| Abstract
| - The interactions between multivalent ions (small ions or polyelectrolytes) and two exponentially growingpolyelectrolyte multilayers, namely, (HA−PLL)n and (HA−PAH)n films, are investigated (HA = hyaluronicacid, PLL = poly-l-lysine, PAH = poly(allylamine)). Ferrocyanide and ferricyanide ions are used as smallion probes. The most striking finding is that, even though these two ions differ only by one charge unit,the ferrocyanide ions induce a partial dissolution of both multilayers whereas these films remain stablein the presence of ferricyanide ions. The dissolution process of (HA−PLL)n films is more rapid than thatof (HA−PAH)n films, indicating a stronger interaction between HA and PAH compared to HA and PLL.This is confirmed by polyelectrolyte exchange experiments: when an (HA−PLL)n multilayer film is putinto contact with a PAH solution, PLL is quantitatively exchanged with the PAH chains and transformedinto an HA−PAH film, whereas an (HA−PAH)n multilayer remains stable in the presence of a PLL solution.
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