A noticeable and persistent protective action against corrosion can be obtained by treatment the aluminium substrate with silane molecules containing a long aliphatic chain (e.g. octadecyltrimethoxysilane: C18), which can markedly increase the hydrophobic properties of the formed silane layer. This considerably retard not only the cathodic reaction, as in the case of a non-functional silanic compound (bis1,2- trioxymethyl-silyl-ethane: BTSE), but also the anodic process. A very prolonged action is also found towards the pitting process in the particularly aggressive chloride solution. At variance with the other silanic compounds, the layer of C18, although not uniform, tends to cover the whole aluminium surface completely and, in fact, its EIS spectra present only one time constant. The aqueous salt solutions may permeate through this layer, but with greater difficulties than in the other cases.
Inhibitive performances towards aluminium corrosion of silanic compounds with a long aliphatic chain
ZUCCHI, Fabrizio;TRABANELLI, Giordano;GRASSI, Vincenzo;FRIGNANI, Alessandro
2003
Abstract
A noticeable and persistent protective action against corrosion can be obtained by treatment the aluminium substrate with silane molecules containing a long aliphatic chain (e.g. octadecyltrimethoxysilane: C18), which can markedly increase the hydrophobic properties of the formed silane layer. This considerably retard not only the cathodic reaction, as in the case of a non-functional silanic compound (bis1,2- trioxymethyl-silyl-ethane: BTSE), but also the anodic process. A very prolonged action is also found towards the pitting process in the particularly aggressive chloride solution. At variance with the other silanic compounds, the layer of C18, although not uniform, tends to cover the whole aluminium surface completely and, in fact, its EIS spectra present only one time constant. The aqueous salt solutions may permeate through this layer, but with greater difficulties than in the other cases.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
