At 142[degrees]C, the oily streak texture of the cholesteric phase
appeared as shown in Fig.
In addition, the observed nanodoped nOBA liquid crystals have displayed threaded nematic and Sm C for n = 6, 7, 9, and 12 and cholesteric phase in nanodoped 8OBA and the phases of Sm A and Sm B in nanodoped 10OBA.
The existence of cholesteric phase in N8OBA particularly is due to electroconvection that is usually existing in nematic liquid crystals of short range Sm C order .
It was denoted (44) that the presence of orange color is a reliable indicator of the cholesteric phase
. Thin films (about 100 [micro]m) of the solution in crossed polarizers are colored in gray gradations (Fig.
A significant advantage regarding the scope of our studies is that the copolymers were cholesteric phase at room temperature.
At last, the cell is sealed and kept at 75[degrees]C, and this temperature corresponds to a stable cholesteric phase for which the materials are viscous.
As no optical activity was observed in the monomers, the detection of a cholesteric phase and an optical rotation for each polymer suggests that for polyesters with this degree of polymerization, containing chiral centers in the main chain and hydroxyl groups of different reactivity, a nonrandom head-to-tail arrangement occurs.
As the material is chiral and exhibits a cholesteric phase at higher temperatures, the phase is classified as [S.sub.[C.sup.*]].
They examine phase diagrams of lyotropic mixtures, phase transitions between periodically organized lytropic phases, isotropic micellar and bicontinuous phases, nematic and cholesteric phases
, and the lyotropic phases in one to three dimensions.
Charlet at Laval University, Quebec, and work on a range of aliphatic esters of HPC that form thermotropic cholesteric phases
However, atropisomerism has already been used in the area of low-molar-mass liquid crystals (LCs) (9, 10) in order to obtain cholesteric phases