Jul 5 2013
Nanoparticles are being explored in various biotechnological and pharmacological fields as they bridge between atomic or molecular structures and bulk materials.
Tungsten has the highest melting point of all the metallic elements. In its purest form, the hardness of tungsten exceeds that of many steels. It has resistance towards acids, alkalis and oxygen.
Tungsten nanoparticles have high surface area which can lower the sintering temperatures, low vapor pressure, unusual quantum confinement and grain boundary effects.
Chemical Properties
The chemical properties of tungsten nanoparticles are outlined in the following table.
| Chemical Data |
| Chemical symbol |
W |
| CAS No. |
7440-33-7 |
| Group |
6 |
| Electronic configuration |
[Xe] 4f14 5d4 6s2 |
Physical Properties
The physical properties of tungsten nanoparticles are given in the following table.
| Properties |
Metric |
Imperial |
| Molar mass |
183.85 g/mol |
- |
Thermal Properties
The thermal properties of tungsten nanoparticles are provided in the table below.
| Properties |
Metric |
Imperial |
| Melting point |
3410°C |
5684°F |
| Boiling point |
3410°C |
5984°F |
Manufacturing Process
Tungsten nanoparticles can be synthesized by the sonoelectrochemical method where a platinum slice is used as anode, titanium-alloy horn connected to an ultrasound generator is used as cathode and a mixture of citric acid, ferrous sulfate, sodium tungstate and tri-sodium citrate acts as an electrolyte.
Generation of ultrasound develops electrochemical reaction and the cavitation effect, which in turn lead to formation of iron-tungsten nanoparticles at the cathode. The iron atoms are then dissolved in the acidic environment.
Applications
The key applications of tungsten nanoparticles are listed below:
- Coatings, plastics, nanowires, nanofibers and textiles
- Microelectronics films
- Electrodes for gas sensors
- Sintering additives
- Alloys for heat sinks, aerospace and electronic package
- Vacuum contactors and vacuum load switches.
Source: AZoNano