Silica-titania composite and structure
A silica-titania composite has a BET specific surface area, as determined by BET analysis of a water vapor adsorption isotherm, in the range of 250 m 2 /g to 500 m 2 /g and a contact angle with water of 100° or greater. In the water vapor adsorption isotherm, an adsorbed amount at relative pressure P/P 0 =0.1 is in a range of 65 cm 3 /g to 120 cm 3 /g, an adsorbed amount at relative pressure P/P 0 =0.5 is in a range of 150 cm 3 /g to 300 cm 3 /g, and an adsorbed amount at relative pressure P/P 0 =0.9 is in a range of 350 cm 3 /g to 500 cm 3 /g.
1. A silica-titania composite comprising:
the silica-titania composite having a BET specific surface area, as determined by BET analysis of a water vapor adsorption isotherm, in a range of 250 m 2 /g to 500 m 2 /g, and
a contact angle with water of 100° or greater, and
in the water vapor adsorption isotherm, an adsorbed amount at relative pressure P/P 0 =0.1 is in a range of 65 cm 3 /g to 120 cm 3 /g, an adsorbed amount at relative pressure P/P 0 =0.5 is in a range of 150 cm 3 /g to 300 cm 3 /g, and an adsorbed amount at relative pressure P/P 0 =0.9 is in a range of 350 cm 3 /g to 500 cm 3 /g.
2. The silica-titania composite according to claim 1 , wherein an elemental ratio of titanium to silicon (Ti/Si) is in a range of 1% to 50%.
3. The silica-titania composite according to claim 1 , wherein an elemental ratio of titanium to silicon (Ti/Si) is in a range of 3% to 20%.
4. The silica-titania composite according to claim 1 , wherein the silica-titania composite is a hydrophobized composite.
5. The silica-titania composite according to claim 1 , comprising a coating layer containing a metal atom having a hydrocarbon group, the metal atom being bonded to a surface of a composite body through an oxygen atom.
6. The silica-titania composite according to claim 5 , wherein the hydrocarbon group is a saturated or unsaturated aliphatic hydrocarbon group having 3 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 27 carbon atoms.
7. The silica-titania composite according to claim 6 , wherein the hydrocarbon group is a saturated aliphatic hydrocarbon group.
8. The silica-titania composite according to claim 7 , wherein the saturated aliphatic hydrocarbon group has 4 to 10 carbon atoms.
9. The silica-titania composite according to claim 1 , wherein the silica-titania composite has a BET specific surface area, as determined by BET analysis of a water vapor adsorption isotherm, in a range of 250 m 2 /g to 500 m 2 /g, and
in an ammonia adsorption isotherm, an adsorbed amount at an ammonia pressure of 10 kPa is in a range of 100 cm 3 /g to 140 cm 3 /g, and an adsorbed amount at an ammonia pressure of 90 kPa is in a range of 120 cm 3 /g to 300 cm 3 /g.
10. The silica-titania composite according to claim 5 , wherein the metal atom is a silicon atom.
11. A silica-titania composite comprising:
the silica-titania composite having a BET specific surface area, as determined by BET analysis of a water vapor adsorption isotherm, in a range of 250 m 2 /g to 500 m 2 /g, and
a contact angle with water of 100° or greater, and
in an ammonia adsorption isotherm, an adsorbed amount at an ammonia pressure of 10 kPa is in a range of 100 cm 3 /g to 140 cm 3 /g, and an adsorbed amount at an ammonia pressure of 90 kPa is in a range of 120 cm 3 /g to 300 cm 3 /g.
12. The silica-titania composite according to claim 11 , wherein an elemental ratio of titanium to silicon (Ti/Si) is in a range of 1% to 50%.
13. The silica-titania composite according to claim 11 , wherein the silica-titania composite is a hydrophobized composite.
14. The silica-titania composite according to claim 11 , comprising a coating layer containing a metal atom having a hydrocarbon group, the metal atom being bonded to a surface of a composite body through an oxygen atom.
15. The silica-titania composite according to claim 14 , wherein the metal atom is a silicon atom.
16. The silica-titania composite according to claim 11 , wherein the silica-titania composite has a BET specific surface area, as determined by BET analysis of a water vapor adsorption isotherm, in a range of 265 m 2 /g to 500 m 2 /g, and
in the water vapor adsorption isotherm, an adsorbed amount at relative pressure P/P 0 =0.1 is in a range of 65 cm 3 /g to 120 cm 3 /g, an adsorbed amount at relative pressure P/P 0 =0.5 is in a range of 150 cm 3 /g to 300 cm 3 /g, and an adsorbed amount at relative pressure P/P 0 =0.9 is in a range of 350 cm 3 /g to 500 cm 3 /g.
17. A structure comprising the silica-titania composite according to claim 1 .