Hybrid organogels and aerogels from co-assembly of structurally different low molecular weight gelators

Supratim Banerjee (1) , das K. Rajat (1, 2, 3) , Pierre Terech (4) , Arnaud de Geyer (5) , Cyril Aymonier (3) , Anne Loppinet-Serani (3) , Guillaume Raffy (2) , Uday Maitra (1) , André del Guerzo (2) , Jean-Pierre Desvergne (2)

1 Department of Organic Chemistry
2 ISM - Institut des Sciences Moléculaires
3 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
4 SPRAM - UMR 5819 - Structures et propriétés d'architectures moléculaire
5 SP2M - UMR 9002 - Service de Physique des Matériaux et Microstructures

The blending of perfluorinated bile ester derivatives with the gelator 2,3-didecyloxyanthracene (DDOA) yields a new class of hybrid organo- and aerogels displaying a combination of optical and mechanical properties that differ from those of pure gels. Indeed, the nanofibers constituting the hybrid organogels emit polarized blue light and display dichroic near-UV absorption via the achiral DDOA molecules, thanks to their association with a chiral bile ester. Moreover, the thermal stability and the mechanical yield stress of the mixed organogels in DMSO are enhanced for blends of DDOA with the deoxycholic gelator (DC11) having a C11 chain, as compared to the pure components' gels. When the chain length of the ester is increased to C13 (DC13) a novel compound for aerogel formation directly in scCO2 is obtained under the studied conditions. A mixture of this compound with DDOA is also able to gelate scCO2 leading to novel composite aerogel materials. As revealed by SAXS measurements, the hybrid and the pure DDOA and DC13 aerogels display cell parameters that are very similar. These SAXS experiments suggest that crystallographic conditions are very favorable for the growth of hybrid molecular arrangements in which DDOA and DC13 units could be interchanged. Specific molecular interactions between two components are not always a pre-requisite condition for the formation of a hybrid nanostructured material in which the components mutually induce properties.

Mots clés: Organics compounds; Physical properties; Gels; Hybrid materials

Domaines: Matériaux

Supratim Banerjee, das K. Rajat, Pierre Terech, Arnaud de Geyer, Cyril Aymonier, et al.. Hybrid organogels and aerogels from co-assembly of structurally different low molecular weight gelators. Journal of Materials Chemistry C, 2013, 1 (20), pp.3305-3316. ⟨10.1039/C3TC30104D⟩. ⟨hal-00828042⟩