What is a chiral dopant?

What is a chiral dopant?

A chiral dopant is known to induce a molecular rearrangement and a subsequent helical twisting in the nematic LC host, affording a cholesteric liquid crystal (CLC).

What is the chiral nematic phase?

The cholesteric (or chiral nematic) liquid crystal phase is typically composed of nematic mesogenic molecules containing a chiral center which produces intermolecular forces that favor alignment between molecules at a slight angle to one another.

What is chiral liquid?

Chiral liquid crystal molecules have the potential to form chiral mesophases. In fact, it was quite a surprise to discover that DNA (which is highly chiral) could form achiral line hexatic phases. (1,2) Normally, chiral molecules lead to chiral phases, where the director twists as it progresses through the phase.

What kind of liquid crystals consist of parallel molecules in layers?

Cholesteric liquid crystals form in thin layers, each one molecule thick; and within each layer the molecules are arranged with their long axes in the plane of the layer and parallel to each other, as a two-dimensional nematic structure.

What is nematic and smectic?

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 a layered molecular structure, whereas cholesteric liquid crystals have molecules in a twisted and chiral arrangement.

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 is liquid crystal and its types?

There are three types of thermotropic liquid crystals: discotic, conic (bowlic), and rod-shaped molecules. Discotics are disc-like molecules consisting of a flat core of adjacent aromatic rings, whereas the core in a conic LC is not flat, but is shaped like a rice bowl (a three-dimensional object).

What is a smectic phase?

physics. Share. Liquid crystal arrangements. In nematic arrangements the crystals are randomly positioned with all their long axes pointing in essentially the same direction, given by a vector known as the director.