Effect of Nucleation Temperature on Detecting Molecular Ions and Charged Nanoparticles with a Diethylene Glycol-Based Particle Size Magnifier

The classical nucleation theory predicts that a decrease in nucleation temperature under a constant saturation ratio increases the energy barrier for homogeneous nucleation to occur; therefore lower nucleation temperature would allow higher saturation ratio inside a condensation particle counter (CPC) while suppressing homogenous nucleation of working fluid vapor below a threshold value. On the other hand, the classical theory also predicts that a decrease in nucleation temperature increases the energy barrier for heterogeneous nucleation to occur, which potentially increases the minimum detectable size of CPC. Accordingly, it is important to investigate experimentally whether higher super-saturation under lower nucleation temperature decreases the minimum detectable size or not. Minimum detectable sizes of a diethylene glycol (DEG)-based nanoparticle size magnifier (nano-PSM) developed by Ito et al. (Ito, E., Seto, T., Otani, Y., and Sakurai, H. [2011]. Aerosol Sci. Technol. 45:1250–1259) were investigat...