학술논문
Microsecond-Pulsed Dielectric Barrier Discharge Plasma-Treated Mist for Inactivation of Escherichia coli In Vitro
Document Type
Periodical
Author
Source
IEEE Transactions on Plasma Science IEEE Trans. Plasma Sci. Plasma Science, IEEE Transactions on. 47(1):395-402 Jan, 2019
Subject
Language
ISSN
0093-3813
1939-9375
1939-9375
Abstract
In this paper, we demonstrate a plasma misting system capable of inactivating Escherichia coli O157:H7 ( E.coli ) in a 4 ft 3 (approximately 100 L) volume with potential for future use in decontaminating fresh produce. Water droplets, with an average diameter of $5~\mu \text{m}$ , are generated via ultrasonic nebulizers and carried by compressed air. These micrometer-sized droplets flowthrough a set of three cylindrical, microsecond-pulsed dielectric barrier discharges (DBDs). We observe the Coulombic fission of droplets up to a critical radius into submicrometer droplets (Sauter mean of approximately 0.3 $\mu \text{m}$ ), measured by a laser diffraction analyzer. E.coli , on agar plates, is inactivated by this mist in a time and flowrate-dependent manner. We hypothesize that the observed antimicrobial effect correlates with the concentration of submicrometer droplets. The observed formation of submicrometer droplets from this volumetric DBD is similar to the bursting of droplets observed with electrospray devices using corona discharges.