Re: Silver Formate AgCHOO

<dufrasne@xxxxxxxxxxx> wrote in message
news:1135343444.263034.196410@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> I am a holographist and I make my own holographic emulsions. I'm
> always looking tor increase sensitivity and reduce exposure time to
> avoid failures caused by movements of the film or object.
> I read in a paper a few years ago that it is possible to increase the
> photographic sensitivity of the emulsions by adding silver formate
> (AgCHOO) to the emulsion.
> Could one among you give me the receipt to make silver formate from
> silver nitrate.
> I do not have much material (I make "kitchen chemistry").
> Thanks in advance.
> Jean
>
[hanson]
1) Since AgOOCH is practically insoluble in water, why don't you
impregnate/soak your emulsion plates/film in AgNO3 solution
rinse and then immerse it into NaOOCH or dilute HCOOH soln
so that the AgOOCH precipitates uniformly in the gel. You may
try also the reverse 1st Na/HOOCH the AgNO3

2) Assuming that you are using already AgI (Silver Iodide) containing
commercial emulsion then additional Ag may not be the sensitivity
increasing agent but the HCOO- ion more likely is it So simply
soak, as your first experiment ,a strip of your film in dilute HCOOH
rinse and dry.

3) Perhaps the oxalate ion from Oxalic acid HOOC-COOH or
Silveroxalate (COO)2Ag2 may be a better sensitizer. Repeat
the above experiments with Oxalic instead Formic compounds.

4) Since you have only small quantities, the explosive nature
of many Ag compounds not be too dangerous. But a puff from
dried quickly heated Ag2(COO)2 is nasty and as aggravating as
are the skin stains that Ag compounds produce. Avoid mixing the
AgNO3 solution with EtOH as explosive Hg-fulminates may form.
Needless to say to have to work in the dark room / deep red light.

Have fun!... Enjoy Chemistry!..... but *** enviros!
ahahaha... ahahanson


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