title: Heterogeneous nucleation experiments bridging the scale from molecular ion clusters to nanoparticles.
abstract: Generation, investigation, and manipulation of nanostructured materials are of fundamental and practical importance for several disciplines, including materials science and medicine. Recently, atmospheric new particle formation in the nanometer-size range has been found to be a global phenomenon. Still, its detailed mechanisms are mostly unknown, largely depending on the incapability to generate and measure nanoparticles in a controlled way. In our experiments, an organic vapor (n-propanol) condenses on molecular ions, as well as on charged and uncharged inorganic nanoparticles, via initial activation by heterogeneous nucleation. We found a smooth transition in activation behavior as a function of size and activation to occur well before the onset of homogeneous nucleation. Furthermore, nucleation enhancement for charged particles and a substantial negative sign preference were quantitatively detected.
authors.affiliation: Fakultät für Physik, Universität Wien, Boltzmanngasse 5, A-1090 Wien, Austria.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Winkler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Steiner
authors.forename: Aron
authors.initials: A
authors.lastname: Vrtala
authors.forename: Hanna
authors.initials: H
authors.lastname: Vehkamäki
authors.forename: Madis
authors.initials: M
authors.lastname: Noppel
authors.forename: Kari E J
authors.initials: KE
authors.lastname: Lehtinen
authors.forename: Georg P
authors.initials: GP
authors.lastname: Reischl
authors.forename: Paul E
authors.initials: PE
authors.lastname: Wagner
authors.forename: Markku
authors.initials: M
authors.lastname: Kulmala