Interface analysis of inorganic films on polyimide with atomic oxygen exposure

Inorganic silica/alumina multilayer films with excellent mechanical and anti-atomic-oxygen erosion properties were fabricated on polyimide by the hybrid implanting and depositing processes. X-ray photoelectron spectroscopy demonstrated that the silica/alumina graded structures consisted of SiO and AlO bonds, as well as AlOSi and AlOC bonds in the transition layers. The results revealed that bonding between the alumina coating and the polymer occurred primarily via AlOC bonds, and SiOAl bonds were formed in the interface between silica and alumina coatings. The multilayer films presented good adhesion property, demonstrating that balanced internal stresses and alternating bonding structures were crucial for enhancing anti-crack performance. The multilayer inorganic films exhibited good anti-atomic-oxygen erosion properties were well matched with the behavior of adhesion property.

► Inorganic multilayer films were fabricated for protection against AO in LEO.
► The graded structures consisted of AlOSi and AlOC bonds in transition layer.
► Multilayer films were stitched by AlOC and SiOAl interconnected bonding networks.
► Balanced internal stress and alternating bonding structure were crucial for stability.