Ammonia, cyclohexane, nitrogen and water adsorption capacities of an activated carbon impregnated with increasing amounts of ZnCl2, and designed to chemisorb gaseous NH3 from an air stream

Investigation of copper oxide impregnants prepared from various precursors for respirator carbons

“…Breakthrough times reported for SO 2 and NH 3 tests are an average of 2-4 measurements for each sample. Detailed descriptions of the testing apparatus and methods used at Dalhousie University have been published in the literature [8,11]. IAC samples tested for HCN adsorption capacity at 3M Canada were exposed to approximately 2000 ppm HCN gas at an overall flow rate of approximately 260 mL/min.…”

“…This advantageous property has been employed in the manufacture of gas mask cartridges for many years [6]. Impregnating activated carbon with strategically selected materials has been shown to greatly enhance adsorption capacity for a wide range of gases [6][7][8][9][10][11]. Copper oxide (CuO) has been shown to be a useful impregnant in the adsorption of a variety of gases [10,12].…”

A combinatorial approach to screening carbon based materials for respiratory protection

“…The carbon contains 0.4% (w/w) ash, is slightly basic with a pH of 8 (measured after immersion in nanopure water) and has a mesh size of 12 × 35, which corresponds to particles between 0.50 and 1.70 mm in diameter [1,31]. Bulk pre-treatment of all activated carbon samples was performed using a procedure previously reported in literature and often referred to as the incipient wetness or imbibing method [11,28,31].…”

“…Impregnated activated carbon (IAC) is normally the material of choice for the adsorption of toxic gases [1,2].…”

Understanding the role of each ingredient in a basic copper carbonate based impregnation recipe for respirator carbons

“…However, the reasons for the success of this impregnant and the reasons for the various ingredients in the recipes are not clearly described in the literature. It has been shown [4][5][6][7] that the dispersion of the impregnant as nanoscopic particles or as a nanoscopic layer on the surface of activated carbon helps to increase the stoichiometric ratio of reaction of the impregnant with the toxic challenge gas. The various ingredients in the ''preferred" recipes affect the dispersion of the impregnant and/or the phase of the impregnant formed at a particular heating temperature.…”