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New developer for PFG-03m

Posted: Wed Jan 19, 2005 3:26 am
by Sergey Vorobyov
Young man need to simple and safe development for holography. Popular developer GP-3 has toxic components – potassium hydroxide and ammonium thiocyanate. I finish research and development new developer from good known developer D-76. His formula is next:Metol 2 g.
Sodium sulfite, anhyd. 100 g.
Hydroquinone 5 g.
Borax cryst. 2 g.
Water to 1 lI add sodium thiosulphate as dissolvent of AgBr in emulsion layer. But I need reduce the quantity of sodium sulfite, because it block to normal work of sodium thiosulphate. It curious case need investigate later. The new formula of developer is:Metol 2 g.
Sodium sulfite, anhyd. 25 g.
Hydroquinone 5 g.
Borax cryst. 2 g.
Sodium thiosulphate 6 g.
Water to 1 lDeluition 1/4 before develop. Time of develop is 6 - 8 min.
You can compare the brightness of holograms (see photo).
I want name this developer "Open Developer" (OD-1). Let each of us improvement this developer!
[ 19 January 2005: Message edited by: Administrator ]

New developer for PFG-03m

Posted: Fri Jan 21, 2005 1:35 am
by Sergey Vorobyov
Two big holograms, 28*40 cm, made to order, was develop in new developer OD-1. Next results:
1. The emulsion have bright yellow-brown color. It means the saize of silver grains is very small (development has phisical essence).
2. The brightness of holograms is good and don't less comparative to GP-3.
3. More applicable time of develop is 10 min.

New developer for PFG-03m

Posted: Fri Jan 21, 2005 2:31 am
by Sergio
With the low sulphite concentration how long does it keep after mixing?In this case the sulphite is preserving the developer being oxidizing from oxygen? It isn't cutting the thiosulphate solvent action?

New developer for PFG-03m

Posted: Fri Jan 21, 2005 5:48 pm
by Martin
Sounds very promising. Next step might be trying a formula based on ascorbic acid and phenidone (instead of hydroquinone and metol) on such grounds.

New developer for PFG-03m

Posted: Sat Jan 22, 2005 2:30 pm
by Sergey Vorobyov
The dilute (1:4) developer save its property long time BEFORE develop. To regret, AFTER develop this developer have big oxygenate and don't work. It is analog GP-3, when you pour out work solution after each developing.
To Martin: of course, this developer mast be improve by all us. The main advantage which I want attain - make safe developer, without toxic components and with satisfactory action (as GP-3).

New developer for PFG-03m

Posted: Fri Jan 28, 2005 6:28 am
by Sergio
Sergey,Did you measure the pH? does the developer need (or you used after development) fixing?

New developer for PFG-03m

Posted: Sat Jan 29, 2005 1:17 am
by Sergey Vorobyov
I don't measure pH of developer before (I have plan make it some late).
Of course, need make fix the photoplate after developing. For PFG-03 enough fix only 1 min in odinry fixing bath (150 g sodium thiosulfate per 1 litre of water, (see my Lesson No. 9 in this site)).[ 29 January 2005: Message edited by: Sergey Vorobyov ]

New developer for PFG-03m

Posted: Sat Jan 29, 2005 9:16 pm
by Sergio
Thanks, SergeySeems that Borax works as a moderate alkaline buffer here, more effective in pH range of 9 - 10.5, I guess.Maybe interesting test (and I propose it for a more safe concentrate) with the pH jump effect, concentrated, the developer have near neutral pH but diluted the pH of the solution increases, An example is the tetrahydroxy borate anion (from borax or other borates) complexed with certain cis-1,2-diols such as sorbitol. Upon dilution, the complex dissociates, liberating free tetrahydroxy borate anions which increase the solution pH. Dissociation of polyborate ions also tends to promote this effect. The ratio of borate to polyol is important and in practice compositions containing approximately 5% borax and 20% sorbitol have been found to be effective. See Borax.com

New developer for PFG-03m

Posted: Tue Feb 01, 2005 11:46 pm
by Sergey Vorobyov
You made very serious analysis of this developer. In the first instance I want measure pH of OD-1, then compare to GP-3 and after them make comment your inferences. I had purchase in "Slavich" some sets of D-76 and fixers and prepare main experiments for prefabricate sets now.

New developer for PFG-03m

Posted: Sun Feb 13, 2005 1:40 pm
by Sergey Vorobyov
I had measure pH of new developer and compare to GP-3. I take next results:GP-3 conc. - 9,8
GP-3 dilute - 9,4
OD-1 conc. - 7,7
OD-1 dilute - 7,9It see, that pH of OD-1 is near to neutral solute (pH=7). So, the time of development is more long. Maybe, need add some soda for increase of pH.[ 13 February 2005: Message edited by: Sergey Vorobyov ]