I am looking for a black polycarbonate membrane pore size that is not listed. Can I dye the standard polycarbonate membrane? How do I do this?
Yes, but we usually recommend the PVP-free polycarbonate membranes. Note that black polycarbonate membranes are used for counting particulates and performing fluorescent microscopy.
If you need to create a black membrane that is not listed on this site, the standard method for rendering polycarbonate membranes black in a lab follows:
Dissolve 2 gm of Irgalan black (Chemical Index, acid black 107) in 1 liter of 2% acetic acid.
Soak membranes in Irgalan black solution for 24 hours.
Rinse with water, air dry.
To obtain a darker black, dry at 180ºF (82ºC) for 15 minutes.
**Note: There have been instances of Irgalan Black "bleeding" off of the membrane. This is not common, but has occurred.