This mechanism was also facilitated by the effect reported by Gehring and Fischer, who showed that the immersion depth of negatively charged particles (zeta potential of PSiFe in KCl was around -18 mV to -48 mV) in salt solution was greater compared to pure water. The difference between isotherms recorded at water subphase in various temperature regimes was explained by analyzing the changes of PNIPAM ligand conformation while crossing LCST. "Open" conformation of PNIPAM (LT) resulted in larger surface areas occupied by PSiFe than in "closed" (HT). At KCl, the trend was similar, but the shift from HT to LT was much more pronounced than at the water subphase. This was a direct consequence of local osmotic pressure governing the arrangement of particles. At LT, more ions were associated with each PSiFe. At HT, PNIPAM ligands interacted intramolecularly, partially screening dipoles within the capping layer, reducing the number of associated ions. More ions at LT caused a separation between PSiFe and a more pronounced shift of isotherm (up to around 5×) compared to HT (up to around 2.6×, cf. Table ).