Hi,

Thanks Shirla for the information. I am also using piranha for PDMS surface
modification, but I find that it is requiring quite a long time (around 10
min) for the surface to be hydrophilic. I guess it will also depend upon the
ratio of H2O2 and H2SO4 in piranha. Can you provide any literature where
somebody has done some work regarding this.

Thanks in advance.

Debashis Maji.



2010/2/10 Shirla Cheng 

> DEBASHIS MAJI,
>
> I have used both piranha and plasma to treat PDMS surfaces. If you want to
> use piranha, the treatment time should be controlled to 10-15 sec. And the
> treatment time with plasma (dry air or O2) should be 40-50 sec, otherwise
> the surface of PDMS will be hardened and crack.
>
> After piranha or plasma treatment, the PDMS surface is highly hydrophilic
> and after that it will gradually become hydrophobic again.
>
> Just for your reference.
>
> Shirla Cheng

--
Thanks & Regards

Debashis Maji,
JRF - Texas Instruments & IIT Kharagpur collaborative Project,
PhD Scholar - School of Medical Science & Technology,
IIT Kharagpur, India - 721302