Roll-to-roll fabrication of large-scale polyorgansiloxane thin film with high flexibility and ultra-efficient atomic oxygen resistance

One of the most widely used and well-established atomic oxygen (AO) protection solutions for low Earth orbit (LEO) satellites is the deposition of protective coatings on polymeric materials. However, manufacturing extensive expanses of these coating materials with good transparency, flexibility, smoothness, ultra-thinness, and exceptional AO resistance remains a critical issue. Herein, we successfully deposited a 400 nm thick polyorgansiloxane (SiO_xC_yH_z) coating with high optical transparency and uniform good adherence on to a 1.2 m wide polyimide surface, by optimizing the distribution of hexamethyldisiloxane and oxygen as precursors in the roll-to-roll compatible plasma-enhanced chemical vapor deposition process. After AO irradiation with the fluence of 7.9×10²⁰ atoms·cm^–2, the erosion yield of the SiO_xC_yH_z-coated Kapton was less than 2.30×10^–26 cm³·atom^–1, which was less than 0.77% of that of the Kapton. It indicates that the SiO_xC_yH_z coating can well prevent the erosion of Kapton by AO. In addition, it was also clarified that a SiO₂ passivation layer was formed on the surface of the SiO_xC_yH_z coating during AO irradiation, which exhibited a 'self-reinforcing' defense mechanism. The entire preparation process of the SiO_xC_yH_z coating was highly efficient and low-cost, and it has shown great potential for applications in LEO.