Silver halide sensitivityy enhancer

Holography related topics.
walschuler
Posts: 12
Joined: Sat Jan 01, 2011 9:38 pm
Location: San Francisco, Ca. USA

Silver halide sensitivityy enhancer

Post by walschuler » Sun Sep 15, 2019 1:49 am

I recently published a brief article on the hypersensitization of silver halide emulsions using a formate pre-soak., which I first mentioned in the Forum more than a decade ago. Took me all this time to try it out.

See: https://www.spiedigitallibrary.org/conf ... 6668.short


19 February 2018
Formate as a sensitivity enhancer of holographic emulsions
in SPIE Proceedings
by William Alschuler

The gain in speed is either 5xs or 10xs, depending on post-exposure processing, with no loss of resolution or diffraction efficiency.

Martin
Posts: 95
Joined: Sat Apr 04, 2015 2:36 am

Re: Silver halide sensitivityy enhancer

Post by Martin » Mon Sep 16, 2019 6:17 am

walschuler wrote:
Sun Sep 15, 2019 1:49 am
I recently published a brief article on the hypersensitization of silver halide emulsions using a formate pre-soak., which I first mentioned in the Forum more than a decade ago. Took me all this time to try it out.

See: https://www.spiedigitallibrary.org/conf ... 6668.short


19 February 2018
Formate as a sensitivity enhancer of holographic emulsions
in SPIE Proceedings
by William Alschuler

The gain in speed is either 5xs or 10xs, depending on post-exposure processing, with no loss of resolution or diffraction efficiency.

That sounds very impressive!

I wonder if the formate treatment works with any holographic AgX emulsion.

Grayham
Posts: 49
Joined: Wed Feb 11, 2015 12:56 pm
Location: Hampshire, UK

Re: Silver halide sensitivityy enhancer

Post by Grayham » Thu Sep 19, 2019 2:11 am

Hi,

Do you have to sign up to this site to read the article?

Grayham

jrburns47
Posts: 115
Joined: Mon Sep 14, 2015 2:48 pm
Location: Oyster Bay, NY

Re: Silver halide sensitivityy enhancer

Post by jrburns47 » Thu Sep 19, 2019 11:45 am

Be a member of SPIE and/or buy a digital library subscription - aka paywall...

Sergio
Posts: 100
Joined: Tue Jan 20, 2015 12:25 pm

Re: Silver halide sensitivityy enhancer

Post by Sergio » Thu Sep 19, 2019 1:20 pm

Grayham wrote:
Thu Sep 19, 2019 2:11 am
Hi,

Do you have to sign up to this site to read the article?

Grayham
For me would be interesting to use with pulsed laser masters but I will try to convince my Lab.

Grayham, I can send you my copy, please PM me.

Grayham
Posts: 49
Joined: Wed Feb 11, 2015 12:56 pm
Location: Hampshire, UK

Re: Silver halide sensitivityy enhancer

Post by Grayham » Sun Sep 22, 2019 9:15 am

Hi Sergio,

I sent you a PM but it's still sitting in the outbox.

Have you seen it or is this a message board problem?

Grayham

Sergio
Posts: 100
Joined: Tue Jan 20, 2015 12:25 pm

Re: Silver halide sensitivityy enhancer

Post by Sergio » Sun Sep 22, 2019 3:49 pm

I received it now. Will send it.

Confirm if the paper is OK

Grayham
Posts: 49
Joined: Wed Feb 11, 2015 12:56 pm
Location: Hampshire, UK

Re: Silver halide sensitivityy enhancer

Post by Grayham » Mon Sep 23, 2019 11:43 am

Hi Sergio,

I have received the paper.

Thank you
Grayham

Grayham
Posts: 49
Joined: Wed Feb 11, 2015 12:56 pm
Location: Hampshire, UK

Re: Silver halide sensitivityy enhancer

Post by Grayham » Mon Sep 23, 2019 12:11 pm

This is an interesting read.
So do the formate ions bond to the AgX when the AgX is exposed to the formate or on exposure to light?

If it's on exposure to the formate then i'm guessing you could wash the plates after the formate soak in a similar way you do with ascorbic acid.
This may stop the colour shift after development if the shift is due to the extra material in the emulsion.

Are you aware of any superadditivity effects with ascorbic acid at all? May be interesting to try this.

Thank you very much for the paper, i'm going to try this out on my home made plates :)

Many Thanks
Grayham

Sergio
Posts: 100
Joined: Tue Jan 20, 2015 12:25 pm

Re: Silver halide sensitivityy enhancer

Post by Sergio » Mon Sep 30, 2019 1:59 pm

Formate ions are inserted onto AgBr crystals on formation.The formate absorbs the hole (+) formed after photon exposure.
This electron - hole pair is formed after the sensitizing dye absorbs the photon energy and transfers it to the crystal. After "absorbing" the hole the formate forms a radical that has the capability of injecting a 2nd electron to reduce another Ag+ ion, so doubling the efficiency.

Ascorbic may even reduce the crystals forming more latent sites. I guess it may be additive, but you need to test.

See:

http://pagesperso.lcp.u-psud.fr/belloni ... es/125.pdf

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