Influence of cerium (IV) ions on the mechanism of organosilane polymerization and on the improvement of its barrier properties

Suegama, P. H.; Melo, Hercílio Gomes de; Benedetti, Assis Vicente; Aoki, Idalina Vieira

doi:10.1016/j.electacta.2008.11.007

Cited by 64 publications

(71 citation statements)

References 45 publications

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“…In this context, sol-gel coatings have been investigated as potential replacements for chromate-based surface treatments for several metals [1][2][3][4][5]. Different silane derivatives have been used to protect metals from corrosion by forming a thin coating that acts as a physical barrier to delay the access of aggressive species to the substrate.…”

Section: Introductionmentioning

confidence: 99%

Improving the corrosion performance of hybrid sol–gel matrix by modification with phosphonic acid

Dalmoro

Santos

Baibich

et al. 2015

Progress in Organic Coatings

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Sol-gel films were prepared using different ratios of two silica precursors, vinyltrimethoxysilane (VTMS) and tetraethylorthosilicate (TEOS), targeting the anticorrosion treatment of aluminum alloy 2024-T3. The electrochemical behavior of the alloy coated with such films, which was studied in a 0.05 mol L -1 NaCl solution, revealed that the VTMS/TEOS ratio drastically affects the anticorrosion performance. Electrochemical impedance spectroscopy (EIS) results provided evidences that the best anticorrosive response occurs with the films prepared from 50% v/v ethanol, 46% v/v water, 3% v/v VTMS and 1% v/v TEOS. Moreover, the effects of the addition of ethylenediamine tetra(methylene phosphonic acid) (EDTPO) to a hybrid sol-gel matrix were examined. The corrosion resistance was considerably improved when the concentration of added phosphonic acid was 3.7510 -5 mol·L -1 . Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analyses revealed that EDTPO-containing films provide a more uniform coverage. Results evidenced the formation of Si-O-Al linkages in the VTMS/TEOS and VTMS/TEOS/EDTPO systems and that the VTMS/TEOS/EDTPO system contained P-O-Al linkages. The P-O-Al bonds, combined with the silica network action, may be responsible for the good anticorrosive behavior of the VTMS/TEOS/EDTPO films.

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Section: Introductionmentioning

confidence: 99%

Improving the corrosion performance of hybrid sol–gel matrix by modification with phosphonic acid

Dalmoro

Santos

Baibich

et al. 2015

Progress in Organic Coatings

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“…In particular cerium III and IV ions has been shown to satisfy several basic requirements expected from a corrosion inhibitor, for example, to increase the degree of polycondensation of the amorphous network, to form insoluble nontoxic oxides and hydroxides, besides to be relatively cheap and easy to handle (Pepe et al, 2004). The effects of cerium ions in the structure of the hybrids deposited by dip-coating has been investigated by several authors (Pepe et al, 2004;Suegama et al, 2009), including our group , showing from the analysis of nuclear magnetic resonance and X-ray photoelectron spectroscopy data the active role of Ce(IV) on the densification of the polysiloxane films, i.e., the finding that free radical reactions between neighboring silanol and ethanol groups, induced by the reduction of Ce(IV), increases the connectivity of the hybrid network, resulting in elevated corrosion protection efficiency of the coatings.…”

Section: Introductionmentioning

confidence: 99%

Corrosion Resistant Coatings Based on Organic-Inorganic Hybrids Reinforced by Carbon Nanotubes

Hammer¹,

Santos²,

Cerrutti³

et al. 2012

Recent Researches in Corrosion Evaluation and Protection

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confidence: 99%

Influence of Ce(III)/Ce(IV) - supplements on the Characteristics of Humidity Sensors with TiO<sub>2</sub> Films Prepared via a Sol-gel Method

Kozhukharov¹,

Nenova²,

Nenov³

et al. 2013

Bol. Soc. Esp. Ceram. Vidr.

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-ions appear to have a beneficial effect on the polymerization of the respective sol-gel systems, when a Ce-compound is added to them [22]. The addition of cerium compounds also leads to the synthesis of advanced ceramics with high ionic and electron conductivity [23]. In particular, Ce-oxide [24,25] and Ce-Ti-oxide films [26,27] have electrical properties, which enable their application in various kinds of sensors, for example, in oxygen gas sensors, developed on the basis of Ti-oxide and Ce-Ti-oxide films [28]. Compared to other frequently used dopants for metal oxide humidity Humidity sensors have been prepared via a sol-gel method to deposit TiO 2 films with additions of Ce-compounds on alumina substrates, with interdigitated silver palladium electrodes. Observations by scanning electron microscopy (SEM) were performed in order to determine the surface morphology of the respective layers. Structural and compositional characterization was done by X-ray diffraction analysis (XRD), and energy dispersive X-ray spectroscopy (EDX) for investigation of the relation between the film structures and the parameters of the respective sensors. The influence of Ce-compounds on the electrical characteristics of the samples as humidity sensing elements has been evaluated by an impedance analyzer.

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Influence of cerium (IV) ions on the mechanism of organosilane polymerization and on the improvement of its barrier properties

Cited by 64 publications

References 45 publications

Improving the corrosion performance of hybrid sol–gel matrix by modification with phosphonic acid

Improving the corrosion performance of hybrid sol–gel matrix by modification with phosphonic acid

Corrosion Resistant Coatings Based on Organic-Inorganic Hybrids Reinforced by Carbon Nanotubes

Influence of Ce(III)/Ce(IV) - supplements on the Characteristics of Humidity Sensors with TiO<sub>2</sub> Films Prepared via a Sol-gel Method

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