Collision dynamics and uptake of water on alcohol-covered ice
Artikel i vetenskaplig tidskrift, 2013

Molecular scattering experiments are used to investigate water interactions with methanol and n-butanol covered ice between 155 K and 200 K. The inelastically scattered and desorbed products of an incident molecular beam are measured and analyzed to illuminate molecular scale processes. The residence time and uptake coefficients of water impinging on alcohol-covered ice are calculated. The surfactant molecules are observed to affect water transport to and from the ice surface in a manner that is related to the number of carbon atoms they contain. Butanol films on ice are observed to reduce water uptake by 20 %, whereas methanol monolayers pose no significant barrier to water transport. Water colliding with methanol covered ice rapidly permeates the alcohol layer, but on butanol water molecules have mean surface lifetimes of less than or similar to 0.6 ms, enabling some molecules to thermally desorb before reaching the water ice underlying the butanol. These observations are put into the context of cloud and atmospheric scale processes, where such surfactant layers may affect a range of aerosol processes, and thus have implications for cloud evolution, the global water cycle, and long term climate.

n-alcohols

mass accommodation

argon collisions

monolayers

butanol

condensation

films

supercooled sulfuric-acid

simulations

evaporation

methanol

Författare

Erik S Thomson

Göteborgs universitet

Xiangrui Kong

Göteborgs universitet

Nikola Markovic

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Panos Papagiannakopoulos

Göteborgs universitet

Jan B. C. Pettersson

Göteborgs universitet

Atmospheric Chemistry and Physics

1680-7316 (ISSN) 1680-7324 (eISSN)

Vol. 13 4 2223-2233

Ämneskategorier

Kemi

DOI

10.5194/acp-13-2223-2013