Optical Diffraction from Silica−Poly(methyl methacrylate) Composite Films
| Autor: | Jagdish M. Jethmalani, Hari Babu Sunkara, Steven L. Willoughby, Bruce J. Ackerson, Warren T. Ford |
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| Rok vydání: | 1997 |
| Předmět: |
Materials science
Colloidal silica Dispersity Analytical chemistry Bragg's law Surfaces and Interfaces Condensed Matter Physics Methacrylate Poly(methyl methacrylate) Amorphous solid chemistry.chemical_compound chemistry visual_art Polymer chemistry Electrochemistry visual_art.visual_art_medium General Materials Science Crystallite Methyl methacrylate Spectroscopy |
| Zdroj: | Langmuir. 13:2633-2639 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la960891h |
| Popis: | Monodisperse, 152 nm diameter, amorphous, colloidal silica particles in methyl methacrylate (MMA) dispersions form crystal lattices and Bragg diffract visible light. Nucleation, growth, and crystallite morphology are observed by polarizing microscopy. Polymerization of 264 μm thick films of the MMA dispersion traps the crystal order in robust silica−poly(methyl methacrylate) (PMMA) composites. UV−vis spectra of 35−45 wt % of silica coated with 3-(trimethoxysilyl)propyl methacrylate (TPM−silica) in MMA dispersions have low percent transmittance (%T) peaks of 4 nm bandwidth at wavelengths between 550 and 508 nm. The silica−PMMA composite films containing 35−37.5 wt % TPM−silica have low %T peaks at 486−490 nm with 12−19 nm bandwidths. Using a 442 nm helium cadmium laser, the Bragg diffraction of a MMA dispersion and a PMMA composite is observed in the reflective mode. |
| Databáze: | OpenAIRE |
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