Doped organically modified silicate

Bardo A.M., Collinson M.M., Higgins D.A. Nanoscale properties and matrix-dopant interactions in dye-doped organically modified silicate thin films. Chan. Mata. 2001 13 2713-2721 Bauer R.K., de Mayo P., Ware W.R., Wu K.C. Surface photochanistry. The photophysics of pyrene adsorbed on silica gel, alumina and calcium fluoride. J. Phys. Chem. 1982 86 3781-3789 Biteau J., Chaput F., Boilot J.-P. Photochromism of spirooxazine-doped gels. J. Phys. Chem. 1996 lOfr. 9024-9031... 

Bardo, A. M., M. M. Collinson and D. A. Higgins (2001). "Nanoscale properties and matrix-dopant interactions in dye-doped organically modified silicate thin films." Chemistry of Materials 13(8) 2713-2721. 

Along with these recent technologies, sol-gel entrapped catalysts made of organically modified silicates (ORMOSIL) doped with one or... 

Scanning electron microscopy (SEM) used to investigate the structure of similar organically modified silicate (ORMOSIL) films shows that certain [Ru(dpp)3]2+-doped octyl-triethylorthosilicate (triEOS)-tetra-ethylorthosilicate (TEOS) composites form uniform, crack-free xerogel films (Figure 6.6) that can be used to construct high-sensitivity oxygen... 

Figure 6.5 A fluorinated organically modified silicate doped with [Ru(dpp)3]2+ is a highly sensitive 02 sensor. Fluorine here ensures unprecedented sensitivity and a remarkable stability (2% drift over 6 months). The material has been implemented in sol-gel handheld oxygen sensors that are already commercialized. (Reproduced from ref. 6, with permission.)...

A 1 1 complex of [Eu(fod)3] and Michler s ketone emits red luminescence under daylight illumination.Chemical shifts in the NMR spectra of adducts of [Ln(fod)3(bipy)] and [Ln(fod)3(phen)] are dipolar in origin.[Eu(ttfa)3(phen)] (ttfa = thenoyltrifiuoroacetonate) has been doped into organically modified silicate matrices on reaction with hexamethyldisilazane, a composite phosphor with high emission intensity was formed.The first perfiuoroacetylaceto-nate complexes have been reported. " ... 

In this chapter, recent progress in several key areas is reviewed. These areas are catagorized by material classification rather than by end-use application (1) bulk silica optics (2) optically active doped silica glasses (3) gel-polymer composites (4) organically modified silicates (ormosils) and (5) gradient-index glasses. These represent the five most significant developments in the area of bulk optical materials by the sol-gel process to date. 

Research is gradually shifting to more complex systems. For instance, very few studies on lanthanide complexes doped into pure silica sol gel glasses are still appearing, whereas present work is more concentrated on lanthanide complexes in organically modified silicates and especially on complexes covalently hnked to the host matrix. But the control of the lanthanide quantity inside the host matrices remains a challenge. 

Yuh S.-K., Bescher E.P., Babonneau F., Mackenzie J.D. Rare-earth doped, low hydroxyl organically modified silicates. Mater. Res. Soc. Symp. Proc. 1994 346 803-808 Zha C., Atkins G.R., Masters A.F. A spectroscopic study of an anhydrous tetraethyl orthosilicate-boric acid-ethanol system. J. Sol-Gel Sci. Tech. 1998 13 103-107 Zha C., Atkins G.R., Masters A.F. Preparation and spectroscopy of anhydrous borosilicate sols and their application to thin films. J. Non-Cryst. Sohds 1998 242 63-67. 

Capozzi, C. A. Pye, L. D. Physical and optical properties of organically modified silicates doped with laser and NLO dyes. Proc. SPIE-Int. Soc. Opt. Eng. 1991, 1513, 320-329. 

J., Yang, Y., and Lo, D. (2005) Near infrared distributed feedback lasers based on LDS dye-doped zirconia-organically modified silicate channel waveguides. 

The Nile Red was doped in various sol-gels to probe their micro-polarity (Lobnik, 2001). Ormosil prepared with higher fractions oformosil precursors are stable after preparation. These materials hold great promise for gas sensing. The nanoscale properties of organically modified sol-gel-derived silicate thin films, in which Nile Red was doped at nanomolecular concentrations, were studied by single-molecule spectroscopic methods (Bardo,2001). 

Impregnated and doped sol-gel hybrids sometimes result in permanent immobilization of the guest molecule with zero observed leaching of the organics. However, because no covalent bonding is involved, some or even the entire organic modifier is removed from the silicate in most cases, particularly when an appropriate solvent is used for extraction. 

Figure 18 Structural and semi-dynamical models of organically modified clay and polymer-clay nanocomposites. Brown discs correspond to silicate platelets, red balls to surfactant headgroups, yellow strings to surfactant alkyl chains, blue strings to polymer chains and the green wire frame to the nitroxide spin label, (a) Organically modified clay, doped with 1 % of spin-labeled surfactant, (b) Intercalated polymer-clay nanocomposite, (c) Exfoliated polymer-clay nanocomposite, (d) Visualization of the dynamics gradient along the surfactant alkyl chain.

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