing β-caryophyllene with O3 did not seem to affect BC IN ability. However, SOA coatings generated from OH oxidation of various organic species did exhibit higher IN onset supersaturation ratio with respect to ice (SSi) compared with bare BC particles, with toluene SOA coating showing an increase of SSi by 0.1–0.15 while still below the homogeneous threshold. n-dodecane and β-caryophyllene-derived SOA only froze in the homogeneous regime. We attribute the inhibition of IN ability to the filling of the pores on the BC surface by the SOA material coating. OH exposure levels of all SOA coating experiments, from an equivalent atmospheric 10 days to 90 days, did not render significant differences in IN potential. Our study suggests that BC particles with large sizes and/or oxidized surfaces generally exhibit better IN ability, and that the organic coating materials can inhibit ice formation.

show abstract

Section: Ice Nucleation On Bc Coated With Soa Materialssupporting

confidence: 75%

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

Zhang¹,

Zhang²,

Wolf³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Three BC proxies were chosen to represent freshly emitted (in other words, unoxidized and more fractal) BC (R2500U), unoxidized compacted BC (R330R), and atmospheric chemically aged BC (COJ300). The morphological characteristics are within the value range of typical amounts of BC emitted from combustion sources and those collected in field observations (e.g., Lapuerta et al, 2007;China et al, 2013China et al, , 2014Vander Wal et al, 2014;China et al, 2015b;Y. Zhang et al, 2019a).…”

Section: Atmospheric Implicationssupporting

confidence: 60%

The effects of morphology, mobility size, and secondary organic aerosol (SOA) material coating on the ice nucleation activity of black carbon in the cirrus regime

Zhang

Wolf

et al. 2020

Atmos. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. There is evidence that black carbon (BC) particles may affect cirrus formation and, hence, global climate by acting as potential ice nucleating particles (INPs) in the troposphere. Nevertheless, the ice nucleation (IN) ability of bare BC and BC coated with secondary organic aerosol (SOA) material remains uncertain. We have systematically examined the IN ability of 100–400 nm size-selected BC particles with different morphologies and different SOA coatings representative of anthropogenic (toluene and n-dodecane) and biogenic (β-caryophyllene) sources in the cirrus regime (−46 to −38 ∘C). Several BC proxies were selected to represent different particle morphologies and oxidation levels. Atmospheric aging was further replicated with the exposure of SOA-coated BC to OH. The results demonstrate that the 400 nm hydrophobic BC types nucleate ice only at or near the homogeneous freezing threshold. Ice formation at cirrus temperatures below homogeneous freezing thresholds, as opposed to purely homogeneous freezing, was observed to occur for some BC types between 100 and 200 nm within the investigated temperature range. More fractal BC particles did not consistently act as superior INPs over more spherical ones. SOA coating generated by oxidizing β-caryophyllene with O3 did not seem to affect BC IN ability, probably due to an SOA-phase state transition. However, SOA coatings generated from OH oxidation of various organic species did exhibit higher IN-onset supersaturation ratio with respect to ice (SSi), compared with bare BC particles, with the toluene-SOA coating showing an increase in SSi of 0.1–0.15 while still below the homogeneous freezing threshold. Slightly oxidized toluene SOA coating seemed to have a stronger deactivation effect on BC IN ability than highly oxidized toluene SOA, which might be caused by oligomer formation and the phase state transition of toluene SOA under different oxidation levels. n-dodecane and β-caryophyllene-derived SOA-coated BC only froze in the homogeneous regime. We attribute the inhibition of IN ability to the filling of the pores on the BC surface by the SOA material coating. OH exposure levels of n-dodecane and β-caryophyllene SOA coating experiments, from an equivalent atmospheric exposure time from 10 to 90 d, did not render significant differences in the IN potential. Our study of selected BC types and sizes suggests that increases in diameter, compactness, and/or surface oxidation of BC particles lead to more efficient IN via the pore condensation freezing (PCF) pathway, and that coatings of common SOA materials can inhibit the formation of ice.

show abstract

“…Champion et al (2019) found that SOA with higher condensed-phase fractions of extremely low volatility organic compounds (ELVOC) and low volatility organic compounds (LVOC) showed an increased viscosity. Zhang et al (2019) measured T g of isoprene SOA components including isoprene hydroxy hydroperoxide (ISOPOOH), isoprene-derived epoxydiol (IEPOX), 2-methyltetrols, and 2methyltetrol sulfates (2-MT-OS), observing a tight correlation between T g and vapor pressure.…”

Section: Introductionmentioning

confidence: 99%

Predictions of the glass transition temperature and viscosity of organic aerosols from volatility distributions

et al. 2020

View full text Add to dashboard Cite

Abstract. Volatility and viscosity are important properties of organic aerosols (OA), affecting aerosol processes such as formation, evolution, and partitioning of OA. Volatility distributions of ambient OA particles have often been measured, while viscosity measurements are scarce. We have previously developed a method to estimate the glass transition temperature (Tg) of an organic compound containing carbon, hydrogen, and oxygen. Based on analysis of over 2400 organic compounds including oxygenated organic compounds, as well as nitrogen- and sulfur-containing organic compounds, we extend this method to include nitrogen- and sulfur-containing compounds based on elemental composition. In addition, parameterizations are developed to predict Tg as a function of volatility and the atomic oxygen-to-carbon ratio based on a negative correlation between Tg and volatility. This prediction method of Tg is applied to ambient observations of volatility distributions at 11 field sites. The predicted Tg values of OA under dry conditions vary mainly from 290 to 339 K and the predicted viscosities are consistent with the results of ambient particle-phase-state measurements in the southeastern US and the Amazonian rain forest. Reducing the uncertainties in measured volatility distributions would improve predictions of viscosity, especially at low relative humidity. We also predict the Tg of OA components identified via positive matrix factorization of aerosol mass spectrometer (AMS) data. The predicted viscosity of oxidized OA is consistent with previously reported viscosity of secondary organic aerosols (SOA) derived from α-pinene, toluene, isoprene epoxydiol (IEPOX), and diesel fuel. Comparison of the predicted viscosity based on the observed volatility distributions with the viscosity simulated by a chemical transport model implies that missing low volatility compounds in a global model can lead to underestimation of OA viscosity at some sites. The relation between volatility and viscosity can be applied in the molecular corridor or volatility basis set approaches to improve OA simulations in chemical transport models by consideration of effects of particle viscosity in OA formation and evolution.

show abstract

Kinetically controlled glass transition measurement of organic aerosol thin films using broadband dielectric spectroscopy

Cited by 13 publications

References 59 publications

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

The effects of morphology, mobility size, and secondary organic aerosol (SOA) material coating on the ice nucleation activity of black carbon in the cirrus regime

Predictions of the glass transition temperature and viscosity of organic aerosols from volatility distributions

Contact Info

Product

Resources

About