Polymer-based composite with outstanding mechanically tunable refractive index
| Autor: | Virgilio Angel González González, Sandra E. Rodil, Moisés Hinojosa, Nasser Mohamed-Noriega |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Nanoparticle 02 engineering and technology 01 natural sciences Inorganic Chemistry chemistry.chemical_compound symbols.namesake Optics Ellipsometry 0103 physical sciences Transmittance Electrical and Electronic Engineering Physical and Theoretical Chemistry Spectroscopy 010302 applied physics chemistry.chemical_classification business.industry Organic Chemistry technology industry and agriculture Polymer 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Membrane chemistry Chemical engineering Barium titanate symbols 0210 nano-technology business Raman spectroscopy Refractive index |
| Zdroj: | Optical Materials. 58:18-23 |
| ISSN: | 0925-3467 |
| DOI: | 10.1016/j.optmat.2016.03.039 |
| Popis: | A composite with high visible light transmittance, mechanically tunable refractive index (RI) and rubber-like mechanical properties, based on poly(dimethylsiloxane) (PDMS) and barium titanate nanoparticles (BT) was prepared on three steps. First, BT nanoparticles were obtained by high-energy milling. Second, the nanoparticles were embedded in PDMS by in-situ polymerization; the BT content was varied up to 1.0 wt% (0.17 vol%). Finally, ∼0.5 mm membranes were prepared by solvent casting. The effect of the BT concentration was examined. Powder XRD and Raman spectroscopy revealed a tetragonal crystal structure for the nanoparticles. SEM images confirmed a mean particle size of ∼64 nm and together with EDX mappings showed a moderate dispersion of the nanoparticles in some membranes, whereas other exhibited agglomerates at the surface. The normal transmittance of the membranes was measured with a spectroscopic ellipsometer while they were stretched in-situ at different percentages. The RI variations as a function of strain were calculated from the transmittance spectra. The results exhibit surprising variations in the RI, up to ∼5 times higher than those associated to PDMS alone, implying that the presence of BT significantly influences the optical response of the PDMS when stretched. However, the response is neither linear nor well understood; further studies must be performed to clarify this new interaction. |
| Databáze: | OpenAIRE |
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