Optical diffraction from silica-poly(methyl methacrylate) composite films
Optical diffraction from silica-poly(methyl methacrylate) composite films
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DOI：
10.1021/la960891h
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发表时间：
1997-05-14
期刊：
影响因子：
3.9
通讯作者：
Ackerson, BJ
中科院分区：
文献类型：
--
作者：
Jethmalani, JM;Sunkara, HB;Ackerson, BJ
在甲基丙烯酸甲酯（MMA）分散体中的单分散的、152 nm直径的、无定形的胶体二氧化硅颗粒形成晶格并且布拉格吸收可见光。通过偏光显微镜观察成核、生长和微晶形态。264 μ m厚的MMA分散体膜的聚合捕获了坚固的二氧化硅-聚（甲基丙烯酸甲酯）（PMMA）复合材料中的晶体顺序。在MMA分散体中的35-45重量%的涂覆有甲基丙烯酸3-（三甲氧基甲硅烷基）丙酯（TPM-二氧化硅）的二氧化硅的UV-可见光谱在550和508 nm之间的波长处具有4 nm带宽的低百分比透射率（%T）峰。含有35- 37.5wt%TPM-二氧化硅的二氧化硅-PMMA复合膜在486-490 nm处具有低的%T峰，带宽为12-19 nm。使用442 nm氦镉激光器，在反射模式下观察到MMA分散体和PMMA复合材料的布拉格衍射。
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 mu m 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.