Rémi Bérard, New Nanocosmos Doctor

On Monday 23rd of September, Rémi Bérard (center of the picture) presented his PhD thesis entitled “Formation and growing of laboratory analogues of cosmic dust : function of metals and C/O ratio exploration”, that was carried out at the IRAP in the framework of the Nanocosmos projet under the direction of Kremena Makasheva (LAPLACE, right side of the picture) and Christine Joblin (IRAP, on the left).

Congratulations!

Summary :

Dust formation is a fundamental topic in both cold plasma physics and astrophysics. This PhD thesis, carried out at the interface between the two fields, aims to better understand the formation of stardust. The problem is treated experimentally in cold plasmas and discussed in the context of the environment of evolved stars.

We observe the formation of successive generations of dust due to pulsed injection of hexamethyldisiloxane (HMDSO: Si2O(CH3)3) in a capacitively-coupled radiofrequency asymmetric plasma sustained in argon. The used molecular precursor contains potential stardust forming elements, like carbon, oxygen, silicon and hydrogen. Our approach involves different steps: study of the dust formation in the plasma, dust collection, characterization of the dust properties and correlation of the plasma parameters with the dust characteristics. We have thus succeeded to identify optimum conditions for the formation of organosilicon dust with typical size of 50 nm.

A major factor impacting dust formation in evolved stars is the variation of the C/O ratio, which is though to determine two large families of stardust, silicates (C/O < 1) and carbonaceous dust (C/O > 1). To explore this effect, we have enriched the Ar/HMDSO mixture with oxygen aiming at a variation of the C/O ratio in the plasma. Above a certain quantity of oxygen, dust is not formed anymore in the plasma. The abundance of oxygen limits dust formation through inhibition of the dust seeds in the gas phase. Instead, deposition of a silica- like matrix is favored.

The role of metals is studied through sputtering of a silver target during organosilicon dust formation. We have demonstrated the formation of dust with composite structure in this case. Dust contains crystalline silver nanoparticles that attach to the amorphous organosilicon dust during their growth phase. Moreover, the presence of silver leads to a large variety of molecules composed of species containing Ag and/or Si and hydrocarbon species. Those molecules reveal a complex chemistry around three competitive processes at molecular scale: dust formation involving molecules such as SiCH3 or SiOCH3, metallic grains with clusters of Agn and aromatic molecules of large size such as C16H10 and C24H12, whose formation path involves radicals and possibly an organometallic chemistry as revealed by AgC5H6 and AgC13H8. The above results demonstrate the undoubted necessity to tackle stardust formation by taking into account the chemical complexity of these media.

Supplementary Cover of the JACS

Members of the Nanocosmos team from the ICMM-Madrid (ESISNA Group of the Institute of Material Science of Madrid), together with other researchers, have published an interesting paper in the JACS, Journal of the American Chemical Society: Atomic hydrogen makes the difference. The supply of atomic hydrogen during the on-surface annealing of PAHs substantially favors the formation of intermolecular covalent C–C bonds. The reason resides in the radical-like intermediate formed as a consequence of molecular super-hydrogenation.

Read more about those interesting results in the paper “On-Surface Hydrogen-Induced Covalent Coupling of Polycyclic Aromatic Hydrocarbons via a Superhydrogenated Intermediate“, one of the Supplementary Cover Art for the Journal of the American Chemical Society (February 27, 2019).

Here is the link to the website and the link to the paper. Congratulations to the team!

Supplementary Cover Art for the manuscript: On-Surface Hydrogen-Induced Covalent Coupling of Polycyclic (10.1021/jacs.8b12239) published in Journal of the American Chemical Society.

The benzylium and tropylium cations identified as two stable C7H7+ isomers


The picture, which is a cover of the journal ChemPhysChem, schematizes the production of the C7H7 ion by dissociative ionization of toluene and the identification, by infrared spectroscopy, of the two isomers produced: the cations benzylium (right) and tropylium (left).

Experiments driven by an international team involving the Institute for Research in Astrophysics and Planetary Sciences (IRAP, Université de Toulouse/CNRS) and the Laboratory of Quantum Chemistry and Physics (LCPQ, Université de Toulouse/CNRS), enabled to identify the two stable isomers of C7H7+ ion.

The ion C7H7is a well-known species in mass spectrometry, formed by ionization of hydrocarbons such as toluene. The two most stable structures proposed for this ion are benzylium and tropylium ions. The first (a benzene with a methylene group) could be identified by its chemical reactivity, but is not the case of the second, whose structure consisting of an aromatic cycle of 7 carbons is predicted by quantum chemistry calculations.

Two structures have been identified for C7H7+ and the vibrational spectra obtained are in agreement with those of benzylium and tropylium ions calculated with the density functional theory. In addition, measures in depletion helped to show that no other isomer was present and this for different precursors used in the production of C7H7+.

The study took advantage of the FELion line, installed on the free electron laser FELIX, in the Netherlands. FELion includes a cryogenic ion trap that allows attaching an atom of rare gas on the ions studied. This technique of tagging allows to implement a spectroscopy of action by dissociating the complexion/atom of rare gas with a single infrared photon unlike the technique usually used of multiple absorption of photons to attain the threshold of dissociation of the ion. This technique has the advantage to probe ions without heating them and so without disrupting their structure through processes of isomerization.

This work of identification of C7H7+ isomers opens up prospects for the study of the growth paths of the hydrocarbon ions in complex environments both on Earth (chemistry of flames, and plasmas) or space (interstellar chemistry and planetary atmospheres as Titan’s).

This interdisciplinary work (INSU/INP/INC) has been initiated as part of the ERC Synergy NANOCOSMOS project in collaboration with the CSIC (Madrid) and involves a collaboration between the universities of Toulouse and Cologne as part of the European Training Network (ETN) EUROPAH.

Scientific paper: 

P. Jusko, A. Simon, S.Banhatti, S. Brünken, C. Joblin (2018) DirectEvidence of the Benzylium and Tropylium Cations as the two long-lived Isomersof C7H7+, ChemPhysChem, doi:10.1002/cphc.201800744 – Archives ouvertes: hal-01880438, arXiv:1809.09375

Link to the INSU news page: Les cations de benzylium et tropylium identifiés comme les deux isomères stables de C7H7+

Contact(s):

New Nanocosmos Doctor


Some news from the young team surrounding our PI from Toulouse, Christine Joblin. Sarah Rodríguez Castillo (third on the left, first row) presented on October 30th 2018 her PhD thesis entitled “Study on the dissociation of astro-PAHs”, that was carried out at the University of Toulouse/CNRS in the framework of the Nanocosmos projet.



Congratulations on this great achievement, Doctor!

Abstract:

Polycyclic Aromatic Hydrocarbons (PAHs) are revealed in astrophysical environments thanks to their characteristic infrared emission after these molecules are subjected to the vacuum ultraviolet (VUV) radiation from nearby massive stars. This interaction regulates their charge state, stability and dissociation mechanisms, which in turn affect the energy balance and the chemistry of the gas in the interstellar medium. In particular, PAHs could contribute to the formation of the most abundant molecule, H2, in photodissociation regions (PDRs). This work aims at contributing to these topics by quantifying the VUV photoprocessing of specific medium-sized PAH cations through experimental studies complemented by computational investigations.The experimental results were gathered from two campaigns at synchrotron facilities: ion trap experiments allowed us to obtain the yields of ionization and fragmentation and the branching ratios between the different photoevents, while from iPEPICO spectroscopy we obtained breakdown curves and RRKM-fitted dissociation rates. We detail the case of the fragmentation processes of two isomers of dibenzopyrene cation (C24H14+) in order to assess the impact of structure on these processes. We present Density Functional Theory calculations and Molecular Dynamics simulations, which evidence the relevance of structure and planarity in these mechanisms and provide a better view on the dissociation pathways and energetics.This work brings significant new data for models that describe the chemical evolution of PAHs in astrophysical environments, including the first measurement of the ionization yield of medium-sized PAH cations as well as several dissociation rates. We also report a new mechanism, involving specific structures with bay areas, that would need to be considered while evaluating the contribution of PAHs to the formation of H2 in PDRs.





The documentary about NANOCOSMOS nominated for BICC awards

BICC is the acronym for “XXIX Bienal Internacional de Cine Científico Ronda-Madrid-México 2018”, the biennial international event for science movies. Our documentary “NANOCOSMOS: Un viaje a lo pequeño” has been selected as finalist in this contest within the category of “Science documentary”.

We are very proud to do our bit in science communication!  Even if we don’t get any prize, we acknowledge the jury for considering our movie for the contest.  We will stay tuned for the date of the ceremony. Let’s cross fingers!

Link to the BICC press release (in Spanish).

Horizon Europe: The New Search and Innovation Framework Programme: Challenges and Opportunities

Next week NANOCOSMOS will be in the workshop “Horizon Europe: The New Search and Innovation Framework Programme: Challenges and Opportunities“, organized in the Universidad Menéndez Pelayo (UIMP) by the Ministry of Science, Innovation and Universities and the Spanish Science Research Council (CSIC) . With several panels, this meeting joins some of the relevant scientific and industrial players around new opportunities and challenges in Horizon Europe for the period 2021-2027. The program of the meeting overviews the three major pillars of the Commission’s proposal, covering all forms of innovation, global challenges through research and innovation for the uptake of innovative solutions in industry and society, as well as investigator driven high quality research and infrastructures.  NANOCOSMOS will be represented by one of its Principal Investigators, José Cernicharo, in the panel “The ERC in Horizon Europe – A Reflection on Interdisciplinarity and Multipotentialities.”

Ve la luz el documental “Nanocosmos: un viaje a lo pequeño”

ENGLISH VERSION BELOW

El documental, que cuenta en formato road-movie los entresijos del nacimiento de los granos de polvo en el espacio, está financiado por la Fundación Española para la Ciencia y la Tecnología – Ministerio de Economía, Industria y Competitividad y el Consejo Superior de Investigaciones Científicas (CSIC) y ha sido producido por la empresa LuzLux.

Tras seis meses de trabajo, el equipo formado por personal de CSIC y la productora LuzLux, entre otros, ha finalizado el documental “Nanocosmos: un viaje a lo pequeño”, una película de carretera que habla del reto tecnológico y humano que hay tras el desarrollo de instrumentación en el área de la astrofísica de laboratorio.

La historia se desarrolla en tres planos: el viaje del equipo de grabación desde Madrid hasta Toulouse, los experimentos de laboratorio explicados por sus responsables y el propio viaje de los granos de polvo cósmico desde que nacen en la envoltura de una estrella evolucionada hasta que pasan a formar parte de algo mucho más grande (una estrella, un planeta o, por qué no, un ser vivo).

Este trabajo quiere transmitir las expectativas de los equipos que luchan por comprender este proceso, el reto tecnológico y humano que supone construir máquinas complejas y lograr reproducir en un laboratorio lo que ocurre en el espacio. El documental, de 40 minutos de duración, circulará por circuitos de cine científico y canales específicos de divulgación científica durante un año, tras lo que estará disponible en la página web de Nanocosmos.

En este enlace podrán ver el tráiler que anuncia el documental, que está disponible en español  con subtítulos en inglés y en francés. También hay una versión con subtítulos en español para personas con discapacidad auditiva.

ENGLISH VERSION

After six months of work, the team formed by CSIC staff and the LuzLux production company, among others, has completed the documentary “Nanocosmos, un viaje a lo pequeño” (a journey to the origins of dust grains), a road movie which talks about the technological and human challenge that lies behind the development of instruments in the area of Laboratory Astrophysics.

The story unfolds in three levels: the journey of the recording team from Madrid (Spain) to Toulouse (France), the laboratory experiments explained by its principal investigators and the journey of the cosmic dust grains since they are born in the envelope of an evolved star until they become part of something bigger (a star, a planet or, why not, a living being).

This work wants to transmit the expectations of the teams struggling to understand this process, the technological and human challenge involved in building complex machines whith a goal: to reproduce in a laboratory what happens in space. The 40-minute documentary will circulate along circuits of scientific movies and specific science channels for a year, and after that it will be available on the Nanocosmos’ website.

In this link you can see the trailer announcing the documentary. The movie is available in Spanish with subtitles in English and French.

Astrochemistry Insights in Science Magazine, by Christine Joblin and José Cernicharo

Cone Nebula (NGC 2264) Credits: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

Detecting the building blocks of aromatics” is the title of this “Insight” written by Christine Joblin and José Cernicharo (both NANOCOSMOS PIs together with J.A. Martín Gago) and talking about the history and importance of the work published by Brett A. McGuire et al. (“Detection of the aromatic molecule benzonitrile (c-C6H5CN) in the interstellar medium“) in the “Science Magazine” (12/01/2018).

This is the summary of the article from C. Joblin and J. Cernicharo:

“Interstellar clouds are sites of active organic chemistry. Many small, gasphase molecules are found in the dark parts of the clouds that are protected from ultraviolet (UV) photons, but these molecules photodissociate in the external layers of the cloud that are exposed to stellar radiation (see the photo). These irradiated regions are populated by large polycyclic aromatic hydrocarbons (PAHs) with characteristic infrared (IR) emission features. These large aromatics are expected to form from benzene (C6H6), which is, however, difficult to detect because it does not have a permanent dipole moment and can only be detected via its IR absorption transitions against a strong background source (2). On page 202 of this issue, McGuire et al. (3) report the detection of benzonitrile (c-C6H5CN) with radio telescopes. Benzonitrile likely forms in the reaction of CN with benzene; from its observation, it is therefore possible to estimate the abundance of benzene itself”.

 

Christine Joblin in a Nanocosmos illustrated talk

Last Saturday, the 2nd edition of the “Illustrated talks” organized by ERCcOMICS took place at Jussieu Campus in Paris with the artist Lorenzo Palloni and the researcher Christine Joblin (one of our Principal Investigators) in the “Fête de la Science 2017” (Science Party). It was an amazing opportunity to share the astronomy and astrophysics behind the Nancosmos project, that has already a comic inspired in its science. This “Fête de la Science” is a celebration of science and technology and thousands of individuals get involved, providing general public the opportunity to discover the wonders of science. “Illustrated talks” are talks where the artist illustrates the scientist live while talking about the project. Congratulations for this outreach initiative!

Watch the full illustrated talk (in french) by Christine Joblin (research director at CNRS Toulouse) & comics artist Lorenzo Palloni at the Fête de la Science in PARIS, Campus de Jussieu, on the 14th of October 2017.

Here, some pictures from the 2nd edition of the illustrated talks with the artist Lorenzo Palloni and the researchers Christine Joblin (ERC Nanocosmos).

Christine Joblin, one of Nanocosmos’ Principal Investigators, participates in an illustrated talk during the “Fête de la Science” last 14th of October in Paris.

“Estrella” (Star in Spanish) is the name of the comic inspired by Nanocosmos.

Christine Joblin during the illustrated talk in Paris.

Lorenzo Palloni is the artist that gave life to the comic inspired by Nanocosmos “Estrella” and draw the stories live during the illustrated talk.

‘Estrella’, a comic inspired by Nanocosmos

homepage-banner-estrella-1The first chapter of ‘Estrella’ is out!

‘Estrella’ is a comic developed by an ERC proyect called ERCcOMIC and inspired by Nanocosmos. As the comic team believes in the power of visual storytelling, they illustrate each in a concrete, memorable and engaging way, drawing inspiration from science through stories and images.

The story of ‘Estrella’, by the artist Lorenzo Palloni, is set in 2106, and mankind is radically evolving. The NANOCOSMOS project has changed the path of astrochemistry and astrophysics, and now is the time for an elderly Estrella Leroux to pass the torch to three young scientists. Yet the story of an impossible journey of a young Estrella as a child inside the “Stardust” (a groundbreaking machine that reproduces the processes of a dying star) calls everything into question. The three budding stargazers will discover that their destiny is bound up with the mysterious Estrella’s, on the border between a surprising past and a never-so-uncertain future!

Don’t miss the story of Estrella and enjoy!

DDaW0FiWsAE8_2c.jpg large