Ussian Academy of Sciences, 119991 Moscow, Russia; [email protected] (M.P.); [email protected] (L.M.); [email protected] (T.Y.); [email protected] (A.M.) CNR-IAS, Via De Marini 6, 16149 Genoa, Italy; [email protected] Correspondence: [email protected]; Tel.: +33-298-456-241 Andrei Nazarov retired form French Corrosion Institute.Citation: Nazarov, A.; Petrunin, M.; Maksaeva, L.; Yurasova, T.; Traverso, P.; Marshakov, A. Vapour Phase Deposition of Thin Siloxane Coatings around the Iron Surface. The Effect of your Layer Structure and Oxygen Adsorption on Corrosion Stability. Coatings 2021, 11, 1217. https:// doi.org/10.3390/coatings11101217 Academic Editor: Rita Bacelar Figueira Received: 12 August 2021 Accepted: 15 September 2021 Published: 4 OctoberAbstract: The mechanism of iron corrosion protection by thin siloxane films was clarified. Quartz crystal microbalance method (QCM) was applied to manage the vapour phase deposition of alkoxysilanes plus the formation of thin siloxane films. It was shown that the addition of water vapour improved the thickness of the grafted siloxane films. Crystal-like films spontaneously grow to 106 monolayers at 100 RH of Ar flow because of the catalytic impact with the surface. X-ray photoelectron (XPS) and Auger spectroscopies analysed the thin siloxane films and Scanning Kelvin Probe (SKP) showed the formation of iron-siloxane bonds passivating the iron surface. The films showed higher hydrophobicity and corrosion inhibition in humid air contaminated by sulphur dioxide. Thick films were less ordered, hydrophilic and accelerated the corrosion of iron. For corrosion protection, the presence of oxygen in the atmosphere is exceptionally important. Within a wet Ar atmosphere, contaminated by sulphur dioxide, the surfaces are certainly not steady and swiftly corroded. Oxygen adsorption stabilizes the surface oxide film that correspondingly preserves the anchoring iron-siloxane bonds and enables corrosion protection by the coating. Keyword phrases: self-ordering siloxane films; hydrophobicity; corrosion protection; adsorption bonds; Scanning Kelvin Probe1. Introduction Corrosion protection of metallic building by polymeric coatings is broadly applied. It was supposed that polymeric coatings protect the substrate by acting as a barrier toward water, oxygen and ions. However, oxygen and water immediately Auranofin Protocol saturate the coating and these species could not be rate-determining things of corrosion protection by sophisticated coatings [1,2]. Kinsella and Mayne and Mayne and Scantlebury found that ionic resistance is a essential aspect in polymer coating stability, known as “resistance inhibition.” The connection in between the ionic resistance of a coating and its protective capability has been pointed out elsewhere [3,4] The ions in polymers diffuse relatively slowly and ionic resistance has been highlighted as a vital (even vital) property of a coating in contemporary performs [5,6]. However, also, the wet adhesion of the polymer for the substrate plus the stability of chemical bonds at the interface can be important things determining the overall coating lifetime [7,8]. Most polymer-metal bonds, which don’t have mechanical Splitomicin Formula interlocking, will ultimately fail when subjected to prolonged moisture exposure and anxiety [7]. The cause is the fact that the speak to of your oxidized metal surface of high surface power and polymeric coating of low surface power is thermodynamically unstable. In the interface, water molecules replace the polymeric coating major.