Silica nanoparticles synthesized from tetraethoxysiliane (TEOS) via a sol-gel process were surface-modified by using 3-(trimethoxysilyl)propyl methacrylate (MSMA) and 1H, 1H, 2H, 2H- perfluorooctyltriethoxysilane (13F). MSMA acted as a coupling agent and a C=C provider, whereas 13F was employed to enhance hydrophobicity. The surface-modified silica particles together with a multi-functional monomer were UV-cured to yield highly transparent thin films (~7 μm) on plastic substrates. Both FE-SEM imaging and UV-visible spectroscopy confirmed uniform dispersion of nano-silica in the hybrid thin films. The coating surfaces were extremely smooth, with average roughness over the range 1.0-2.3 nm based on profilometric measurements. X-ray photoelectron spectroscopy indicated that surface-modified silica particles have migrated to the top surface to reduce the surface energy. Therefore, only a small dosage of 1 mol% (vs. TEOS) was enough to engender surface hydrophobicity with water contact angle of 100°. Furthermore, all of the prepared coatings were hard with pencil hardness reached 6H, and they adhered strongly to the poly(methyl methacrylate) substrate according to the peel test.
關聯:
Journal of applied science and engineering 18(4), p.387-394
