Chemical methods vapor deposition

The CVD method is a technique to produce microporous membranes by deposition of a solid inside the pores of mesoporous membranes, thus reducing the pore size through chemical reactions in a gaseous medium at an elevated temperature. The reactions to deposit a solid inside the pores of mesoporous membranes can be thermal decomposition, oxidation, or hydrolysis of precursors, as summarized in Table 2.4. 

Membrane Porous substrate Raw material Peptizing agent Additive Membrane thickness (pm) Membrane pore size (nm) Ref. 

Zr02 a-Al203 Zirconyl chloride (Zr0Cl2-8H20) Oxalic acid/ HCl PVA 1.2 4.3 [9] 

Ti02 a-Al203 Ti-tetra- isopropoxide (TTl) (Ti(OC3H2)4) HNO3 PVA or hydroxypropyl cellulose (HPC) 1 3.5-5 [8] 

ALO3 Thermal decomposition 2A1(0C3H7)2 AI2O3 + 6C3H6 + 3H2O 

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Carbon coated Si-based anode materials were successfully synthesized by chemical vapor deposition methods. Coated materials performed well during the coin cell testing. Future work on this section... 

Anode materials are most typically deposited by evaporation, sputtering, or chemical vapor deposition methods. Other methods such as screen printing, laser ablation, electrochemical deposition, etc., have also been used. 

Liu J, Czerw R, Carroll DL (2005a) Large-scale synthesis of highly aligned nitrogen doped carbon nanotubes by injection chemical vapor deposition methods. Journal of Materials Research 20 538-543. 

Hi) Chemical Vapor Deposition Method All commercial production of MWCNTs is based on catalytic CVD processes. The CVD processes are basically of two types the catalyst is either deposited on a substrate or the catalyst precursor is continuously fed with the gas stream. 

Field emission cathodes described in this paper were produced by means of low temperature chemical vapor deposition method of carbon nanotubes from ethanol vapor. The substrate temperature during the deposition was 500 °C. This paper summarizes research results of prepared field emission cathodes. 

Guo, L. and Chen, G. (2007a), High-quality diamond film deposition on a titanium substrate using the hot-filament chemical vapor deposition method. Diam. Relat. Mater., 16(8) 10. 

Chemical vapor deposition method is used as an alternative to circumvent the limitations of the other synthetic methods. In chemical vapor deposition method, a substrate is prepared with a layer of metal catalyst particles, most commonly nickel, cobalt, iron, or a combination of these materials. The diameter of the grown nanotubes is related to the size of the metal particles. The substrate is heated to approximately 700°C. To initiate the growth of nanotubes, two gases are bled into the reactor a process gas (such as ammonia, nitrogen, hydrogen, etc.) and... 

Matsumura H., Low temperature depostition of silicon nitride by the catalytic chemical vapor deposition method, Jpn. J. Appl. Phys. 28 (1989) pp.2157-2160. 

MOCVD. See Metalorganic chemical vapor deposition method... 

Vapor deposition. Both physical and chemical vapor deposition methods can be used to prq)are dense inorganic membranes. In either process, vaporization of the membrane material to be deposited is effected by physical means (such as thermal evaporation and sputtering) or chemical reactions. 

Ci LJ, Zhou ZP, Yan XQ, Liu DF et al (2003) Resonant Raman scattering of double wall carbon nanotubes prepared by chemical vapor deposition method. J Appl Phys 94(9) 5715-5719... 

S. Van, H. Maeda, K. Kusakabe, and S. Moro-Oka, Thin palladium membrane formed in support pores by metal-oiganic chemical vapor deposition method and application to hydrogen separation, IruL Eng, Chem. Res. Ji 616 (1994). 

Yamakita S, Katada N, Niwa M (2005) Shape-selective adsorption of substituted benzalde-hyde isomers by a molecular sieving silica overlayer prepared by the chemical vapor deposition method using organic template on tin oxide. Bull Chem Soc Jpn 78 1425... 

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. 

The method of preparation has a considerable effect on the catalytic properties of supported gold. Coprecipitation, deposition-precipitation, chemical vapor deposition methods are especially effective for depositing gold as nanoparticles with diameters smaller than 5 nm and with strong interaction with the supports. 

M. Kohzaki, K. Uchida, K. Higuchi, and S. Noda, Laige-aiea high-speed diamond deposition by RF induetion thermal plasma chemical vapor deposition method, Jpn. 

E. Kondoh, K. Tanaka, and T. Ohta, Homoepitaxial growth of diamond by an advanced hot-filament chemical vapor deposition method, J. Appl. Phys., 74(3) 2030-2035 (1993)... 

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