Use of Variable Frequency Microwaves to Control the Teflon Profile of Gas Diffusion Media

A system for fabricating diffusion media for a fuel cell, said system comprising:

• a device for applying a solvent including a fluorocarbon to a diffusion media substrate;
• and
• a heating apparatus for drying the solvent on the substrate, wherein the heating apparatus uses electromagnetic radiation to dry the substrate, said heating apparatus varying the frequency of the electromagnetic radiation.

A system for fabricating diffusion media for a fuel cell, said system comprising:

• a device for applying a solvent including PTFE particles to a carbon fiber substrate;
• and
• a heating apparatus for drying the solvent on the substrate, wherein the heating apparatus uses microwave radiation to dry the substrate, said heating apparatus varying the frequency of the microwave radiation within a frequency range of about 500 MHz to about 1000 GHz, wherein the dried diffusion media substrate has a carbon to fluorine (C/F) ratio between 8 and 20.