A First Example of a Lyotropic Smectic C* Analog Phase: by Johanna. R Bruckner

By Johanna. R Bruckner

In this thesis Johanna Bruckner studies the invention of the lyotropic counterpart of the thermotropic SmC* section, which has turn into well-known because the merely spontaneously polarized, ferroelectric fluid in nature. via polarizing optical microscopy, X-ray diffraction and electro-optic experiments she firmly establishes points of the constitution of the unconventional lyotropic liquid crystalline part and elucidates its attention-grabbing houses, between them a reported polar electro-optic impression, analogous to the ferroelectric switching of its thermotropic counterpart. The helical floor nation of the mesophase increases the basic query of ways chiral interactions are "communicated" throughout layers of kind of disordered and achiral solvent molecules that are positioned among adjoining bi-layers of the chiral amphiphile molecules. This thesis bridges an enormous hole among thermotropic and lyotropic liquid crystals and pioneers a brand new box of liquid crystal research.

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A First Example of a Lyotropic Smectic C* Analog Phase: Design, Properties and Chirality Effects

During this thesis Johanna Bruckner experiences the invention of the lyotropic counterpart of the thermotropic SmC* part, which has develop into recognized because the purely spontaneously polarized, ferroelectric fluid in nature. through polarizing optical microscopy, X-ray diffraction and electro-optic experiments she firmly establishes points of the constitution of the unconventional lyotropic liquid crystalline section and elucidates its attention-grabbing homes, between them a said polar electro-optic impression, analogous to the ferroelectric switching of its thermotropic counterpart.

Additional resources for A First Example of a Lyotropic Smectic C* Analog Phase: Design, Properties and Chirality Effects

Example text

14]). The individual phases in Fig. 9 are separated by biphase regions. In some cases it is also possible to observe the formation of inverse micelles at very low solvent concentrations. This leads to a mirror imaged phase diagram of the one shown in Fig. 9. Even though the solvent concentration is the most important parameter for the occurrence of particular mesophases, the effect of temperature is not completely negligible. Hence, it is also possible to find high and low temperature mesophases at the same solvent concentration.

The local director of the SmC* phase is represented by a nail. The symbols ● and ○ correspond to cross sections of +2π and −2π disclinations (redrawn after [11]) unwinding lines at the top and the bottom part of the sample may be shifted by p/2 if the anchoring conditions are antiparallel as depicted in Fig. 4a. Thus, the observed periodic pattern of dark and light stripes may correspond to p/2 instead of p. To check if this is the case, the sample has to be brought slightly out of focus. If every second stripe becomes sharper and every other becomes more diffuse, the distance between two lines is equal to p/2 (Fig.

White light from a lamp is led through a polarizer to give linearly polarized light. The linearly polarized light is focused on the sample which is placed in a hot stage. Then the light is collected by an objective and passes a second polarizer, the so-called analyzer. The analyzer is turned by 90° with respect to the polarizer. If the sample is Fig. 3 Polarizing Optical Microscopy 33 optically anisotropic in the plane perpendicular to the light path, it converts the linearly polarized light into elliptically polarized light and the observed picture appears bright.

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