title: Lack of Aggregation of Molecules on Ice Nanoparticles.
abstract: Multiple molecules adsorbed on the surface of nanosized ice particles can either remain isolated or form aggregates, depending on their mobility. Such (non)aggregation may subsequently drive the outcome of chemical reactions that play an important role in atmospheric chemistry or astrochemistry. We present a molecular beam experiment in which the controlled number of guest molecules is deposited on the water and argon nanoparticles in a pickup chamber and their aggregation is studied mass spectrometrically. The studied molecules (HCl, CH3Cl, CH3CH2CH2Cl, C6H5Cl, CH4, and C6H6) form large aggregates on argon nanoparticles. On the other hand, no aggregation is observed on ice nanoparticles. Molecular simulations confirm the experimental results; they reveal a high degree of aggregation on the argon nanoparticles and show that the molecules remain mostly isolated on the water ice surface. This finding will influence the efficiency of ice grain-mediated synthesis (e.g., in outer space) and is also important for the cluster science community because it shows some limitations of pickup experiments on water clusters.
authors.forename: Andriy
authors.initials: A
authors.lastname: Pysanenko
authors.forename: Alena
authors.initials: A
authors.lastname: Habartová
authors.forename: Pavla
authors.initials: P
authors.lastname: Svrčková
authors.forename: Jozef
authors.initials: J
authors.lastname: Lengyel
authors.forename: Viktoriya
authors.initials: V
authors.lastname: Poterya
authors.forename: Martina
authors.initials: M
authors.lastname: Roeselová
authors.forename: Juraj
authors.initials: J
authors.lastname: Fedor
authors.forename: Michal
authors.initials: M
authors.lastname: Fárník