Archives pour la catégorie News

Visit of Prof. Juan Carlos Colmenares

This week, we have received our collaborator Prof. Juan Carlos Colmenares , from the Institute of Physical Chemistry (Polish Academy of Sciences) in our group.

Prof.-Juan-Carlos-Colmenares

He presented a conference entitled : « Nanoengineering semiconductor-based hybrid photocatalysts:  materials for environmental and energy applications« . The abstract of the conference is available here.

Great to share many ideas for research collaborations together especially on photocatalysis and sonochemistry! Thank you Juan Carlos!

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More about Prof. Colmenares here.

Our new article in Ultrasonics Sonochemistry!

Effect of Low Frequency Ultrasound on the Surface Properties of Natural Aluminosilicates

L. Novikova,* P. Ayrault, C. Fontaine, G. Chatel,* F. Jérôme and L. Belchinskaya

Abstract

Structural and surface properties of different natural aluminosilicates (layered, chain and framework structural types) exposed of 20 kHz ultrasound irradiation (0-120 min) in aqueous and 35% wt. aqueous H2O2 dispersions were studied by X-ray diffraction (XRD), dynamic light scattering (DLS), nitrogen adsorption-desorption, thermal analysis, and Fourier transform infrared spectroscopy (FTIR) techniques. It was confirmed that sonication caused slight changes in the structure of investigated minerals whereas their textural properties were significantly affected. The aqueous dispersions of montmorillonite (Mt), clinoptilolite (Zlt), glauconite (Glt) and palygorskite (Pal) were represented by several particles size fractions according to DLS-study. Ultrasound irradiation produced a decrease of the average particle diameter by 4-6 times in water and by 1.3-5 times in H2O2 dispersions except for Pal, which underwent strong agglomeration. A significant increase of total pore volume and pore diameter was observed for Glt sonicated in H2O2 dispersions whereas for Pal mainly micropore volume sharply increased in both aqueous and H2O2 dispersions.

Available on the website of Ultrasonics Sonochemistry

Also read our review article in Applied Clat Science entitled « How efficiently combine sonochemistry and clay science? » 

Our new article in Green Chemistry!

Heterogeneous catalytic oxidation for lignin valorization into valuable chemicals: What results? What limitations? What trends?

Ronan Behling, Sabine Valange and Gregory Chatel*

Abstract

Lignin, a renewable polymer derived from the lignocellulosic biomass represents more than 20% of the total mass of the Earth’s biosphere. However, 98% of lignin is burned as a source of energy in the pulp and paper industry, essentially due to its complex structure. Today, the valorization of lignin into the production of value-added chemicals represents a real challenge in terms of both sustainability and environmental protection. The present contribution aims to provide a critical discussion on the crucial choice of the starting material to study lignin valorization. Next, a comparison between the different oxidation routes investigated by chemists over the past several years is presented, with emphasis on the major difficulties encountered. The main current challenges regarding the heterogeneous catalytic oxidation of lignin and derivatives are also highlighted. A particular focus is given to innovative strategies favoring mild reaction conditions. Finally, we provide some recommendations and routes worthy of interest in this studied area of research in order to generate value-added chemicals from lignin oxidation through the use of heterogeneous catalysts.

Graphical abstract

Available on the website of Green Chemistry

Seminar of the French Chemical Society

During two days, all the representives of the sections of French Chemical Society, have taken part in the annual seminar to discuss the future actions of the Society. The young chemists have been well represented through each Club de Jeunes and the French Young Chemists’ Network (RJ-SCF).

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The board of the RJ-SCF.

More about the seminar here.

Visit of Prof. Audrey Moores

This week, we have received our collaborator Prof. Audrey Moores, from McGill University (Montreal, Canada) in our group.

AUDRE

She presented a conference entitled : « Atom economy in Nanoscience: Solvent, Reducer and Ligand free avenues to access metal nanoparticles« . The abstract of the conference is available here.

The week has been very productive, since we have submitted a new international proposal to continue our collaboration. Great ideas for research and teaching collaborations!

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More about Prof. Audrey Moores here.

Our new article in Applied Clay Science

How efficiently combine sonochemistry and clay science?

G. Chatel,* L. Novikova and S. Petit

Abstract

Clays are widespread materials of natural origin, possessing various surface active sites, exchangeable and structural, as well as micro- and mesoporous structures that allow their application in ion-exchange, adsorption and catalytic processes. A recent trend has been to combine clays to ultrasound irradiations (sonochemistry) in a range of different applications and the results demonstrate significant and occasionally surprising synergetic effects. Indeed, ultrasound can lead to significant changes in the properties and behaviors of clays depending on the choice of ultrasonic parameters. Here, the advantages and limitations of the clay science/sonochemistry combination have been critically highlighted in different applications, to understand how, and inwhich respects,
ultrasound could become an essential and efficient tool of clay chemistry in the future.

TOC

Available on the website of Applied Clay Science

Great collaboration with experts in clay science from Russia and from my Institute!

ACS National Meeting at Boston

Great week at Boston for the 250th ACS National Meeting and Exposition at Boston, MA.

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Thanks to the Young Chemists Crossing Borders program (YCCB), I attend to the ACS national meeting and some activities organized by Young Chemists Committee! A great thank to Lee Johnson, Felicia Lucci, Jens Breffke and the others for their hospitality and their availability.

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I would like to thank also the organizers of the Green Chemistry and Environment Symposium, Sherine Obare, Alina Balu and Rafael Luque, to give me the opportunity to present a talk entitled « Investigation of sonochemistry for biomass conversion: That sounds like a good idea! » (Find the abstract here)

Boston Green chem