Development and collection efficiency of an electrostatic precipitator for in-vitro toxicity studies of nano- and submicron-sized aerosols

The direct air-liquid interface (ALI) in vitro exposure method are used for high-throughput screening of nanoparticle toxicity, due to the relatively low capital required and the low cost of labor compared to animal and in vivo experiments. In this study, a new ALI exposure chamber using an electrostatic precipitator (ESP-ALI) was designed to improve the nano- and submicron-sized particle collection efficiency on the air-liquid exposure interface. Particle penetration tests were performed to characterize the performance under different operating conditions. The effects of different geometric dimensions and operating conditions were explored, and the similarity-scaling process was applied to reveal the hidden effects underlying the experimental data. The penetration results show that the developed electrostatic precipitator is able to efficiently collect particles with a size of up to 300. nm under a DC electric field of 5.0. kV/cm and at a flow rate of up to 1.5. lpm. The electrospray charging technique was also tested with this ESP-ALI system and proved to enhance the ALI collection efficiency without ozone generation. In addition, the particles collected on the exposure interface are uniformly distributed under various operating conditions, as supported by consistent dimensionless precipitation densities.