Dr. Nimmy John V
Its has been a decade that LCD’s are being part of our life style, almost all of the electronic gadgets hold hands together with this wonderful display technology. The core of all these devices is a mysterious liquid, which is known as liquid crystal. As the name apprises, It’s a blend of solid and liquid or in other words it can be expounded as a solid that can flow. The serendipitous discovery of liquid crystal happened during the year 1888, when an Australian botanist named Friedrich Reinitzer, observed an abnormal behavior for a compound named cholesteryl benzoate. He was able to observe two melting point for this compound, a cloudy liquid at 145 degree celsius, and a clear liquid at 179 degree celsius. It was captivating, and he contacted the German physicict named Otto Lehman, to investigate more about this magic liquid. Lehman’s microscopic observation was astonishing and controversial to the scientific world then. Later on the properties of liquid crystal were being explored terribly by the scientific world, which made its walk from the research labs to the electronic markets.
Liquid crystals are rod shaped molecules which are dipolar in nature (having positive and negative part), they have an orderly arrangement similar to that of a crystal. When an electric field is applied the rod shaped molecules will align along the direction of the field. Liquid crystal can also act as a light valve which can guide the light that passes through. These properties of liquid crystal are being exploited in the electronic industry, LCD- liquid crystal display. Liquid crystals has made their mark in switchable windows or smart glass applications, which are available in markets. This glass is constructed by trapping liquid crystals as micro droplets inside a polymer matrix. The molecules are randomly arranged inside these micro droplets and scatters the light to become opaque. When a field is applied liquid crystal molecules will align along the direction of the field and light passes through, making it transparent. Electronic industries use the thermotropic liquid crystals, which exhibits liquid crystal property only at a particular range of temperature. Soap water which we use in our everyday life is also a liquid crystal, which is categorized as lyotropic liquid crystals. These lyotropic are formed by mixing an amphiphilic molecule (having polar and non-polar part) with a solvent, under appropriate condition. There are a wide range of application for liquid crystal other than use in electronic gadgets. One among them is thermochromic application, thermochromic liquid crystal exhibit a specific color at a particular temperature. This type of liquid crystals is being used to develop thermometers and cancer detectors.
