@article {1282, title = {Pre-treatments applied to oxidized aluminum surfaces to modify the interfacial bonding with bis-1,2-(triethoxysilyl)ethane (BTSE) - Part I. High-purity Al with native oxide}, journal = {Applied Surface Science}, volume = {252}, number = {5}, year = {2005}, note = {ISI Document Delivery No.: 993WHTimes Cited: 5Cited Reference Count: 39}, month = {Dec}, pages = {1293-1304}, type = {Article}, abstract = {A remote microwave-generated H-2 plasma and heating to 250 degrees C were separately used to modify high-purity oxidized aluminum surfaces and to assess whether these treatments can help enhance adhesion with bis-1,2-(triethoxysilyl)ethane (BTSE) coatings. Different initial oxide surfaces were considered, corresponding to the native oxide and to surfaces formed by the Forest Products Laboratory (FPL) treatment applied for either 15 or 60 min. BTSE is applied from solution at pH 4, and competing processes of etching, protonation (to form OH groups) and coupling (to form Al-O-Si interfacial bonds) occur at the solid-liquid interface. Scanning electron microscopy (SEM) was used to determine how the topographies of the modified Al surfaces changed with the different pre-treatments and with exposure to a buffer solution of pH 4. Secondary-ion mass spectrometry (SIMS) was used to determine the direct amount of Al-O-Si interfacial bonds by measuring the ratio of peak intensities 71-70 amu, while X-ray photoelectron spectroscopy (XPS) was used to determine the overall strength of the silane coating adhesion by measuring the Si 2p signals before and after application of an ultrasonic rinse to the coated sample. Measured Al 2p and O 1s spectra helped assess how the different pre-treatments modified the various Al oxidized surfaces prior to BTSE coating. Pre-treated samples that showed increased Al-O-Si bonding after BTSE coating corresponded to surfaces, which did not show evidence of significant etching after exposure to a pH 4 environment. This suggests that such surfaces are more receptive to the coupling reaction during exposure to the BTSE coating solution. These surfaces include all H-2 plasma-treated samples, the heated native oxide and the sample that only received the 15 min FPL treatment. In contrast, other surfaces that show evidence of etching in pH 4 environments are samples that received lower amounts of Al-O-Si interfacial bonding. Overall, heating improved the BTSE adhesive bonding for the native Al oxide, while H-2 plasma treatment improved the BTSE bonding for surfaces that had initially been FPL-treated for 15 and 60 min. (c) 2005 Elsevier B.V All rights reserved.}, keywords = {aluminum, ESCA, OXIDATION, PARALLEL FACTOR-ANALYSIS, silane adsorption, SILANE COUPLING AGENTS, SIMS, SPECTROSCOPY, surface pre-treatment, THIN-FILMS, TOF-SIMS, X-ray photoelectron, XPS, XPS INVESTIGATIONS, ZIRCONIUM-OXIDE}, isbn = {0169-4332}, url = {://000233985900014}, author = {Teo, M. and Kim, J. and Wong, P. C. and Wong, K. C. and Mitchell, K. A. R.} } @article {1004, title = {Investigations of interfaces formed between bis-1,2-(triethoxysilyl)ethane (BTSE) and aluminum after different Forest Product Laboratory pre-treatment times}, journal = {Applied Surface Science}, volume = {221}, number = {1-4}, year = {2004}, note = {ISI Document Delivery No.: 759CXTimes Cited: 11Cited Reference Count: 28}, month = {Jan}, pages = {340-348}, type = {Article}, abstract = {The adhesion performance of bis-1,2-(triethoxysilyl)ethane (BTSE) coatings on high-purity aluminum surfaces, which have been subjected to a Forest Products Laboratory (FPL) pre-treatment for different times, has been assessed with secondary-ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). After coating, SIMS measurement of the ratio of peak intensities at 71 to 70 amu is used to identify the direct Al-O-Si bonding. The overall strength of the silane adhesion is assessed by comparing measurements of the Si 2p signals before and after application of an ultrasonic rinse to the coated sample. For the shorter FPL pre-treatment times (<10 min), substantial BTSE adsorption occurs on less-firmly anchored parts of the oxide which can be removed by the sonication test. The optimal adhesive bonding is indicated by these more microscopic studies to occur with the pre-treatments in the 10-25 min range, and this is in close correspondence with the normal FPL recipe that has been identified by performance in macroscopic tests. Pre-treatments longer than 25 min modify the surface topography further and give less direct Al-O-Si bonding, although the total BTSE adsorption is essentially constant and the adhesion remains strong enough to survive the sonication test. (C) 2003 Elsevier B.V. All rights reserved.}, keywords = {ADHESION, ALLOY-COATED STEEL, aluminum, corrosion, DURABILITY, GAMMA-GLYCIDOXYPROPYLTRIMETHOXYSILANE, metals, silane adsorption, SILANES, SIMS, surface pre-treatment, SURFACES, TECHNOLOGY, TOF-SIMS, XPS}, isbn = {0169-4332}, url = {://000187721700043}, author = {Teo, M. and Kim, J. and Wong, P. C. and Wong, K. C. and Mitchell, K. A. R.} }