History repeats itself: There’s something in the water
Dave Fang posted a poster in 2010 about particles found in DI water. I encountered the same issue during the nano-pocket permeability experiment. He said, “I’ve become increasingly suspicious of membrane clogging during the … permeability experiments.” I conducted an experiment with ultrapure water (UPW), typically filling a 1L glass container from a UPW machine. I examined the water using a Leica microscope (63x) and observed a significant number of particles/bacteria.

It is evident that there is a significant number of particles/bacteria present on the cover glass.
Several steps were taken to address this issue:
- Cleaned the 1 L water container with soap.
- Cleaned the tubes with ethanol.
- Filtered the water using a 10,000 MWCO filter.
