Advisory Committee Chair
Advisory Committee Members
Jo Anne Balanay
Date of Award
Degree Name by School
Doctor of Philosophy (PhD) School of Public Health
Activated Carbon Fiber (ACF) is an adsorbent material that can be used to re-move volatile organic compounds (VOCs) from the air. Unlike granular adsorbents that are currently used in organic vapor respirators, ACF is a self-supporting fiber structure that can be tailored into non-woven forms and can potentially be used to support particu-late filtration. While ACF-containing respirators first appear in patent literature in the 1980s, the use of ACF in respiratory protection has not been widely considered in the PPE market in the intervening years. To develop the concept of an ACF-containing N95 that offers particulate filtration in addition to nuisance-level or short-term VOC protection, the filtration and adsorption behavior of three “off-the-shelf” ACFs (ACFF 1200, ACFF 1800, and ACFF 2000) was determined using flow conditions and challenge concentrations that are relevant to respir-atory protection devices. In order to describe ACF properties that are relevant to adsorp-tion, each ACF was characterized in terms of specific surface area, limiting micropore volume, bulk density, characteristic energy of adsorption, and equilibrium adsorption ca-pacity. ACF performance was also compared to performance of a thin carbon adsorbent that is currently used in nuisance odor particulate respirators. We found that ACFF 1200, the lowest surface area ACF used by our laboratory, had greater 10% breakthrough times for a 200 ppm challenge of toluene, hexane and MEK (respectively) than the nuisance odor adsorbent from a commercially available respirator (3M™ 2097). iv Our filtration studies indicate that ACF can be predictably layered to yield greater filtration efficiency; however, in their current form, the ACFs used by our laboratory likely pose too great a pressure drop to be used as the exclusive filtration medium in an N95 respirator when tested according to NIOSH standard test protocol. In general, these results suggest that ACF is best suited as an adjunct to, rather than the primary means of filtration in an N95 respirator. In conclusion, our studies demonstrate that ACF has properties (i.e., high specific surface area (m2/g), high adsorption capacity, and rapid adsorption kinetics) that make it a good candidate for use in thin, N95-style respirators for nuisance-level VOCs.
Summers, Margaret C., "Filtration and Adsorption Performance of Activated Carbon Fiber: Applications for Respiratory Protection" (2022). All ETDs from UAB. 339.