PHY-850: Special Topics in CM: Intro to liquid crystal physics

Molecules” of anisometric shapes often form fluidic but orientationally ordered phases, called liquid crystals. Various entities, from small organic molecules to millimeter-size grains, from lifeless colloids to swimming microorganisms, can form liquid crystal phases. In the first part of the course, we will discuss equilibrium liquid crystal systems. We will begin with a survey of the variety of phases in the liquid crystal family. Then we will look into the Maier-Saupe and Onsager theories that describe the condensation of nematic from an isotropic phase. We will investigate the elasticity and viscosity of nematics with both symmetry and material arguments. We will conclude this part with discussions on defects. In the second half, we will look into active liquid crystals, i.e. systems driven out-of-equilibrium at “molecule” level. We will look into the dynamic features of these new systems that result from the competition of orientational order and active stress. This course will be mainly lectures, but compensated by paper discussion, lab tours, and basic experiments.