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A series of waterborne coatings obtained from aqueous dispersions of fluorinated polyurethane ionomers were characterized by Differential Scanning Calorimetry (DSC), Contact Angle measurements (CA), and Electrochemical Impedance Spectroscopy (EIS) with evaluation of water uptake and barrier properties at prolonged exposure. All the considered materials showed two glass transition temperatures and the formation of highly hydrophobic surfaces with CA values against water well above 100°. On the other hand the compositive parameters of the polymers-presence and concentration of cationic as well as anionic groups, linear or crosslinked molecular structure-showed a significant effect on the electrochemical behaviour. In particular it resulted that less water absorption is shown by coatings with lower ionic character, while crosslinked anionomer structures show excellent long-term barrier properties. The research offers useful indication towards the design of a new class of hydrophobic barrier coatings from aqueous dispersions.

Self-assembled monolayers of cysteine (CYST) have been constructed on polycrystalline gold (polyAu) electrode at different immersion times (t immer ) in order to characterize them by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Oxidative desorption experiments allowed the calculation of the surface coverage, whereas reductive desorption informed about the binding of CYST to different gold domains. Desorption products showed different diffusion ability. The maximum coverage was already achieved at short t immer , although progressive reordering of CYST molecules led to a relevant decrease of the defects at long time, as ascertained by EIS. Functionalization of polyAu-CYST electrodes with the enzyme microperoxidase MP-11 performed by following two different binding methods showed that the enzymatically catalyzed reduction of H 2 O 2 is enhanced when the -COOH residues of the MP-11 undecapeptide chain are firstly activated and then linked to the -NH 2 functional groups of the non-activated CYST layer formed on the polyAu surface.