Ultra-thin metal oxide and carbon-metal oxide films prepared by atomic layer deposition (ALD)
Ultra-thin porous films are deposited on a substrate in a process that includes laying down an organic polymer, inorganic material or inorganic-organic material via an atomic layer deposition or molecular layer deposition technique, and then treating the resulting film to introduce pores. The films are characterized in having extremely small thicknesses of pores that are typically well less than 50 nm in size.
1. A process for producing a porous film on a substrate, comprising (a) applying a 0.5 to 50 nm-thick film of an alucone, zinc-ethylene glycol hybrid polymer, or titanium-ethylene glycol hybrid polymer to at least a portion of the surface of a substrate via an atomic layer deposition process, and (b) forming pores in the hybrid film by oxidizing the hybrid film by heating the film in the presence of air or oxygen at a temperature of at least 400° C. to burn out the organic portion of the alucone, zinc-ethylene glycol hybrid polymer, or titanium-ethylene glycol hybrid polymer or by contacting the film with water to hydrolyze the alucone, zinc-ethylene glycol hybrid polymer, or titanium-ethylene glycol hybrid polymer and remove the organic portion of the film.
2. The process of claim 1 , wherein the porous film has a thickness of at least 2 nm.
3. The process of claim 2 , wherein the porous film has a thickness of up to 30 nm.
4. The process of claim 3 , wherein the porous film has a surface area of at least 10 m 2 /g.
5. The process of claim 4 , wherein the porous film has a surface area of at least 100 m 2 /g.
6. The process of claim 5 , wherein the porous film has pores in the size range of from 2 to 100 angstroms.
7. The process of claim 6 , wherein the porous film is free of pores having widths greater than 1000 angstroms.
8. The process of claim 7 wherein the substrate material is or contains catalytic material; a reagent for a chemical reaction; a porous support for a membrane or filtration device; a pharmaceutical or nutrient; or a MEMS device or sensor.