hide
Free keywords:
light scattering; poly(dimethylsiloxane); nematic liquid crystal
Abstract:
The phase diagram of poly(siloxanes) and low molecular weight liquid crystals as obtained by polarized optical microscopy have shown a peculiar behavior : Transitions from a nematic to an isotropic and from an isotropic miscibility gap to a single isotropic phase take place in two steps interpreted as onset and end of transitions. This behavior has been observed in various systems and particular in those involving poly(dimethylsiloxane) (PDMS) and 4-cyano-4'-n-pentyl-biphenyl (5CB). In order to confirm this behavior we performed static light scattering on blends of PDMS (M-w=45000g/mol) and 5CB at different compositions. These experiments covered a temperature range from 20 to 115degreesC and several scattering angles.
