MUMBAI, India, Nov. 2 -- Intellectual Property India has published a patent application (202641127346 A) filed by National Institute Of Technology Warangal on October 26, 2026, for A Process For Controlled Atmospheric Fabrication Of Activator-Doped Rare-Earth-Free Long- Afterglow Powder.
Inventors include Kak Durga Prasad; and Haranath Divi.
The application for the patent was published on October 30, 2026, under issue no. 44/2026.
Abstract: TITLE: A PROCESS FOR CONTROLLED ATMOSPHERIC FABRICATION OF ACTIVATOR-DOPED RARE-EARTH-FREE LONG-AFTERGLOW POWDER The present invention relates to a process for preparing a rare-earth-free long-afterglow luminescent powder. The process comprises zinc sulphide (ZnS) as a host material, cupric chloride as an activator, a co-activator comprising aluminum, gallium, barium, magnesium, indium, chlorine, fluorine, bromine and iodine, de-ionized water, a refractory heat-treatment container and a controlled gaseous atmosphere. Approximately 1000 g of 99.99% purity zinc sulphide is thoroughly blended with 156 mg of cupric chloride and 500 mg of co-activator, followed by drying at approximately 80°C. The dried blended material is introduced into the refractory heat-treatment container and treated at 600-1300°C for 30 minutes to 3 hours through the controlled gaseous atmosphere to obtain treated material. The treated material is washed with hot de-ionized water, ground, sieved and dried at 60°C to obtain the luminescent powder having a particle size of 5-70 µm. The controlled gaseous atmosphere comprises a group VIA-containing gas and may further comprise a group VIIA-containing gas in a volume ratio of 1:0.1 to 1:1. The resulting powder is excitable through radiation within 200-550 nm and exhibits long-afterglow luminescence.
Disclaimer: Curated by HT Syndication.
