Photonic silica microspheres

As shown in Fig. 8.9A, a full-color photonic crystal device was designed and fabricated in a form of electrochemical cell (Arsenault et al., 2007). The device was based on a two-component composite, that is, silica microspheres and polyferrocenylsilane (PFS). The silica microspheres with an ordered self-assembly array were deposited on ITO glass substrate and served as the inactive structural scaffold. PFS with pendant unsaturated C=C bonds were incorporated into the lattice spacing of silica microspheres and polymerized... 

Yamasaki T., Tsutsui T. Fabrication and optical properties of two-dimensional ordered arrays of silica microspheres. Ipn. J. Appl. Phys. 1999 38 5916-5921 Yang P., Rizvi A.H., Messer B., Chmelka B.F., Whitesides G.M., Stucky G.D. Patterning porous oxides within microchannel networks. Adv. Mater. 2001 13 427431 Ye Y.H., Mayer T.S., Khoo I.C., Divliansky I.B., Abrams N., Mallouk T.E. Self-assembly of three-dimensional photonic-crystals with air-core line defects. I. Mater. Chem. 2002 12 3637-3639... 

Ordered macroporous materials (OMMs) are a new family of porous materials that can be synthesized by using colloidal microspheies as the template. - The most unique characteristics of OMMs are their uniformly sized macropores arranged at micrometer length scale in three dimensions. Colloidal microspheres (latex polymer or silica) can self assemble into ordered arrays (synthetic opals) with a three-dimensional crystalline structure. The interstices in the colloidal crystals are infiltrated with a precursor material such as metal alkoxide. Upon removal of the template, a skeleton of the infiltrated material with a three-dimensionally ordered macroporous structure (inverse opals) is obtained. Because of the 30 periodicity of the materials, these structures have been extensively studied for photonic applications. In this paper, the synthesis and characterization of highly ordered macroporous materials with various compositions and functionalities (silica, organosilica, titana, titanosilicate, alumina) are presented. The application potential of OMMS in adsorption/separation is analyzed and discussed. 

Colloidal photonic crystals are often synthesized from monodisperse microspheres of PMMA, PS, and silica. The use of functionalized microspheres can increase the performance of certain photonic devices and CCTP has been successful in the synthesis of NC-loaded photonic crystals with a polymerizable macromonomer. Monodisperse microspheres composed of a PS core with a poly(methacrylic acid) (PMAA) shell were synthesized through an emulsion copolymerization of PMAA macromonomers synthesized by CCTP with PS. It was found that the CdZnS NCs capped with PMAA macromonomers could be anchored to the microsphere surface as the PMAA acts as a ligand. These colloidal crystals are then formed into a film, yielding well-ordered, hexagonal close packed structures that show pH-responsive behavior. All films with different hydrodynamic diameters simultaneously exhibit brilliant colors from red to blue, providing a promising avenue for the next generation of photonic devices. 

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