CPM Seminar

I will report on experimental and theoretical investigations of a system composed of colloidal inclusions embedded in a cholesteric liquid crystal. The presence of the inclusions leads to the stabilization of a dense network of linear defects that are prevented from annealing by the energetical preference of the inclusions to be located at the nodes of the network. On appropriate time scales, the described defect network structure can be viewed as a cross-linked network of elastic bonds, and gives raise to gel-like rheological behavior. The cholesteric liquid is thus converted to a "defect-mediated solid". The cholesteric system can serve as a model for a more general class of solids formed when particles are mixed with layered materials such as smectic liquid crystals and block copolymers.

Wednesday, April 28th 1999, 15:30
Ernest Rutherford Physics Building, room 114