DSI Seminar presented by : Dr. André Linhares Rossi

Dr. André Linhares Rossi (Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brésil)

Abstract : In this seminar, I will present results from experimental studies on the crystallization process of calcium carbonates and phosphates, using high-spatial-resolution techniques such as transmission electron microscopy and synchrotron beamline techniques. Both materials are abundant on Earth in the form of minerals and biominerals (such as the skeletons of vertebrates and invertebrates). Furthermore, they have commercial and environmental significance. The crystallization process can follow non-classical pathways, in which amorphous or crystalline precursors may be present prior to the final phase. The effect of organic additives (polymers and phosphonates) on the crystallization process has also been studied.

Contact : Jacques Werckmann (jacques.werckmann@ipcms.unistra.fr)

Seminar Axis 3 présented by : Dr Sagarika MISHRA

Dr Sagarika MISHRA (School of Physics & Astronomy University of St Andrews)

Abstract:

Overuse of herbicides and pesticides has led to persistent agrochemical residues that threaten environmental health, creating a pressing need for efficient detection strategies in aqueous media. Here, we report luminescent carbazole-based molecules designed to sense a group of pesticides and herbicides, including trifluralin and DNOC. The sensor molecules readily form highly luminescent nanoaggregates in near aqueous environments. Aggregation behaviour was examined through emission measurements and fluorescence lifetime measurements across varying DMSO/water fractions from 0 % to 99 % water in DMSO. Particle sizes determined by SEM and DLS confirmed nanoscale aggregates of 20 nm to 950 nm diameter. These nanoaggregates display strong sensitivity as fluorescence-quenching sensors toward multiple common pesticides, achieving detection limits in the nanomolar to micromolar range, highlighting their potential as efficient luminescent probes for monitoring environmental pollutants.

Seminar “Axe 2 NanoBioSciences”

Jérémie Léonard : Ultrafast Spectroscopy reveals the working principles of (bio-)molecular, light-activated sensors

Stephane Bellemin : Theranostic agents based on metal transition complexes against cancer

Seminar IPCMS presented by: Christophe COPÉRET

Speaker : Christophe COPÉRET  (ETH Zurich, Department of Chemistry and Applied Biosciences)

Abstract : Most efficient chemical processes used in industry rely on heterogeneous catalysis. While the search for more sustainable processes and the changes in environmental policies impose the continuous development of more efficient catalysts, we have currently little understanding of the structure of the actives in these processes. Hence, due to their inherent complexity, heterogeneous catalysts have been mostly developed empirically.

Here, we will show how constructing active sites, one atom at a time on surfaces, enables molecular-level understanding and implementation of rational approaches for the improvement of catalytic processes. We will first illustrate how this approach enables to generate selective single-site catalysts. We will next show how from these isolated (single) sites, one can generate and understand far more complex systems such as supported nanoparticles, where interfaces, alloying… play a critical role. This lecture will be developed around these themes and will show how the development of advanced characterization tools augmented by computational approaches can provide useful information to bridge the gap between fundamental and applied (industrial) catalysis. Furthermore, alternative complementary approaches based on data-driven high-throughput experimentations will be also discussed, paving the way for automated discovery and development of catalysts.

Seminar “Axe 2 NanoBioSciences”

Program :

Mariana Longuinho : Projet ANR Altamiante : Combining chemical and biological treatment for asbestos alteration and exploring siderophore-producing Pseudomonas on mineral interface

Damien Mertz : Advances in porous iron oxide core@shell nanosystems: chemical engineering, physical properties, polymer brush grafting (review)