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Photonic Properties (photonic + property)
Selected AbstractsMetal-Free Click Polymerization: Synthesis and Photonic Properties of Poly(aroyltriazole)sADVANCED FUNCTIONAL MATERIALS, Issue 12 2009Anjun Qin Abstract Regioselective 1,3-dipolar polycycloadditions of tetraphenylethene (TPE)-containing diazides 1,3 and bis(aroylacetylene) 4 are initiated by simple heating, affording poly(aroyltriazole)s (PATAs) PI,PIII with high molecular weights in high yields. The PATAs are completely soluble in common organic solvents and stable at temperatures up to 358,°C. Thanks to their TPE units, the polymers show aggregation-induced emission and work as explosive sensors with high sensitivity. The PATAs are optically transparent in the whole visible spectral region. Their refractive indexes can be tuned to a great extent (,n,,,0.08) by simply changing their alkyl spacer lengths. The modified Abbé numbers of the PATAs are very high (up to 273), indicative of very low optical dispersions in the telecommunication-important wavelength region. UV irradiation through a photomask quenches the light emissions of the polymers, enabling the generation of two-dimensional fluorescent images without development. The polymers can be readily photo-crosslinked, yielding three-dimensional patterns with high resolutions. [source] Bio-Inspired Bottom-Up Assembly of Diatom-Templated Ordered Porous Metal Chalcogenide Meso/NanostructuresEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2009Han Zhou Abstract We put forward a novel and straightforward sonochemical process as a generic bottom-up assembly routeto produce ordered porous metal chalcogenide meso/nanostructures by templating of diatom frustules. We work with one of the most beautiful species of diatoms, Coscinodiscus lineatus, as a representative of diatoms with central symmetry, and with ZnS as the prototype, as it is a high refractive index material and is a typical material widely used in optics and photonics. ZnS replicas have been successfully synthesized from the interaction between the reactive surfaces of the frustules and the precursors under ultrasound. The inorganic replicas copy the morphology of the ordered porous structure and inherit its optical property, such as the existence of the photonic bandgap of the diatom frustules. It is possible to achieve tunable photonic properties in the replicas by assembly of various metal chalcogenide semiconductors of different refractive indexes. This bio-inspired discovery provides insight into the facile synthesis of elaborate meso/nanostructures from these marine microbes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Nanostructures: Biodegradable Porous Silicon Barcode Nanowires with Defined Geometry (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010Mater. The cover illustrates a forest of bicolor porous silicon nanowires with modulated porosity. M. Ferrari et al. report on page 2231 the synthesis of biodegradable porous silicon barcode nanowires with segment-specific morphological, mechanical, and photonic properties by metal-assisted etching. The presented phase diagrams of nanostructures contribute to clarify the competing roles of metal nanoparticles and ions in the formation of various silicon nanostructures, enabling application-specific design. [source] Formation and applications of stable 10 nm to 500 nm supramolecular porphyrinic materialsISRAEL JOURNAL OF CHEMISTRY, Issue 3 2005Charles Michael Drain Nanoscaled materials of organic dyes are of interest for a variety of potential applications because of the rich photonic properties that this class of molecules can impart. One mode to form such nanoscaled materials is via self-organization and self-assembly, using reasonably well understood methods in supramolecular chemistry. But there are inherent complexities that arise from the use of organic-based supramolecular materials, including stability toward dioxygen, structural stability, and nanoarchitectures that may change with environmental conditions. Porphyrinoids have rich photonic properties yet are remarkably stable, have a rigid core, are readily functionalized, and metalation of the macrocycle can impart a plethora of optical, electronic, and magnetic properties. While there are many <10 nm porphyrinic assemblies, which may or may not self-organize into crystals, there is a paucity of 10,500 nm porphyrinic materials that can be isolated and stored. A variety of strategies towards the latter nanoscopic porphyrinic materials are discussed in terms of design, construction, and nanoarchitecture. The hierarchical structures include colloids, nanorods, nanotubes, nanorings, and nano-crystalline materials. This prolegomenon emphasizes the supramolecular chemistry, structure-stability, and structure-function relationships. The goal herein is to examine general trends and delineate general principles. [source] | ||||||||||