title: The effect of co-impregnated acids on the performance of Zn-based broad spectrum respirator carbons.
abstract: Impregnated activated carbons (IACs) that are used in multi-gas respirator applications usually contain copper and/or zinc impregnants. Co-impregnating with properly selected acids can improve the distribution of the metallic impregnant on the carbon and improve the gas adsorption capacity of the IAC. In this work a comparative study of some common acids co-impregnated with a zinc nitrate (Zn(NO(3))(2)) precursor is performed. The IACs were heated in an inert atmosphere at temperatures which promoted the thermal decomposition of Zn(NO(3))(2) to zinc oxide (ZnO). The gas adsorption properties of the IACs were tested using ammonia (NH(3)), sulphur dioxide (SO(2)) and hydrogen cyanide (HCN) challenge gases. Powder X-ray diffraction (XRD) was used to identify the impregnant species present after heating and to study impregnant distribution. Gravimetric analysis was used to determine the impregnant loading, and help to identify the impregnant species after heating. The interactions between the co-impregnated acid and Zn(NO(3))(2) precursor during heating are discussed. The relationship between impregnant species and gas adsorption capacity is discussed.
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3J5.
authors.forename: J W H
authors.initials: JW
authors.lastname: Smith
authors.forename: J V
authors.initials: JV
authors.lastname: Romero
authors.forename: T R
authors.initials: TR
authors.lastname: Dahn
authors.forename: K
authors.initials: K
authors.lastname: Dunphy
authors.forename: L M
authors.initials: LM
authors.lastname: Croll
authors.forename: J R
authors.initials: JR
authors.lastname: Dahn
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D000148:Acids, Noncarboxylic / Q000737:chemistry*; D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D009566:Nitrates / Q000737:chemistry*; D012134:Respiratory Protective Devices; D013644:Tartrates / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D000148:Acids, Noncarboxylic; D009566:Nitrates; D013644:Tartrates; D017967:Zinc Compounds; D002244:Carbon; C042103:zinc nitrate; D019342:Acetic Acid; D015034:Zinc Oxide; C029768:tartaric acid