Deposition sol-gel

PZN-PT, and YBa2Cug02 g. For the preparation of PZT thin films, the most frequently used precursors have been lead acetate and 2irconium and titanium alkoxides, especially the propoxides. Short-chain alcohols, such as methanol and propanol, have been used most often as solvents, although there have been several successful investigations of the preparation of PZT films from the methoxyethanol solvent system. The use of acetic acid as a solvent and chemical modifier has also been reported. Whereas PZT thin films with exceUent ferroelectric properties have been prepared by sol-gel deposition, there has been relatively Httle effort directed toward understanding solution chemistry effects on thin-film properties. 

GL 18] [R 6a] [P 17] A sol-gel deposited catalyst used in a fixed-bed reactor gave higher conversion than a micro-channel catalyst impregnated on a porous alumina layer [17]. This was due to the higher geometric surface area of the sol-gel deposited catalyst. 

According to Ref. [12], template for synthesis of nanomaterials is defined as a central structure within which a network forms in such a way that removal of this template creates a filled cavity with morphological or stereochemical features related to those of the template. The template synthesis was applied for preparation of various nanostructures inside different three-dimensional nanoporous structures. Chemically, these materials are presented by polymers, metals, oxides, carbides and other substances. Synthetic methods include electrochemical deposition, electroless deposition, chemical polymerization, sol-gel deposition and chemical vapor deposition. These works were reviewed in Refs. [12,20]. An essential feature of this... 

Typically, in solution-phase film deposition, a precursor coating is applied to a surface and heated, whereupon the elimination of solvent leads to localized crystallization and separation of solid particles. To prevent these processes, metal-organic precursors can be commonly employed for sol-gel deposition (see Chapter 2), wherein the organic ligands essentially act as vehicles to promote glass formation. Ultimately, embedded organic ligands... 

Ozer, N. 2001. Optical properties and electrochromic characterization of sol-gel deposited ceria films. Solar Energy Mater. Solar Cells 68 391-400. 

N. Ozer C. M. Lampert, Electrochromic performance of sol-gel deposited WO3-V2O5 films. Thin Solid Films 1999, 349, 205-211. 

There exist a variety of methods to synthesize quasi-one-dimensional nanostructured materials, which include but not limited to vapor phase growth, template-assisted synthesis, sol-gel deposition, surfactant-assisted growth, sonochemical method, hydrothermal method, and electrochemical deposition [21], Among the various methods, the electrochemical anodization method is one of the simplest and cheapest methods to synthesize ordered quasi-one-dimensional nanostructure. 

The silica membrane was prepared through sol-gel deposition and chemical vapor deposition methods. The porous a-alumina tube (O.D., 5.0 mm I.D., 3.5 mm length, 300 mm), supplied by Nano Pore Materials Co. Ltd., Korea, was used as a support. The mean pore size and porosity of the support tube were 0.1 pm and 35%, respectively. Tlie effective length of membrane was 100-150 mm at the middle of the tube, and both edges were glazed with a SiO2-BaO-CaO sealant (Nippon Electric Glass, GA-13), and then calcined at 1200°C. 

A related study showed the important influence aging of the sol has on the topographical structure of sol-gel deposited titania coatings developed as precursors for subsequent calcium phosphate deposition from SBFs (Peltola et al., 2000). In their study, different sol-gel-derived titania coatings were produced on titanium... 

Dip coating is essentially a process akin to sol-gel deposition but differs from it by using a volatile suspension medium that quickly evaporates during withdrawing... 

The mechanical properties of sintered apatites has limited their application to low stress areas in the body. To overcome this difficulty, apatites are applied as coatings on the surface of metallic implants where high loads on the implant are expected. Various coating options are available including thermal spraying, sputter deposition, pulsed laser deposition, sol-gel deposition, electrophoretic coating, electrodeposition, and biomimetic deposition. These are discussed in turn. 

J.X. Liu, D.Z. Yang, F. Shi, Y.J. Cai, Sol-gel deposited Ti02 film on NiTi surgical alloy for biocompatibihty improvement . Thin Solid Films, 429, 225-230,... 

The sol-gel process generally involves the transition from a Uquid sol into a solid gel phase. Inorganic metal salts or metal organic compounds, such as metal alkoxides, may be used as precursors. The sol-gel deposition process usually has four steps ... 

The nanostructures can be deposited into the nano-pores by electrodeposition or sol-gel deposition methods. The advantages of being low cost and repeatable, together with their potential compatibility with silicon technologies, make these nanostructure synthesis procedures interesting. Despite its simplicity, template-based growth is characterized by the production of polycrystalline nanowires, which can limit their potential for both fundamental studies and applications. 

Portet, C., P. L. Taberna, P. Simon, and C. Laberty-RoberL 2004. Modification of A1 current collector surface by sol—gel deposit for carbon—carbon supercapacitor applications. Electrochimica Acta 49 905—912. 

Another widely used approach in this area is a sol-gel process. In order to create surface roughness after deposition of thin films, a secondary component is included in the sol-gel deposition process which can be removed later by dissolution in hot water or sublimation. The removal of the secondary components gives porous structures. Subsequent lluorinated silane coating can render these sol-gel processed films superhydrophobic [81-83]. Microporous structures can be created through phase separation of organic polymer solutions and then used as a template for sol-gel processing of porous silica substrates. Ruorosilane treatment of these substrates produces superhydrophobic surfaces [84]. 

Fig. 6.7 AEM topographical images in air of sol-gel deposited onto HOPG a MEMOS, b APTOS, and c GOPMOS. [Prom Ref. 56 with permission]...

Chen, C.-T, Chen, Y.-C. (2004) Desorption/Ionization Mass Spectrometry on Nanocrystalline Titania Sol-Gel-deposited Films. Rapid Commun. Mass Spectrom. 18 1956-1964. 

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