2017年6月14日星期三

Tungsten Oxide Photochromic Influence Factors

Tungsten oxide photochromic incluence factors are various. In addition to the structure and composition of itself, which the atmosphere the tungsten oxide exist will also impact on its chromogenic performance. Considered from the internal structure of tungsten oxide, there are different structures of tungsten oxide there. From relatively stable triclinic, monoclinic to cubic, tetragonal and very unstable hexagonal bronze, pyrochlore phase, but the most studied at the present is amorphous (a-WO3) or polycrystalline (c-WO3) film’s photochromic properties. After the study found that a-WO3 compared with c-WO3 has a good photochromic property, mainly because c-WO3 has lattice defects or small surface area or others. 

tungsten oxide photo


The internal factors which mentioned above is the main reasons of determine the material properties, and external also has great impact on tungsten oxide photochromic which can not be underestimated, especially on different atmosphere. From colored aspects, some of the hydrogen or hydroxyl organic vapors is good for matachromatism reaction rate and improve absorption intensity of tungsten oxide. Respect for bleaching aspect,it will affected by the oxidizing gas largely, such as O3, H2Oand FE2 (SO43 and so on. These factors for improve the tungsten oxide photochromic performance have great help, but also conducive to the production of a more favorable performance photochromic material.


If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595
Fax: +86 592 5129797

Special Forms Tungsten Oxide Producing Methods

Nano tungsten oxide has strong organizational ability to grow and in a stable reaction conditions the interactions between molecular are fairly obvious. Molecular can epitaxial growth which is in accordance with lattice arrangement strictly and to form the formation ratio complete and single component structure. With the improvement of nano technology, now there have been some special forms tungsten oxide, including arborescent, clitheriform, nanorods, nanowires and other special forms. 

special forms tungsten oxide photo


There are many producing methods for special form nano tungsten oxide which can be divided into three types: high-temperature synthesis, hydrothermal synthesis method, and solution low temperature synthesis method. Although high-temperature synthesis method is most common, but it has high requirements in equipment so this method is difficult wildly be used. The hydrothermal synthesis method is acidification W (CO) 6 and ammonium tungstate, the reaction is from 2 to 100 hours at 160-200 ℃ range in autoclave for produce different shapes of nanorods. This method is low cost so it can be widely used than high-temperature synthesis method. Solution low temperature synthesis method is a new invention so in produce special morphology tungsten oxide is not mature, but the method has attracted much attention and the prospects are very broad.


If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595
Fax: +86 592 5129797

Tungsten Oxide of Bronze Phase

Tungsten bronzes are a special class compounds which is non-stoichiometric and the chemical formula is MXWO3 (0 <X <1). The M of MXWO3 can be an alkali metal, calcium, strontium, barium, rare earth metals, copper, ammonium, hydrogen and so on. Such compounds are more exist in hexagonal, cubic and tetragonal, its structure is basis on WO6 octahedral structural, forming a layered having a six-membered, five- or four-membered ring channels through the apex of a rigid skeleton structure of tungsten oxide structure. 


cesium tungsten bronze photo

Tungsten oxide compounds in bronze phase  has special physical properties, which generally has a high electronic conductivity and faster ion transport properties, which conducts electricity can achieve 2.5 × 106Ω-1m-1, is a low-temperature superconductors. Recently it was widely used in electrochromic displays, electrode and PH sensors and other area, so then it becomes a hot issue again. Many methods for preparing tungsten oxide bronze, common in three ways: a solution of chemical reduction, electrochemical reduction, thermal reduction method.



If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595

Fax: +86 592 5129797

Laser Powder Influence Tungsten Oxide Nanowire

Using different power laser radiation study tungsten oxide nanowires found that with increasing laser power (0.72mw ~ 20mw), the Raman spectra of tungsten oxide nanowire has significant changes, when the laser power Raman spectra of tungsten oxide nanowire is low the Raman signal also not strong. Peak shape and peak data will not change much. As the power increases, the Raman signal also increases. When the laser power is increase to certain strength, then tungsten oxide will react with oxygen become tungsten trioxide. At this time the tungsten trioxide is monoclinic phase.

tungsten oxide photo

When the laser powder drops to 3mw the Raman peaks has been unable to return to the peak, indicating that the oxidation process is irreversible. With the laser power is increased again, tungsten trioxide nanowire phase transition from monoclinic phase to β phase, has studying by the changing of laser power found the monoclinic phase of tungsten oxide change to the β phase so the this process is reversible. Laser powde has an impact on tungsten oxide nanowires, Keywords: tungsten oxide nanowires, laser power.


If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595
Fax: +86 592 5129797

Blue Tungsten Oxide Forms Influence Tungsten Powder Particle

Blue tungsten oxide forms including composition, phase composition, surface area, particle size and oxygen index and so on. Blue tungsten oxide particle size has a significant impact at the tungsten powder reduction on tungsten powder particle size, which the coarse blue tungsten is good for producing fine tungsten powder, because coarse blue tungsten oxide particles in the process of reduction has good permeability can exclusion vapor water which have a greater advantage. 

To a certain extent, blue tungsten oxide specific surface area also affect tungsten powder particle size having a large specific surface area of ​​blue tungsten oxide in favor of   producing fine tungsten powder. Because the more advanced blue tungsten oxide surface area, the greater its reaction interface, reducing activity, the better. 
blue tungsten oxide photo


In the study also found the relative composition of blue tungsten oxide will effect tungsten powder particle size this is also can not be ignored. After comparing the different components of blue tungsten oxide along with the effect of hydrogen reduction found that phase component ATB and W20O58 blue tungsten oxide reduction fine tungsten powder better than other blue tungsten oxide which containing more tungsten trioxide. And with ATB basic phase of blue tungsten, reducing effect at low temperatures is good than other blue-phase component of tungsten. ATB Blue Tungsten is hexagonal structure, because this structure is unstable, having a large number of lattice defects, developed specific surface area, with a high reduction activity.

If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595
Fax: +86 592 5129797

Process Parameters Influence Blue Tungsten Oxide Reducing Tungsten Powder Particle Size

In addition to the blue tungsten oxide form affects tungsten powder particle size, the process parameters also affect the size of tungsten powder.

Influence of process parameters on the tungsten powder particle size is mainly hydrogen mode, heating systems and hydrogen influence humidity. There are two kinds of hydrogen modes, one is cis hydrogen mode and the other is inverse hydrogen. The study found that cis hydrogen mode reduction of tungsten powder particle size is significantly thinner than the inverse hydrogen mode. ATB phase blue tungsten powder at low temperature with cis hydrogen mode can producing tungsten powder particle size thinner, narrow distribution, and the nature the better. 

blue tungsten oxide photo

In heating system, the researchers found that heating from a low temperature and the heating process more gentle process are good for the producing fine tungsten powder. At the same time hydrogen humidity also impact on the tungsten powder particle size, at the same other process parameters, continuously push the boat and single boat reduction effect is not the same, which is mainly due to different hydrogen humidity. Cis hydrogen mode is good for retrain tungsten powder grow up so producing of fine particles tungsten powder should be used cis hydrogen mode.


If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595
Fax: +86 592 5129797

Small Size Violet Tungsten Oxide Particle Affecting Factors (2)

After the study, we found that violet tungsten oxide particle affecting factors includes raw material (APT) particle size and production process conditions. Production process conditions include reducing temperature, heating rate, water vapor and hydrogen pressure ratio, material thickness and reaction time.

Firstly, the influence factor is water vapor and hydrogen partial pressure ratio, which are water vapor and hydrogen partial pressure ratio increases and the size of products larger. This is mainly due to the formation of hydrogen gas to form a volatile humidity hydrous tungsten oxide, tungsten oxide which is easy to cover the finer particles, so that the particle size increases. 

violet tungsten oxide photo

Secondly, the impact factor is heating rate, after experiment found that to produce fine particles the heating speed should not too fast. When the reduction in a tube furnace, the heating rate depends on the furnace temperature gradient and push the boat speed, hence reducing the furnace temperature gradient and push the boat speed are conducive to obtain fine particles of violet tungsten oxide. 

Thirdly, the reduction temperature influence violet tungsten oxide particle size. When the temperature increase the particle is grouping up. At the same time the reducing time also impacts on violet tungsten particles, the greater the reduction reaction of the longer particle size. Finally, the thickness of the material layer, the material thickness is larger, the larger the particle size of the product.



If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595

Fax: +86 592 5129797

Small Size Violet Tungsten Oxide Particle Affecting Factors(1)

With the development of research, the ultra-fine particles as a new material have been widely used in modern industry and science. Violet tungsten oxide (VTO) has special properties and structure so get a lot of favor in producing ultrafine tungsten powder. During producing tungsten powder not only process conditions is important but the raw marital particle size is also an important factor. Therefore, to study violet tungsten oxide particle affecting factors is very important.

violet tungsten oxide photo

Producing violet tungsten oxide is through boatload an amount of ammonium paratungstate and pushes it into the reduction furnace hot zone. At the same time add a certain proportion of hydrogen and steam mixture to heat at a certain temperature, after a period heat preserving then cooling to obtain.

During the reaction, the factors that influence the violet tungsten oxide grain size are the raw material (APT) particle size and production process conditions. Production process conditions include reducing temperature, heating rate, water vapor and hydrogen pressure ratio, material thickness and reaction time. The study showed that, the relationship between violet tungsten oxide and raw material particle size is raw materials get smaller the particle size is smaller.


If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696      +86 592 5129595
Fax: +86 592 5129797