Improved barrier performance of metal alkoxide-modified methyltrimethoxysilane films

Homogeneously modified methyltrimethoxysilane (MTMS) films used as the barrier layers were fabricated on stainless steel substrates by introducing only very low amount of metal alkoxide, e.g. tetrabutyl orthotitanate or tetrabutyl orthozirconate into the silane/ethanol/water precursors. The modified films exhibit tremendous improvement in their barrier performance, along with higher compactness, hydrophobicity and thickness. Solution analysis of the silane precursors indicated that both the hydrolysis and condensation reactions of MTMS were significantly facilitated in the presence of metal alkoxide. A schematic description for the promoted formation of metal alkoxide-modified silane films which is in accordance with our findings is given.