The solution behavior of the polymeric surfactant Pluronic F127 (PEO(99)PPO(65)PEO(99)) and its adsorption behavior on aqueous-silica and aqueous-air interfaces, as well as the disjoining pressure isotherms of asymmetric films (silica/aqueous film/air) containing F127, are studied. The interfacial properties of adsorbed F127 layers (the adsorbed amount Gamma and the thickness h) as well as the aqueous wetting film properties [film thickness (h) and refractive indexes] were studied via ellipsometry. The solution properties of F127 were investigated using surface tensiometry and light scattering. The interactions between the air-water and silica-water interfaces were measured with a thin film pressure balance technique (TFB) and interpreted in terms of disjoining pressure as a function of the film thickness. The relations between the behaviors of the asymmetric films, adsorption at aqueous air, and aqueous silica interfaces and the solution behavior of the polymeric surfactant are discussed. Special attention is paid to the influence of the concentrations of F127 and NaCl. Addition of electrolyte lowers the critical micelle concentration, diminishes adsorption on silica, and increases the thickness of the asymmetric film.

The aerospace industry progressively develops alternatives for chromic acid anodizing, because Cr(VI) is known to be toxic and carcinogenic. In this work, potentiodynamic anodizing of AA1050 and AA2024-T3 clad was performed in phosphoric-sulfuric acid (PSA) and sulfuric acid (SAA). All anodizing cycles started with a linear voltage sweep, followed by a constant voltage, or a dynamic voltage. Current density responses were recorded during each anodizing cycle and comprised different stages, which could be related to growth phases of the anodic oxide film. Interesting differences were found between cycles with an intermediate increase in anodizing voltage versus cycles with an intermediate decrease in voltage. Cycles including an increase in voltage resulted in higher anodic oxide formation efficiencies because of a temporary exceedance of the steady state current (recovery period) directly after the voltage step. Also, a sudden decrease in voltage led to distinct border between a fine and coarse region in the film morphology, while a sudden increase in voltage did not. For prolonged anodizing in PSA, coarsening of the upper film part was observed because of the high solubility of Al 2 O 3 in phosphoric acid. Pore walls close to the outer surface did not only get thinner, but completely dissolved in the electrolyte. Consequently, anodic oxide formation efficiencies were higher for SAA than for PSA.

A gold-aluminium material combination is typically employed as an interconnection for microelectronic devices. One of the reliability risks of such devices is that of corrosion of aluminium bond pads resulting from the galvanic coupling between an aluminium bond pad and a gold wire. The research presented in this manuscript focuses on studying bond pad corrosion by selecting an appropriate model system and a dedicated set of electrochemical and analytical experimental tools. Taking into account the complex three-dimensional structure and the small dimensions of Au-Al interconnections (around 50-100 mm), a dedicated and novel experimental approach was developed. Au-Al covered silicon chips were developed under clean room conditions. Three-dimensional electrodes were mimicked as flat, two-dimensional bond pad model systems, allowing the use of microelectrochemical local probe techniques. Thin gold films were applied on Ti-Al covered silicon surfaces, and their morphology and electrochemical behaviour were analysed using the localised electrochemical cell, scanning vibrating electrode technique, scanning electron microscopy-energy dispersive X-ray spectroscopy, scanning electron microscopy-focused ion beam and Auger electron spectroscopy. The results revealed that the electrochemical behaviour of thin gold films was influenced by the underlying metal layers and the microstructural changes during heat treatment. The effect of the underlying layers on the electrochemical properties of the top gold layer was attributed to a mixed potential behaviour and microgalvanic interactions, which was more pronounced after heat treatment. Overall, the current experimental approach can be employed to study the mechanism of electrochemical events that are occurring on metallic interconnections in different electronic devices.