Buckling Instabilities and Recoil Dynamics in Free-Standing Liquid Crystal Filaments – Tanya Ostapenko

Date: Mon. May 18th, 2015, 12:30 pm-1:30 pm
Location: Rockefeller 221

Quasi-one-dimensional free-standing fluid structures are not often found in nature, but may be formed by any material that can overcome capillary instability. Once this instability is suppressed, long filaments, with a length-to-diameter ratio greater than �, may form. Liquid crystals are an extraordinary system that can form free-standing fluid filaments with length-to-diameter ratios exceeding 7000. Buckling instabilities in freestanding liquid crystal filaments formed from bent-core liquid crystals in the B7 phase may be induced in a variety of ways, e.g. by acoustical or electrical vibration. However, this talk will focus on instabilities induced by compressing the filament, as well as those from a mechanical or thermal rupture. Different phenomena manifest themselves depending on the velocity at which the filament is compressed or ruptured, as well as the filament’s size and shape. Regardless of the buckling method, a characteristic wavelength develops, which is related to the elastic modulus of the filament. These results are compared to those for viscous, isotropic, non-Newtonian fluids, where we find that the liquid crystalline structure of the filament contributes to complex structural formations and behavior.