Silica-titania films

Such an application was introduced when adsorption isotherms of sol-gel films were recorded by ellipsometry (Martin, 1990). The refractive index of silica-titania films was... 

Jiwei, Z, Liangying, Z, Xi, Y., and Hodgson, S.N.B. (2001) Characteristics of laser-densified and conventionally heat treated sol-gel derived silica-titania films. Surf. Coat. Technol., 138 (2-3),... 

Karasinski, P., Tyszkiewicz, C., Rogozinski, R Jagiarz, J., and Maziu, J. (2011) Optica) rib waveguides based on soi-gel derived silica-titania films. Thin Solid Films, 519, 5544-5551. 

Similarly, CdS NCs capped with mercaptopro-pyltrimethoxysilane (MPTMS) were added to alcohohc solutions of TEOS or TMOS and subsequently incorporated into sihca matrices. Pb and Hg-based NCs have also been synthesized with MPTMS as the capping agent, and the role of the pendant siloxy groups is again to anchor the NCs to the sihca, silica-titania, or zirconia networks. Zirconia films doped with PbS NCs were prepared with refractive indices up to 1.53 and a third-order susceptibility value of 1.3 X 10 esu. Higher refractive index sihca-titania sol gel films doped with PbS (n = 1.63) were also fabricated. ... 

The type of mesostructure obtained depends strongly on the surfactant to inorganic ratio. In fact, there is a close correlation between the surfactant to solvent ratio in the phase diagram of a surfactant and the surfactant to inorganic ratio in the mesostructured materials obtained. Alberius et al. demonstrated this correlation by the so-called general predictive synthesis approach. They used the phase diagrams of the water-surfactant system to guide the synthesis of mesoporous silica and titania films. There was a very close correlation between the values of the volume fraction of the surfactant over which different phases are obtained in the water-surfactant system and in the silica-surfactant and titania-surfactant systems. 

FIGURE 77 Impact resistance of films as a function of the polymer melt index. The addition of poisons to the reactor affects LCB levels in the polymer. In contrast to 02, CO diminishes elasticity, which in turn results in less orientation in the blown film, and therefore improved impact and tear resistance. (Cr/silica-titania catalyst, activated at 650 °C, polymer density of 0.938 g mL, film thickness 25 pm). 

In a generic study, sol-gel-derived titania films were deposited to mimic as closely as possible the native oxide layer found on titanium implants (Haddow et al., 1996). The effects of dip rate, sintering temperature and time on the chemical composition of the films, their physical structure and thickness, and adherence to a silica substrate were investigated. These films are to be used as substrates in an in vitro model of osseointegration. 

Figure 35.4. Schematic pathway to mesostructured silica / titania mixed oxide films.

FIGURE 1.296 SEM image of mesoporous silica film (a) with Ag nanoparticles or (b) alone (inset shows normal cross-section of the film). (With kind permission from Springer Science-HBusiness Media /. Sol-Gel Sci. TechnoL, Ag nanoparticles deposited onto silica, titania and zirconia mesoporous hlms synthesized by sol-gel template method, 50, 2009, 216-228, Krylova, G.V., Gnatyuk, Yu.L, Smirnova, N.P., Eremenko, A.M., and Gun ko, V.M., Copyright 2009.)... 

Krylova, G.V., Gnatyuk, Yu.L, Smirnova, N.R, Eremenko, A.M., and Gun ko, V.M. 2009. Ag nanoparticles deposited onto silica, titania and zirconia mesoporous films synthesized by sol-gel template method. 

The templated titania gel films were prepared by the following method. From the practical point of view, highly porous titania film is important. Titania sols were prepared by hydrolysis of TNB in ethanol solution with addition of EACAC using acid catalyst. The gel films were prepared by spin coating at 2,500 ipm for 30 s on silica glass substrates. Spin coating was repeated up to five times. The wet gel films were immersed into an ethanol solution of surfactants, CTAC or BTAC, at 60°C for 1 h, and dried at 90°C for 24 h (surfactant-modified gel films) [30-32]. The dried gel films were annealed at 500°C for 2 h. The preparation methods are summarized in Figure 7.2. 

As far as the latter systems are concerned, in order to enhance activity or abrasion resistance of a sol-gel titania film, silica can be added, which may substantially modify its performance even at low concentrations. 

The mostly used methods to monitor LbL deposition on monodisperse PS-latex particles for various substances are SPLS method and microelectrophoresis. Inorganic (magnetite, silica, titania and fluorescent quantum dots) nanoparticles [32-34], lipids [35-37] and proteins (albumin, immunoglobulin and others) [29, 38, 39] were incorporated as building block for shell formation on colloidal particles. In paper [39] the construction of enzyme multilayer films on colloidal particles for biocatalysis was demonstrated. The enzyme multilayers were assembled on submicrometer-sized polystyrene spheres via the alternate adsorption of poly(ethyleneimine) and glucose oxidase. The high surface area bio-multilayer coated particles formed were subsequently utilized in enzymatic catalysis. The step-wise coating of different lipids alternated with polyelectrolytes was performed by adsorption of preformed vesicles onto... 

Syms R.R.A., Holmes A.S. Deposition of thick silica titania sol-gel films on Si substrates. J. Non-Cryst. Solids 1994 170 223-233... 

Shimomura K., Tsurami T., Ohba Y., Daimon M. Jpn. Preparation of lead zirconate titanate thin film by hydrothermal method. J. Appl. Phys. 1991 31 2174—2177 Syms R.R.A., Holmes A.S. Deposition of thick silica titania sol-gel films on Si substrates. J. Non-Cryst. Solids 1994 170 223-233... 

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