Monolithic organic aerogels derived from single amino-acid based supramolecular gels: physical and thermal properties
| Autor: | Sébastien Son, Danielle Barth, Florent Allix, Yves Jannot, Alain Degiovanni, Guillaume Pickaert, Brigitte Jamart-Grégoire, Vincent Felix |
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| Přispěvatelé: | Laboratoire de Chimie Physique Macromoléculaire (LCPM), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Réactions et Génie des Procédés (LRGP) |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Infrared
General Chemical Engineering Supramolecular chemistry 02 engineering and technology Conductivity 010402 general chemistry 7. Clean energy 01 natural sciences Porosité Contact angle Thermal conductivity Thermal insulation Organic chemistry [CHIM]Chemical Sciences Aérogel Capacité calorifique Chemistry business.industry [CHIM.ORGA]Chemical Sciences/Organic chemistry Supercritical drying Aerogel General Chemistry [CHIM.MATE]Chemical Sciences/Material chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences Chemical engineering Conductivité thermique 0210 nano-technology business |
| Zdroj: | RSC Advances RSC Advances, Royal Society of Chemistry, 2016, 6 (104), pp.102198-102205. ⟨10.1039/C6RA20803G⟩ |
| ISSN: | 2046-2069 |
| DOI: | 10.1039/C6RA20803G⟩ |
| Popis: | International audience; Highly porous materials have numerous applications in research field such as filtration and collection devices, catalysis, and electric devices or in acoustic and thermal insulation. In the later one, inorganic and / or macromolecular chemical gels, are extensively studied. Here, a new type of monolithic aerogel, made of self-assembled small organic molecules, is described. Those low-molecular weight aerogels (LMWA) are prepared from amino acids based (phenylalanine or leucine) supramolecular gels by using a CO2 supercritical drying process. The organogels and aerogels exhibit very interesting properties. Indeed, gelator molecules are able to immobilize aromatic solvents such as toluene or tetralin at low concentrations. Melting enthalpies (H) are calculated for both gelator molecules and for both solvents. In the case of aerogels, an important hydrophobic character, a very low density and remarkable thermal properties are observed. For the former one, measured contact angles are found between 110 and 114°. As for the second, those organic aerogels belong to the family of the lightest porous materials in the world with densities as low as 4.3 kg m-3. And finally, thermal measurements show that these LMWAs present a low thermal conductivity under atmospheric pressure (λ=26.5 mW·m-1·K-1) and very low thermal 20 conductivity under vacuum (λ=4 mW·m-1·K-1 at 10-2 mbar). Moreover, the measurement of the radiative conductivity demonstrated that LMWAs are a very scattering material; 80 to 90% of infrared radiations are stopped. Such characteristics make these materials viable candidates for use in thermal insulation |
| Databáze: | OpenAIRE |
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