title: Self-assembling and chiral nematic properties of organophilic cellulose nanocrystals.
abstract: Cotton cellulose nanocrystals with different aspect ratios have been dispersed in cyclohexane as a model apolar solvent, using surfactants. Above a critical concentration, which was higher than that in water, the suspensions spontaneously phase separated into a chiral nematic mesophase. According to Onsager's theory, the phase separation is controlled by the aspect ratio, while being influenced by the polydispersity. The sample with the highest aspect ratio did not show any phase separation but instead shows an anisotropic gel phase at high concentration. Experimental critical concentrations were found to be much lower than the predicted ones, revealing an attractive interaction between the rods. Chiral nematic pitches as small as 2 mum were found to be much lower than those measured in water, due to stronger chiral interactions in the apolar medium.
authors.affiliation: Centre de Recherches sur les Macromolécules Végétales-CNRS, F-38041 Grenoble Cedex 9, France.
authors.forename: Samira
authors.initials: S
authors.lastname: Elazzouzi-Hafraoui
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Putaux
authors.forename: Laurent
authors.initials: L
authors.lastname: Heux
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D053758:Nanoparticles; D013237:Stereoisomerism
chemical_list: D002482:Cellulose