| 1. |
- Idla, K., et al.
(author)
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Good adhesion between chemically oxidized titanium and electrochemically deposited polypyrrole
- 2000
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In: Electrochimica Acta. - 0013-4686 .- 1873-3859. ; 45:13, s. 2121-2130
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Journal article (peer-reviewed)abstract
- A method for producing extremely adhesive polypyrrole (Ppy) films is described. The electrochemical synthesis of Ppy on thin chemically pre-oxidized Ti layers produces a mechanically strong, shiny polymer film with extremely good adhesion. Adhesion of Ppy films on Ti metal without chemical pre-oxidation is very weak. Two multilayer systems are described with Ppy as an electrochemically active layer, chemically oxidized Ti (TixOy) as a thin adhesive layer, and either a Si-wafer or Al foil as a substrate. Ppy films survive more than 6000 reduction-oxidation cycles in aqueous electrolyte without delamination. The possible mechanisms of enhanced adhesion are discussed. Those are: (1) increased adhesion due to changes in the chemical composition and surface structure of the pre-oxidized Ti, (2) the possibility of the chemical oxidation of pyrrole on the metal surface in addition to the electrochemical polymerization, (3) the adsorption of pyrrole molecules onto pre-oxidized Ti surface by interaction with Ti hydroxides on surface, and (4) the simultaneous growth of TixOy and Ppy.
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| 2. |
- Idla, K, et al.
(author)
-
XPS and SIMS study : adhesion of polypyrrole film on titanium
- 2000
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In: Surface and Interface Analysis. - 0142-2421 .- 1096-9918. ; 30:1, s. 557-560
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Journal article (peer-reviewed)abstract
- We have investigated why chemically preoxidized Ti (TixOy) shows strongly enhanced adhesion towards electrochemically deposited polypyrrole (Ppy) films as compared to Ti substrate with only native oxide overlayers, The XPS and SIMS results indicate that considerable amounts of TixOy are present 50-200 nm above the nominal Ppy interface. On the basis of XPS background analysis, supported by the results of SIMS, we suggest that the formation of a titanium-Ppy intermediate layer during the electrochemical synthesis leads to the enhanced adhesion observed. Copyright (C) 2000 John Wiley & Sons, Ltd.
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