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aerosol processing: a wind of innovation in the field of advanced heterogeneous catalysts

CHEMICAL SOCIETY REVIEWS 2018年第11期47卷 4112-4155页

作者： Debecker, Damien P. Le Bras, Solene Boissiere, Cedric Chaumonnot, Alexandra Sanchez, Clement Catholic Univ Louvain Inst Condensed Matter & Nanosci Pl Louis Pasteur 1Box L4-01-09 B-1348 Louvain La Neuve Belgium PSL Univ CNRS Lab LCMCP Sorbonne UnivColl France F-75005 Paris France IFP Energies Nouvelles Etab Lyon Rond Point Echangeur Solaize BP 3 F-69390 Solaize France

aerosol processing is long known and implemented industrially to obtain various types of divided materials and nanomaterials. The atomisation of a liquid solution or suspension produces a mist of aerosol droplets which can then be transformed via a diversity of processes including spray-drying, spray pyrolysis, flame spray pyrolysis, thermal decomposition, micronisation, gas atomisation, etc. The attractive technical features of these aerosol processes make them highly interesting for the continuous, large scale, and tailored production of heterogeneous catalysts. Indeed, during aerosol processing, each liquid droplet undergoes well-controlled physical and chemical transformations, allowing for example to dry and aggregate pre-existing solid particles or to synthesise new micro-or nanoparticles from mixtures of molecular or colloidal precursors. In the last two decades, more advanced reactive aerosol processes have emerged as innovative means to synthesise tailored-made nanomaterials with tunable surface properties, textures, compositions, etc. In particular, the "aerosol-assisted sol-gel'' process (AASG) has demonstrated tremendous potential for the preparation of high-performance heterogeneous catalysts. The method is mainly based on the low-cost, scalable, and environmentally benign sol-gel chemistry process, often coupled with the evaporation-induced self-assembly (EISA) concept. It allows producing micronic or submicronic, inorganic or hybrid organic-inorganic particles bearing tuneable and calibrated porous structures at different scales. In addition, pre-formed nanoparticles can be easily incorporated or formed in a "one-pot'' bottom-up approach within the porous inorganic or hybrid spheres produced by such spray drying method. Thus, multifunctional catalysts with tailored catalytic activities can be prepared in a relatively simple way. This account is an overview of aerosol processed heterogeneous catalysts which demonstrated interesting performance in vario

关键词： HETEROGENEOUS catalysts HETEROGENEOUS catalysis aerosol spray analysis CHEMICAL amplification NANOPARTICLES analysis

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Use of Calculated Physicochemical Properties to Enhance Quantitative Response When Using Charged aerosol Detection

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ANALYTICAL CHEMISTRY 2017年第3期89卷 1772-1777页

作者： Robinson, Max W. Hill, Alan P. Readshaw, Simon A. Hollerton, John C. Upton, Richard J. Lynn, Sean M. Besley, Steve C. Boughtflower, Bob J. GlaxoSmithKline Gunnels Wood Rd Stevenage SG1 2NY Herts England GlaxoSmithKline Gunnels Wood Rd Stevenage North Ireland 41 Flat 1 Thelwall Lane Warrington WA4 1LJ Cheshire England

Universal quantitative detection without the need for analyte reference standards would offer substantial benefits in many areas of analytical science. The quantitative capability of high-performance liquid chromatography (HPLC) with charged aerosol detection (CAD) was investigated for 50 compounds with a wide range of physical and chemical properties. It is widely believed that CAD is a mass detector. Quantification of the 50 compounds using a generic calibrant and mass calibration achieved an average error of 11.4% relative to 1H NMR. Correction factors are proposed that estimate the relative surface area of particles in the detector, taking into account the effects of the density and charge of analytes. Performing these corrections and quantifying with surface area calibration, rather than mass, shows considerably improved linearity and uniformity of detection, reducing the average error relative to 1H NMR to 7.1%. The accuracy of CAD quantification was most significantly improved for highly dense compounds, with traditional mass calibration showing an average error of 34.7% and the newly proposed surface area calibration showing an average error of 5.8%.

关键词： aerosol spray analysis QUANTITATIVE chemical analysis SURFACE chemistry HIGH performance liquid chromatography NUCLEAR magnetic resonance spectroscopy

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Droplet Assisted Inlet Ionization for Online analysis of Airborne Nanoparticles

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ANALYTICAL CHEMISTRY 2017年第2期89卷 1059-1062页

作者： Horan, Andrew J. Apsokardu, Michael J. Johnston, Murray V. Univ Delaware Dept Chem & Biochem Newark DE 19716 USA

Airborne nanoparticles play a key role in climate effects as well as impacting human health. Their small mass and complex chemical composition represent significant challenges for analysis. This work introduces a new ionization method, droplet assisted inlet ionization (DAII), where aqueous droplets are produced from airborne nanoparticles. When these droplets enter the mass spectrometer through a heated inlet, rapid vaporization leads to the formation of molecular ions. The method is demonstrated with test aerosols consisting of polypropylene glycol (PPG), angiotensin II, bovine serum albumin, and the thermometer compound p-methoxybenzylpyridinium chloride. High-quality spectra were obtained from PPG particles down to 13 nm in diameter and sampled masses in the low pictogram range. These correspond to aerosol number and mass concentrations smaller than 1000 particles/cm(3) and 100 ng/m(3), respectively, and a time resolution on the order of seconds. Fragmentation of the thermometer ion using DAII was inlet temperature dependent and similar in magnitude to that observed with a conventional ESI source on the same instrument. DAII should be applicable to other types of aerosols including workplace aerosols and those produced for drug delivery by inhalation.

关键词： NANOPARTICLES analysis IONIZATION (Atomic physics) AIR pollutants DROPS SPECTRUM analysis POLYPROPYLENE oxide aerosol spray analysis MASS spectrometry

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Atomic Force Microscopy-Infrared Spectroscopy of Individual Atmospheric aerosol Particles: Subdiffraction Limit Vibrational Spectroscopy and Morphological analysis

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ANALYTICAL CHEMISTRY 2017年第17期89卷 8594-8598页

作者： Bondy, Amy L. Kirpes, Rachel M. Merzel, Rachel L. Pratt, Kerri A. Holl, Mark M. Banaszak Ault, Andrew P. Univ Michigan Dept Chem Ann Arbor MI 48109 USA Univ Michigan Dept Environm Hlth Sci Ann Arbor MI 48109 USA

Chemical analysis of atmospheric aerosols is an analytical challenge, as aerosol particles are complex chemical mixtures that can contain hundreds to thousands of species in attoliter volumes at the most abundant sizes in the atmosphere (similar to 100 nm). These particles have global impacts on climate and health, but there are few methods available that combine imaging and the detailed molecular information from vibrational spectroscopy for individual particles <500 nm. Herein, we show the first application of atomic force microscopy with infrared spectroscopy (AFM-IR) to detect trace organic and inorganic species and probe intraparticle chemical variation in individual particles down to 150 nm. By detecting photothermal expansion at frequencies where particle species absorb IR photons from a tunable laser, AFM-IR can study particles smaller than the optical diffraction limit. Combining strengths of AFM (ambient pressure, height, morphology, and phase measurements) with photothermal IR spectroscopy, the potential of AFM-IR is shown for a diverse component particles, liquid liquid phase separated particles (core shell morphology), and ambient atmospheric particles. The spectra from atmospheric model systems (ammonium sulfate, sodium nitrate, succinic acid, and sucrose) had clearly identifiable features that correlate with absorption frequencies for infrared-active modes. Additionally, molecular information was obtained with <100 nm spatial resolution for phase separated particles with a 150 nm shell and 300 nm core. The subdiffraction limit capability of AFM-IR has the potential to advance understanding of particle impacts on climate and health by improving analytical capabilities to study water uptake, heterogeneous reactivity, and viscosity.

关键词： ATMOSPHERIC aerosol analysis ATOMIC force microscopy INFRARED spectroscopy aerosol spray analysis COLLOID analysis

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Viscosity and electric properties of water aerosols

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DOKLADY PHYSICS 2016年第9期61卷 429-434页

作者： Shavlov, A. V. Sokolov, I. V. Dzhumandzhi, V. A. Russian Acad Sci Inst Earths Cryosphere Siberian Branch Ul Malygina 86 Tyumen 625000 Russia Tyumen Ind Univ Ul Volodarskogo 38 Tyumen 625000 Russia

The flow of water mist in a narrow duct has been studied experimentally. The profile of the velocity of drops has been measured, and the viscosity of the mist has been calculated using the Navier-Stokes equation. It has been found that at low gradients of the rate of shear the viscosity of the mist can exceed that of clean air by tens and even hundreds of times. The electric charge of the drops has been measured. It has been found that the viscosity of the mist differs from that of clean air at gradients of the rate of shear that are less than the frequency of the establishment of electric equilibrium between the drops. A comparative analysis of the viscosities of the mist and a drop cluster has been carried out, and the dependence of the viscosity of the water aerosol on the radius and the charge of the drops has been predicted. The possible role of aerosols that contain submicron drops in the known "clear air turbulence" problem has been shown.

关键词： aerosol spray analysis VISCOSITY ELECTRIC properties NAVIER-Stokes equations TURBULENCE

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Upgraded technique to analyze the vertical structure of the aerosol component of the atmospheres of giant planets

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KINEMATICS AND PHYSICS OF CELESTIAL BODIES 2013年第6期29卷 291-300页

作者： Ovsak, A. S. Natl Acad Sci Ukraine Main Astron Observ UA-03680 Kiev Ukraine

To analyze the behavior of the optical thickness of aerosols or the ratio of the optical thicknesses of the aerosol and gas components in the spectral absorption bands of atmospheric gases with depth, we developed a software package. The package structure includes the units for the following operations: (1) to calculate the Legendre expansion coefficients x (i) of the phase function and the volume scattering coefficient sigma(0) of the polydisperse medium with the specified refractive index and the size distribution function N(r) with the use of the code developed by M.I. Mishchenko;(2) to generate the array containing the pairs of the single scattering albedo omega and the geometric albedo A (g) for the models of a semi-infinite homogeneous medium with the parameters determined in the previous step;(3) to determine the single scattering albedo values from the comparison of the calculated and measured values of the geometric albedo for each of the measured points in the examined absorption band of the atmospheric gas (accounting for the change of the phase function due to Rayleigh scattering);(4) to calculate the spectral values of the effective optical depths tau(eff) of the levels, where the intensity field of light diffusely reflected by the investigated atmosphere is formed;(5) to derive the scattering and absorption components of the effective optical depth (tau (eff) (s) and tau (eff) (v) ) from the values of omega and tau(eff);(6) from the values of tau (eff) (v) to determine the amount of the absorbing gas NL (in km-amg) along the line of sight and, from these values, the atmospheric pressure p(NL) and the gas component of the scattering portion of the optical depth tau (g) (lambda(0)) at the wavelength lambda(0) = 887.2 nm;(7) from the values of tau (eff) (s) (lambda) and tau (g) (lambda, NL), to find the aerosol component tau (a) (lambda, NL);(8) to build the plots of tau (a) (lambda) or the ratio tau (a) (lambda)/tau (g) (lambda) reduced to lambda(0) = 88

关键词： aerosol spray analysis ATMOSPHERIC pressure measurement COMPUTER software development POLYDISPERSE media REFRACTIVE index MATHEMATICAL models ALBEDO RAYLEIGH scattering

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Effects of NO_y Aging on the Dehydration Dynamics of Model Sea spray aerosol

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JOURNAL OF PHYSICAL CHEMISTRY A 2013年第20期117卷 4214-4222页

作者： Woods, Ephraim, III Heylman, Kevin D. Gibson, Amanda K. Ashwell, Adam P. Rossi, Sean R. Colgate Univ Dept Chem Hamilton NY 13346 USA

The reactions of NO, species in the atmosphere with sea spray aerosol replace halogen anions with nitrate. These experiments show the effect of increasing the nitrate content of model sea spray aerosol particles on the morphology changes and the phase transitions driven by changes in relative humidity (RH). The components of the model particles include H2O, Na+, Mg2+, Cl-, NO3-, and SO42-. Tandem differential mobility analyzer (TDMA) measurements yield the water content and efflorescence relative humidity (ERH) of these particles, and probe molecule spectroscopic measurements reveal subsequent phase transitions and partially characterize the salt composition on the surface of dry particles. The results show three effects of increasing the nitrate composition: decreasing the EFH (46 to 29%), production of a metastable aqueous layer on the surface of effloresced particles, and decreasing the sulfate content near the surface of dry particles. For the mixtures studied here, the initial crystallization event NaCl. For particles that contain a substantial metastable aqueous layer following efflorescence, probe molecule spectroscopy shows a second crystallization at a lower RI-I. This subsequent phase transition is likely the formation of Na2SO4. Homogeneous nucleation theory (HNT) using a semiempirical formulation predicts the ERR of all mixtures within 2.0% RH, with a mean absolute deviation of 1.0%. The calculations suggest that structures associated with highly concentrated or supersaturated magnesium ions strongly affect the interfacial tension between the NaCl crystal nucleus and the droplet from which it forms. forms a core of

关键词： DEHYDRATION (Chemistry) aerosol spray analysis NITRIC oxide analysis ANION separation MORPHOLOGY NITRATES PHASE transformations (Physics)

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Asian Industrial Lead Inputs to the North Pacific Evidenced by Lead Concentrations and Isotopic Compositions in Surface Waters and aerosols

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ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011年第23期45卷 9874-9882页

作者： Gallon, Celine Ranville, Mara A. Conaway, Christopher H. Landing, William M. Buck, Clifton S. Morton, Peter L. Flegal, A. Russell Univ Calif Santa Cruz Inst Marine Sci Santa Cruz CA 95064 USA Univ Calif Santa Cruz WIGS Lab Dept Microbiol & Environm Toxicol Santa Cruz CA 95064 USA Florida State Univ Dept Earth Ocean & Atmospher Sci Tallahassee FL 32306 USA

Recent trends of atmospheric lead deposition to the North Pacific were investigated with analyses of lead in aerosols and surface waters collected on the fourth Intergovernmental Oceanographic Commission Contaminant Baseline Survey from May to June, 2002. Lead concentrations of the aerosols varied by 2 orders of magnitude (0.1-26.4 pmol/m(3)) due in part to variations in dust deposition during the cruise. The ranges in lead aerosol enrichment factors relative to iron (1-119) and aluminum (3-168) were similar, evidencing the transport of Asian industrial lead aerosols across the North Pacific. The oceanic deposition of some of those aerosols was substantiated by the gradient of lead concentrations of North Pacific waters, which varied 3-fold (32.7-103.5 pmol/kg), were highest along with the Asian margin of the basin, and decreased eastward. The hypothesized predominance of Asian industrial lead inputs to the North Pacific was further corroborated by the lead isotopic composition of ocean surface waters ((206)pb/(207)pb = 1.157-1.169;Pb-208/Pb-206 = 2.093-2.118), which fell within the range of isotopic ratios reported in Asian aerosols that are primarily attributed to Chinese industrial lead emissions.

关键词： Industrial pollution Atmospheric lead Atmospheric deposition Sea water analysis aerosol spray analysis Lead isotopes

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