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Zangmeister CD, Radney JG, Staymates ME, Vicenzi EP, Weaver JL. Hydration of Hydrophilic Cloth Face Masks Enhances the Filtration of Nanoparticles. ACS APPLIED NANO MATERIALS 2021; 4:2694-2701. [PMID: 34192243 PMCID: PMC8078198 DOI: 10.1021/acsanm.0c03319] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/23/2021] [Indexed: 05/11/2023]
Abstract
Under high humidity conditions that mimic respiration, the filtration efficiency (FE) of hydrophilic fabrics increases when challenged with hygroscopic nanoparticles, for example, respiratory droplets containing SARS-CoV-2. The FE and differential pressure (ΔP) of natural, synthetic, and blended fabrics were measured as a function of relative humidity (RH) for particles with mobility diameters between 50 and 825 nm. Fabrics were equilibrated at 99% RH, mimicking conditions experienced when worn as a face mask. The FE increased after equilibration at 99% RH by a relative percentage of 33 ± 12% for fabrics composed of two layers of 100% cotton when challenged by 303 nm-mobility-diameter NaCl aerosol. The FE for samples of synthetics and polyester/cotton blends was unchanged upon equilibration at 99% RH. Increases in FE for 100% cotton fabrics were a function of particle size with a relative increase of 63% at the largest measured particle size (825 nm). The experimental results are consistent with increased particle capture due to H2O uptake and growth as the particles traverse the fabric.
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Affiliation(s)
- Christopher D. Zangmeister
- Material
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - James G. Radney
- Material
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Matthew E. Staymates
- Material
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Edward P. Vicenzi
- Material
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
- Museum
Conservation Institute, Smithsonian Institution, Suitland, Maryland 20746, United States
| | - Jamie L. Weaver
- Material
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
- Museum
Conservation Institute, Smithsonian Institution, Suitland, Maryland 20746, United States
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O’Shaughnessy PT, LeBlanc L, Pratt A, Altmaier R, Rajaraman PK, Walenga R, Lin CL. Assessment and Validation of a Hygroscopic Growth Model with Different Water Activity Estimation Methods. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2020; 54:1169-1182. [PMID: 33100458 PMCID: PMC7577510 DOI: 10.1080/02786826.2020.1763247] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/21/2020] [Accepted: 04/21/2020] [Indexed: 05/21/2023]
Abstract
Hygroscopic growth models are currently of interest as aids for targeting the deposition of inhaled drug particles in preferred areas of the lung that will maximize their pharmaceutical effect. Mathematical models derived to estimate hygroscopic growth over time have been previously developed but have not been thoroughly validated. For this study, model validation involved a comparison of modeled values to measured values when the growing droplet had reached equilibrium. A second validation process utilized a novel system to measure the growth of a droplet on a microscope coverslip relative to modeled values when the droplet is undergoing the initial rapid growth phase. Various methods currently used to estimate the water activity of the growing droplet, which influences the droplet growth rate, were also compared. Results indicated that a form of the hygroscopic growth model that utilizes coupled-differential equations to estimate droplet diameter and temperature over time was valid throughout droplet growth until it reached its equilibrium size. Accuracy was enhanced with the use of a polynomial expression to estimate water activity relative to the use of a simplified estimate of water activity based on Raoult's Law. Model accuracy was also improved when constraining the film of salt solution surrounding the dissolving salt core at saturation.
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Affiliation(s)
| | - Lawrence LeBlanc
- Mechanical Engineering, University of Iowa, Iowa City, Iowa, USA
| | - Alessandra Pratt
- Occupational & Environmental Health, University of Iowa, Iowa City, Iowa, USA
| | - Ralph Altmaier
- Occupational & Environmental Health, University of Iowa, Iowa City, Iowa, USA
| | | | - Ross Walenga
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Ching-Long Lin
- Mechanical Engineering, University of Iowa, Iowa City, Iowa, USA
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Abstract
Although too small to be seen with the human eye, atmospheric particulate matter has major impacts on the world around us, from our health to global climate. Understanding the sources, properties, and transformations of these particles in the atmosphere is among the major challenges in air quality and climate research today. Significant progress has been made over the past two decades in understanding atmospheric aerosol chemistry and its connections to climate. Advances in technology for characterizing aerosol chemical composition and physical properties have enabled rapid discovery in this area. This article reviews fundamental concepts and recent developments surrounding ambient aerosols, their chemical composition and sources, light-absorbing aerosols, aerosols and cloud formation, and aerosol-based solar radiation management (also known as solar geoengineering).
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Affiliation(s)
- V. Faye McNeill
- Department of Chemical Engineering, Columbia University, New York, New York 10027
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Bzdek BR, Collard L, Sprittles JE, Hudson AJ, Reid JP. Dynamic measurements and simulations of airborne picolitre-droplet coalescence in holographic optical tweezers. J Chem Phys 2017; 145:054502. [PMID: 27497560 DOI: 10.1063/1.4959901] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We report studies of the coalescence of pairs of picolitre aerosol droplets manipulated with holographic optical tweezers, probing the shape relaxation dynamics following coalescence by simultaneously monitoring the intensity of elastic backscattered light (EBL) from the trapping laser beam (time resolution on the order of 100 ns) while recording high frame rate camera images (time resolution <10 μs). The goals of this work are to: resolve the dynamics of droplet coalescence in holographic optical traps; assign the origin of key features in the time-dependent EBL intensity; and validate the use of the EBL alone to precisely determine droplet surface tension and viscosity. For low viscosity droplets, two sequential processes are evident: binary coalescence first results from the overlap of the optical traps on the time scale of microseconds followed by the recapture of the composite droplet in an optical trap on the time scale of milliseconds. As droplet viscosity increases, the relaxation in droplet shape eventually occurs on the same time scale as recapture, resulting in a convoluted evolution of the EBL intensity that inhibits quantitative determination of the relaxation time scale. Droplet coalescence was simulated using a computational framework to validate both experimental approaches. The results indicate that time-dependent monitoring of droplet shape from the EBL intensity allows for robust determination of properties such as surface tension and viscosity. Finally, the potential of high frame rate imaging to examine the coalescence of dissimilar viscosity droplets is discussed.
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Affiliation(s)
- Bryan R Bzdek
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Liam Collard
- Department of Mathematics, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - James E Sprittles
- Mathematics Institute, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Andrew J Hudson
- Department of Chemistry, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Jonathan P Reid
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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Julin J, Shiraiwa M, Miles REH, Reid JP, Pöschl U, Riipinen I. Mass accommodation of water: bridging the gap between molecular dynamics simulations and kinetic condensation models. J Phys Chem A 2013; 117:410-20. [PMID: 23253100 PMCID: PMC3600785 DOI: 10.1021/jp310594e] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 12/18/2012] [Indexed: 12/25/2022]
Abstract
The condensational growth of submicrometer aerosol particles to climate relevant sizes is sensitive to their ability to accommodate vapor molecules, which is described by the mass accommodation coefficient. However, the underlying processes are not yet fully understood. We have simulated the mass accommodation and evaporation processes of water using molecular dynamics, and the results are compared to the condensation equations derived from the kinetic gas theory to shed light on the compatibility of the two. Molecular dynamics simulations were performed for a planar TIP4P-Ew water surface at four temperatures in the range 268-300 K as well as two droplets, with radii of 1.92 and 4.14 nm at T = 273.15 K. The evaporation flux from molecular dynamics was found to be in good qualitative agreement with that predicted by the simple kinetic condensation equations. Water droplet growth was also modeled with the kinetic multilayer model KM-GAP of Shiraiwa et al. [Atmos. Chem. Phys. 2012, 12, 2777]. It was found that, due to the fast transport across the interface, the growth of a pure water droplet is controlled by gas phase diffusion. These facts indicate that the simple kinetic treatment is sufficient in describing pure water condensation and evaporation. The droplet size was found to have minimal effect on the value of the mass accommodation coefficient. The mass accommodation coefficient was found to be unity (within 0.004) for all studied surfaces, which is in agreement with previous simulation work. Additionally, the simulated evaporation fluxes imply that the evaporation coefficient is also unity. Comparing the evaporation rates of the mass accommodation and evaporation simulations indicated that the high collision flux, corresponding to high supersaturation, present in typical molecular dynamics mass accommodation simulations can under certain conditions lead to an increase in the evaporation rate. Consequently, in such situations the mass accommodation coefficient can be overestimated, but in the present cases the corrected values were still close to unity with the lowest value at ≈0.99.
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Affiliation(s)
- Jan Julin
- Department of Applied Environmental Science and Bert Bolin Centre for Climate Research, Stockholm University, SE-10691 Stockholm, Sweden.
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Frosch M, Bilde M, DeCarlo PF, Jurányi Z, Tritscher T, Dommen J, Donahue NM, Gysel M, Weingartner E, Baltensperger U. Relating cloud condensation nuclei activity and oxidation level ofα-pinene secondary organic aerosols. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016401] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- M. Frosch
- Department of Chemistry; University of Copenhagen; Copenhagen Denmark
| | - M. Bilde
- Department of Chemistry; University of Copenhagen; Copenhagen Denmark
| | - P. F. DeCarlo
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
- Center for Atmospheric Particle Studies; Carnegie Mellon University; Pittsburgh Pennsylvania USA
| | - Z. Jurányi
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
| | - T. Tritscher
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
| | - J. Dommen
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
| | | | - M. Gysel
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
| | - E. Weingartner
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
| | - U. Baltensperger
- Laboratory of Atmospheric Chemistry; Paul Scherrer Institut; Villigen Switzerland
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Barahona D, Sotiropoulou R, Nenes A. Global distribution of cloud droplet number concentration, autoconversion rate, and aerosol indirect effect under diabatic droplet activation. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd015274] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Engelhart GJ, Moore RH, Nenes A, Pandis SN. Cloud condensation nuclei activity of isoprene secondary organic aerosol. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd014706] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kristensson A, Rosenørn T, Bilde M. Cloud Droplet Activation of Amino Acid Aerosol Particles. J Phys Chem A 2009; 114:379-86. [DOI: 10.1021/jp9055329] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adam Kristensson
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark, Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden, and Institut de Recherches sur la Catalyse et l’Environnement de Lyon, UMR 5256 CNRS/Université Lyon 1, 2 avenue Albert Einstein, F-69629 Villeurbanne Cedex, France
| | - Thomas Rosenørn
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark, Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden, and Institut de Recherches sur la Catalyse et l’Environnement de Lyon, UMR 5256 CNRS/Université Lyon 1, 2 avenue Albert Einstein, F-69629 Villeurbanne Cedex, France
| | - Merete Bilde
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark, Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden, and Institut de Recherches sur la Catalyse et l’Environnement de Lyon, UMR 5256 CNRS/Université Lyon 1, 2 avenue Albert Einstein, F-69629 Villeurbanne Cedex, France
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Fountoukis C, Nenes A, Meskhidze N, Bahreini R, Conant WC, Jonsson H, Murphy S, Sorooshian A, Varutbangkul V, Brechtel F, Flagan RC, Seinfeld JH. Aerosol-cloud drop concentration closure for clouds sampled during the International Consortium for Atmospheric Research on Transport and Transformation 2004 campaign. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007272] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Christos Fountoukis
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia USA
| | - Athanasios Nenes
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia USA
| | - Nicholas Meskhidze
- School of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta Georgia USA
| | - Roya Bahreini
- Environmental Science and Engineering; California Institute of Technology; Pasadena California USA
| | - William C. Conant
- Environmental Science and Engineering; California Institute of Technology; Pasadena California USA
| | - Haflidi Jonsson
- Center for Interdisciplinary Remotely-Piloted Aircraft Studies; Naval Postgraduate School; Monterey California USA
| | - Shane Murphy
- Department of Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - Armin Sorooshian
- Department of Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - Varuntida Varutbangkul
- Department of Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - Fred Brechtel
- Environmental Science and Engineering; California Institute of Technology; Pasadena California USA
| | - Richard C. Flagan
- Environmental Science and Engineering; California Institute of Technology; Pasadena California USA
| | - John H. Seinfeld
- Environmental Science and Engineering; California Institute of Technology; Pasadena California USA
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