Experimental simulation of Titan’s stratospheric photochemistry: benzene
(C6H6) ices
Abstract
We performed laboratory experiments to the photochemical evolution
induced by long-UV radiations of benzene ices in Titan’s atmosphere. The
aim of this study was to investigate if photo-processed benzene ices
could lead to the formation of aerosols analog to the ones observed in
Titan’s stratosphere. Prior to that, spectroscopic properties of
amorphous and crystalline benzene ices were studied as a function of the
temperature, using infrared spectroscopy. UV photolysis experiments (l
> 230nm) of benzene ices lead to the formation of volatile
photo-products of which fulvene is identified and of a residue,
dominated by nCH IR features which demonstrate that pure aromatic-based
polymeric structures are not sufficient to explain the composition of
Titan’s haze layer present in the stratosphere. However, we provide a
characterization of long-UV-induced benzene-containing aerosols analogs,
which will contribute to Titan’s surface organics layer which is of
prime interest in the context of the future Dragonfly space mission.