Preparation and characterization of cerium doped silica sol–gel coatings on glass and aluminum substrates

Sol–Gel Synthesis of Tunable Cerium Titanate Materials

“…Despite rare earth ions stabilize the trivalent state, as it has been stated before, cerium compounds usually exhibit the coexistence of Ce 3+ and Ce 4+ species because of its particular electronic configuration. [36,37] The electron donation ability of Ce(III) facilitates the excitation of an electron from the 4f to the 5d shell, showing characteristic broad bands in the UV region between 330 and 200 cm -1 , although the main absorption band is around 310 cm -1 . [38] By other hand, Ce(IV) favors charge transfer (CT) transitions from the host ligands to the rare earth ions.…”

Self-healing coatings in anti-corrosion applications

“…Coatings produced using the sol-gel technique can be composed of several oxides whereby various protective properties can be obtained. In the literature, one can find descriptions of coatings containing SiO 2 , ZrO 2 , TiO 2 , as well as a cerium addition [78,79,81,[85][86][87][88][89][90][91][92][93][94][95][96]. Such coatings are used as a substitute for the chromate-based system, mainly to protect steel or aluminium alloys.…”

“…These coatings are enriched with substances improving corrosion resistance, such as cerium incorporated into montmorillonite nanoparticles, MBT or 2-mercaptobenzimidazole (MBI) [92,99]. The self-healing of the coating by means of lanthanides ions takes place as a result of the diffusion of these ions to the substrate surface and the formation of an insoluble layer of oxides and hydroxides (a cathodic inhibitor) [78,79,[85][86][87]. The effectiveness of inhibiting action of Ce(III) and Ce(IV) ions is comparable with that of the Cr(VI) ion [101].…”

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

“…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.…”