Sweat and food stains can ruin your favorite clothes. But bleaching agents such as hydrogen peroxide or dry-cleaning solvents that remove stains aren't options for all fabrics, especially delicate ones. Now, researchers in ACS Sustainable Chemistry & Engineering report a simple way to remove yellow stains using a high-intensity blue LED light. They demonstrate the method's effectiveness at removing stains from orange juice, tomato juice and sweat-like substances on multiple fabrics, including silk.
    • XeroxCool@lemmy.worldEnglish
      2·
      4 days ago

      Good question and I’d like to know. From the linked paper in the linked article,

      (445 nm; 1.25 W/cm2)

      Sunlight is 1000W/m2, which I believe to be the sum of all wavelengths. 1m2 is 10,000cm2, so their light would have a total energy of 12,500W/m2 if I did my metric right. I’ve wandered into a field I don’t have all the info were.

      rerouting

      Let me try running around in Watts. I picked out a royal blue, 450-465nm Cree XE-G LED from LEDSupply. At max 3,000mA, forward voltage is 3.7v. That’s 11.1W of energy consumed. I’m not sure how to find an exact efficiency ratio, but Wikipedia puts it around 30% light, 70% heat in the page on “thermal management of high power LEDs). For reference, incandescent is about 10/90%. From there, I’ll round down for optics and call it 3w total light. That gives you the light output density for 2.4cm2, or an 18mm circle, or like a 3/4” circle, or a little less than a US penny. All with a fist-sized heatsink and a fan. Per LED.

      I think.