In-situ photopolymerization of polyfunctional liquid-crystalline monomers leads to anisotropic networks with a well-controlled and stable molecular organization. By polymerizing chiral monomers cholesteric networks are formed. The pitch of the molecular helix in these networks can be controlled between 180 nm and infinity. By a special process making use of photo-induced diffusion during the polymerization process, cholesteric networks are made with a pitch that varies gradually over the thickness of the film. These films may be optimized on reflection of circularly polarized light over the entire visible spectrum. The films are highly useful as non-absorbing polarizers for power-efficient liquid crystal displays.
|Title of host publication||Chemical and physical networks|
|Editors||K. Nijenhuis, te, W.J. Mijs|
|Place of Publication||New York|
|Publication status||Published - 1998|
|Name||The Wiley Polymer Networks Group review series|