Quantcast
Polarization Microscope Image of Liquid Crystals Image 12
1388 of 3588

Polarization Microscope Image of Liquid Crystals (Image 12)

November 2, 2010
Mathematically created model of smectic layers in three neighboring focal, conic domains. [Image 12 of 12 related images. Back to Image 1.]

More about this Image In smectic A, rod-like, elongated molecules are arranged parallel to each other, forming layers of monomolecular length, shown as surfaces in the model. The layers are stacked on top of each other and are flexible. When the smectic layers bend, they tend to preserve their equidistance, as it is fixed by the molecular length. The restriction of constant layer thickness leads to a peculiar geometry of deformations, so-called focal conic domains, in which the smectic layers are wrapped around line defects in the form of ellipses and hyperbolae. The smectic order was discovered and correctly identified from an optical observation of textures similar to the one shown here, on the basis of geometrical properties of ellipses and hyperbolae, before X-ray techniques were invented. This mathematically created model of smectic layers in three neighboring, focal conic domains explains the texture seen in Polarization Microscope Image of Liquid Crystals (Image 11).

This image was created by Oleg D. Lavrentovich, director and professor of chemical physics at the Liquid Crystal Institute & Chemical Physics Program at Kent State University. The complex, 3-D molecular arrangements in liquid crystals and other soft materials reflect a rich variety of physical mechanisms that represent the focus of Lavrentovich's research.

Recent research in Lavrentovich's lab (supported by National Science Foundation grants DMR 05-04515, DMR 07-10544 and DMR 09-06751), explore what the physical mechanisms are behind the complex, 3-D molecular architectures; what controls the molecular order in space; and what controls the time dynamics of this order. The goal is to learn how to construct self-assembled complex materials with unique structural, electric and optical properties. Liquid crystals have already been a technological revolution through their liquid crystal displays, and much more is on the horizon of current knowledge if we were to explore and utilize more complex molecular arrangements than those in these displays. (Date of Image: exact date unknown)


comments powered by Disqus