title: Electrochemically mediated atom transfer radical polymerization from a substrate surface manipulated by bipolar electrolysis: fabrication of gradient and patterned polymer brushes.
abstract: We report the first ever use of electrochemically mediated atom transfer radical polymerization (eATRP) employing a bipolar electrochemical method for the fabrication of both gradient and patterned polymer brushes. A potential gradient generated on a bipolar electrode allowed the formation of a concentration gradient of a Cu(I) polymerization catalyst through the one-electron reduction of Cu(II) , resulting in the gradient growth of poly(NIPAM) brushes from an initiator-modified substrate surface set close to a bipolar electrode. These polymer brushes could be fabricated in three-dimensional gradient shapes with control over thickness, steepness, and modified area by varying the electrolytic conditions. Moreover, by site-selective application of potential during bipolar electrolysis, a polymer brush with a circular pattern was successfully formed. Polymerization was achieved using both a polar monomer (NIPAM) and a nonpolar monomer (MMA) with the eATRP system.
authors.affiliation: Department of Electronic Chemistry, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan) http://www.echem.titech.ac.jp/∼inagi/e-index.html.
authors.forename: Naoki
authors.initials: N
authors.lastname: Shida
authors.forename: Yuki
authors.initials: Y
authors.lastname: Koizumi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nishiyama
authors.forename: Ikuyoshi
authors.initials: I
authors.lastname: Tomita
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Inagi
keywords: electrochemistry; gradient material; patterning; polymer brushes; polymers