Binary Mixtures of Colloidal Cellulose Nanocrystals and Laponite for Preparation of Functional Nanocomposites

Cellulose nanocrystals (CNCs) are attractive substances with interesting colloidal self-assembly behaviour and rheological properties due to their rigid rod morphology. Aqueous dispersion characteristics as well as the rheological, optical, and structural properties of binary mixtures of CNCs and Laponite (L) are investigated in detail. As the concentration of CNC increased, the interparticle distance decreased exhibiting excellent birefringent properties, which were confirmed by imaging the samples placed between cross polarizers. We obtain various complex structures by using the binary mixtures of CNCs and Laponite. A phase diagram consisting of sol, isotropic gel, and birefringent nematic gel phases is obtained. To go further, we demonstrate the fabrication of nanocomposite thin films and aerogels from the binary colloidal mixtures. For the former, they can be used as efficient absorbers of model pollutants such as Nile blue and Rhodamine B dyes in solution, while as-obtained aerogels display enhanced flame retardation behaviour. Our findings envisage that this system will serve as a model binary system of one and two dimensions with complex interactions.