Nanomaterials in Liquid Crystal Mediated Interactions – Rajratan Basu
Date: Mon. March 28th, 2016, 4:00 pm-5:00 pmLocation: Rockefeller 221
In liquid crystals (LC) the effect of nonmesogenic guest-nanoparticles on the LC’s bulk properties often rests on the molecular identification at the nanoscale in order to share and disseminate the `information’ coded into the nanostructure of the nanoparticles. I will present two types of nanomaterials and their intriguing interactions with LCs. Graphene is a twodimensional crystalline carbon allotrope where carbon atoms are densely packed in a regular sp2- bonded atomic-scale hexagonal pattern. This graphene nanostructure can used to enhance the tilted smectic-C order in an LC, giving rise to a faster ferroelectric switching. The presence of graphene can improve the electro-optic response and decrease the rotational viscosity of an LC. In a different direction, BaTiO3 ferroelectric spherical nanoparticles possess permanent dipole moments that can locally align the LC molecule at the nanoscale. These BaTiO3 nanoparticleinduced local LC domains show non-volatile nano-electromechanical memory effect in the isotropic phase. This memory effect can be enhanced significantly by modifying the nanoparticle-surface by attaching polymer threads. This memory effect can also be tuned by varying the length of the polymer threads.