GROWth of large carbon molecules and metal-carbon NANOparticles driven by organometallic clusters. – GROWNANO

The GROWNANO project aims at investigating the incorporation of metals in the gas-phase formation of carbon-rich dust as well as the role of metals in the growth of large carbon molecules via the chemistry of organometallic clusters. The central motivation for this project is related to stardust, its formation and richness of components with emphasis on dust formed in a carbon-rich environment. Stardust is made of nanograins (sizes of less than ~100 nm) with two main classes of dust composition: carbon-based (carbonaceous nanoparticles and polycyclic aromatic hydrocarbons) and oxide-based (silicates) dust, which is mainly attributed to the value of the C/O abundance ratio during their formation in the envelope of asymptotic giant branch stars and the ejecta of supernovae. These environments comprise a range of densities and temperatures and carry chemical complexity involving as main elements H, C, O and N but also less abundant species such as Si, S and metals (Ti, Al, Mg, Fe). The GROWNANO project is positioned on this last track, namely on studying the role of metals and more specifically Fe in stardust formation and hydrocarbon molecular growth. Besides its impact in astrochemistry, unveiling the role of iron in dust formation is also of critical interest to investigate the controlled growth and properties of various types of iron nanoparticles or mixed iron-carbon nanoparticles in order to push the limits of their knowledge in nanoscience and of their use in different nanotechnology fields.
To achieve a complete description of the role of metals in stardust formation, one should consider different scales, critical for the dust growth: (i) small molecules or clusters, representing the required seeds to initiate the dust growth, (ii) larger molecules/clusters including organometallic complexes, and (iii) mixed metal-carbon nanoparticles, playing a role in the morphology and dust structure. In order to investigate this continuum of species, we will make use of three complementary reactors: a Laser Vaporization, a Plasma and a Computational one. Applying various, ex situ, in situ and in silico analytical techniques, among others, mass spectrometry, infrared spectroscopy, electron microscopy, Density Functional Theory calculations, we will characterize the produced organometallic complexes, large hydrocarbons, mixed metal(iron)-carbon clusters and nanoparticles. Gathering the results of all these studies, the main outcome of the project will be to propose reactive/catalytic seeds and scenarii for the formation of large hydrocarbons and metal-carbon nanoparticles in the gas-phase. The multi-disciplinary context and the large diversity of used methods, for both experiments and numerical simulations, lay down the originality of the GROWNANO project and guarantee its ability to go beyond the state of the art.