Non-monotonic variation in the streaming potential in polyelectrolyte grafted nanochannels mediated by ion partitioning effects.

Background: Polyelectrolyte grafted 'soft' nanochannels are known to enhance electrokinetic energy conversion efficiency, paving the way for a sustainable energy harvesting mechanism. However, the true potential of their efficacy remains to be tapped, as attributed to a deficit in accounting for the interplay between solution pH and ion partitioning effect arising due to permittivity contrast between the coated layer and the bulk media, leading to predictions of an erroneous ionic distribution and a wrongly estimated electrokinetic response.

Results: We unravel the electrokinetic behavior of a pH-regulated zwitterionic polyelectrolyte layer grafted nanofluidic system.