Kinetics of homogeneous nucleation and condensation of n-butanol at high supersaturation

Abstract

We have measured rate constants for the homogeneous nucleation and condensation of n-butanol in a supersonic nozzle. Because our setup works at stagnation pressures of up to 10 bars we could extend the temperature range for which nucleation data is available by approximately 50 K to values between 263 K and 277 K. We observe peak nucleation rates of the order of 5 × 10 24 m − 3 s − 1 , a typical value expected in supersonic nozzles. We find that our data can be very well described by Hale's scaling formalism but that this formalism slightly underpredicts the scaled nucleation rate at our temperatures. This is in contrast to a trend observed earlier by others. We suspect this to be due to our high temperatures ( T / T C ≈ 0.5) as Hale's scaling formalism that is applicable only at T / T C < 0.5. A value for the sticking probability ζ = 1.29 × 10 − 3 is found in our analysis. This rather low value is obtained because of the neglection of the Kelvin effect necessary for a fast numerical implementation of the specific method chosen to analyze our data. The same concept will be applied to study the kinetics of the homogeneous nucleation and condensation of zinc in future.