(142bf) Hydrothermal Degradation of Bis-Silane Films

Functionalized silanes are widely used as protective
coatings and interface coupling agents. 
Certain bis silanes, for example, are effective anti-corrosion
agents.  In virtually every
application, the longevity of the film is a key performance parameter.  Here we use neutron and x-ray
reflectivity to study the hydrothermal response of bis-silane films.  Of particular interest is the response
of silanes with amine and poly sulfur bridging groups as well as mixture of
these silanes.  The mixture is
known to afford better protection than either of the neat silanes.  Films were first studied at room
temperature–dry, in the presence of D₂O vapor and in the
presence of liquid D₂O. These studies showed considerable water
penetration, but minimal degradation. 
The amino-bridged film showed unusual behavior in that the film in
contact with liquid D₂O 
swelled less than when in contact with D₂O vapor.  These films were also hydrothermally
conditioned in H₂O for various time periods at 80 C.  Surprisingly, the hydrophilic amino
film showed less degradation than the hydrophobic sulfur bridged film.