Definition of Fluorescent Brighteners
Common names for fluorescent brighteners include white dye, optical brighteners, and simple brighteners. It is an organic molecule without color that, when exposed to ultraviolet light, can generate fluorescence. Its brightening effect is based on the optically complementary color theory, which allows yellowing materials that have been treated with fluorescent brighteners to absorb UV light outside of the visible range and convert it into visible light that is blue or yellow.
Fluorescent brighteners contain organic substances that can enhance the whiteness of fabrics and paper. The brightness of the treated fabric also rises, making it whiter, as a result of a portion of UV radiation turning into visible light to be reflected out with an enhanced overall reflection quantity compared to non-processing cloth after the whitening process. Additionally, it can make colorful materials more vivid. Unlike chemical bleaching, fluorescent brightener preserves the color and intensity of the fabric. But if a fabric or piece of paper has a darker background, direct brightening without bleaching won't produce satisfactory results.
Application
Fluorescent brighteners are primarily used in the textile sector to increase shine and improve the whiteness of various natural and synthetic materials. Its use for paper, plastics, leather, soap, synthetic detergent, and other daily necessities has expanded quickly in recent years.
Laundry detergents frequently contain brighteners to provide the appearance of cleaner clothing. Consumers dislike how normally cleaned laundry appears yellowish. Fluorescent brighteners have taken the position of bluing, which was previously used to achieve the same result.
Many papers, especially high-brightness papers, include brighteners, giving them a brightly fluorescent look when exposed to UV light. Since banknote paper does not include optical brighteners, a frequent technique for identifying fake currency is to look for fluorescence.
Cosmetics have also used fluorescent brighteners. One use is in shampoos and conditioners for grey or blonde hair, where the brightener can improve the hair's sparkle and luminosity while also removing dull, yellowish discoloration without making the hair darker. The optical brightener microspheres in some cutting-edge face and eye powders illuminate shadowy or dark parts of the skin.