Study on the effects of depositing parameters on the protection performance of plasma polymerized hexamethyldisiloxane coatings

Aluminium thin film is widely used for high reflectivity reflector. However, it is readily corroded in a variety of environments and in oxygen saturated water. Coatings deposition on it is considered as a way of increasing its corrosion resistance. Among all available deposition techniques, the use of plasma-assisted technologies has grown rapidly. Organosilicon monomers have been successfully used as precursors of Si-based films and among them hexamethyldisiloxane (HMDSO) has gained increasing interest owing to its lower cost and higher deposition rates comparing to similar silicon containing monomers. This work studies the effects of depositing parameters on the structure and composition of the coating and at last on the corrosion protection performance concerning their use as protective coatings on reflective aluminum metallisations. Therefore, we have done a serial of experiments and got corresponding samples with different parameters such as HMDSO glow discharge power and depositing time. In the experiments, the plasma polymerized HMDSO thin films have been obtained in a DC glow discharge from the monomer vapor. And then the corrosion protection performances are analyzed by environment experiments. To analyze the reason of the deposition parameters effect on protection performances, the chemical structure and composition of the films have been analyzed.