Electrophoretic deposition of functional organic molecules and composite films

2,2′-Bicinchoninic acid (BiqCOOH) exhibits a set of functional properties, which motivated the work of fabricating BiqCOOH films. Thin films of BiqCOOH were prepared potentiodynamically or under constant-voltage conditions from the solutions of dipotassium salt of 2,2′-bicinchoninic acid (BiqCOOK) in water or ethanol-water solvent. Electron microscopy investigations showed that the electrochemical assembly of BiqCOOH in aqueous solutions resulted in fibrous morphology while a flower-like morphology, containing rectangular prism-shaped particles, was the result in ethanol-water solutions. The anodic deposition mechanism for BiqCOOH has been proposed based on the analysis of cyclic voltammetry (CV), electron microscopy and FTIR data. The polyaromatic BiqCOOK molecules, containing chelating ligands, showed adsorption on a range of different materials, such as Pd, NiO and multi-walled carbon nanotubes (MWCNT). An electrophoretic deposition (EPD) method allowed for the manufacturing of Pd, NiO and MWCNT films using BiqCOOK as anionic dispersing and binding species. The results of this investigation have generated new possibilities in creating individual material and composite films for applications based on their functional properties.