Thermotropic liquid crystals flow behaviour

E. M. Andresen and G. R. Mitchell, Orientational behaviour of thermotropic and lyotropic liquid crystal polymer systems under shear flow. Europhys. Lett. 43, 296-301 (1998). 

Such data has similarities with earlier studies on lyotropic aqueous solutions of HPC (15,16). The equivalent orientational behaviour in steady state shear flow for a 55% w/v aqueous HPC solution is shown in Figure 12. These data also show three regimes although the level of preferred orientation at low shear rates is clearly greater for the aqueous solution, and the distinction between regimes 2 3 are blurred. Lyotropic HPC and thermotropic PPC have considerably different concentrations of liquid crystal forming molecule (55% and 100%), yet their responses to the flow field are similar. It is emphasized that we can make direct comparisons between these two materials since the derivative PPC and the lyotropic solutions were prepared from the polymer Klucel E which was used to prepare the aqueous solutions. 

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