title: Characterization of diffusion-controlled mass transport through nanoporous and nanothin films plasma polymerized on a sputtered platinum electrode.
abstract: We demonstrate the diffusion mode of various redox chemical species through a plasma-polymerized nanothin coating with nanometer-sized pores on a sputtered platinum (Pt) electrode. In this work, hexamethyldisiloxane plasma-polymerized films (PPFs) were added onto the sputtered platinum film, both of which were sequentially deposited in the same vacuum chamber. Results of atomic force microscopy, X-ray photoelectron spectroscopy, and electrochemical studies showed that the PPF provided the platinum electrode with a coating with a complete surface coverage. Sub-nanometer-sized pores (less than 1 nm) responsible for a highly crosslinked polymer network in the PPF coatings offered diffusivity-controlled permeation of redox molecules (i.e., size-exclusivity) rather than solubility-controlled permeation (i.e., chemoselectivity). Consequently, variation of the plasma power could give control over the size of the nanometer-sized cavities.
authors.affiliation: Department of Electronic Engineering, Shibaura Institute of Technology, 3-9-14 Shibaura, Minato-ku, Tokyo 108-8548, Japan. muguruma@sic.shibaura-it.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Muguruma
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Itazu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Miura