The thin
films were prepared with NanoStracto Sequence equipment by sequential dipping of the glass substrates into aqueous solutions of polyelectrolytes with rinsing between each deposition step. PAH (Mw = 70,000 g mol1, Sigma–Aldrich) was
used as the polycation, and PAA (Mw = 90,000 g mol1, Polysciences) was used as the polyanion. All polyelectrolytes were used as received, without further purification, and were prepared as 0.01 mol L1 solutions (based on the repeat-unit molecular weight). The pH values of the polyelectrolyte solutions were adjusted to the desired pH with a 0.10 mol L1 solution of HCl or NaOH.