TiO2?

[jsmoove]

I remember reading something a while ago on here about TiO2. Can it be used as a photographic medium? Just curious.

Photocatalytic Surface - Breaks down organic matter when exposed to UV

Titanium dioxide (TiO2) is incorporated into surfaces where it functions as a catalyst, that creates free radicals from water molecules in the air when exposed to UV light (<387 nm). The highly reactive free radicals break down organic matter, micro-organisms (e.g. bacteria), and pollutants...

www.materialsampleshop.com

 

[gone]

If it creates free radicals, whoa! Guess it's OK if encapsulated, but will it stay there? Definitely a known cause of cancer if it gets in someone's lungs.

 

[nmp]

I remember reading something a while ago on here about TiO2. Can it be used as a photographic medium? Just curious.

Photocatalytic Surface - Breaks down organic matter when exposed to UV

Titanium dioxide (TiO2) is incorporated into surfaces where it functions as a catalyst, that creates free radicals from water molecules in the air when exposed to UV light (<387 nm). The highly reactive free radicals break down organic matter, micro-organisms (e.g. bacteria), and pollutants...

www.materialsampleshop.com

Intriguing idea. Look up the CHIBA process - which uses free-radical cross-linking of gelatin, gum etc to form an image. Presumably one can make a white (TiO2) pigmented concoction with an appropriate medium and apply on a black paper to make a positive image. If things work out the way it would seem in theory. Like is the photo-activity enough to reach critical gel-point in the matrix so it becomes insoluble with exposure doses that are practical. I have no idea.

:Niranjan.

 

[koraks]

Look up the CHIBA process - which uses free-radical cross-linking of gelatin, gum etc to form an image.

That crossed my mind as well.

Presumably one can make a white (TiO2) pigmented concoction with an appropriate medium and apply on a black paper to make a positive image.

Indeed, the opacity of TiO2 would be a thing to keep in mind. The way you describe it, it could be exploited. For a negative-working process, it would be a problem. I wonder how much TiO2 would be needed to make a gelatin emulsion like a carbon tissue harden; perhaps the image-forming pigment can still overpower the whiteness of the TiO2.

Since TiO2 is considered non-toxic, it's a really interesting avenue for experimentation.

 

[nmp]

Incidentally the same property of TiO2 made it problematic as a whitener for RC photo papers (not without adding anti-oxidants and UV absorbers.)

:Niranjan.