Pedot Filtering Problem

Hi! All
I was wondering if anyone has advice on filtering/storage of
Pedot-PSS. We purchased the high conductivity solution (about 10-100
ohm/square) from Aldrich and stored it in a fridge.
We now notice (after a few months of storage) that pedot is
precipitating on the sidewalls. Also, filtering it using nylon/pvdf
filter/cellouse nitrate paper (tried 0.2micron and 5 micron) seems to
be problematic...
I would appreciate any ideas on optimal storage (room temp?) and
filtering procedures for this material. Further, in there data on the
change viscosity and other parameters with filter size?
Regards
Rama