EVERYDAY SCIENCE

Detailed explanation-1: -Optical brighteners are synthetic chemicals which are added to the liquid and detergent powder to make clothing appear whiter, brighter and cleaner. They are the modern day replacements for the decades old method of bluing adding small amounts of blue dye to fabric to make it appear whiter.

Detailed explanation-2: -Laundry Cleaning of Textiles Also called optical brighteners, these are fluorescent materials that can absorb UV light and emit visible (blue–violet) light [55]. Thus, once deposited on fabrics, they enhance the whiteness or brightness appearance of white or lightly coloured fabrics.

Detailed explanation-3: -Optical brighteners also called fluorescent whitening agents (FWAs) are hydrophilic water-soluble compounds used in laundry detergents. They are mainly anionic diamino stilbene (DAS) or distyryl biphenyl (DSBP) derivatives displaying a low aquatic toxicity.

Detailed explanation-4: -4, 4′-diamino-2, 2′-stilbenedisulfonic acid is a popular optical brightener. 4, 4’-bis(benzoxazolyl)-cis-stilbene and 2, 5-bis(benzoxazol-2-yl)thiophene (shown here) are also intensely fluorescent and used as optical brighteners, e.g., in laundry detergents.