Tungsten can block oxygen, acid and alkali metals. It is a metal with strong corrosion resistance.
The most common oxidation state of tungsten is + 6 valence, but it also has an oxidation state between - 2 and + 6. The most common oxide is yellow tungsten trioxide, WO3, which can dissolve in alkaline water to form WO4. Carbon and powdered tungsten can be heated to form tungsten carbides (W2C and WC). W2C is usually not easy to react chemically, but it is easy to produce tungsten hexachloride (WCl6) with chlorine.
In neutral or acidic aqueous solutions, tungsten can form heterogeneous polymeric acids and polyatomic ionic acids. With the interaction between tungstate and acid, soluble metastable “paratungstate A” anion w7o6 – 24 is formed first, Then it is transformed into the “paratungstate B” anion h.2w12o10 – 2 with low solubility, and finally the stable state is achieved, which is more acidic into the soluble metatungstate anion h2w12o6 – 40. The metatungstate ion exists as a symmetrical dodecatungstate octahedron (Keggin structure) 。 Many other polyatomic ionic acids exist in metastable species, including the substitution of two hydrogen atoms in the center of metatungstate with phosphorus to form variable heterogeneous polymeric acids, such as phosphotungstic acid.
Tungsten Trioxide can form embedded compounds with alkali metals, known as bronze, such as Sodium Tungsten Bronze and Cesium Tungsten Bronze.
Using ammonium tungstate, ammonium molybdate and thiourea as raw materials, transition metal molybdenum tungsten disulfide nanosheets with adjustable phase state were prepared by hydrothermal method under specific reaction conditions. These nanosheets were dripped or sprayed on the gold cross electrode to prepare a gas sensor. The detection of acetone gas, a biomarker of diabetes, was realized at 1ppm concentration, which is of great significance to the realization of non-invasive detection of diabetes.
Chinatungsten Online is the professional designer & producer of Tungsten and Molybdenum Whether standard or customized. Tell us what you need, and we guarantee to deliver high-quality products and services in time. Any inquires or more details, please visit h5.chinatungsten.com or contact by email: sales@chinatungsten.com.
