What pH do ascorbates exhibit developing activity at?

[Athiril]

I read somewhere they don't develop much if at all until the pH is quite high.

I wan't to formulate a developer where the ascorbate pretty much regenerates another developing agent and doesn't do much developing itself.

For this purpose, at what pH should I stay under?

 

[Alan Johnson]

This guy has done a lot, see his archive for sodium ascorbate SALS 12:
http://www.ascorbate-developers.blogspot.com

 

[Gerald C Koch]

In low pH developers such as D-76 or Xtol, the developing action is due to the metol or the Dimezone. The other developing agent either hydroquinone or ascorbate ion serves only to regenerate the metol or the Dimezone.

The answer to your question is any pH greater than 8.0 and less than 10.0. The higher the pH the more rapid the development and the coarser the grain.

Considering that there are already dozens or hundreds of developers of the type you describe is there a particular reason you wish to formulate a new one?. The formulas of many of thesedevelopers have been published. On a previous thread I menntioned that the two chemistss who created Xtol spent over a year of work before they even had a prelimiinary formula to propose to kodak. What you are seeking to do is not easy. If you are not a trained chemist it will be even more difficult.

 

[Relayer]

For this purpose, at what pH should I stay under?

don't worry. ascorbate need very high pH like 11-12 and more.