Phthalocyanine Based Advanced Corrosion Resistant Coatings By LbL Technique

Corrosion on metallic surfaces has been an ongoing and serious problem in the aeronautical industry. Advanced materials used for anticorrosive purposes contain heavy metals that damage the nature. Therefore, there is a need for improvement on environmental friendly coatings especially for the aeronautical industry.

In this study, anticorrosive thin film coatings are fabricated in order to prevent the metallic surfaces from the corrosive effect of singlet oxygen. Layer-by-layer (LbL) method is preferred as an alternative to literature. By the help of LbL it is possible to control the thickness and stability of the films. Oppositely charged materials (e.g polyelectrolytes) cover the surface of the substrate (glass, metal, Si-plate) by electrostatic attraction[1, 2]. Dip and spray LbL techniques are applied to obtain smooth and homogenous layers of polyelectrolytes and phthalocyanines[3]. The phthalocyanines have been embedded between the bilayers or tetralayers of thin multilayer films to get rid of corrosive effects of the highly reactive singlet oxygen by utilizing singlet oxygen reducing capability of these metal-centered compounds[4].

Electrochemical corrosion characterizations are performed to measure the corrosion resistance of the thin films. For this purpose, potentiodynamic polarization, Tafel, impedance and corrosion chamber tests are studied. Mechanical integrity of the films plays a great significance for demanding applications. Hardness/elastic modulus properties are analyzed to test the resistance of films. 

 

References:

1.    Decher, G., Hong, J. D., Schmitt, J., Buildup of Ultrathin Multilayer Films by a Self-Assembly Process .3. Consecutively Alternating Adsorption of Anionic and Cationic Polyelectrolytes on Charged Surfaces. Thin Solid Films, (1992). 210(1-2)(831-5).

2.    Decher, G., Fuzzy Nanoassemblies: Toward Layered Polymeric Multicomposites. Science, 1997. 277(5330): p. 1232-1237.

3.    El Harakeh, M., et al., Charge separation and photocurrent polarity-switching at CdS quantum dots assembly in polyelectrolyte interfaced with hole scavengers. Phys Chem Chem Phys, 2009. 11(28): p. 5962-73.

4.    Dumoulin, F., et al., Synthetic pathways to water-soluble phthalocyanines and close analogs. Coordination Chemistry Reviews, 2010. 254(23-24): p. 2792-2847.