Cellulosic aerogels for energy applications
Résumé
Coming from soft chemistry (e.g. sol-gel), chemical nature and nanostructuration of aerogels can be softly tailored. Moreover, they can be lightweight and they can present very high specific area (larger than 1000 m²/g) with narrow (or even broad) pore size distribution. Such structural characteristics make them potentially interesting for various applications. A large majority of the studies dedicated to aerogels are dealing with inorganics (SiO2, TiO2, ZrO2...). Anyway, some class of organic aerogels are known to present high interest. Such materials are particularly considered as organic precursors for new nanostructured carbons. Most of the corresponding samples are coming from Resorcinol-Formaldehyde (RF) systems. During the past decade, further studies on organic aerogels for thermal insulation have addressed other kinds of aerogels, mainly based on polyurethane , and very recently polydicyclopentadiene systems. Within these sphere, except original works of Kistler, only very few works concern use of natural products. Knowing that cellulose is one of the most abundant natural materials, one can guess that combining sol-gel science and cellulose could be of high interest. Some works on elaboration of porous cellulose via drying of physical cellulose-based gels can be found but they are dealing with macroporous foams not really aerogels. , Some years ago, one of the first aerogel attempt with cellulose derivatives has been published. On this basis, we have developed a softer route (i.e. using a non toxic isocyanate). We have then examined the pyrolysis impact on the resulting carbonaceous green materials and evaluated its use as catalyst support for PEM fuel cell electrodes. Here is presented a very brief overview of the related studies we have performed since then.
Domaines
Energétique
Origine : Fichiers produits par l'(les) auteur(s)
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