Ferroelectric liquid crystal-polymer composites

To produce novel LC phase behavior and properties, a variety of polymer/LC composites have been developed. These include systems which employ liquid crystal polymers (5), phase separation of LC droplets in polymer dispersed liquid crystals (PDLCs) (4), incorporating both nematic (5,6) and ferroelectric liquid crystals (6-10). Polymer/LC gels have also been studied which are formed by the polymerization of small amounts of monomer solutes in a liquid crystalline solvent (11). The polymer/LC gel systems are of particular interest, rendering bistable chiral nematic devices (12) and polymer stabilized ferroelectric liquid crystals (PSFLCs) (1,13), which combine fast electro-optic response (14) with the increased mechanical stabilization imparted by the polymer (75). 

Ferroelectric liquid crystals with very fast switching times have been prepared for evenmal use in various sensing and switching devices. Other areas of materials research include the synthesis of spin-labeled polymers for sensing composite interface properties, the structure and function of polymer-stabilized synthetic membranes, and polymers for various sensor applications. 

In general, research on classes of materials is connected with that on materials with specific properties but includes somewhat more general research on composites, polyurethanes, epoxies, fluoropolymers, ferroelectric liquid crystals (especially those with fast switching times), polymer-polymer miscibility, double network elastomers, crystallization in polymers, polymeric Langmuir-Blodgett and other multilayer films, and polymer-stabilized synthetic membranes. 

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Sato H, Fujikake H, Lino Y, Kawakita M, Kikuchi H (2002) Flexible grayscale ferroelectric liquid crystal device containing polymer walls and networks. Jpn J Appl Phys 41 5302-5306 Sato H, Fujikake H, Kikuchi H, Kurita T (2003) Rollable polymer stabilized ferroelectric liquid crystal device using thin plastic substrates. Opt Rev 10(5) 352-356 Schrader DM, Jean YC (1988) Positron and positronium chemistry. Elsevier, Amsterdam Shinkawa K, Takahashi H, Fume H (2008) Ferroelectric liquid crystal cell with phase separated composite organic film. Ferroelectrics 364 107-112 Simha R, Somcynsky T (1969) On the statistical thermodynamics of spherical and chain molecule fluids. Macromolecules 2 342-350... 

In the Landolt-Bdmstein data collection, ferroelectric and antiferroelectric substances are classified into 72 families according to their chemical composition and their crystallographic structure. Some substances which are in fact neither ferroelectric nor antiferroelectric but which are important in relation to ferroelectricity or anti-ferroelectricity, for instance as an end material of a solid solution, are also included in these families as related substances. This subsection surveys these 72 families of ferroelectrics presented in Landolt-Bornstein Vol. III/36 (LB III/36). Nineteen of these families concern oxides [5.1,2], 30 of them concern inorganic crystals other than oxides [5.3], and 23 of them concern organic crystals, liquid crystals, and polymers [5.4]. Table 4.5-1 lists these families and gives some information about each family. Substances classified in LB 111/36 as miscellaneous crystals (outside the families) are not included. 

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