scholarly journals Secondary organic material formed by methylglyoxal in aqueous aerosol mimics – Part 1: Surface tension depression and light-absorbing products

2009 ◽  
Vol 9 (4) ◽  
pp. 15541-15565 ◽  
Author(s):  
A. N. Schwier ◽  
E. L. Shapiro ◽  
N. Sareen ◽  
V. F. McNeill
Keyword(s):  
Surface Tension ◽  
Organic Material ◽  
Aldol Condensation ◽  
Aerosol Particles ◽  
Ammonium Ion ◽  
Inorganic Salts ◽  
Solution Composition ◽  
Tropospheric Aerosol ◽  
Seed Aerosol ◽  
Nitrate Solutions

Abstract. We show that methylglyoxal forms light-absorbing secondary organic material in aqueous ammonium sulfate and ammonium nitrate solutions mimicking tropospheric aerosol particles. The light-absorbing products form on the order of minutes, and solution composition continues to change over several days. The results suggest an aldol condensation pathway involving the participation of the ammonium ion. Aqueous solutions of methylglyoxal, with and without inorganic salts, exhibit surface tension depression. Methylglyoxal uptake could potentially change the optical properties, climate effects, and heterogeneous chemistry of the seed aerosol over its lifetime.

scholarly journals Light-absorbing secondary organic material formed by glyoxal in aqueous aerosol mimics

2009 ◽  
Vol 9 (7) ◽  
pp. 2289-2300 ◽  
Author(s):  
E. L. Shapiro ◽  
J. Szprengiel ◽  
N. Sareen ◽  
C. N. Jen ◽  
M. R. Giordano ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Inorganic Salt ◽  
Aerosol Particles ◽  
Ammonium Ion ◽  
Pendant Drop ◽  
Tropospheric Aerosol ◽  
Surface Active ◽  
Visible Wavelengths ◽  
Seed Aerosol

Abstract. Light-absorbing and high-molecular-weight secondary organic products were observed to result from the reaction of glyoxal in mildly acidic (pH=4) aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol particles. High-molecular-weight (500–600 amu) products were observed when ammonium sulfate ((NH4)2SO4) or sodium chloride (NaCl) was present in the aqueous phase. The products formed in (NH4)2SO4 or ammonium nitrate (NH4NO3) solutions absorb light at UV and visible wavelengths. Substantial absorption at 300–400 nm develops within two hours, and absorption between 400–600 nm develops within days. Pendant drop tensiometry measurements show that the products are not surface-active. The experimental results along with ab initio predictions of the UV/Vis absorption of potential products suggest a mechanism involving the participation of the ammonium ion. If similar products are formed in atmospheric aerosol particles, they could change the optical properties of the seed aerosol over its lifetime.

scholarly journals Light-absorbing secondary organic material formed by glyoxal in aqueous aerosol mimics

2009 ◽  
Vol 9 (1) ◽  
pp. 59-80 ◽  
Author(s):  
E. L. Shapiro ◽  
J. Szprengiel ◽  
N. Sareen ◽  
C. N. Jen ◽  
M. R. Giordano ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Inorganic Salt ◽  
Aldol Condensation ◽  
Aerosol Particles ◽  
Pi Conjugated ◽  
Tropospheric Aerosol ◽  
Surface Active ◽  
Visible Wavelengths ◽  
Seed Aerosol

Abstract. Light-absorbing and high-molecular-weight secondary organic products were observed to result from the reaction of glyoxal in mildly acidic (pH=4) aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol particles. High-molecular-weight (500–600 amu) products were observed when ammonium sulfate ((NH4)2SO4) or sodium chloride (NaCl) was present in the aqueous phase. The products formed in the (NH4)2SO4 solutions absorb light at UV and visible wavelengths. Substantial absorption at 300–400 nm develops within two hours, and absorption between 400–600 nm develops within days. Pendant drop tensiometry measurements show that the products are not surface-active. The experimental results along with ab initio predictions of the UV/Vis absorption of potential products suggest that an aldol condensation mechanism is active in the glyoxal-(NH4)2SO4system, resulting in the formation of pi-conjugated products. If similar products are formed in atmospheric aerosol particles, they could change the optical properties of the seed aerosol over its lifetime.

scholarly journals Secondary organic material formed by methylglyoxal in aqueous aerosol mimics

2010 ◽  
Vol 10 (3) ◽  
pp. 997-1016 ◽  
Author(s):  
N. Sareen ◽  
A. N. Schwier ◽  
E. L. Shapiro ◽  
D. Mitroo ◽  
V. F. McNeill
Keyword(s):  
Organic Material ◽  
Aldol Condensation ◽  
Bimolecular Reaction ◽  
Ionization Mass ◽  
Aerosol Formation ◽  
Hydronium Ion ◽  
Rate Limiting Step ◽  
Tropospheric Aerosol ◽  
Heterogeneous Processes ◽  
Rate Limiting

Abstract. We show that methylglyoxal forms light-absorbing secondary organic material in aqueous ammonium sulfate and ammonium nitrate solutions mimicking tropospheric aerosol particles. The kinetics were characterized using UV-Vis spectrophotometry. The results suggest that the bimolecular reaction of methylglyoxal with an ammonium or hydronium ion is the rate-limiting step for the formation of light-absorbing species, with kNH4+II=5×10−6 M−1 min−1 and kH3O+II≤10−3 M−1 min−1. Evidence of aldol condensation products and oligomeric species up to 759 amu was found using chemical ionization mass spectrometry with a volatilization flow tube inlet (Aerosol-CIMS). Tentative identifications of carbon-nitrogen species and a sulfur-containing compound were also made using Aerosol-CIMS. Aqueous solutions of methylglyoxal, with and without inorganic salts, exhibit significant surface tension depression. These observations add to the growing body of evidence that dicarbonyl compounds may form secondary organic material in the aerosol aqueous phase, and that secondary organic aerosol formation via heterogeneous processes may affect seed aerosol properties.

scholarly journals Viscosity and phase state of aerosol particles consisting of sucrose mixed with inorganic salts

2021 ◽  
Author(s):  
Young-Chul Song ◽  
Joseph Lilek ◽  
Jae Bong Lee ◽  
Man Nin Chan ◽  
Zhijun Wu ◽  
...  
Keyword(s):  
Organic Material ◽  
Phase State ◽  
Aerosol Particles ◽  
Calcium Nitrate ◽  
Heterogeneous Reactions ◽  
Ternary Mixtures ◽  
Inorganic Salts ◽  
Inorganic Particles ◽  
Viscosity Measurements ◽  
Order Of Magnitude

Abstract. Research on the viscosity and phase state of aerosol particles is essential because of their significant influence on the particle growth rate, equilibration times and related evolution of mass concentration as well as heterogeneous reactions. So far, most studies of viscosity and phase state have been focused on organic aerosol particles, yet data on how viscosity can vary when the organic materials are mixed with inorganic salts remain scarce. Herein, using a bead-mobility and a poke-and-flow technique, we quantified viscosities at 293 ± 1 K for binary mixtures of organic material/H2O and inorganic salts/H2O, as well as ternary mixtures of organic material/inorganic salts/H2O over the atmospheric relative humidity (RH) range. Sucrose as the organic species, and calcium nitrate (Ca(NO3)2) or magnesium nitrate (Mg(NO3)2) as the inorganic salts were examined. For binary sucrose/H2O particles, the viscosities gradually increased from ~3 × 10−2 to > ~1 × 108 Pa s as RH decreased from ~75 % to ~25 %. Compared with the results for the sucrose/H2O particles, binary Ca(NO3)2/H2O and Mg(NO3)2/H2O particles showed drastic enhancements to > ~1 × 108 Pa s at low RH close to the efflorescence RH. For ternary mixtures of sucrose/Ca(NO3)2/H2O or sucrose/Mg(NO3)2/H2O, with organic-to-inorganic mass ratios of 1 : 1, the viscosities of the particles gradually increased from ~3 × 10−2 to greater than ~1 × 108 Pa s for RH values from ~75 % to ~5 %. Compared to the viscosities of the Ca(NO3)2/H2O particles, higher viscosities were observed for the ternary sucrose/Ca(NO3)2/H2O particles, with values increased by about 1 order of magnitude at 50 % RH and about 6 orders of magnitude at 35 % RH. Moreover, we applied a thermodynamics-based group-contribution model, AIOMFAC-VISC, to predict aerosol viscosities for the studied systems. The model predictions and viscosity measurements show good agreement within ~ 1 order of magnitude in viscosity. The viscosity measurements indicate that the studied mixed organic–inorganic particles range in phase state from liquid to semi-solid or even solid across the atmospheric RH range at a temperature of 293 K. These results support our understanding that organic/inorganic/H2O particles can exist in a liquid, semisolid, or even a solid state in the troposphere.

scholarly journals Viscosity and phase state of aerosol particles consisting of sucrose mixed with inorganic salts

2021 ◽  
Vol 21 (13) ◽  
pp. 10215-10228
Author(s):  
Young-Chul Song ◽  
Joseph Lilek ◽  
Jae Bong Lee ◽  
Man Nin Chan ◽  
Zhijun Wu ◽  
...  
Keyword(s):  
Organic Material ◽  
Phase State ◽  
Aerosol Particles ◽  
Calcium Nitrate ◽  
Heterogeneous Reactions ◽  
Ternary Mixtures ◽  
Inorganic Salts ◽  
Inorganic Particles ◽  
Viscosity Measurements ◽  
Order Of Magnitude

Abstract. Research on the viscosity and phase state of aerosol particles is essential because of their significant influence on the particle growth rate, equilibration times, and related evolution of mass concentration as well as heterogeneous reactions. So far, most studies of viscosity and phase state have been focused on organic aerosol particles, yet data on how viscosity can vary when the organic materials are mixed with inorganic salts remain scarce. Herein, using bead-mobility and poke-and-flow techniques, we quantified viscosities at 293 ± 1 K for binary mixtures of organic material / H2O and inorganic salts / H2O, as well as ternary mixtures of organic material / inorganic salts / H2O over the atmospheric relative humidity (RH) range. Sucrose as the organic species and calcium nitrate (Ca(NO3)2) or magnesium nitrate (Mg(NO3)2) as the inorganic salts were examined. For binary sucrose / H2O particles, the viscosities gradually increased from ∼ 3 × 10−2 to ≳1 × 108 Pa s as RH decreased from ∼ 75 % to ∼ 25 %. Compared with the results for the sucrose / H2O particles, binary Ca(NO3)2/H2O and Mg(NO3)2/H2O particles showed drastic enhancements to ≳1 × 108 Pa s at low RH close to the efflorescence RH. For ternary mixtures of sucrose / Ca(NO3)2 / H2O or sucrose / Mg(NO3)2 / H2O, with organic-to-inorganic mass ratios of 1:1, the viscosities of the particles gradually increased from ∼ 3 × 10−2 to greater than ∼ 1 × 108 Pa s for RH values from ∼ 75 % to ∼ 5 %. Compared to the viscosities of the Ca(NO3)2/H2O particles, higher viscosities were observed for the ternary sucrose / Ca(NO3)2 / H2O particles, with values increased by about 1 order of magnitude at 50 % RH and about 6 orders of magnitude at 35 % RH. Moreover, we applied a thermodynamics-based group-contribution model (AIOMFAC-VISC, Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients Viscosity) to predict aerosol viscosities for the studied systems. The model predictions and viscosity measurements show good agreement within ∼ 1 order of magnitude in viscosity. The viscosity measurements indicate that the studied mixed organic–inorganic particles range in phase state from liquid to semi-solid or even solid across the atmospheric RH range at a temperature of 293 K. These results support our understanding that organic / inorganic / H2O particles can exist in a liquid, semisolid, or even a solid state in the troposphere.

scholarly journals The Cloud Condensation Nuclei (CCN) properties of 2-methyltetrols and C3–C6 polyols from osmolality and surface tension measurements

2008 ◽  
Vol 8 (5) ◽  
pp. 17237-17256 ◽  
Author(s):  
S. Ekström ◽  
B. Nozière ◽  
H.-C. Hansson
Keyword(s):  
Surface Tension ◽  
Organic Acids ◽  
Organic Compounds ◽  
Organic Material ◽  
Cloud Condensation Nuclei ◽  
Global Scale ◽  
Cloud Formation ◽  
Inorganic Salts ◽  
High Solubility ◽  
Critical Supersaturation

Abstract. A significant fraction of the organic material in aerosols is made of highly soluble compounds such as sugars (mono- and polysaccharides) and polyols, including the 2-methyltetrols, methylerythritol and methyltreitol. The high solubility of these compounds has brought the question of their potentially high CCN efficiency. For the 2-methyltetrols, this would have important implications for cloud formation at global scale because they are thought to be produced by the atmospheric oxidation of isoprene. To investigate this question, the complete Köhler curves for C3–C6 polyols and the 2-methyltetrols have been determined experimentally from osmolality and surface tension measurements. Contrary to what expected, none of these compounds displayed a critical supersaturation lower than those of inorganic salts or organic acids. Their Raoult terms show that this limited CCN efficiency is due to their absence of dissociation in water, this in spite of slight surface-tension effects for the 2-methyltetrols. Thus, compounds such as sugars and polyols would not contribute more to cloud formation in the atmosphere than any other organic compounds studied so far. In particular, the presence of 2-methyltetrols in aerosols would not particularly enhance cloud formation in the atmosphere, contrary to what has been suggested.

scholarly journals Microscopic Evidence for Phase Separation of Organic Species and Inorganic Salts in Fine Ambient Aerosol Particles

2021 ◽  
Vol 55 (4) ◽  
pp. 2234-2242
Author(s):  
Weijun Li ◽  
Lei Liu ◽  
Jian Zhang ◽  
Liang Xu ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Phase Separation ◽  
Aerosol Particles ◽  
Inorganic Salts ◽  
Ambient Aerosol ◽  
Organic Species ◽  
Microscopic Evidence

Surface Activity Research of Cationic Gemini Surfactants

2013 ◽  
Vol 690-693 ◽  
pp. 2076-2080
Author(s):  
Zhen Zhong Fan ◽  
Lan Lan Li ◽  
Li Feng Zhang ◽  
Qing Wang Liu
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Surface Activity ◽  
Surfactant Concentration ◽  
Gemini Surfactant ◽  
Gemini Surfactants ◽  
Ph Value ◽  
Inorganic Salts ◽  
Cationic Gemini Surfactant ◽  
Cationic Gemini Surfactants

Cationic Gemini surfactant concentration, the inorganic salts added and the pH value of surface tension obtained cationic gemini surfactant critical micelle concentration is 0.4mmol / L;by adding three kinds of inorganic salts NaCl, MgCl2, and Na2SO4 ,which Na2SO4 has the greatest impact on surface tension, followed by MgCl2.The surface minimum tension of the pH ranged from 9 to 11 , indicating that the surface activity of cationic gemini surfactants achieved the highest.

Confocal Microprobe Raman Imaging of Urban Tropospheric Aerosol Particles

2006 ◽  
Vol 40 (4) ◽  
pp. 1300-1306 ◽  
Author(s):  
Yann Batonneau ◽  
Sophie Sobanska ◽  
Jacky Laureyns ◽  
Claude Bremard
Keyword(s):  
Aerosol Particles ◽  
Raman Imaging ◽  
Tropospheric Aerosol
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