Hi Avinash,

  What material are your channels made from? If it is PDMS then you might have
had them change back to a hydrophobic state. I hear that if a plasma activated
channel is left in air for even a short time (~hours) at room temperature,
hydrophobic sections of the polymer will migrate to the surface thus creating a
larger back pressure and causing hydrophobic material in the flow stream to
precipitate out.  So evidently you should keep PDMS chips in water at all times.

Hope this helps,
Michael


On Mar 13, 2013, at 4:41 PM, Avinash sahu  wrote:

> hi all,
> I have some issue related to microchannel hope you can resolve it. Please
> suggest me the way to remove the blockage and cleaning procedure  in
> microchannel. One of the my microchannel was blocked by bromothymolblue dye
> and Phenolphthalein dye solution and in other channel I had good flows like
> slug, stratified etc at starting but now not even slug flow is not comming.
> The slug flow comes at lower  flow like 0.01 - 0.1 ml/min. I am using Y
> junction mirochip 150x150 micrometer. I tried using Isopropyl alcohol,
> acetone, 35% HCL,35%H2O2,  H2SO4, sonication at 35 Hz and 135 Hz for both
> cleaning and blockage purpose, nothing is working. Please help me with this
> I will be thankful for you.
>
> --
> Avinash Sahu
> MS Research Scholar
> Chemical Engineering
> IIT Madras (T.N.) 600036
> 9003387409(M)
> Profile Page
> http://www.che.iitm.ac.in/~spush/avinash.html
> For details on the International Conference  Mathematics in Chemical
> Kinetics and Engineering- please visit
> http://www.mackie2013.iitm.ac.in/
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