TITANIUM DIOXIDE COATINGS AND METHODS OF FORMING IMPROVED TITANIUM DIOXIDE COATINGS
Methods for forming titanium dioxide coatings are disclosed. Sol-gel compositions may be coated on a substrate having a roughened surface, and subsequently the coated substrate may be heated at a temperature sufficient to form an anatase titanium dioxide coating. Substrates having roughened surfaces and comprising such coatings are also disclosed.
1 . A method of improving at least one of antimicrobial properties, self-cleaning properties, hydrophilicity, and activation time of a titanium dioxide coating, said method comprising:
preparing a titanium dioxide sol-gel composition;
providing a substrate having a roughened surface;
coating the roughened surface of the substrate with the sol-gel composition; and
heating the coated substrate to form an anatase titanium dioxide coating.
2 . The method of claim 1 , wherein the roughened surface of the substrate is formed by etching the surface of the substrate chemically or mechanically.
3 . The method of claim 2 , wherein the roughened surface of the substrate is formed by etching the surface of the substrate with an acid.
4 . The method of claim 1 , wherein the acid is chosen from hydrochloric acid and nitric acid.
5 . The method of claim 1 , wherein the roughened surface of the substrate has a mean square roughness ranging from about 3.75 nm to about 16 nm.
6 . The method of claim 1 , wherein the substrate is glass.
7 . The method of claim 6 , wherein the substrate is chosen from clear glass and low-iron glass.
8 . The method of claim 1 , wherein the coated substrate is heated at a temperature of about 600° C. or greater.
9 . The method of claim 1 , wherein the anatase titanium dioxide coating further comprises a roughened surface.
10 . A method of forming an anatase titanium dioxide coating on a roughened surface of a substrate, said method comprising;
preparing a titanium dioxide sol-gel composition;
providing a substrate having a roughened surface;
coating the roughened surface of the substrate with the sol-gel composition; and
heating the coated substrate to form an anatase titanium dioxide coating.
11 . The method of claim 10 , wherein the roughened surface of the substrate is formed by etching the surface of the substrate chemically or mechanically.
12 . The method of claim 11 , wherein the roughened surface of the substrate is formed by etching the surface of the substrate with an acid.
13 . The method of claim 12 , wherein the acid is chosen from hydrochloric acid and nitric acid.
14 . The method of claim 10 , wherein the roughened surface of the substrate has a mean square roughness ranging from about 3.75 nm to about 16 nm.
15 . The method of claim 10 , wherein the substrate comprises a glass substrate.
16 . The method of claim 15 , wherein the glass substrate is chosen from clear glass and low-iron glass substrates.
17 . The method of claim 10 , wherein the coated substrate is heated at a temperature of about 600° C. or greater.
18 . The method of claim 10 , wherein the anatase titanium dioxide coating further comprises a roughened surface.
19 . An antimicrobial and/or self-cleaning laminate, comprising:
a substrate having a roughened surface;
an anatase titanium dioxide coating on the roughened surface of the substrate.
20 . The antimicrobial and/or self-cleaning laminate of claim 19 , wherein the roughened surface of the substrate has a mean square roughness ranging from about 3.75 nm to about 16 nm.
21 . A titanium dioxide-coated substrate, wherein said titanium dioxide coating is made by:
preparing a titanium dioxide sol-gel composition;
providing a substrate having a roughened surface;
coating the roughened surface of the substrate with the sol-gel composition; and
heating the coated substrate to form an anatase titanium dioxide coating.