Functionally graded SiOx(=1~4) hybrid films with enhanced weather resistance and anti-electric properties prepared by one-step atmospheric-pressure plasma deposition

With the ongoing revolution of large-scale power transmission, higher requirements are put on operation stability of insulation surface to overcome complicated natural-electrical stresses. Here, we develop a one-step plasma-enhanced chemical vapor deposition (PECVD) method to fabricate graded organic-inorganic siloxane hybrid films using only polydimethylsiloxane (PDMS) as the precursor, significantly enhancing the surface weather resistance and anti-electric properties of insulation. Through customizing waterfall-like PECVD strategy with attenuated fragmenting-crosslinking reactions of PDMS precursor, graded SiO x(=1~4) hybrid films with distributed nanostructure morphologies and molecular compositions are deposited on epoxy resin substrate. The films exhibit gradient structures of surface morphologies (from nanoparticles accumulation to smooth), deposits thickness (from 11 μm to 3 μm) and chemical states (from inorganic SiO 4 to quasi-organic SiO 1~3 ). Owing to its unique graded structure, the graded SiO x hybrid films contribute to a typical wettability gradient surface from super-hydrophobicity to hydrophilicity, which promotes water resistance and water evaporation on insulation surface. Besides, the graded films could regulate surface capacitance and homogenize electric field distribution along material surface, leading to the improvement of flashover voltage. Quantum chemistry calculation is further conducted to reveal multistage synthesis mechanism of the waterfall-like PECVD for graded film fabrication. The one-step PECVD strategy provides a novel avenue for graded hybrid film preparation and high-performance surface modification, which has great potential for use in both electrical insulation and semiconductor manufacturing.