Iodine
Iodine is a non-metallic chemical element that belongs to the halogen group in the periodic table. It is known for its distinctive deep violet color in its vapor form and its shiny, dark-gray appearance in solid form. Iodine plays a critical role in various biological, medical, and industrial applications due to its unique chemical properties, such as high reactivity and the ability to form compounds with many elements.
One of the most important functions of iodine is in human health, where it is an essential trace element required for the synthesis of thyroid hormones. These hormones—thyroxine (T4) and triiodothyronine (T3)—are crucial for regulating metabolism, growth, and development. A deficiency in iodine can lead to conditions such as goiter, hypothyroidism, and developmental disorders. To combat iodine deficiency, many countries implement iodine fortification programs, such as the addition of iodine to table salt (iodized salt).
In the medical field, iodine and its compounds have a long history of use. Iodine solutions are widely used as antiseptics and disinfectants. For example, povidone-iodine is commonly applied to skin before surgical procedures to reduce the risk of infection. Iodine is also used as a contrast agent in radiographic imaging procedures, particularly in X-rays and CT scans, due to its high atomic number, which allows it to absorb radiation effectively and enhance image contrast.
Iodine’s role extends into various industrial applications. It is used in the manufacture of pharmaceuticals, dyes, inks, and catalysts. Iodine compounds serve as intermediates in chemical synthesis and are involved in the production of acetic acid, nylon, and other specialty chemicals. In the field of electronics, iodine is utilized in the production of polarizing films for liquid crystal displays (LCDs). It also plays a role in the vulcanization of rubber and the stabilization of polymers.