What is smectic C phase?
The smectic-C phase and those listed below it have molecules tilted with respect to the layers. Continuous in-plane rotational symmetry, present within smectic-A layers, is broken in the hexatic-B phase, but a proliferation of dislocations maintains continuous translational symmetry within its layers.
What is difference between nematic vs smectic phase?
The key difference between nematic, smectic, and cholesteric liquid crystals is that nematic liquid crystals have no ordered structure of molecules, and smectic liquid crystals have layered molecular structure, whereas cholesteric liquid crystals have the molecules in a twisted and chiral arrangement.
What are cholesteric phases?
[kə′les·tə·rik ‚fāz] (physical chemistry) A form of the nematic phase of a liquid crystal in which the molecules are spiral.
What is smectic liquid?
Smectic liquid crystals consist of flat layers of cigar-shaped molecules with their long axes oriented perpendicularly to the plane of the layer.
What is smectic liquid crystal with example?
Summary of Phases and Order
| untilted | tilted |
|---|---|
| Smectic-A | Smectic-C layering breaks translational symmetry; in smectic-C molecules are tilted |
| Hexatic SBSI SK | Like the smectic A they are stacks of liquid layers but the molecules tend to be positioned along a hexagonal lattice within each plane |
What is a nematic phase?
The simplest liquid crystal phase is called the nematic phase (N). It is characterized by a high degree of long range orientational order but no translational order. Molecules in a nematic phase spontaneously order with their (for calamitic molecules) long axes roughly parallel.
What are the three different phases of liquid crystals?
Liquid crystals can be divided into thermotropic, lyotropic and metallotropic phases. Thermotropic and lyotropic liquid crystals consist mostly of organic molecules, although a few minerals are also known.
What is the chiral nematic phase?
is called the chiral pitch and is generally of the order of hundreds of nanometres, the wavelength of visible light. A non-chiral nematic phase can be thought of as a chiral nematic with an infinite pitch.
What is the main difference between liquids and liquid crystals?
Liquids are nearly incompressible fluids that have the ability to flow. The key difference between liquid crystal solid and liquid is that liquid crystals have properties of conventional liquids, and solid crystals and solids have tightly bound atoms or molecules, whereas liquids have loosely bound atoms or molecules.
What is crystalline vs crystal?
“Crystal” is a noun that refers to a rock containing atoms structured in a repeating manner that extend in all spatial dimensions. 2. “Crystalline” is an adjective that describes rocks possessing properties or qualities of crystals.
What happens between G1 and S phase of mitosis?
Between G1 and S phase, the cell decides if it wants to grow. Some cells that do not divide include bone cells and blood cells (they do not undergo mitosis). These cells do not go through S or G2. They stop at G1 or G0.
What happens during the mitotic phase?
The mitotic phase is the short period of the cell cycle in which changes from short to much longer interphases for the preparation for cell division.
What happens during prometaphase of mitosis?
Typically, the nucleus genetic material is in chromatin; the chromatin fibers become coiled at the onset of this phase, resulting to discrete chromosomes. 3. Prometaphase: This is one of the phases of mitosis that is sometimes referred to as part of the end of prophase and an early stage of metaphase.
What does lag type mitosis indicate?
For example, lag-type mitosis (non-attached condensed chromatin in the area of the mitotic figure) indicates high risk human papillomavirus infection -related Cervical cancer. Normal and atypical forms of mitosis in cancer cells.