Nano particles are the ultra-fine particles with the diameter １～100nm such as the size of the polymer including the proteins, DNA, and so on. 1 nm is 、the amount of one-billionth of 1m. In analogy, the size of the Earth is assumed to be 1 m, diameter marbles (about 12mm) is 1nm. The nano particles have the large specific surface area and the reactive properties in comparison with bulk solids. The special properties of the electric, optical, magnetical, and others of nano-particles are expected to the application for the various uses.
Water have three fundamental states: the solid, the liquid, and the gas. However water becomes super critical fluid which is called supercritical water (SCW) at a temperature and pressure above the critical point (374℃、 and 22MPa). At a supercritical phase, there is no distinction between the liquid and the gas. The SCW have the lower density and the lower dielectric constant in comparison with the liquid phase.
While the metal salt solution with the water solvent are used for the nanoparticle synthesis, organic compound dissolves to the non-polar organic solvents. It is difficult to mix uniformly between the water (dielectric constant: 78) and the organic solvent (2-20).
However the dielectric constant of water decreases with increases the temperature and becomes 2-10 at the supercritical phase. It takes place to mix the water solution of metal salt and the organic solvent with organic compound uniformly. The supercritical water brings the possibility of the synthesis of organic-inorganic hybrid nano-particles.
This is a frequently asked question on the exhibition.
The nanoparticles have been known recently, however, how to use - is not being readily known. Following figure shows the use of nanoparticles.
Innovation in a wide range of industries is expected to the environmental field and energy field, such as the semiconductor-related components (power device), the optical element (special light modulator), the display materials (such as multi-function transparent film).
For example, the nanoparticles do not scatter the light much due to the small size. It can be applied to the transparent conductive film. It is not limited to the optical properties. There are several application such as the cosmetics, the electronics, the painting, the conductive ink, and so on.
In the flow reactor, the flow of the aqueous solution of metal salt at room temperature is merged with the SCW flow. Then the metal oxide nanoparticles are precipitated in the SCW by dehydration or hydrolysis reaction. In addition, the flow of solvent of an organic modifier are merged to modify the surface of nano particles. Then the organic-inorganic hybrid nanoparticles are synthesized.
It is also possible to accommodate your request. We can change the mixing part of the flows and adjust the reaction time by changing the pipe length after mixing. Introducing a reducing agent to synthesize metal particles is also available. It can also be heated after mixing among all lines of flow. Thus, large number of method according to your needs will be possible. In order to use the high-temperature and high-pressure, you need to check the leak properly after the screw tightening. Then you can test for various reactions under the various mixing method.