Lyotropic liquid-crystalline phases description

The formation of liquid-crystalline phases of cellulosics, especially of the lyotropic kind, has yet to be explained. Certainly the chain stiffness may have to be taken into account as one of the factors in question, but the solvent-polymer interaetion may have to be considered as well. In the next section, models for the description of the pitch as a chiral property and models to... 

Liquid crystal materials can be grouped into two main classifications, thermotropics and lyotropics. A thermotropic phase is one that can form by heating or cooling a material. Just as we see a phase transition between solid and liquid as we heat and melt ice, in thermotropic liquid crystals, additional melting points can be observed in between the solid and the liquid phases. These are the thermotropic liquid crystalline phases. A lyotropic liquid crystal phase is formed by molecules dissolved in a solvent, and phases form at certain concentrations in that solvent. In this chapter, we focus on descriptions of the thermotropic liquid crystal phases. Lyotropics, although also liquid crystals, are described in detail in Chapter 3 on surfactants. 

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