Transparent Polymer Nanocomposite with Three-Dimensional ZnO Thin-Shell with High UV-Shielding Performance

This paper introduces a nontrivial concept of transparent nanocomposite with a three-dimensional (3D) ZnO thin-shell, as a UV-shielding reinforcement which absorbs all ranges of UV light, including UV-A (320 nm - 400 nm). The continuous and ordered geometry of the 3D ZnO thin-shell, uniformly distributed in an epoxy matrix, efficiently captures incident UV light by repeatedly scattering and absorbing the UV light at the epoxy-ZnO interfaces. Proximity-field nanoPatterning (PnP) and atomic layer deposition (ALD) can be employed to produce a 3D ZnO thin-shell array on a large scale (>1 inch2). The fabricated 3D ZnO/epoxy nanocomposite film exhibits excellent UV-shielding performance, blocking 95.20 % of UV-A light. Transmittance at the edge of the UV-A range (400 nm) is suppressed by 64 % (from 86 % to 31 %), while transmittance in the visible range (550 nm) is retained (from 90 % to 75 %). Moreover, the UV-shielding capability of the 3D nanocomposite film can be tailored by controlling the ZnO shell thickness from 0 nm to 45 nm. The 3D ZnO/epoxy nanocomposite provides a good option for next-generation transparent UV-shielding films.