Spectral sensitizing dyes

[Athiril]

Anything been done with anthocyanins?

[Photo Engineer]

These are very weak dyes and may have been used. IDK for sure. Anthrocyanines are also used but are weak and higher in molecular weight so you get less bang for the buck. Phthalocyanines or Merocyanines are often used. Look at Brooker's Merocyanine as an example. Leslie Brooker was the founder of the dye lab at EK and his work points directions for dye usage. Today, all dyes at EK are numbered using the Brooker system and so we have B-11774 and etc....

PE

[Athiril]

A thought occurred to me.. can we just recycle the dyes that get washed out of a commercial film in a pre-wash?

[Photo Engineer]

How do you separate the dyes? There are many there!

PE

[Kirk Keyes]

The rinse water could be extracted with organic solvent using a separatory funnel. Look up the EPA liquid-liquid extraction. Still sounds like a lot of work...

[Athiril]

How do you separate the dyes? There are many there!

PE

They wont be effective mixed?

[Photo Engineer]

The rinse water could be extracted with organic solvent using a separatory funnel. Look up the EPA liquid-liquid extraction. Still sounds like a lot of work...

Kirk;

Sensitizing dyes used currently are highly ionic!

Dan;

The mix is ok, but if you want red only, you have a problem just as an example. And, the dye mix would include acutance dyes and trimmer dyes among others.

PE

[Kirk Keyes]

Salt the dye out and adjust the pH when you do the extraction. That always helps push ionic compounds out of water and into solvent!

Then use a HPLC (High Pressure Liquid Chromatograph) machine to separate the compounds.

Only about $10,000 in equipment if you make it youself or buy a used one!

It could be done, if one really wanted too... but I bet you could buy the dyes cheaper by the time one teaches themself how to do it.

[Mustafa Umut Sarac]

If you search in open course ware of MIT , there are many videos on these separation processes. Each of of them told very detailed and available at Youtube also.

[holmburgers]

Ok, update to an old(ish) thread.

This dye, Erythrosine B (CAS: 54530) or Acid Red 51, is available here on eBay for chump change. This dye is in the Kodak list above.

I'm really interested in finding cheap sensitizing dyes for spectral sensitizing, and not necessarily because I am going to try to make a color-sensitive film tomorrow, but to put the possibilities forth so that anyone making emulsions might be inclined to experiment with this stuff down the road.

Sure they might not be the best or most efficient, but they will work, no?

Also, to make panchromatic dichromated gelatin for holograms they use methylene blue as a red sensitizer and Rhodamine G6 for blue/green. Do these dyes have any effect on silver-halides?