'A color that never fades—without dyes'... Korea University develops vivid nanopigments, a key to displays

[Financial News] Researchers in South Korea have developed a vivid pigment technology whose colors do not fade over time, using only the principle of light reflection and no chemical dyes. The technology is expected to find applications in a range of industries, including display color filters and next-generation coatings.
A research team led by Professors Lee Seung-woo and Cho Yong-deok of Korea University’s KU-KIST Graduate School of Convergence and Department of Convergence Energy Engineering announced on the 5th that it had developed “structural-color nanopigments” by combining gold and selenium to dramatically enhance color vividness.
Conventional dyes change color when their molecules break down after prolonged exposure to light. By contrast, “structural color,” produced when microscopic structures—like those in peacock feathers—reflect specific light, has the advantage of retaining its color for a long time. However, existing technologies have been limited in their ability to render specific colors vividly.
The research team addressed this problem by creating a double-layered structure in which gold nanoparticles are encased in a selenium shell. The structure was designed so that the two materials interfere with each other when they respond to light, producing the desired colors with greater purity and vividness. The quality factor (Q-factor), a measure of color vividness, also improved substantially compared with existing pigments.
The research team successfully used the pigment to make water-based ink and paint Vincent van Gogh’s masterpiece The Starry Night. It also demonstrated the pigment’s potential as an optical material by mixing it into UV-curable resin to produce color filters used in smartphone and TV screens.
Professor Lee Seung-woo said, “This research has opened up a new way to preserve vivid, varied colors for a long time without dyes,” adding, “It will be used in a range of industries, including printing inks, automotive coatings and optical films.”
The findings were published online in Advanced Materials, an international journal in the field of materials science. 

[email protected] Kim Man-gi Reporter