Unraveling Aqueous Alcohol Freezing : new theoretical tools from graph theory to extract molecular processes in MD simulations DOI
Rawan Abouhaidar, Sana Bougueroua, Denis Duflot

et al.

Faraday Discussions, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 29, 2024

Ice clouds in the upper troposphere are crucial for regulating Earth's climate by affecting stratospheric humidity and global radiative balance. A key aspect of cloud formation is heterogeneous ice nucleation, influenced surface properties aerosol particles, particularly those with chemical groups capable hydrogen bonding water. Short-chained alcohols, such as 1-pentanol 3-hexanol, which readily accumulate at liquid-vapor interface, particular interest due to their potential impact on despite role freezing processes being underexplored. To address this gap, molecular dynamics (MD) simulations combined topological graph analysis (GT) were used investigate onset water-alcohol temperatures ranging from 283 K 192 K. Both macroscopic properties, like tension solubility, microscopic including incorporation alcohols within 2D-film water, analyzed. The results indicate that adsorbed films 3-hexanol significantly influence freezing, forming more organized efficiently packed layers compared thus reducing effectively. novel application based representation intra- inter-molecular interactions a revealed insertion alcohol molecules into collective hydrogen-bonded 2D network water surface, promoting enhanced six-membered H-bonded rings lower temperatures. This effect was pronounced 1-pentanol, proved efficient than facilitating creation ice-like structures-a critical precursor formation. These findings offer valuable insights governing significant implications understanding science dynamics.

Language: Английский

The surface tension and cloud condensation nuclei (CCN) activation of sea spray aerosol particles DOI Creative Commons
Judith Kleinheins, Nadia Shardt, Ulrike Lohmann

et al.

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(2), P. 881 - 903

Published: Jan. 22, 2025

Abstract. In marine environments, sea spray aerosol (SSA) particles have been found to contain surface-active substances (surfactants) originating from the surface microlayer. These surfactants can lower tension of SSA particles, facilitating their activation cloud droplets. This effect is not considered in classical Köhler theory, which assumes droplets be homogeneous with a pure water. this study condensation nuclei (CCN) activity calculated theory compared more complex calculation that considers bulk–surface partitioning, lowering, and liquid–liquid phase separation. The model approach presented here combines multi-component Eberhart for monolayer an (Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients, AIOMFAC). combination allows calculating curves surfactant-containing large number compounds first time. sensitivity we show organic categorized into weak, intermediate, strong CCN based on separation factor water S1i component σi. For quaternary system it shown high content hydrophobic material (i.e. surfactants) Aitken mode does necessarily prevent good but rather facilitates effective via lowering. Since common climate models use parameterizations are these results suggest small might underestimated models.

Language: Английский

Citations

1
Properties of Surface-Active Organics in Aerosol Particles Produced from Combustion of Biomass Fuels under Simulated Prescribed-Fire and Wildfire Conditions DOI Creative Commons

Ariana M. Deegan,

Chase K. Glenn, Omar El Hajj

et al.

ACS ES&T Air, Journal Year: 2025, Volume and Issue: 2(2), P. 264 - 276

Published: Jan. 3, 2025

The interfacial properties of the organic fraction biomass burning aerosols (BBA), such as critical micelle concentration (CMC) and surfactant composition, may vary based on origin moisture content fuel resulting combustion conditions. Surfactant total particle mass, surface tension minimums, CMC values organics extracted from fresh aged BBA produced using beds Georgia ecoregions (Piedmont, Coastal Plain, Blue Ridge) with contents representative prescribed fires or drought-induced wildfires were measured high resolution mass spectrometry, UV–vis spectroscopy, pendant drop tensiometry. Surface minimums all low (<45 mN m–1), surfactants ∼2% mass. was tied to conditions, highest fractions present in most efficient (highest temperature) combustion. Aging a potential aerosol oxidative flow reactor resulted an increase dependence conditions have implications for microphysics fires.

Language: Английский

Citations

0
Confocal fluorescence imaging of levitated particles and microdroplets DOI
Michael I. Jacobs,

Emilie T. Aleman,

Rachel G. Zepeda

et al.

Aerosol Science and Technology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 12

Published: Jan. 28, 2025

Language: Английский

Citations

0
Morphology Rather Than Surface Tension Determines CCN Activity of Submicron Inorganic Salt/Organic Oxidized Sulfur Mixed Particles DOI Creative Commons
Chun Xiong,

Binyu Kuang,

Xueyan Chen

et al.

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(5)

Published: March 4, 2025

Abstract Organic oxidized sulfur (OOS) compounds, particularly surface‐active ones like organosulfates and organosulfonates, constitute a significant atmospheric reservoir play crucial role in cloud formation. Due to limited measurements, the physical characteristics of OOS aerosols under high relative humidity (RH) subsequent activation potential remain unclear. In this study, we measured phase state, surface tension morphology mixtures containing inorganic salts (sodium chloride (NaCl) ammonium salfate (AS)) RH (>99.5%), investigated their condensation nuclei (CCN) activity. We found that κ CCN studied ranged from 0.15 0.37, showing negative relationship with molar volume. chemistry‐derived Chem agreed well for short carbon chain length (≤4), which could be explained by ideal solution because liquid slight reduction compared water. However, overpredicted 35% 17% on average NaCl–OOS AS–OOS long (seven eight), respectively, was opposite results inorganic–dicarboxylic acid previously reported. Although notably decreased 25%–44%, inorganic–OOS exhibited core‐shell shell suppressed water uptake, whereas particles homogeneous state thus not inhibiting uptake. Based results, emphasize pivotal surfactant determining aerosol thereby activations.

Language: Английский

Citations

0
Surface tension predictions during hygroscopic growth and cloud droplet activation using a simple kinetic surfactant partitioning model DOI
Ewald Werner, Michelle Hammond, Alison Bain

et al.

Aerosol Science and Technology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 13

Published: March 26, 2025

Language: Английский

Citations

0
Source characteristics and gas-particle partitioning of alkylated polycyclic aromatic hydrocarbons in coal combustion emissions DOI
Cheng Yang, Fang Yin, Hao Wang

et al.

Atmospheric Environment, Journal Year: 2025, Volume and Issue: unknown, P. 121231 - 121231

Published: April 1, 2025

Language: Английский

Citations

0
Analysis of Atmospheric Particles: From the Bulk to the Interface DOI
Ting Lei, Maofa Ge, Weigang Wang

et al.

Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: April 30, 2025

Language: Английский

Citations

0
Exploring How the Surface-Area-to-Volume Ratio Influences the Partitioning of Surfactants to the Air–Water Interface in Levitated Microdroplets DOI
Michael I. Jacobs,

M. Johnston,

Shahriar Mahmud

et al.

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: 128(46), P. 9986 - 9997

Published: Nov. 12, 2024

Quantitative characterization of the surface microdroplets is important to understanding and predicting numerous chemical physical processes, such as cloud droplet formation accelerated chemistry in microdroplets. However, it increasingly appreciated that compositions do not necessarily match those macroscale solution due their large surface-area-to-volume (SA–V) ratios confined volumes. In this work, we explore how both size composition affect by measuring equilibrium tensions levitated containing a single surfactant. We measure critical micelle concentrations (CMCs) for surfactants various strengths (macroscale CMC values ranging from 0.02 10 mM) with radii 5 25 μm. accurately model using an partitioning only requires adsorption parameters measurements inputs. Our predicts have "effective CMC" always larger value than corresponding CMC. some instances, effective surfactant several orders magnitude its solubility limit. present simple expression depends on SA–V ratio microdroplet. Ultimately, our experimental results can be used broadly predict microdroplet when investigating surface-driven or estimating activation.

Language: Английский

Citations

1
Quantifying surface tension of metastable aerosols via electrodeformation DOI Creative Commons
Vahid Shahabadi,

Benjamin Vennes,

Ryan Schmedding

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Dec. 2, 2024

Accurate surface tension measurements are key to understanding and predicting the behavior of atmospheric aerosols, particularly their formation, growth, phase transitions. In Earth's atmosphere, aerosols often exist in metastable states, such as being supercooled or supersaturated. Standard tensiometry instruments face challenges accessing these states due large sample volumes they require rapid changes near surfaces. We present an instrument that uses a strong electric field, nearing dielectric strength air, deform aerosol microdroplets measure contact-free, humidity-controlled environment. A dual-beam optical trap holds single between two electrodes excites Raman scattering. When high voltage is applied, droplet deformations reach tens nanometers. These small shape precisely measured through splitting morphology-dependent resonances, seen sharp peaks spectra. Our cover water activities where droplets supersaturated, region with limited previous data, show good agreement existing data comparisons possible. Unlike prior levitation-based methods, this approach measures systems viscosities over 102 Pa s without relying on dynamic processes. Atmospheric states. Here, authors non-contact method for measuring using electrodeformation scattering, which enables precise measurement

Language: Английский

Citations

1
Evaluating the Extraction and Quantification of Marine Surfactants from Seawater through Solid Phase Extraction and Subsequent Colorimetric Analyses DOI Creative Commons
Rachel L. Bramblett, A. A. Frossard

ACS ES&T Water, Journal Year: 2024, Volume and Issue: 4(11), P. 4836 - 4846

Published: Oct. 25, 2024

Surfactants are amphiphilic molecules that adsorb to interfaces and affect the interfacial tension. in seawater can impact gas-exchange, surface properties, composition fate of sea spray aerosol. The accurate quantification surfactants their classes is crucial constraining effect role air-sea exchanges. Here, we evaluate optimize a solid phase extraction (SPE) method paired with colorimetry UV-vis spectroscopy quantify concentrations anionic, cationic, nonionic seawater. We compare tandem SPE two-step different elution volumes interferents. Improved efficiencies were obtained an 8 mL acetonitrile separate ENVI-18 ENVI-Carb extractions, instead tandem. With complex surfactant mixtures, presence anionic interfered cationic caused underestimations up 83%. Using analyzing each extract separately during colorimetric help avoid effects interferents ensure more representative surfactants. this method, average ranged from 0.04 0.06 μM. At highest concentrations, class comprised 23% 21% 56%

Language: Английский

Citations

0