In the nematic phase, the centres of gravity of the elongated molecules are arranged at random and the long axes of the molecules are oriented in a certain direction. In the smectic phase, the centres of gravity of the elongated molecules are arranged in equidistant planes and are mobile in two dimensions. In both these phases the molecules can rotate around their long axes. In the cholesteric phase, the structure is the same as that of nematic phase but has an additional twist about an axis perpendicular to the long axes of molecules.nFor about twenty years after their discovery in 1888 many scientists doubted the very fact of existence of matter in this form. Consequently they were regarded as laboratory curiosities rather than potentially useful or theoretically important objects of study. Although research into liquid crystals did reach a peak in the early 1930's, interest soon waned and very little important work was done.
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