Sciencemadness Discussion Board

In search of fading pigments

okitew - 19-4-2019 at 00:19

I'm looking for a pigment that will permanently disappear upon exposure to light/UV, say after a few hours.

Ideally, this pigment will be dark initially, cheap, and nontoxic. Any ideas?

The best option I've found so far is chlorophyll, but I need something darker that will fade more quickly.

Mr. Rogers - 21-4-2019 at 13:42

Nope! I never signed that contract!! See...

okitew - 23-4-2019 at 03:49

Quote: Originally posted by Mr. Rogers  
Nope! I never signed that contract!! See...

lol.... Nice.

But no, I actually need it for an obscure photography application.

Actually, I'll go so far as to say that it would be key to a new photographic process, and that I'd share that process with whoever submitted a workable solution, and if they think it's worth patenting, I'll support submitting it as a joint patent.

Disappearing ink won't work afaik because it must fade from light exposure only while dry.

[Edited on 23-4-2019 by okitew]

phlogiston - 23-4-2019 at 05:38

rhodopsin
methylene blue

You can also combine a radical-generating photoiniatior (eg benzoylperoxide, hydrogen peroxide, azobisisobutyronitrile, titanium dioxide) with an organic dye sensitive to radicals.

You may find this paper interesting:

Photoassisted bleaching of dyes utilizing TiO2 and visible light
Epling GA et al (2002) Chemosphere 46:561-570

http://nathan.instras.com/documentDB/paper-253.pdf

okitew - 24-4-2019 at 11:05

Quote:
Quote: Originally posted by phlogiston  

methylene blue

Why didn't I think of that? What can't that stuff do?
Quote: Originally posted by phlogiston  
You can also combine a radical-generating photoiniatior (eg benzoylperoxide, hydrogen peroxide, azobisisobutyronitrile, titanium dioxide) with an organic dye sensitive to radicals.

You may find this paper interesting:

Photoassisted bleaching of dyes utilizing TiO2 and visible light
Epling GA et al (2002) Chemosphere 46:561-570

http://nathan.instras.com/documentDB/paper-253.pdf

This is useful. Thanks!