Development and Performance Evaluation of Aerosol Generator of MWCNTs for Inhalation Toxicology

Carbon nanotubes (CNTs) are one of the nanomaterials that were discovered by Iijima in 1991 for the first time. CNTs have long cylindrical and axi-symmetric structures. CNTs are made by rolling graphene sheets. Because of theirlarge length-to-diameter ratio, they are called nanotubes. CNTs are categorized as single-walled carbon nanotubes(SWCNTs) or multi-walled carbon nanotubes (MWCNTs) based on the shell structures. CNTs are broadly used invarious fields, such as scanning probe microscopy, ultra fine nano balance and medicine, due to their extraordinarythermal conductivity, electrical and mechanical properties. Because long, straight CNTs have the same shape asasbestos, which cause cancer in cells lining the lung, there have been many studies on the effects of MWCNTs onhuman health that have been conducted. Stable atomization of CNTs is very important for the estimation of inhalationtoxicity. In the present study, electro-static assisted axial atomizer (EAAA), which is the instrument that usesMWCNTs and aerosolizes them by transforming the single fiber shape using ultrasonic dispersion and electric field,was invented. EAAA consists of a ultrasonic bath for dispersion of MWCNTs and a particle generator for atomizingsingle fibers. The performance evaluation was conducted in order to assess the possibilities of 6-hour straightatomization with stability, which is the suggested exposure time in a day for the estimation of inhalation toxicity