title: Impact of physical properties on ozone removal by several porous materials.
abstract: Models of reactive uptake of ozone in indoor environments generally describe materials through aerial (horizontal) projections of surface area, a potentially limiting assumption for porous materials. We investigated the effect of changing porosity/pore size, material thickness, and chamber fluid mechanic conditions on the reactive uptake of ozone to five materials: two cellulose filter papers, two cementitious materials, and an activated carbon cloth. Results include (1) material porosity and pore size distributions, (2) effective diffusion coefficients for ozone in materials, and (3) material-ozone deposition velocities and reaction probabilities. At small length scales (0.02-0.16 cm) increasing thickness caused increases in estimated reaction probabilities from 1 × 10(-6) to 5 × 10(-6) for one type of filter paper and from 1 × 10(-6) to 1 × 10(-5) for a second type of filter paper, an effect not observed for materials tested at larger thicknesses. For high porosity materials, increasing chamber transport-limited deposition velocities resulted in increases in reaction probabilities by factors of 1.4-2.0. The impact of physical properties and transport effects on values of the Thiele modulus, ranging across all materials from 0.03 to 13, is discussed in terms of the challenges in estimating reaction probabilities to porous materials in scenarios relevant to indoor environments.
authors.affiliation: Nanyang Technological University and Berkeley Education Alliance for Research in Singapore , Singapore 639798.
authors.forename: Elliott T
authors.initials: ET
authors.lastname: Gall
authors.forename: Richard L
authors.initials: RL
authors.lastname: Corsi
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Siegel
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry; D003252:Construction Materials; D004058:Diffusion; D008420:Manufactured Materials; D008628:Mercury / Q000032:analysis; D008851:Micropore Filters; D008962:Models, Theoretical; D010126:Ozone / Q000302:isolation & purification*; D010209:Paper; D055585:Physical Phenomena; D016062:Porosity; D012212:Rheology
chemical_list: D002606:Charcoal; D010126:Ozone; D002482:Cellulose; D008628:Mercury