Raman- and Mie-spectroscopic studies of the cooling behaviour of levitated, single sulfuric acid/H2O microdroplets

Abstract

Acidic aerosols aloft: The behaviour of supercooled, single sulfuric acid/H2O microdroplets with respect to concentration and temperature relaxation can be investigated with Raman- and Mie-scattering techniques upon scavenging of such particles in a vertical laser beam. The rates of relaxation by water evaporation prevent such particles from homogeneous freezing forming either H2O, ice or sulfuric acid trihydrate (see picture). Instead thermodynamically stable solutions are formed.