Cholesteric Liquid Crystals

Production of liquid crystals involves difficult chemistry, but it is well within the scope of Pressure Chemical’s expertise. We have been successfully producing cholesteric liquid crystals for a wide variety of downstream applications for nearly 50 years. In fact, the cholesterol-based liquid crystals that Pressure Chemical manufactures are the materials used to make the “mood rings” starting back in the 1970s.
The temperature sensing and color changing abilities of liquid crystals make them suitable for use in a wide range of thermometers and in industries such as healthcare products, clothing, pigments, paints, advertising specialties and other novelties. Cholesteric liquid crystals are also used extensively in cosmetic products to provide a shining, shimmering appearance and creamy texture in lip gloss and skin moisturizers. These materials are natural products.

Cholesteric liquid crystals are also known as chiral nematic liquid crystals. The organic molecules that make these liquid crystals are chiral (they have no internal planes of symmetry) and the resulting liquid crystals are chiral. The molecules stack on top of each other in cylinders. The stacking results in a helical structure which gives rise to interesting optical effects. The pitch of the helix depends on the mixture of molecules used to make the liquid crystal.

Chiral Nematic (Cholesteric) Phase: In a cholesteric phase the nematic molecules have chirality, i.e. they have a preferential twist with respect to one another. The cholesteric phase was named after the cholesterol molecule, where this structure was first observed!

Reference: http://soft-matter.seas.harvard.edu/index.php/Phase_transitions_in_liquid_crystals

Pressure Chemical can produce specific liquid crystal compounds as well as blends that maintain their color over an extended temperature range. These blend colors include blue, green, red, violet and orange which can be made to hold their color over a 10°C to 60°C range.

Pressure Chemical liquid crystals are produced in periodic production campaigns to fulfill custom orders of a number of frequently utilized products and blends. Contact us now to learn more about these Liquid Crystal products.