damont ([personal profile] damont) wrote2006-08-31 02:30 pm

I'd like to see these!

The other day I was out shopping. Right now it's Back To School Sale time, so things like crayons and colored pencils and markers are all on sale. I picked up three packages of fine line Crayola markers for Pennsic Heralds Point, which cost a total of two bucks. But while I was there, I looked at the colors offered in the "Bright Colors" collection. Among the offerings are "Infra Red" and "Ultra Violet".

All marketing hype, of course. But the geek in me wants to see Crayola sell markers that are *truly* colored infrared and ultraviolet. *Those* would be cool to have.

[identity profile] 3fgburner.livejournal.com 2006-08-31 07:34 pm (UTC)(link)
From the Chirurgeons' list - phosphate detergents are UV colored :-).

[identity profile] sskipstress.livejournal.com 2006-08-31 07:56 pm (UTC)(link)
If by "UV colored" you mean "absorbs light in the UV region" any detergent that contains optical brighteners will do that, whether or not they contain phosphates. And then They'll re-emit the absorbed energy in the visible light spectrum. Under black light, they fluoresce. In college I painted the hallway in my dorm with liquid tide and replaced the fluorescent tubes with black lights for a party.

Phosphate is used for softening water, binding with the metallic ions like Fe and Ca in wash water so the surfactants in the detergent don't bind with them before binding with the soil particles on the dirty laundry.

When you mix phosphates which increase the cleaning ability of the detergent with optical brighteners which absorb UV light and re-emit it as visible light in the blue region of the spectrum, whites get whiter, brights get brighter. At least in America. I've heard that in China a yellowish white is considered whiter than a bluish white.

It's so nice when I get to put what I learned in college to use :)

[identity profile] 3fgburner.livejournal.com 2006-08-31 08:01 pm (UTC)(link)
Thanks.
"To leave school, is to leave life"
-- an alien in Alan Dean Foster's "Quozl"

[identity profile] dr-zrfq.livejournal.com 2006-09-01 01:39 pm (UTC)(link)
Thanks!

Now all I must do is convince Crayola to make a marker with no color except that... and likewise a marker whose dyes only absorb IR.

[identity profile] sskipstress.livejournal.com 2006-09-01 02:34 pm (UTC)(link)
It's funny, I learned a lot about UV radiation, but very little about IR. You could probably do colorless and IR-radiating by using 2 colorless chemicals that create an exothermic reaction.