Liquid crystals

The study of liquid crystals began between 1850 and 1880 with the observation of strange substances, mostly of biological origin, with multiple melting points. Their true discovery, however, is attributed to the Austrian botanist F. Reinitzer, who in 1888 was the first to recognize the opalescent fluid state of a cholesterol derivative as a new state of matter. German physicist O. Lehmann, designer of the first polarizing microscope with a heated stage, proposed the name liquid crystal in 1890, and it was in 1922 that the Frenchman G. Friedel established the classification and nomenclature of the most common phases: nematic, smectic and cholesteric states.

Research into liquid crystals was very active until 1930, but remained relatively dormant until 1958. The revival and growth of the discipline from 1960 onwards were due to the appearance of new synthetic liquid crystals, the theoretical interest aroused by their varied critical and structural properties, and above all their technological applications, the most successful of which are displays.