Protective Internal Coatings for Porous Substrates
A material contains open pores in which the channels and pores that are internally coated with at least one layer of phosphorus-containing alumina. Such material is formed by infiltrating a porous material one or more times with a non-colloidal, low-viscosity liquid coating precursor, drying, and curing the coating precursor to form a phosphorus-containing alumina layer within pores of the material.
1 . A composition comprising:
a material saturated with a non-colloidal solution of a phosphor-alumina precursor having an aluminum-to-phosphorous atomic ratio of 0.5:1 to 15:1;
the material saturated with the non-colloidal solution adapted to form a liquid film having a thickness of 5 to 250 nm on pore walls of a porous inorganic substrate; the liquid film consisting of the non-colloidal solution.
2 . The composition of claim 1 , wherein the material is a cloth, a sponge, or porous material.
3 . The composition of claim 1 , wherein the non-colloidal solution includes an alcohol solvent selected from the group consisting of methanol, ethanol, n-propanol, i-propanol, n-butanol, 2-butanol, t-butanol, and a mixture thereof.
4 . The composition of claim 1 , wherein the phospho-alumina precursor has an aluminum-to-phosphorous atomic ratio of 4:1 to 15:1.
5 . The composition of claim 1 , wherein the liquid film is formed by liquid migration from the material into a pore structure of the porous inorganic substrate.
6 . A composition comprising:
a saturated sponge adapted to maintain continuous contact of a non-colloidal solution of a phosphor-alumina precursor with a porous inorganic substrate thereby migrating the non-colloidal solution into a pore structure of the porous inorganic substrate.
7 . The composition of claim 6 , wherein migrating the non-colloidal solution into the pore structure forms a liquid film having a thickness of 5 to 250 nm on pore walls of a porous inorganic substrate.
8 . The composition of claim 6 , wherein the non-colloidal solution of the phosphor-alumina precursor has an aluminum-to-phosphorous atomic ratio of 0.5:1 to 15:1.
9 . The composition of claim 6 , wherein the non-colloidal solution has a viscosity below 150 cSt.
10 . A composition comprising:
a saturated cloth adapted to maintain continuous contact of a non-colloidal solution of a phosphor-alumina precursor with a porous inorganic substrate thereby migrating the non-colloidal solution into a pore structure of the porous inorganic substrate.
11 . The composition of claim 10 , wherein migrating the non-colloidal solution into the pore structure forms a liquid film having a thickness of 5 to 250 nm on pore walls of a porous inorganic substrate.
12 . The composition of claim 10 , wherein the non-colloidal solution of the phosphor-alumina precursor has an aluminum-to-phosphorous atomic ratio of 0.5:1 to 15:1.
13 . The composition of claim 10 , wherein the non-colloidal solution has a viscosity below 150 cSt.