The fabrication and characterization of poly(vinylcarbazole) (PVK)-conjugated polymer network (CPN) anticorrosion coatings on flat surfaces, steel coupons or indium tin oxide (ITO) glass substrates, is reported. Electrochemical deposition methods (potentiostatic and potentiodynamic) were employed by anodic oxidation of the carbazole side units in the PVK chains, resulting in electrodeposition of a cross-linked or network macromolecular structure. This is different from traditional conjugated polymer (CP) coatings made up of mostly linear species derived from direct electropolymerization of small molecule monomers. The coating composition was characterized by attenuated total reflection infrared spectroscopy (ATR-IR) and photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) allowed morphological comparison between the coatings in terms of deposition technique and surface roughness. Electrochemical impedance spectroscopy (EIS) was subsequently carried out on PVK-coated steel coupons to evaluate the performance of such coatings in an accelerated corrosion environment. The deviation from the ideal (i.e., perfectly dielectric) capacitor-like behavior and Bode plot data suggested that the CPN approach of electrodeposited PVK coatings resulted in very good protection against weathering of engineering metals.

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Hybrid and nanostructured ultrathin films of polyaniline (PANI) were fabricated using combined layer-by-layer (LbL) and surface sol−gel (SSG) processing with titanium oxide (TiO x ) layers. This enabled modulation of the electrochemical and the doping−dedoping process of the electroactive conjugated polymer with respect to thickness, presence of another polyelectrolyte, and intercalation of the inorganic slabs. The structure, composition, and viscoelastic behavior were proven by UV−vis absorbance, FT-IR, XPS, and QCM-D measurements. Spectroelectrochemical behavior showed that the oxidative stability of the films brought about the nanostructure control of the LbL process. On the other hand, the presence of the inorganic layer resulted in preventing electron transfer based on quinoid to benzenoid, Q → B, transitions. Thus, pairing the LbL assembly and the SSG process yielded a highly ordered, tunable structure in which the electrochemical behavior was modulated and correlated with diffusion-related arguments (Cottrell equation) of a blocking effect of the sol−gel layer. Further studies will be made on evaluating possible applications in thin film battery and capacitor devices.

A protocol for nanostructuring and electropolymerization of a hybrid semiconductor polycarbazole-titanium oxide ultrathin film is described. Ultrathin (<100 nm) films based on polycarbazole precursor polyelectrolytes and titanium oxide (TiOx) have been fabricated by combining the layer-by-layer (LbL) and surface sol-gel layering techniques. Film growth was followed and confirmed through UV-vis spectroscopy, ellipsometry and quartz crystal microbalance with dissipation (QCM-D). Subsequent anodic electrochemical oxidation of the carbazole pendant units afforded a conjugated polymer network (CPN) film within intercalating TiOx layers of cross-linked and π-conjugated carbazole units. Cyclic voltammetry (CV), UV-vis, and fluorescence spectroscopy measurements confirmed this process. The LbL-driven polyelectrolyte deposition process resulted in a quantified electrochemical response, proportional to the number of layers, while the TiOx acted as a dielectric spacer limiting electron transfer kinetics and attenuating energy transfer in fluorescence. Electro-optical properties were compared with other polycarbazole thin film materials with respect to bandgap energy (Eg). The straightforward protocol in film nanostructuring and barrier/dielectric properties of the inorganic oxide slab (denoted here as, TiOx) should enable applications in organic light-emitting diodes (OLEDs), dielectric mirrors, planar waveguides, and photovoltaic devices for these hybrid ultrathin films.

The fabrication and characterization of a hybrid polymer p-n junction-type thin film via electropolymerization of NPs and a precursor polymer is described. Blends of TiO 2 NPs, CdSe NCs, Cbz-COOH, and PVK were utilized to enable electrochemical deposition on ITO glass substrates. Spectroscopic, microscopic, and wetting measurements confirmed thin film fabrication. CV yielded a CPN nanocomposite with electropolymerized (i.e., crosslinked) carbazole units embedding CdSe NCs. Absorption and emission measurements confirmed a charge transfer mechanism between the crosslinked carbazole and the NCs resulting in a p-n junction-type thin film on ITO; with the observed quenching of CdSe NC emission. Several possible applications of such thin films are also discussed.