by Joe Farina » Mon Dec 06, 2021 7:13 am
I noticed an interesting thing (to me, at least) in that paper:
"Substrate preparation
Suitable glass needs to be first cleaned by ordinary household detergent. Further cleaning can be
done overnight soaking in nitric acid, or better 5 min in Cairo acid. These dangerous chemicals can be
avoided using plasma treatment. Dielectric barrier discharge is excited by pulsed high voltage on
glass surface create high reactive species from plain air, which burn every organic contamination.
Then sublayer is applied, best adhesion promotion is created by applying 0.05% of (3-
Aminopropyl)triethoxysilane in acetone. Apply by cotton swab in thin layer, less is better.
After one
hour unreacted silane needs to be washed by etanol or acetone."
That's the first time I've seen that "unreacted silane needs to be washed by ethanol or acetone." In the past, I've let the silane/solvent evaporate and dry, and left any unreacted silane in place, prior to coating the gelatin layer. I've never had any emulsion-lifting problems, so I wonder if this step is really needed. I also use the same silane for pre-treatment prior to laminating glass-to-glass using Hxtal epoxy, and so far, no problems. But now I wonder if the unreacted silane should be removed.
On the subject of cleaning/subbing glass, I stumbled across an interesting product which seems to "rock" with regards to cleaning glass: Bar Keeper's Friend. In the past, I've used TSP, but I plan to use this product, which seems to have a brutal cleaning effect on glass. It contains oxalic acid, which appears to be the key ingredient. It also contains feldspar (Mohs hardness 6, hardness of glass ~5.5), and should be used carefully on glass.
https://www.barkeepersfriend.com/oxalic ... ic-of-bkf/I noticed an interesting thing (to me, at least) in that paper:
"Substrate preparation
Suitable glass needs to be first cleaned by ordinary household detergent. Further cleaning can be
done overnight soaking in nitric acid, or better 5 min in Cairo acid. These dangerous chemicals can be
avoided using plasma treatment. Dielectric barrier discharge is excited by pulsed high voltage on
glass surface create high reactive species from plain air, which burn every organic contamination.
Then sublayer is applied, best adhesion promotion is created by applying 0.05% of (3-
Aminopropyl)triethoxysilane in acetone. Apply by cotton swab in thin layer, less is better. [b]After one
hour unreacted silane needs to be washed by etanol or acetone[/b]."
That's the first time I've seen that "unreacted silane needs to be washed by ethanol or acetone." In the past, I've let the silane/solvent evaporate and dry, and left any unreacted silane in place, prior to coating the gelatin layer. I've never had any emulsion-lifting problems, so I wonder if this step is really needed. I also use the same silane for pre-treatment prior to laminating glass-to-glass using Hxtal epoxy, and so far, no problems. But now I wonder if the unreacted silane should be removed.
On the subject of cleaning/subbing glass, I stumbled across an interesting product which seems to "rock" with regards to cleaning glass: Bar Keeper's Friend. In the past, I've used TSP, but I plan to use this product, which seems to have a brutal cleaning effect on glass. It contains oxalic acid, which appears to be the key ingredient. It also contains feldspar (Mohs hardness 6, hardness of glass ~5.5), and should be used carefully on glass.
https://www.barkeepersfriend.com/oxalic-acid-magic-of-bkf/