Paper PS+SE-FrM8
Atmospheric Plasma Deposition of Transparent Organosilicate Multifunctional Coatings on Plastics in Air

Friday, October 23, 2015, 10:40 am, Room 210A

Atmospheric plasma deposition is a versatile coating process that enables deposition on large and/or complex shapes in air. The low temperature plasma and solvent free process allows deposition on, and simultaneous functionalization of plastic substrates in a single step. Building on our previous studies, we demonstrate a highly efficient deposition method using two precursors, an inorganic tetraethoxysilane (TEOS) and an organic 1, 5-cyclooctadiene (CYC), to deposit multi-layer organosilicate transparent coatings on poly methyl methacrylate (PMMA) and silicon (Si) substrates with atmospheric plasma deposition in air. The coatings deposition rate, transparency, chemical composition and adhesion with the PMMA substrate were investigated. Using only the TEOS precursor, high density and elastic modulus coatings were deposited on PMMA but with poor adhesion. The addition of the organic CYC precursor allowed controlled incorporation of organic components into the coating molecular network which significantly improved adhesion. The deposition rate increased from ~65 nm/min for the single precursor to ~130 nm/min for the two precursor process. The coatings exhibited ~100% transmittance in the visible wavelength range. FTIR and Raman spectroscopy of the coatings showed that the organic component (-C-C-)_n in the coatings can be incorporated to form an organosilicate molecular network. This incorporation increased the coating deposition rate and also resulted in mechanical plasticity in the coatings. The adhesion of coatings with PMMA increased from ~2 J/m² to ~10 J/m² and the Young’s modulus ranged from 22GPa to 34GPa. Coatings structures including composition and coating thickness to achieve optimized hardness and adhesive properties are reported.