Method for photocatalytically hydrophilifying surface and composite material with photocatalytically hydrophilifiable surface
US6090489A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 1998 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Jun 19, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31504
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for hydrophilifying the surface of a substrate by taking advantage of photocatalytic action. The substrate has a photocatalytic titania coating (10). The surface of the photocatalytic coating (10) bears the solid acid that increases a hydrogen bond component (.gamma..sub.S.sup.h) in the surface energy in the solid/gas interface of the coating. Photoexcitation of the photocatalyst enhances the hydrogen bond component (.gamma..sub.S.sup.h) in the surface energy of the photocatalytic coating (10), accelerating the physical adsorption of molecules of water in the atmosphere through a hydrogen bond (16) onto hydrogen atoms in a terminal OH group (12), bonded to a titanium atom, and a bridge OH group (14) on the surface of the coating. This results in the formation of a high density, physically adsorbed water layer (18) on the surface of the photocatalytic coating (10), thus permitting the surface of the substrate to be easily hydrophilified. The method is applicable to antifogging, antifouling, selfcleaning and cleaning of articles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.