Abstract
We investigate the effects of shear flow on the smectic phase of thermotropic and lyotropic liquid crystals. We show that shear flow transforms a smectic-A thermotropic liquid crystal into an orthorhombic solid by the suppression of undulation fluctuations. In contrast, the lyotropic L± phase exhibits, in addition, a very striking enhancement of short-wavelength concentration fluctuations a phenomenon that is analogous to a well-known effect in polymer solutions. We demonstrate this result, using both hydrodynamic theory and a microscopic model based on the Helfrich theory of membranes. The dispersion relation of the concentration fluctuations is in qualitative agreement with recent experiments on the L± phase in shear flow.
| Original language | English |
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| Pages (from-to) | 994-1008 |
| Number of pages | 15 |
| Journal | Physical Review A |
| Volume | 45 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1992 |