Liquid crystals of carbon nanotubes and graphene Auteur(s): Zakri Cécile, Blanc C., Grelet Eric, Zamora-Ledezma C., Puech Nicolas, Anglaret E., Poulin Philippe (Article) Publié: Philosophical Transactions Of The Royal Society Of London. Series A, Containing Papers Of A Mathematical Or Physical Character, vol. 371 p.pp. 1-15 (2013) Texte intégral en Openaccess : Ref HAL: hal-00797442_v1 DOI: 10.1098/rsta.2012.0499 WoS: 000315792800013 Exporter : BibTex | endNote 53 Citations Résumé: Liquid crystal ordering is an opportunity to develop novel materials and applications with spontaneously aligned nanotubes or graphene particles.Nevertheless, achieving high orientational order parameter and large monodomains remains a challenge. In addition, our restricted knowledge of the structure of the currently available materials is a limitation for fundamental studies and future applications. This paper presents recent methodologies that have been developed to achieve large monodomains of nematic liquid crystals. These allow quantification and increase of their order parameters. Nematic ordering provides an efficient way to prepare conductive films that exhibit anisotropic properties. In particular, it is shown how the electrical conductivity anisotropy increases with the order parameter of the nematic liquid crystal. The order parameter can be tuned by controlling the length and entanglement of the nanotubes. In the second part of the paper, recent results on graphene liquid crystals are reported. The possibility to obtain water-based liquid crystals stabilized by surfactant molecules is demonstrated. Structural and thermodynamic characterizations provide indirect but statistical information on the dimensions of the graphene flakes. From a general point of view, this work presents experimental approaches to optimize the use of nanocarbons as liquid crystals and provides new methodologies for the still challenging characterization of such materials. Commentaires: 15 pages |