Materials Chemistry

Biography

Biography: Seydina Ibrahima KEBE

Abstract

Over the last years, crucial issues for our developped countries such as on-continuing urban development, climate changes, long term viability of production and consumption systems, degradation of populations health, atmospheric and water pollutions, uses of natural resources... are at the heart of the many debates with both social and economical challenges. For instance, evaluating and reducing the impact of chemicals on the environment require a global vision, ranging from analytical chemistry, treatment of contaminated effluents and to optimization of synthetic methods towards environmentally-friendly processes. In this contribution, metal nanoparticles-decorated polymeric monoliths are proposed as smart nanostructured materials providing efficient solutions for trace detection of pollutants (parabens, pesticides, phenols and anilines) in real samples as well as chemical treatment of toxic chemicals (nitroarenes) into their benign counterparts. Indeed, polymer monolith exibit channel-like pores allowing fast mass transfer and can be easily synthesized with a large panel of surface chemical functionality. As such, polymeric monoliths have been successfully applied in many fields of flow chemistry including chromatography separation, SERS detection and support for catalysis. Herien, polymeric monoliths based on N-acryloxysuccinimide were synthesized within micro-channels through easy and energy-efficient UV-driven processes. In a further step, implementation of click strategies usually referred to as atom economy methods, have been implemented to functionalizing the surface of monoliths with chelating groups allowing the robust anchoring of metal nanocatalysts.[1] The as-obtained nancomposites were characterized by a combination of complementary methods such energy dispersive analysis, Raman spectroscopy and electron microscopy providing chemical composition, structural and morphological information.[2] As a major result, it will be shown that controlling the surface molecular structure of monoliths enables (i) designing miniaturized separation columns allowing the successful separation of parabens with efficiencies as high as the ones reported for commercial systems; (ii) the specific immobilization of nanometals (Au, Pd, Pt, Ag). Of particular interest, it will be shown that the in-situ synthesis of nanoparticles with controlled shape (nanoflowers & nanocubes vs. nanospheres), size and size distribution, at the monolith’s surface leads to the design of microreactors allowing the flow-through catalytic decontamination reactions of pesticides such as Trifluralin, and pendimetalin. Superiority of flow-through monoliths vs their bulk counterpart is undoubtedly demonstrated, notably in terms of reaction time, selectivity in chemical reaction, no need of catalyst recovery, reaction yield and easiness of product work-up.