Products and Mechanisms of Ozone Reactions with Oleic Acid for Aerosol Particles Having Core−Shell Morphologies

Abstract. The composition of atmospheric aerosol particles has been found to influence their micro-physical properties and their interaction with water vapour in the atmosphere. Core-shell models have been used to investigate the relationship between composition, viscosity and equilibration time-scales. These models have traditionally relied on the Fickian laws of diffusion with no explicit account of non-ideal interactions. We introduce the Maxwell-Stefan diffusion framework as an alternative method, which explicitly accounts for non-ideal interactions through activity coefficients. E-folding time is the time it takes for the difference in surface and bulk concentration to change by an exponential factor and was used to investigate the interplay between viscosity and solubility and the effect this has on equilibration time-scales within individual aerosol particles. The e-folding time was estimated after instantaneous increases in relative humidity to binary systems of water and an organic component. At low water mole fractions, viscous effects were found to dominate mixing. However, at high water mole fractions, equilibration times were more sensitive to a range in solubility, shown through the greater variation in e-folding times. This is the first time the Maxwell-Stefan framework has been applied to an atmospheric aerosol core-shell model and shows that there is a complex interplay between the viscous and solubility effects on aerosol composition that requires further investigation.

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Density changes of aerosol particles as a result of chemical reaction

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-4-6431-2004 ◽

2004 ◽

Vol 4 (5) ◽

pp. 6431-6472 ◽

Cited By ~ 11

Author(s):

Y. Katrib ◽

S. T. Martin ◽

Y. Rudich ◽

P. Davidovits ◽

J. T. Jayne ◽

...

Keyword(s):

Oleic Acid ◽

Oxygen Content ◽

Chemical Reactions ◽

Aerosol Particles ◽

Ozone Exposure ◽

Spherical Particles ◽

Aerodynamic Diameter ◽

Layer Density ◽

Aerosol Mass ◽

Mobility Diameter

Abstract. This paper introduces the capability to study simultaneously changes in the density, the chemical composition, the mobility diameter, the aerodynamic diameter, and the layer thickness of multi-layered aerosol particles as they are being altered by heterogeneous chemical reactions. A vaporization-condensation method is used to generate aerosol particles composed of oleic acid outer layers of 2 to 30 nm on 101-nm polystyrene latex cores. The layer density is modified by reaction of oleic acid with ozone for variable exposure times. For increasing ozone exposure, the mobility diameter decreases while the vacuum aerodynamic diameter increases, which, for spherical particles, implies that particle density increases. The aerosol particles are confirmed as spherical based upon the small divergence of the particle beam in the aerosol mass spectrometer. The particle and layer densities are calculated by two independent methods, namely one based on the measured aerodynamic and mobility diameters and the other based on the measured mobility diameter and particle mass. The uncertainty estimates for density calculated by the second method are two to three times greater than those of the first method. Both methods indicate that the layer density increases from 0.89 to 1.12 g·cm−3 with increasing ozone exposure. Aerosol mass spectrometry shows that, concomitant with the increase in the layer density, the oxygen content of the reacted layer increases. Even after all of the oleic acid has reacted, the layer density and the oxygen content continue to increase slowly with prolonged ozone exposure, a finding which indicates continued chemical reactions of the organic products either with ozone or with themselves. The results of this paper provide new insights into the complex changes occurring for atmospheric particles during the aging processes caused by gas-phase oxidants.

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Phase, Morphology, and Hygroscopicity of Mixed Oleic Acid/Sodium Chloride/Water Aerosol Particles before and after Ozonolysis

The Journal of Physical Chemistry A ◽

10.1021/jp211429f ◽

2012 ◽

Vol 116 (24) ◽

pp. 6159-6168 ◽

Cited By ~ 39

Author(s):

Benjamin J. Dennis-Smither ◽

Kate L. Hanford ◽

Nana-Owusua A. Kwamena ◽

Rachael E. H. Miles ◽

Jonathan P. Reid

Keyword(s):

Oleic Acid ◽

Sodium Chloride ◽

Aerosol Particles ◽

Phase Morphology ◽

Water Aerosol ◽

Before And After ◽

Chloride Water

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Synthesis, characterization and tribological behavior of oleic acid-capped core-shell lanthanum borate-SiO2 composites

Industrial Lubrication and Tribology ◽

10.1108/ilt-06-2011-0041 ◽

2014 ◽

Vol 66 (1) ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Zhengfeng Jia ◽

Yan-qiu Xia ◽

Xin Shao ◽

San-ming Du

Keyword(s):

Oleic Acid ◽

Tribological Properties ◽

Friction And Wear ◽

Thermo Gravimetric Analysis ◽

Core Shell ◽

Gravimetric Analysis ◽

Content Type ◽

Aisi 1045 Steel ◽

Aisi 1045 ◽

1045 Steel

Purpose – The purpose of this paper is to investigate the tribological properties of poly-alpha-olefin (PAO) with nano/microstructure core-shell lanthanum borate-SiO2 composites (OCLS). Design/methodology/approach – Oleic acid-capped core-shell lanthanum borate-SiO2 composites were synthesized by an easy way. The composites were characterized by means of Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The friction and wear behaviors of the quenched AISI 1045 steel specimens sliding against AISI 52100 steel under the lubrication of PAO containing OCLS were comparatively investigated with PAO containing SiO2 additive on an Optimol SRV reciprocating friction and wear tester. On the other hand, the tribological properties of the PAO containing OCLS were also investigated on four-ball tester. Findings – The diameter of OCLS was about 20 nm, and the thickness of the SiO2 shell was less than 5 nm. The ratio of oleic acid (OA) is about 15 percent. The PAO containing OCLS possesses much better tribological properties than that of pure PAO and PAO containing SiO2 additive. Originality/value – The PAO+OCLS possess a better friction reducing and antiwear properties than pure PAO. The new additive can improve the tribological ability of machinery.

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Oxidative aging of mixed oleic acid/sodium chloride aerosol particles

Journal of Geophysical Research Atmospheres ◽

10.1029/2012jd018163 ◽

2012 ◽

Vol 117 (D20) ◽

Cited By ~ 26

Author(s):

Benjamin J. Dennis-Smither ◽

Rachael E. H. Miles ◽

Jonathan P. Reid

Keyword(s):

Oleic Acid ◽

Sodium Chloride ◽

Aerosol Particles ◽

Oxidative Aging

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Silica Coating of Metal-Loaded H-ZSM-22 to Form the Core-Shell Nanostructures: Characterization, Textural Properties, and Catalytic Potency in the Esterification of Oleic Acid

International Journal of Chemical Engineering ◽

10.1155/2021/5321383 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Maryam Haghighi ◽

Mehranoosh Fereidooni

Keyword(s):

Oleic Acid ◽

Electron Microscope ◽

Active Sites ◽

Maximum Yield ◽

Operating Conditions ◽

Molar Ratio ◽

Emission Spectrometry ◽

Esterification Reaction ◽

Core Shell ◽

The Core

In this study, ZSM-22 was synthesized using N,N-diethylaniline as a template through a hydrothermal method. The proton and various metals such as zirconium, strontium, and iron were immobilized on the surface of obtained zeolites through the ion exchange method. The catalysts were studied by Fourier-Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption isotherms, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) elemental analysis, and Temperature-Programmed Desorption of ammonia (TPD-NH3) technique for determining the number of acid sites. In the esterification reaction of oleic acid, the operating conditions such as catalyst dosage, temperature, molar ratio of methanol to oil, and reaction time were optimized and adjusted at 11 wt%, 70°C, 10 : 1, and 48 h subsequently. The maximum yield% of 48.07% was achieved in the presence of Zr-H-ZSM-22 at optimum conditions. In order to improve the efficiency of three zeolites Zr-H-ZSM-22, Fe-H-ZSM-22, and Sr-H-ZSM-22, the core-shell structures with SiO2 coating were prepared. Zr-H-ZSM-22@SiO2 was less active than Zr-H-ZSM-22 due to the SiO2 coverage of Lewis active sites.

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Effect of mixing structure on the water uptake of mixtures of ammonium sulfate and phthalic acid particles

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-2179-2021 ◽

2021 ◽

Vol 21 (3) ◽

pp. 2179-2190

Author(s):

Weigang Wang ◽

Ting Lei ◽

Andreas Zuend ◽

Hang Su ◽

Yafang Cheng ◽

...

Keyword(s):

Growth Factor ◽

Relative Humidity ◽

Water Uptake ◽

Phthalic Acid ◽

Aerosol Particles ◽

Core Shell ◽

Hygroscopic Growth ◽

The Core ◽

Mass Fractions ◽

Mixing States

Abstract. Aerosol mixing state regulates the interactions between water molecules and particles and thus controls aerosol activation and hygroscopic growth, which thereby influences visibility degradation, cloud formation, and its radiative forcing. There are, however, few current studies on the mixing structure effects on aerosol hygroscopicity. Here, we investigated the hygroscopicity of ammonium sulfate / phthalic acid (AS / PA) aerosol particles with different mass fractions of PA in different mixing states in terms of initial particle generation. Firstly, the effect of PA coatings on the hygroscopic behavior of the core-shell-generated mixtures of AS with PA was studied using a coating hygroscopicity tandem differential mobility analyzer (coating HTDMA). The slow increase in the hygroscopic growth factor of core-shell-generated particles is observed with increasing thickness of the coating PA prior to the deliquescence relative humidity (DRH) of AS. At relative humidity (RH) above 80 %, a decrease in the hygroscopic growth factor of particles occurs as the thickness of the PA shell increases, which indicates that the increase of PA mass fractions leads to a reduction of the overall core-shell-generated particle hygroscopicity. In addition, the use of the Zdanovskii–Stokes–Robinson (ZSR) relation leads to the underestimation of the measured growth factors of core-shell-generated particles without consideration of the morphological effect of core-shell-generated particles, especially at higher RH. Secondly, in the case of the AS / PA initially well-mixed particles, a shift of the DRH of AS (∼80 %, Tang and Munkelwitz, 1994) to lower RH is observed due to the presence of PA in the initially well-mixed particles. The predicted hygroscopic growth factor using the ZSR relation is consistent with the measured hygroscopic growth factor of the initially well-mixed particles. Moreover, we compared and discussed the influence of mixing states on the water uptake of AS / PA aerosol particles. It is found that the hygroscopic growth factor of the core-shell-generated particles is slightly higher than that of the initially well-mixed particles with the same mass fractions of PA at RH above 80 %. The observation of AS / PA particles may contribute to a growing field of knowledge regarding the influence of coating properties and mixing structure on water uptake.

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Synthesis and magnetooptic characterization of Cu-doped ZnO/MgO and ZnO/oleic acid core/shell nanoparticles

RSC Advances ◽

10.1039/c6ra01453d ◽

2016 ◽

Vol 6 (50) ◽

pp. 44820-44825 ◽

Cited By ~ 3

Author(s):

J. Mikulski ◽

B. Sikora ◽

K. Fronc ◽

P. Aleshkevych ◽

S. Kret ◽

...

Keyword(s):

Oleic Acid ◽

Magnetic Behavior ◽

Core Shell ◽

Shell Nanoparticles ◽

Ion Doping ◽

Doped Zno ◽

Core Shell Nanoparticles

The effect of Cu ion doping on the photoluminescence (PL) and magnetic behavior of ZnO/MgO and ZnO/oleic acid core/shell nanoparticles is investigated.

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