CMC gel alternative process
As previously mentioned, Habib Saidane has posted a video of his new process using CMC and Ferric ammonium citrate as the photosensitizer:
So I started thinking what else could we use as sensitizer. I found that Sodium Benzoate is cheap and could be a photoinitiator so I started testing it yesterday. Indeed, there's a reaction with UV light. I don't want to share amounts yet because I've barely started looking into this. But I was certainly able to change the solubility of CMC. The reaction is similar and suffers from the same oxygen inhibition that the citrate and oxalate from the Chiba process suffer. Yesterday I tested adding an acid. It turns out that if you add an acid, you create benzoic acid in the mix which can then absorb UV light. In my test I setup a bunch of samples with varying UV exposure and chemical mixes, and as you can see there are some clear winners where the stuff completely dissolved or stayed solid.
A few of the most interesting things about this experiment are the very nice mixing and suspension of carbon in the liquid and the shear thickening. The liquid glop almost becomes slime when adding acid and sodium benzoate. In some ratios, the shear thickening is crazy good. By itself CMC swells ridiculously.
Looking at cell (3,8) where there was some solid at the surface that then frilled, that's pretty much how most of the clean cells failed or were cleaned. Meaning that those White spots represent probably good combinations of the ingredients to make a Carbon-like process. I mean that the tissue would be exposed, developed with hydrogen peroxide, then bonded to a substrate and finally pealed from the temporary support.
Another thing to note is how most rows have little gas bubbles. The paper did not react to acid, so the bubbles are probably from CO2 forming while the Sodium Benzoate is being transformed into sodium ions and Benzoic ions forming benzoic acid and CO2. I could be totally wrong.
I will be trying to make a Carbon transfer with this soon. But also I will be trying citrate and oxalate to see if and how each chemical works to form an image. I also will be trying mixes between CMC, Gelatin and Gum Arabic.