title: Immobilization of nanobeads on a surface to control the size, shape and distribution of pores in electrochemically generated sol-gel films.
abstract: Electrochemically assisted deposition of an ormosil film at a potential where hydrogen ion is generated as the catalyst yields insulating films on electrodes. When the base electrode is modified with 20-nm poly(styrene sulfonate), PSS, beads bound to the surface with 3-aminopropyltriethoxysilane (APTES) and using (CH3)3SiOCH3as the precursor, the resulting film of organically modified silica (ormosil) has cylindrical channels that reflect both the diameter of the PSS and the distribution of the APTES-PSS on the electrode. At an electrode modified by a 20-min immersion in 0.5 mmol dm-3APTES followed by a 30-s immersion in PSS, a 20-min electrolysis at 1.5 V in acidified (CH3)3SiOCH3resulted in an ormosil film with 20-nm pores separated by 100 nm. Cyclic voltammetry of Ru(CN)64-at scan rates above 5 mVs-1yielded currents controlled primarily by linear diffusion. Below 5 mVs-1, convection rather than the expected factor, radial diffusion, apparently limited the current.
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", UOS, Campus di Rimini, Università di Bologna, Rimini, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Ciabocco
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", UOS, Campus di Rimini, Università di Bologna, Rimini, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Berrettoni
authors.affiliation: Scuola di Scienze e Tecnologie, Università di Camerino, Camerino, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Zamponi
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH USA 45056.
authors.forename: James A
authors.initials: JA
authors.lastname: Cox
keywords: Electrochemical sol-gel processing; Electrode modification; Organically modified silica films; Polystyrene nanobeads; Templated pores