Diamagnetic Anisotropy of Liquid Crystalline Side Chain Polysiloxanes in the Nematic and Smectic Phases

Abstract
We report here the first results on the diamagnetic anisotropy δχ of some thermotropic side chain polymers (polysiloxanes). Kinetic effects for the bulk orientation of the nematic phase under a strong external field (H=15,25 103 Gauss) are observed smaller than with linear polymers. The shorter the flexible spacer between the mesogenic part and the backbone is the stronger these effects are. Concerning the temperature dependence, the saturated magnetic anisotropy increases regularly with decreasing temperature in the same extent than for other nematic of LC monomers or linear polymers.