Hi,
I am using a very high concentration of rhodamine 6g dye relative to a
couple of papers that I have read about the concentrations that have
been used to make flow visualization.

My concentration is about 0.5g/L

Since Rhodamine 6g is not soluble in water, I initially dissolve the
dye with ethanol and then add water.

When I pass this thru the microchannel using 3 streams Left, Right and middle.

the left and the right streams contain dye mixed with water and the
middle one contains just pure water.

The Channel is made of PDMS, which is bonded to glass slide using
plasma cleaner.

I notice that there are some particles that start to accumalate along
the channel, which is in contact with the dye streams. I can flush it
with ethanol, but my purpose is not solved as these particles are
visible right away and are stuck to the channel. Is there any solution
to problem?

Any help will be greatly appreciated.

Thanks a bunch,
Vishwa