Abstract
Inorganic nanoparticle films (TiO2, ITO, ZnO, Al2O3, and SiO2) were prepared using the micelle disruption method by which a nonionic surfactant with an azobenzen group (AZPEG) was reduced electrochemically. The surfactant, which adsorbed onto the inorganic nanoparticles to disperse them in aqueous solution, was desorbed from nanoparticles by electrolysis of the surfactant micelles. Particle films are formed if the nanoparticles had sufficient hydrophobicity to attach to the electrode. The inorganic nanoparticles were treated with silane-coupling agents to impart hydrophobicity, and silane-coupling agents of the type affected the particle film formation because the particle hydrophobicity was changed with the silane-coupling agents of the type. The AZPEG concentration in particle dispersions played an important role in forming particle films: optimal AZPEG concentration to form particle films was present. The optimal AZPEG concentration increased continuously with increasing specific surface area of the inorganic nanoparticles. After the nanoparticles had covered the electrode surface, nanoparticle film growth proceeded because AZPEG diffused through spaces in nanoparticle films. It was then reduced on the electrode.
