Preparation of patterned diffusion media
US7241474B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2004 |
| Grant date | Jul 10, 2007 |
| Priority date | — |
| Expiry date | Apr 9, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Gas diffusion media for use in fuel cells are provided that contain a pattern of deposited hydrophobic polymer such that less than 100% of the surface of the diffusion media is covered with hydrophobic polymer. The media are made by first wetting a sheet of carbon fiber paper in an aqueous emulsion of the hydrophobic polymer. The wetted sheet is contacted with a pattern member containing one or more openings oriented to correspond to a predetermined or desired pattern of hydrophobic polymer deposition. While still in contact with the pattern member, the sheet is heated or otherwise treated to cause evaporation of the water from the sheet. Evaporation while in contact with the pattern member takes place in such a way that hydrophobic polymer is concentrated in the sheet at the openings of the pattern member by the process of evaporation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.