Superhard transparent hybrid nanocomposites for high fidelity UV-nanoimprint lithography

• Published in: Polymer (Guilford) Vol. 54; no. 22; pp. 6177 - 6183
• Main Authors: González Lazo, Marina A., Blank, Maïté, Leterrier, Yves, Månson, Jan-Anders E.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 18.10.2013; Elsevier
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Hybrid nanocomposites; Hyperbranched polymer; Polymer industry, paints, wood; Technology of polymers; UV nanoimprint lithography; UV nanoimprint lithography; Hybrid nanocomposites; Hyperbranched polymer; Viscoelasticity; Hybrid material; Silica; Photopolymerization; Optical properties; Crosslinked polymer; Nanocomposite; Manufacturing; Photolithography; Patterning; Light scattering; Ester polymer; Mechanical properties; Nanoimprint lithography; Experimental study; Microhardness; Acrylate polymer; Sol gel process; Morphology; Prepolymer; Light trap; Transparent material; Reflectance
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2013.09.004

Transparent hyperbranched acrylate nanocomposites were produced using different combinations of silica nanoparticles and silicon-based sol–gel precursors. The nanocomposites were processed using a dual-cure UV polymerization and condensation scheme. The viscosity of hybrid suspensions was found to be one to two orders of magnitude lower than that of particulate composites with the same equivalent silica fraction. The Vickers microhardness of the polymer was 112 MPa. It was equal to 190 MPa and 148 MPa for the hybrid composites and particulate composites with 20 vol% SiO2, respectively, and it was equal to 287 MPa for the hybrid material with 30 vol% SiO2. Light-trapping textures in the form of random sub-micron pyramidal features were replicated in the hybrid composites from a nickel template using UV-nanoimprint lithography. After optimization of the dual-cure process sequence, a very high replication fidelity was obtained for all investigated compositions, leading to a haze above 99% over the visible light spectrum and a very effective light scattering performance in a broad angular exposure. [Display omitted]