Liquid crystals helical self-assembly

Cellulose and some derivatives form liquid crystals (LC) and represent excellent materials for basic studies of this subject. A variety of different structures are formed, thermotropic and lyotropic LC phases, which exhibit some unusual behavior. Since chirality expresses itself on the configuration level of molecules as well as on the conformation level of helical structures of chain molecules, both elements will influence the twisting of the self-assembled supermolecular helicoidal structure formed in a mesophase. These supermolecular structures of chiral materials exhibit special optical properties as iridescent colors, and... 

Kim KT, Park C, Kim C, Winnik MA, Manners I (2006) Self-assembly of dendron-helical polypeptide copolymers organogels and lyotropic liquid crystals. Chem Commnn 1372-1374... 

M. Mathews, N. Tamaoki, Reversibly tunable helicity induction and inversion in liquid crystal self-assembly by a planar chiropdc trigger molecule. Chem. Commun. 3609-3611 (2009)... 

We have formulated a geometrical, mathematical theory for CMF ordering during their deposition, which allows production of axial, helical, crossed, helicoidal, and random wall textures (Emons 1994 Emons and Kieft 1994 Emons and Mulder 1997 1998 2000 2001 2001 Emons et al. 2002 Mulder et al. 2004). Before reviewing our theory, we first discuss the most important alternate CMF ordering hypotheses that have been proposed (1) microtubule-directed CMF orientation, (2) self-assembly like liquid crystals, (3) templated incorporation hypothesis. In addition, we will respond to criticism that has been put forward against the geometrical theory and discuss those predictions from the theory that can be tested experimentally and, therefore, potentially, verify or falsify the theory. 

As discussed in Chapter 5, chiral liquid crystals exhibit modulated groimd states and are therefore self-assembled PEG materials. The simplest of them is the cholesteric liquid crystal, which is a one-dimensional photonic band-gap material if the helical pitch is in the visible wavelength range. As illustrated in Chapter 5, such structure leads to selective reflection rendering a color to the material. The helical—and therefore the color—is sensitive to... 

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