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Grignard B.,University of Liege | Vaillant A.,University of Mons | De Coninck J.,University of Mons | Piens M.,Coating Research Institute CoRI | And 3 more authors.

Superhydrophobic aluminum surfaces with excellent corrosion resistance were successfully prepared by electrospinning of a novel fluorinated diblock copolymer solution. Micro- and nanostructuration of the diblock copolymer coating was obtained by electrospinning which proved to be an easy and cheap electrospinning technology to fabricate superhydrophobic coating. The diblock copolymer is made of poly(heptadecafluorodecylacrylate-co-acrylic acid) (PFDA-co-AA) random copolymer as the first block and polyacrylonitrile (PAN) as the second one. The fluorinated block promotes hydrophobicity to the surface by reducing the surface tension, while its carboxylic acid functions anchor the polymer film onto the aluminum surface after annealing at 130 °C. The PAN block of this copolymer insures the stability of the structuration of the surface during annealing, thanks to the infusible character of PAN. It is also demonstrated that the so-formed superhydrophobic coating shows good adhesion to aluminum surfaces, resulting in excellent corrosion resistance. © 2010 American Chemical Society. Source

Brusciotti F.,Vrije Universiteit Brussel | Batan A.,Free University of Colombia | Batan A.,University of Namur | De Graeve I.,Vrije Universiteit Brussel | And 8 more authors.
Surface and Coatings Technology

Thin silane films with the incorporation of nano-dispersed CeO2 particles have been deposited by dip-coating over aluminium substrates. The silane molecule under investigation is bis-1,2-(triethoxysilyl)ethane (BTSE), which has been used as a water-based solution in order to fulfill the industry need for reducing the impact on human health and environment. The influence of the nano-oxides on the silane was first analyzed in the solution by means of 29Si NMR, which showed that the ageing and stability of BTSE are not affected by the presence of CeO2 nanoparticles in the silane matrix. The chemical interactions between CeO2 nanoparticles and the BTSE in the cured coating were investigated by XPS, and the results pointed to the possible formation of a bond between Ce and Si. Field emission scanning electron microscopy (FE-SEM), field emission Auger electron spectroscopy (FE-AES) and focused ion beam coupled with transmission electron microscope (FIB-TEM) were used to investigate the film structure and surface morphology. A major challenge in the formation of thin layers with the incorporation of nano-oxides is to avoid the formation of particles agglomeration, which affects the film uniformity and might create preferential paths for corrosion attack. This issue has been overcome and the resulting films appear uniform and homogeneous, with the nanoparticles well embedded in the silane matrix and always covered by a thin silane layer. Electrochemical impedance spectroscopy (EIS) measurements have been performed on the samples and the results show how the barrier properties of the thin silane films are improved by the addition of CeO2 nano-dispersed particles. © 2010 Elsevier B.V. Source

Batan A.,Free University of Colombia | Batan A.,University of Namur | Brusciotti F.,Vrije Universiteit Brussel | De Graeve I.,Vrije Universiteit Brussel | And 6 more authors.
Progress in Organic Coatings

Silane coatings are applied to metal surfaces for various purposes, e.g., to form a protective layer against corrosion or to act as a primer for subsequent coating. In this work bis-1,2-(triethoxysilyl) ethane (BTSE) was used as a precursor to deposit coatings on Al 99.99% substrates with three different techniques: dipcoating (water based solution), vacuum plasma and atmospheric plasma. Infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS) and field emission gun-scanning electron microscope (FE-SEM) were used to characterise the structure, composition and surface morphology of the silane coatings. The aim of this investigation is to compare the surface and bulk characteristics of the films prepared with the three different methods, in order to get information on how the BTSE molecule is modified by the deposition technique. The results show that films could be deposited by both vacuum and atmospheric plasma, besides the more traditional wet dipcoating. The layers deposited by vacuum plasma can be considered as hybrid organic-inorganic, comparable to the silane layers obtained by dipcoating. Atmospheric plasma treatment, however, leads to the formation of more inorganic films richer in Si-O bonds. XPS and FTIR measurements show the presence of Si-O-Si bonds, while Si-O-Si, Si-O-C, Si-O and Si-CH3 absorption bands are revealed by IRRAS measurements. © 2010 Elsevier B.V. Source

Batan A.,Free University of Colombia | Batan A.,University of Namur | Mine N.,University of Namur | Douhard B.,University of Namur | And 8 more authors.
Chemical Physics Letters

Silane and silane-like films were deposited from bis-1,2-(triethoxysilyl) ethane by vacuum and atmospheric plasma onto aluminium. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used for probing the aluminium/plasma polymer film interface. An AlOSi+ fragment was identified at nominal mass m/z = 70.9539 amu, indicating a strong chemical interaction (formation of a covalent bond) at the substrate/film interface. Until now, this strong silane-aluminium interaction has never been observed in plasma polymer BTSE films. Ageing tests in an ultrasonic water bath combined with X-ray photoelectron spectroscopy measurements allowed to indirectly confirm good adhesion, and therefore the formation of a chemical bond at the interface. © 2010 Elsevier B.V. All rights reserved. Source

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