The heterogeneous reactions of CF3OH with bulk liquid water and sulfur
ic acid solutions were studied in wetted-wall flow reactors with chemi
cal ionization detection of CF3OH. Heterogeneous reaction probabilitie
s (gamma) increase strongly with increasing activity of water (e.g., g
amma = 4 x 10(-4) On 60 wt% H2SO4 at 206 K and 8 x 10(-2) on 40 wt% at
211 K). The heterogeneous loss of CF3OH was also studied on submicron
sulfuric acid aerosol in an atmospheric pressure laminar flow reactor
. The aerosol reaction probabilities increase linearly with increasing
particle radius (r < 0.5 mu m, 40 and 50 wt% sulfuric acid at 250 K),
suggesting that CF3OH uptake is volume limited for stratospheric aero
sol. These measurements indicate that CF3OH will have a lifetime of a
few days in the troposphere due to its loss on cloud particles, but a
much longer lifetime with respect to heterogeneous loss in the stratos
phere.