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Panchromatic Emulsion

Hi Everyone,but especialy Ron
www.holowold.com/holo/paper.html
The above refference is to a paper by Blyth,et al. It mentions 2 dyes for green and red sensitzation.
The rest of the paper is about making a holographic plate by diffusion. I assume that the silver/halide grains are so very tiny that the plate would be worthless to anything but holography. But would these dyes be apropriate for spectral sensitization of emulsions? One of the dyes is easy to get. But the other is on the Sigma-Aldrich "Don`t sell to individuals' list.
Cheers,
Bill
 
Bill - your link is bjorken, there's a typo - people should try this one instead:
Dead Link Removed
 
Well, for the list Ron posted, I see Neocyanine, Kryptocyanine, Pinacyanol, Orthochrome-T, Ethyl Red, Piniflavole, Eosin, and Eyrthrosine as ones that are listed in the IR book I mentioned above. So it looks like a lot of those dyes have found use that's lasted for over 100 years.

I also noticed 5-(p-Dimethylbenzylidene) rhodamine. That name looks really familiar, so I looked and checked CAS numbers, and it's also called 5-(p-Dimethylaminobenzylidene) rhodanine (notice the difference in the "n" and "m" in rhodanine/rhodamine). That an indicator that I use in the lab to titrate solutions of - get this - silver nitrate! The indicator is yellow in acetone solution, and when it reached the endpoint with silver nitrate, the solution becomes salmon color (under high pH of the titration).

It's pretty cheap - $60/10g
http://www.fishersci.com/wps/portal...methylaminobenzylidene+rhodanine+&catCode=ALL

Another, Congo Red - common indicator - $35/5g, or if indicator grade works, really cheap - $63/500g.
http://www.fishersci.com/wps/portal...ut=true&brCategoryId=null&hlpi=y&fromSearch=Y

Ethyl Red Iodide - $70/5g,
http://www.fishersci.com/wps/portal...ut=true&brCategoryId=null&hlpi=y&fromSearch=Y

Neocyanine - $83/1g
http://www.fishersci.com/wps/portal...alogCode=RE_SC&keyWord=neocyanine&catCode=ALL

Kryptocyanine - $40/1g
http://www.fishersci.com/wps/portal...ut=true&brCategoryId=null&hlpi=y&fromSearch=Y

1,1'-Diethyl-2,2'-cyanine Iodide - 500mg/$65.
http://www.fishersci.com/wps/portal...ut=true&brCategoryId=null&hlpi=y&fromSearch=Y
 
Hi Kirk,
My guss is that Fisher will not sell all of these dyes to just anyone. Aldrich would not sell the Diethyl Cyanine Iodide to me,
no mater how well I explained to them what I intended to do with it. Mabe the Formulary could buy them, then resell to us at twice the price.
Bill
P.S. Sor ry about the ttypo. Ido t.hat al ot. No Spelche k here.
 
4,5,4',5'-Dibenzo-3,3'-diethyl-9-methylthiocarbocyanine bromide

Kirk Keyes said:
I also noticed 5-(p-Dimethylbenzylidene) rhodamine. That name looks really familiar... an indicator that I use in the lab to titrate solutions of - get this - silver nitrate!
Click to expand...

Kirk;

You might want to look on you shelf for "Stains All" too!

It is related to the dyes Ron mentioned- but off hand, I am not sure how effective it is... anyway it should be readily available to you!

Ray
 
Ray - I've never heard of "Stains All" before - I ain't no stinkin biochemist - but it looks like a good candidate. And the price is similar to the others I've listed.
 
wildbillbugman said:
My guss is that Fisher will not sell all of these dyes to just anyone. Aldrich would not sell the Diethyl Cyanine Iodide to me,
no mater how well I explained to them what I intended to do with it.
Click to expand...

Bill - try to find a local chemistry supply house that you can go to and talk with them directly. Are there any that you dealt with from your professional life? If you let them know you worked in the technical field you did, they my be a bit more compliant. I have a feeling that works for me with my local chem store - I'm been buying from them for 20 years, both professionally and for personal stuff.

They may be able to resell to you directly, and perhaps at a little less than having it shipped from Montana...
 
dwross said:
Here's some info that I hope will be useful, or at least entertaining.

http://www.thelightfarm.com/Map/WhatsNew/whatsnew.htm
Click to expand...

Denise - nice python (?) app, like google books. But they smaller size is unreadable/usable, at least on my laptop, and the large version does not seem to load.

The larger page shows this where the image should be:
<img src="/Map/Books/PhotoEmulsion/Contents1.jpg" "/>

Is there one too many quote marks at the end of the line?

Kirk
 
With all the "meth labs" in my neck of these woods, you'd think that I could score some Diethyl cyanine iodide! I think I'll go over to "The Park" around 1:00AM and ask around.
Been nice knowing you all,
Bill
 
dwross said:
Thanks for the beta test, Kirk! There was a typo in the code.
Click to expand...

Denise - wow - that was quick. Maybe take another look. The larger pages are the same size as the smaller ones - about 1 inch high and about the same wide. But it does show an image for the larger page now.
 
wildbillbugman said:
Hi Everyone,but especialy Ron
www.holowold.com/holo/paper.html
The above refference is to a paper by Blyth,et al. It mentions 2 dyes for green and red sensitzation.
Click to expand...

See also http://cabd0.tripod.com/holograms/id3.html
And here is a practical commercial applications of it: www.smartholograms.com/

wildbillbugman said:
The rest of the paper is about making a holographic plate by diffusion. I assume that the silver/halide grains are so very tiny that the plate would be worthless to anything but holography.
Click to expand...

That's the billion Dollar question! I don't really know the answer but my guess is this method might be worth a try in the photographic area also. I assume forming larger grains won't be rocket science...
Personally, I am involved with holography, so I am far from being particularly knowledgeable about photographic emulsions.
These bathing/sensitizing methods have been known for quite a while now, actually since the early days of photography. They're often complicated and not easy to do in a consistent repeatable manner. Obviously, you can't use these methods to produce photographic emulsions on a large scale.That said, they may still be of value to test a few things in a quick way. Moreover, they don't require sophisticated lab technology, no pAg measurements, no double jets etc.

The beauty of Jeff Blyth's method is that it provides an incredible speed increase – despite the lack of sulfur/gold sensitization. The big speed enhancement stems from ascorbic acid reduction sensitization, done simultaneously with spectral sensitization. That's pretty amazing. Blyth's method allows for speed levels almost on par with the Agfa materials (until the late 90s Agfa used to be the market leader for holographic emulsions) – at a grain size 50% smaller than those commercial emulsions!
 
I assume forming larger grains won't be rocket science..


Hi,
Jeff uses difussion to intoduce the silver nitrate into the gelain coating. Unless I am way off, the only way to vary grain sise would be to coat a pre-existing, larger grain silver halide emulsion on the glass, then then spectraly sensitize the coating with dyes + ascorbic acid.
Do you have a source for the dyes Jeff used ?
Bill
 


Yes, with the Diffusion method you can also spectrally sensitize a unsensitized AgX emulsion subsequently. In contrast to former bathing methods, this one uses a halide/dye/ascorbate solution for sensitization. I think it's this combination that does the spectral sensitization more efficiently than previous attempts.

As for forming larger grains with the Diffusion method, you could well do that by adapting the bath concentration. E.g. increasing the amount of halide most certainly does increase grain size. Similarly, longer bathing periods in the halide bath will equally favor the production of larger grains. Furthermore, you might increase the temperature of these baths and the drying section etc.
 
wildbillbugman said:
Dear Hologram,
I wonder, why the lithium bromide and not potasium or ammonium bromide?
Bill
Click to expand...

According to Jeff Blyth lithium bromide does form smaller grains than potassium bromide (I am not sure about ammonium bromide). Furthermore, LiBr has better solubility in alcohols – that may be important when using certain sensitizing dyes.
 
Just a note for y'all.

Making an emulsion in-situ on a plate or film support yields a very slow emulsion due to the lack of proper solution emulsification steps. So, although it can be done, the results are slow emulsions.

Spectrally sensitizing them on plates has also been very difficult due to uniformity problems and other technical details. It can be done, but not with the efficiency that is achieved by doing it in the solution of pre-melt.

For those that have counter arguments, all I can say is that I have access to those who have done the above both ways. This was a summary of their comments.

PE
 
Why is there a problem with purchasing sensitizing dyes? Is there some use that wI don't know about that makes them a 'banned' substance?

Joe
 
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