Title :

Isotopic and structural signature of experimentally irradiated organic matter

Author(s) :

Laurent, Boris [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Roskosz, Mathieu [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Remusat, Laurent [Auteur]
Laboratoire de Minéralogie et Cosmochimie du Muséum [LMCM]
Leroux, Hugues [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Vezin, Herve [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Depecker, Christophe [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Journal title :

Geochimica et Cosmochimica Acta

Volume number :

142

Pages :

522-534

Publication date :

2014

HAL domain(s) :

Planète et Univers [physics]/Astrophysique [astro-ph]
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Sciences de la Terre
Chimie/Matériaux
Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]

English abstract : [en]

The effects of electron irradiation on the structure and the D/H signature of a synthetic analogue of extraterrestrial insoluble organic matter (IOM) were studied. Polyethylene terephthalate (PET) was chosen because it ...
Show more >The effects of electron irradiation on the structure and the D/H signature of a synthetic analogue of extraterrestrial insoluble organic matter (IOM) were studied. Polyethylene terephthalate (PET) was chosen because it contains both aliphatic and aromatic functional groups. A 900 nm-thick film was irradiated with electrons within the energy range 4–300 keV, for different run durations. Temperature influence was also tested. Irradiated residues were structurally and isotopically characterized by infrared spectroscopy (IR), electronic paramagnetic resonance (EPR), and Secondary Ion Mass Spectrometry (SIMS). With increasing energy deposition, spectroscopic results indicate (i) a gradual amorphization with chain scissions, (ii) an increase of CH2/CH3 and (iii) the formation of quinones. The EPR study shows that mono- and biradicals (organic species with one or several unpaired valence electrons) are also formed during irradiation. As these structural modifications occur, the δD (initially at −33‰ relative to SMOW) decreases first during a transient step and then stabilizes at ∼+300‰. There is a strong correlation between the changes recorded by the different methods and the electron dose. Deposited energy appears to be the key parameter to induce these modifications. In this respect a low-energy electron irradiation causes more damages than high energy ones. Based on our data and considering the current solar electron flux, the irradiation at moderate energy (1–10 keV) can produce significant D-enrichments of the IOM in a timescale compatible with the evolution of a typical protoplanetary disk.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
ENSCL
CNRS
INRA

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2019-05-16T16:44:49Z
2021-02-16T08:08:21Z