Chris,
If you can lay your hands on a copy of Photograhic Chemistry volume one
(English Translation!) by Pierre Glafkides, you will find in the chapter
on slow emulsions, formulae for Wet Collodian, Dry Collodian, and
sensitised Cellulose Acetate Silver Halide Emulsions, together with
references to the use of Poly Vinyl Alcohol etc.
There are also a number of other synthetic polymers based on cellulose
such as alcohol soluble cellulose aceto propionate or the water soluble
carboxy methyl celluloses, which might be worth looking at if you have
friends in the surface coating industry.
Alex.
-- Alex Nanson alec@norlex.demon.co.uk Gloucester UK.