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New research reveals novel behavior characteristics of liquid crystals, fluids with aligned phases of constituent molecules. The formation of different phases during drying leads to dramatically different fluid movement and solid deposition. It also provides insight needed for the control of drying solutions of macromolecules that occur in many dyes and pharmaceutical formulations.
One researcher had been experimenting with Sunset Yellow, a dye that gives Doritos and orange soft drinks their bright colors, when he accidentally spilled some of the material. During drying, the Sunset Yellow concentration varied within the drop, and microscope images revealed the formation of different fluid phases, such as the isotropic liquid (random), liquid crystal nematic (aligned) and liquid crystal columnar (cylindrically packed) phases, that segregate to different regions of the drop.Image credit: Zoey Davidson, University of Pennsylvania
