Surface sol-gel deposition

Guo, W., H. Y. Lu, and N. F. Hu, 2006. Comparative bioelectrochemical study of two types of myoglobin layer-by-layer films with alumina Vapor-surface sol-gel deposited AI2O3 films versus AIO3 nanoparticle films. Electrochim Acta 52 123-32. 

Wang, G., Lu, H. and Hu, N. (2007) Electrochemically and catalytically active layer-by-layer films of myoglobin with zirconia formed by vapor-surface sol-gel deposition. Journal of Electroanalytical Chemistry, 599, 91-9. 

Figure 24.3 Surface sol-gel deposition (adapted from Refs [16,17]).

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. 

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... 

The key effect of oxide supports on the catalytic activities of metal particles is exerted through the interface between oxides and metal particles. The key objective of this study is to develop synthesis methodologies for tailoring this interface. Here, an SSG approach was introduced to modify the surface of mesoporous silica materials with ultrathin films of titanium oxide so that the uniform deposition of gold precursors on ordered mesoporous silica materials by DP could be achieved without the constraint of the low lEP of silica. The surface sol-gel process was originally developed by Kunitake and coworkers.This novel technology enables molecular-scale control of film thickness over a large 2-D substrate area and can be viewed as a solution-based... 

Figure 4. The modification of Ti02 support by A1203 using a surface-sol-gel method for loading gold nanoparticles via deposition-precipitation [115], Al(sec-OC4F[9)3 was used as the precursor. The scheme is drawn according to the description in Ref [115],...

Mesoporous silica SBA-15 was uniformly covered with one-layer titanium oxide by a hydrol3dic surface sol-gel process by Dai and co-workers [151] and ultra-small gold nanoparticles (0.8-1 nm) were deposited on the resulting material via a DP technique. This catalyst has also shown high catal3dic activity for CO oxidation. 

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. 

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. 

PANI/TiO film coated on titanium foil was successfully prepared using the sol-gel method for the preparation of TiO film followed by its dipping into the PANI solution in tetrahydrofuran and subsequent drying in air [122]. Nanostructured ultrathin [(TiOyPAA/PANI/PAA) TiOJ films were fabricated using surface sol-gel processing with TiO layers followed by layer-by-layer deposition of polyacrylic acid (PAA) and PANI from their solutions [124]. Anatase TiO -NPs, commercially available or prepared by various methods, were used in the majority of the PANI/TiO syntheses [40-67,69-79,94,97,102], whereas the rutile TiO -NPs [68,114] or a mixture of anatase and rutile TiO [80] were used rarely. 

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]. 

Portet, C. 2004. Modification of Al current collector surface by sol-gel deposit for carbon-carbon supercapacitor applications. Electrochimica Acta, 49,905-912. 

After etching, a carbonaceous coating can be applied by chemical vapor deposition [6] or carbonaceous sol-gel deposit methods [7] deemed capable of further decreasing the internal resistances of ES cells as low as 0.4 fl.cm. Therefore, new and modified current collector surface treatment techniques can promise to further decrease internal cell resistance and improve the overall performance of modern ESs. 

In the broadest meaning, chemical solution deposition comprises a wide range of different methods, all having one thing in common the use of a liquid solution as a precursor. For the deposition of ultrathin films, many variants of such routes have been applied. Here, we distinguish routes based on a surface-limited reaction, namely, liquid ALD or surfece sol-gel, from downscaled sol-gel deposition methods through spin coating. 

Sol-gel film.s deposited on a grit-blasted aluminum surface give performance close to PAA bonds (Fig. 22) with generally cohesive failures observed in wedge tests. Given that one application of this treatment is repair, the performance is... 

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