Dear All,
I posted this msg last week. I think I need to describe my
problems with more details.
I have had this methanol surfactant or lubricant problem for a while,
and couldn't figure out why. I hope you can give me some hints.
I am trying to align and attach a thin-layer of PDMS (100 um thick)
onto a glass slide. Because PDMS will permenantly bond to glass, it
will be extremely difficult to align patterns without lubricant.
Lubricant provides PDMS some short-time freedom of motion.
As suggested by many others, I applied 99.9% methanol
onto the surface of PDMS film after oxygen plasma treatment (60sec @ 30W),
then bring the PDMS film with glass slide together. Immediately after
alignment (less than 1 min), I place them in an oven or on hotplate
(85C) for 15-20 min, in
order to evaporate methanol.
But after that, I only found that PDMS doesn't stick to glass slide at
all. I mean, not just certain areas don't stick, it is the entire piece of
PDMS doesn't stay on the glass slide.
In contrast, if I don't apply methanol in between, PDMS would have a
pretty good adhesion on glass slides.
Has anyone had such problem before? What would you think the problem
is? Should I clean my glass slides further? Should I try purer methanol? Any
comments will be appreciated. Thanks.
--
Best Regards,
Yu Xiang