Download Smith, M.A. "Functionalized nanoparticles as

binding layer for negative NPs, it was not considered a negative result for residual
polymer to remain on the membrane. If applied in a membrane system, the
polyDADMAC layer would be replenished anyway.
Figure 5.1. Acid cleaning of polyDADMAC-coated SW30HR resulted in significant but incomplete
removal of the polymer.
PolyDADMAC was also subjected to a NaOH cleaning solution of pH 13 for 8
hours. Though the cleaning conditions exceeded the manufacturer recommendations for
exposure time to high pH, some insights were gained from the single measurement data
collected (Table 5.1). While the polyDADMAC-coated membrane had a zeta potential of
+14 mV and the negative zeta potential of an acid-cleaned sample indicated some
removal of the polyDADMAC layer, the base-cleaned sample retained a positive zeta
potential of +8 mV. It is unclear from the experiments performed whether the decrease in
zeta potential was caused by damage to the membrane by the caustic solution over an
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