Abstract:

The electrochem. assisted codeposition of sol-gel thin films on stainless steel is described. Specifically, electrodeposition of films based on aminopropyltriethoxysilane (APTS), and its codeposition with propyltrimethoxysilane (PrTMOS) and phenyltrimethoxysilane (PhTMOS) has been accomplished by applying neg. potentials. The latter increases the concn. of hydroxyl ions on the stainless steel surface and thus catalyzes the condensation and deposition of the sol-gel films. The films were characterized by profilometry, electrochem. impedance spectroscopy (EIS), a.c. voltammetry (ACV), goniometry, at. force microscopy (AFM) and SEM. AFM and SEM anal. of codeposited APTS:PrTMOS films disclosed the structural changes induced by altering the deposition soln. compn. and the applied potential. Codeposited APTS:PhTMOS did not show any structural differences from their electrodeposited homopolymers, while Nano Scratch Test clearly revealed the changes in the elastic and adhesion properties, suggesting the formation of an APTS:PhTMOS composite. EIS of the films showed good resistance towards penetration of hydrophilic species, such as hexacyanoferrate. ACV measurements of the homo and codeposits showed the decrease of the interfacial capacity as a result of the electrochem. deposition. In essence, controllable sol-gel films with tunable chem. and phys. properties based on controlling the combination of the precursors, pH and electrochem. properties can be electrodeposited on conducting surfaces. The application of this approach has been demonstrated by coating a stainless steel coronary stent. [on SciFinder(R)]

Notes:

CAPLUS AN 2010:1430390(Journal)