Solvent-Free and Highly Transparent SiO2 Nanoparticle–Polymer Composite with an Enhanced Moisture Barrier Property

Solvent-free SiO 2 –poly(trimethylolpropane triacrylate) (SiO 2 –PTPT) nanocomposites are successfully fabricated for an encapsulation layer by surface modification of a SiO 2 nanoparticle. In order to lead surface-initiated polymerization and introduce structural similarity between a SiO 2 surface and polymer, the surface of the SiO 2 nanoparticles are modified with [3-(methacryloyloxy)propyl]trimethoxysilane. The modified SiO 2 nanoparticle dispersed in trimethylolpropane triacrylate (TPT) is converted to a SiO 2 –PTPT nanocomposite under UV irradiation. Because SiO 2 incorporated in a polymer generates a tortuous path and absorbs a water molecule, the SiO 2 –PTPT nanocomposite shows a considerably lower water vapor transmission rate than PTPT. All of the nanocomposite films are highly transparent (over 98%) in the visible region before and after humidity aging tests. Furthermore, a li…