Methanol nucleation in a supersonic nozzle.

We determined the partial pressures p(Jmax), temperatures T(Jmax), monomer supersaturations S(Jmax), and characteristic times Δt(Jmax ) corresponding to the maximum nucleation rates of methanol in a supersonic nozzle. We found that T(Jmax) increased from 202.2 K to 223.7 K as p(Jmax) increased from 67.1 to 413.2 Pa, while the maximum nucleation rate J(max) changed by less than a factor of 4 over the measurement range. Our nucleation rates appear reasonably consistent with measurements in other devices and are within one order of magnitude of the nucleation rates predicted by classical nucleation theory.