Heterogeneous Chemistry of Butanol and Decanol with Sulfuric Acid:  Implications for Secondary Organic Aerosol Formation

Levitt, Nicholas P.; Zhao, Jun; Zhang, Renyi

doi:10.1021/jp065245y

Cited by 32 publications

(40 citation statements)

References 34 publications

(83 reference statements)

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“…However, it is likely that H 2 SO 4 will have a much larger effect on processing of soot aerosols than organics, and condensation of H 2 SO 4 largely determines the aerosol hygroscopicity. Also, H 2 SO 4 condensed on aerosol particles may promote heterogeneous reactions of carbonyls and alcohols (31,32).…”

Section: Resultsmentioning

confidence: 99%

Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processing

Zhang

Khalizov

Pagels

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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761

709

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The atmospheric effects of soot aerosols include interference with radiative transfer, visibility impairment, and alteration of cloud formation and are highly sensitive to the manner by which soot is internally mixed with other aerosol constituents. We present experimental studies to show that soot particles acquire a large mass fraction of sulfuric acid during atmospheric aging, considerably altering their properties. Soot particles exposed to subsaturated sulfuric acid vapor exhibit a marked change in morphology, characterized by a decreased mobility-based diameter but an increased fractal dimension and effective density. These particles experience large hygroscopic size and mass growth at subsaturated conditions (<90% relative humidity) and act efficiently as cloud-condensation nuclei. Coating with sulfuric acid and subsequent hygroscopic growth enhance the optical properties of soot aerosols, increasing scattering by Ϸ10-fold and absorption by nearly 2-fold at 80% relative humidity relative to fresh particles. In addition, condensation of sulfuric acid is shown to occur at a similar rate on ambient aerosols of various types of a given mobility size, regardless of their chemical compositions and microphysical structures. Representing an important mechanism of atmospheric aging, internal mixing of soot with sulfuric acid has profound implications on visibility, human health, and direct and indirect climate forcing.climate ͉ clouds ͉ radiative properties ͉ human health ͉ anthropogenic pollution S oot aerosols produced from fossil-fuel combustion, automobile and aircraft emissions, and biomass burning are ubiquitous in the atmosphere, comprising Ϸ10-50% of the total tropospheric particulate matter (1-6). Once emitted into the atmosphere, soot particles are subjected to several aging processes, including adsorption or condensation of gaseous species (7-9), coagulation with other preexisting aerosols, and oxidation (10-12). Model calculations have shown that, when associated with other nonabsorbing aerosol constituents (e.g., sulfate), soot seems more absorptive and exerts a higher positive direct radiative forcing, and the warming effect by soot nearly balances the net cooling effect of other anthropogenic aerosols (5, 13). Also, on the basis of mesoscale model simulations, absorption of solar radiation by internally mixed soot aerosols causes warming in the middle atmosphere and reduction in cloudiness over the tropics (4). The mixing state and associated physical, optical, and geometrical properties of soot particles are of critical importance in evaluating the effects of light-absorbing aerosols and improving climate predictions by using global climate models (GCMs). Current knowledge on such an issue is very limited for developing an accurate representation of soot particles in GCMs, leading to underestimation of climatic forcing (14).Hygroscopic aerosols also act as cloud-condensation nuclei (CCN) that impact cloud formation and the lifetime and albedo of clouds (4, 6). Freshly generated soot particles exist...

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Section: Resultsmentioning

confidence: 99%

Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processing

Zhang

Khalizov

Pagels

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

761

709

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“…Garland et al (2006) also demonstrated that reactions of a high concentration of hexanal vapor (0.01 atm) with highly concentrated SA seed particles produce aerosols with up to 88 wt% of organics. Other groups have also shown that enhanced uptake into acidic particles occurs to commonly found VOCs that possess reactive functional groups (susceptible to proton addition), such as olefins (Limbeck et al 2003;Liggio et al 2007;Liggio and Li 2008), hydroxyls (Levitt et al 2006;Noziere et al 2006), epoxides (Surratt et al 2008;Minerath and Elrod 2009), and alkylamines (Wang et al 2010). It is proposed that the acidic medium in the particle phase acts as a catalyst (Jang et al 2002(Jang et al , 2004Liggio and Li 2006a) in particle-phase reactions of carbonyls, forming high-molecular-weight products that tend to stay in the particle phase.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Reactive Uptake of Nonanal by Acidic Aerosols in the Presence of Particle-Phase Organics

Chan

2011

Aerosol Science and Technology

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An electrodynamic balance was used to examine the effect of the presence of particle-phase organics on the acid-catalyzed reactive uptake of nonanal (NL) vapor. Uptake experiments were conducted by using sulfuric acid (SA) particles, oleic acid/SA (hydrophobic), and levoglucosan/SA (hydrophilic) mixed particles with 6 ppm (approximately) gas-phase NL at about 3% relative humidity. SA reacted with the mixed organics prior to NL uptake to form organic products, denoted as OleA * and Levo * , and with NL to form hydrophobic NL * (particle-phase organics). Fresh SA particles had small mass increases (5%-13%) at the start of NL exposure (0-40 min) even though they are highly acidic. However, OleA * /SA mixed particles of about 30-70 wt% of OleA * took up NL swiftly during the first 40 min. For example, the mass increase of a 33 wt% OleA * particle jumped to 120%. As the organic product, NL * , accumulated, the uptake rate of SA particle increased and the mass increase surged to 150% at 100 min. Afterwards, the mass increase started to level off which yielded a sigmoid uptake curve. For OleA * /SA particles, the uptake rate gradually slowed down resulting in physicalabsorption-like uptake kinetics. The physical uptake of NL by a pure OleA * surrogate was negligible (<1%) showing that the large uptake of OleA * /SA particles were attributed to the enhanced reactive uptake of NL in the presence of hydrophobic OleA * . Conversely, the hydrophilic Levo * /SA particles were incompatible with NL, and they showed insignificant enhanced uptake compared with the SA particles. Overall, the acidic uptake of NL is highly dependent on the chemical nature and weight percentages of particle-phase organics in mixed particles. Presence of hydrophobic organic materials in particles enhanced the reactive uptake of NL.

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“…Field measurements indicated that pinonic acids represent an important constituent of nanosized particles over forests (9). Also, oxygenated organic species, which are formed from oxidation of biogenic hydrocarbons (10)(11)(12), may engage in heterogeneous reactions to lead to aerosol growth (13)(14)(15).…”

mentioning

confidence: 99%

Formation of nanoparticles of blue haze enhanced by anthropogenic pollution

Zhang

Wang

Khalizov

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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246

240

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The molecular processes leading to formation of nanoparticles of blue haze over forested areas are highly complex and not fully understood. We show that the interaction between biogenic organic acids and sulfuric acid enhances nucleation and initial growth of those nanoparticles. With one cis-pinonic acid and three to five sulfuric acid molecules in the critical nucleus, the hydrophobic organic acid part enhances the stability and growth on the hydrophilic sulfuric acid counterpart. Dimers or heterodimers of biogenic organic acids alone are unfavorable for new particle formation and growth because of their hydrophobicity. Condensation of lowvolatility organic acids is hindered on nano-sized particles, whereas ammonia contributes negligibly to particle growth in the size range of 3-30 nm. The results suggest that initial growth from the critical nucleus to the detectable size of 2-3 nm most likely occurs by condensation of sulfuric acid and water, implying that anthropogenic sulfur emissions (mainly from power plants) strongly influence formation of terrestrial biogenic particles and exert larger direct and indirect climate forcing than previously recognized.aerosol ͉ biogenic ͉ climate ͉ nucleation ͉ forest

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Heterogeneous Chemistry of Butanol and Decanol with Sulfuric Acid: Implications for Secondary Organic Aerosol Formation

Cited by 32 publications

References 34 publications

Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processing

Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processing

Enhanced Reactive Uptake of Nonanal by Acidic Aerosols in the Presence of Particle-Phase Organics

Formation of nanoparticles of blue haze enhanced by anthropogenic pollution

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