How long does plasma treatment last?

Hi!

I was wondering about the plasma treatment; primarily I was wondering how long do the effects of the treatment last? If there is a need to revert the surface to a more hydrophobic state, how long would the MEA need to sit in room air? (I'm talking about standard arrays with TiN electrode and Si3N4 insulation.)

Also, what kinds of oxygen plasma parameters do people use? (Time, RF power, vacuum etc.)

Has anyone tried UV/ozone treatment and if so what process times did you use and how did it work?

Thank you in advance!

Hi Ville,

the effect of plasma treatment disappears gradually. As a rule of thumb I would say MEAs are good for roughly two weeks after plasma treatment.

We use a small Harrick Plasma cleaner with air that just has settings off, low, medium and high. We use it at high for about 90s. MEAs are after the treatment stored for two days, This gives us a reasonable balance between hydrophobic and hydrophilic properties of the surface.

However preferences vary: We have customers who use it on the same day and other who feel that plasma is not needed at all if a matrix based coating is used... So please see this only as personal preferences ;-)

Thomas

Hi Thomas,

Thanks for the quick reply. Just tried a basic plasma cleaner and at least the wetting properties of the MEA surface seem really good right afterwards.

Best, Ville