Factors Tungsten Oxide Mesoporous Structure (B)

Ethanol and distilled water as a dispersing agent, silicon and silicon acid mesoporous materials than 3:1, the calcined at 600℃ and after HF treatment of tungsten oxide N2 adsorption - desorption, N2 adsorption - desorption isotherms at relatively pressure (p / p0) is between 0.1 to 0.2 of a sudden the weak, the relative pressure of about 0.6-0.8 adsorption curve there is a clear conflict more, and there is between the branch and the adsorption and desorption branches noticeable lag ring, which is produced by the N2 in the pores of capillary condensation phenomenon, which also indicates that the material prepared mesoporous channels.

Preparation of mesoporous material having pore diameter of two-channel. Reasons for the formation may be due to the dual aperture silicotungstic acid SiO2 pore filling during the filling of dissatisfaction, or in the process of formation of the tungsten oxide polymerization between molecules caused some vacancies in the bore, so when removing the SiO2 pores becomes large so that, while forming a double-aperture is ethanol and distilled water as the dispersant, silicotungstic acid material than the silicon mesopores 3/1 when calcined at 600 ℃ tungsten oxide mesoporous material prepared The structural parameters, the specific surface area can be seen that the dispersant is prepared using ethanol as tungsten oxide mesoporous material with a pore volume of distilled water are higher than the dispersant.

Ethanol at room temperature The contact angle of the mesoporous silica surface was 11°, the water contact angle of the surface of the mesoporous silica is 26 °, than ethanol distilled water described mesoporous silica having better wetting properties, more conducive to the silicon acid into the pores of the silica and the formation of mesoporous materials.

Mesoporous silica as a hard template, and silicon acid compound, and then the HF treatment to remove silica prepared by having a large specific surface area and pore size of mesoporous tungsten oxide dual optimum conditions are: Silicotungstic acid and mesoporous silica composite material ratio (m (WO3) / m (SiO2)) in between 3 to 4:1, and calcined at 600-750 ℃. When using ethanol as a dispersant compound , the resulting mesoporous WO3 specific surface area and pore volume than when distilled water as the dispersant large, mainly due to ethanol ratio of distilled water to the mesoporous silica having better wetting properties.

Tungsten Powder Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

• < Prev
• Next >