Electrografting

Bureau et al. (1) developed a method for forming a polymer film that behaved as a conductor or semiconductor on its surface by layering using electrografting. 

Fig. 4. Nanopatterning of alkynes using a conducting AFM tip for cathodic electrografting on H/Si(lll). The process is shown schematically at the left while representative line scans after electrografting with different alkynes are shown on the right. The observed heights in the AFM scans correlate well with the expected heights. Adapted from [39].

In order to improve the surface properties of carbon fibers without affecting the mechanical properties of the reinforcing fibers, various monomers, including pyrrole and carbazole, were used to electrograft conjugated copolymers and produce homogeneous and continuously coated carbon fiber surfaces <2001SM391>. 

J.H., and Wang, T.H. (2010) Electrografted poly (N -mercaptoethyl acrylamide) and Au nanoparticles-based organic/inorganic film a platform for the high-performance electrochemical biosensors. Chemistry-An Asian Journal, 5 (4), 919-924. 

Li and Niu et al. [69] employed the BmimPF -supported SWCNT electrode to execute electrografting poly(V-succinimidyl acrylate) (PNSA) onto their surfaces. 

ELECTROGRAFTING OF ORGANIC MONOLAYERS ON SILICON FOR MOLECULAR ELECTRONICS... 

In this article, we demonstrate cathodic electrografting of two different molecules on Si—H substrates (i) a a-molecule of short chain length. octyltrichlorosilane (CH3-(CH2)7-SiCl3 OTS) and (ii) a new a-Jl molecular rectifier. 5-(4-undecenyloxyphenyl)-10,15,20-triphenylporphyrin(2) (TPP-C11). 

Figure 2. Schematic showing two-step electrografting process of OTS (R represents the CH3 group) monolayer on Si via formation of Si—Si bonds.

Typical CVs for different scans are shown in Fig. 5. The peak observed for scan-1 at around -0.35 V is attributed to the oxidation of the vinyl group of the TPP-C11. Presence of only a single peak indicates the electron transfer from the Si substrate to the vinyl group is irreversible, and therefore represents the electrografting of the molecule. The gradual vanishing of the oxidation peak with... 

L. M. Santos, J. Ghilane, C. Fave, P.-C. Lacaze, H. Randriamahazaka, L. M. Abrantes, and J.-C. Lacroix, Electrografting polyaniline on carbon through the electroreduction of diazonium salts and the electrochemical polymerization of aniline, J. Phys. Chem. C, 112, 16103-16109 (2008). 

NFs acted as an oxidant to oxidatively polymerize aniline. Consequently, Mn O was completely consumed while PANl/TiO -NFs were formed. Composite fiber film having a PANI nanowire-on-TiO nano/microfiber hierarchical nano/microstructure was fabricated by electrospinning, calcinations and in situ polymerization [121], The photocatalytic electrodeposition of PANI in nanotubular TiO host matrice was recently reported by Janaky ef a/. [ 108]. TiO films were initially electrosynthesized on titanium foil by anodization at different voltages in fluoride-containing aqueous media, and then the PANI was electrografted onto the entire surface of... 

Our work employs electrochemically initiated polymerization (EIP) which is an easy and flexible method to produce surface coatings of various kinds. The technique makes use of the decomposition of an electro-active initiator at an electrode to start a free-radical polymerization. The polymer is formed directly at the electrode surface. As a consequence, the films adhere tightly to the surface. Adhesion is based on physisorption of the hydrogel to the metal. Note in this context that EIP is different from electrografting of conductive polymers. In EIP, the initiator is the electro-active species, rather than the monomer. Recently, we reported on the formation of thermoresponsive poly-A -isopropylacrylamide (pNIPAm) hydrogel coatings on gold surfaces based on this approach. ... 

Figure 9.7 Electrografting of amine groups on MWCNTs and postfunctionalization with complex 2 through amide links [51], This is a simplified representation of the structure of the material for sake of clarity The number of phenylene residues is indeed arbitrary and attachment of the nickel complex to two or more surface amine groups not excluded.

Scheme 6.1 Reductive electrografting of aryldiazonium on a carbon surface.

Scheme 6.4 Oxidative electrografting of amine on carbon surface.

Thus prepared layers have been further modified to develop electrocatalysts and sensors. Polypyridyl ruthenium-oxo complexes are of particular interest as efficient oxidants for a wide variety of organic molecules, including aromatic hydrocarbons, olefins, alcohols, and ketones. One such electrocatalyst was prepared by first electrografting bipyridine at an applied positive potential followed by treating the modified surface with [Ru tl2(DMSO)(terpyridine)] and then CFjSOjH/HjO [104]. Enhanced electrochemical activity has also been observed for the reduction of oxygen at anthraquinone-modified GC electrodes in 0.1 M KOH solution [105,... 

Scheme 6.6 Oxidative electrografting of alcohol on carbon surface.

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