I wonder if this is related to yellowing plastics? Retr0brighting with peroxide and sunbriting (putting yellowed plastics out in the sun) are already common treatments in the retro community. I’ll have to give it a try on some of my old hardware
> The blue light reduced the yellow stain substantially more than hydrogen peroxide or UV exposure. In fact, UV exposure generated some new yellow-colored compounds.
Here's the key piece of information for me, it's not just light doing this or higher energy blue being close enough to UV to get things done, the blue light tested outperforms UV at destroying some of these yellowing compounds.
It would be nice in followup research to see Figure S8 [1] with an additional dimension for irradiation with various frequencies, not just 445 nm.
It looks like Amazon has some "therapy bulbs"[2] close to the correct frequency for $30, now I wish I hadn't thrown away some of those old yellowed pillows so I could do some science.
There is probably some math to do about the availability of free radicals from bleach versus a set period of sunlight at a certain time of year, in a certain part of the world.
I tried drying linens and clothes outside the first time I moved from an apartment (with strict controls on what can and cannot be seen on the balcony) to a single family home. I quickly stopped because there was so much dust that would accumulate on your freshly washed clothes in the time they were hung outside. That's not to mention bird poop or feral cats deciding to do some stretching on your sheets.
1.25 watt/centimeter² ~= 853.75 lumen/centimeter², eg. not a terribly exotic brightness assuming you are ok treating a small area at a time. One of those small LED light panels would probably be in the right ballpark if you positioned it very close to the target.
Let's model a shirt with a cylinder, and let's flat it in to rectangle. Some 50 cm x 100 cm could be OK for a quick estimate. It's 5000 cm, so 6.25 kW if we want to make it work fast. The OP wrote about 10 minutes. Let's relax it to a little more than 1 kW not to be inconvenient to other home activities and we get a 1 hour time. Probably that will help with heat management too.
But 50x100 is not particularly large (think of bed linen) and yet it could take a lot of space in a house. Maybe some small area handheld device that one can apply to stains and leave it there until it turns off with a timer?
What intensity is “high-intensity?” The article doesn’t give a number. Is this something that can be done with a few bright LEDs or do you need a specialized lighting array?
There's even special formulas of hydrogen peroxide, arrowroot, and oxyclean, with raging debates on the proper ratios, how long to keep them in the sun, etc:
I feel like the removal of yellowing from things like Apple II computers known colloquially as 'retrobriting' as showing in your video is more the use of peroxide compounds which are not used in the article.
"The blue light reduced the yellow stain substantially more than hydrogen peroxide or UV exposure. In fact, UV exposure generated some new yellow-colored compounds."
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[ 2.4 ms ] story [ 83.4 ms ] threadHere's the key piece of information for me, it's not just light doing this or higher energy blue being close enough to UV to get things done, the blue light tested outperforms UV at destroying some of these yellowing compounds.
It would be nice in followup research to see Figure S8 [1] with an additional dimension for irradiation with various frequencies, not just 445 nm.
It looks like Amazon has some "therapy bulbs"[2] close to the correct frequency for $30, now I wish I hadn't thrown away some of those old yellowed pillows so I could do some science.
1. https://pubs.acs.org/doi/10.1021/acssuschemeng.5c03907
2. https://www.amazon.com/Aumtrly-Light-Therapy-Irradiance-Cove...
(Also, the additional energy/heat will help drying, so you pay for the hardware but the energy consumption for the light is totally free.)
I dry my linens outside (I'm not American), and no chemical bleach beats the effectiveness of the sun turning oxygen and water to peroxide.
https://en.wikipedia.org/wiki/Flemish_Market_and_Washing_Pla...
Though I think this is possibly a depiction of a step in linen production, rather than the maintenance of used linen.
But anyway yeah it used to be a normal part of life people were used to seeing.
https://en.wikipedia.org/wiki/Bleachfield
> 445 nm; 1.25 W/cm2
But 50x100 is not particularly large (think of bed linen) and yet it could take a lot of space in a house. Maybe some small area handheld device that one can apply to stains and leave it there until it turns off with a timer?
https://youtu.be/aFGS9xaaO_M
There's even special formulas of hydrogen peroxide, arrowroot, and oxyclean, with raging debates on the proper ratios, how long to keep them in the sun, etc:
https://www.callapple.org/vintage-apple-computers/apple-ii/s...
"The blue light reduced the yellow stain substantially more than hydrogen peroxide or UV exposure. In fact, UV exposure generated some new yellow-colored compounds."