What are liquid crystals give an example and an application for the same?
For example, many proteins and cell membranes are liquid crystals. Other well-known examples of liquid crystals are solutions of soap and various related detergents, as well as the tobacco mosaic virus, and some clays.
What are the important properties of liquid crystals?
Liquid crystal materials generally have several common characteristics. Among these are a rod-like molecular structure, rigidness of the long axis, and strong dipoles and/or easily polarizable substituents.
What are the applications of liquid crystal in pharmaceutical industry?
Liquid crystal formulations have been used in cosmetics and pharmaceutical controlled release dosage forms. These formulations get enhanced penetration of biologically active materials like vitamin A) through the skin.
What do you understand by liquid crystals?
A liquid crystal is a state of matter between liquid and solid (a “mesophase”). They change shape like a fluid but have the molecular alignment characteristics of a solid crystal.
Is liquid crystal toxic?
Liquid crystals comprise of about 10–25 compounds (Zhuang et al., 2012) whereas other studies claim that their toxicity is minimal (Tsydenova and Bengtsson, 2011). However, some companies try to eliminate the use of chlorine in LCD manufacturing with the aim of gaining potential environmental benefits.
What is liquid crystal in physical pharmaceutics?
The liquid crystalline state combines properties of both liquid and solid state and are divided in two main types, i.e. thermotropic and lyotropic liquid crystals, depending on whether liquid crystalline state is reached either by increasing the temperature or by adding a solvent.
Which pharma drug exist as liquid crystal?
Introduction
| Drug Substances Forming LCs | Category | Type of Liquid Crystals |
|---|---|---|
| Diclofenac | NSAID | Lamellar, lyotropic LCs |
| Leukotriene | Anti-inflammatory | Thermotropic LCs |
| Cromolyn | Antiasthmatic | Cholesteric lyotropic LCs or smectic thermotropic LCs |
| Cyclosporine | Immunosuppresive | Smectic thermotropic LCs |
What are liquid crystals made of?
Many liquid crystals are simple polymeric organic compounds. We tend to think of polymers as flexible (polythenes etc.) so for liquid crystals the polymers have to incorporate a rigid section, either in the long polymer section (main chain liquid crystals) or attached to the polymer as a ‘side chain’.
What liquid crystals are used in LCD?
LCDs utilize either nematic or smectic liquid crystals. The molecules of nematic liquid crystals align themselves with their axes in parallel, as shown in the figure.
What is the difference between glasses and liquid crystal?
crystalline solids: molecules are ordered in a regular lattice; fluids: molecules are disordered and are not rigidly bound; glasses: molecules are disordered but are rigidly bound. It has a distinctly different structure with properties of both liquids and solids.
Is liquid crystal flammable?
They are known for their high temperature resistance, excellent mechanical properties, good solvent resistance and low water absorption compared to other heat-resistant polymers. They have good electrical insulation properties, low flammability and a low coefficient of thermal expansion.