Coating of a stainless steel tube-wall catalytic reactor with thermally treated polysiloxane thick films.
Résumé
Homogeneous polysiloxane films were deposited on a 316L stainless steel by plasma assisted chem. vapor deposition process. Thicknesses up to 10mm were developed. The organosilicon films were then thermally treated under air and the influence of calcinations conditions was investigated by IR spectroscopy, Raman microscopy and XPS. On all films, it appears that the structure varies according to the thermal treatment parameters. Indeed the surface compn. appears to be SiO1.8 which might represent a structure close to amorphous silica whereas the deepest layers retain a variable org. nature. Under the severer treatments, the nature of the deposit evolves toward a low reticulated glass-like silicon oxide but cannot be related to an amorphous silica structure. At 1273K the steel remains coated and hidden despite visible but non penetrating cracks of the upper layer of the phys. barrier.