화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.114, No.10, 3483-3488, 2010
Coefficients of Evaporation and Gas Phase Diffusion of Low-Volatility Organic Solvents in Nitrogen from Interferometric Study of Evaporating Droplets
Evaporation of motionless, levitating droplets Of pure, low-volatility liquids Was Studied with interferometric methods. Experiments were Conducted oil charged droplets in the electrodynamic trap in nitrogen at atmospheric pressure at 298 K. Mono-, di-, tri-, and tetra(ethylene glycols) and 1,3-dimethyl-2-imidazolidinone were Studied. The influence of minute impurities (<0.1%) upon the process of droplet evaporation was observed and discussed. The gas phase diffusion and evaporation coefficients were found from droplet radii evolution under the assumption of known vapor pressure. Diffusion coefficients were compared with independent measurements and calculations (in air). Good agreement was found For mono- and di(ethylene glycols), and for 1,3-dimethyl-2-imidazolidinone, which confirmed the used vapor pressure Values. The value of equilibrium vapor pressure for tri(ethylene glycol) was proposed to be 0.044 +/- 0.008 Pa. The evaporation coefficient was found to increase from 0.035 to 0.16 versus file molecular Mass of the compound.