In this article, we will introduce nanofiber products that effectively utilize the “nanosize effect,” one of nanofiber’s properties.
This effect is caused by the nanofiber’s nanosize thickness. It produces “hydrodynamic properties,” “optical properties,” etc. This creates an ultra-high performance filter that can completely block sub-micron particles (*Name of particles smaller than 1μm and up to 0.1μm) while maintaining a low pressure drop. In addition, since the diameter of the nanofiber is shorter than the wavelength of light, diffuse reflection of light is reduced, creating a highly transparent fiber, which is expected to be used for electronic paper with excellent light transmission.
With a thickness of 10~1000th of commercially available ultrafine fibers (1 micron), these fibers have the following two properties.
Any substance that comes in contact with the nanofibers will cause slip flow. Therefore, when molecules or particles of fluid come in contact with nanofibers, slip flow occurs, resulting in very low pressure drop. Also, when liquid crystal molecules in contact with the nanofibers are driven, sliding occurs and frictional resistance is reduced, resulting in high responsiveness. Nanofibers have high flexibility, and films, fabrics, and flat plates that come in contact with nanofibers also have improved flexibility due to their slipping.
These properties and technologies have led to the development of
and other fields where commercialization is implemented and expected.
Nanofibers have diameters in the wavelength range of X-rays to visible light. Consequently, when the diameter of the nanofibers is smaller than the wavelength of visible light, light passing through the nanofibers is less diffusely reflected, resulting in a highly transparent fabric. In addition, when the diameter of the nanofibers is equal to the wavelength of visible light, a structural coloration can occur.
These properties and technologies will led to the development of
In particular, nanofiber electronic paper has
and other properties.
The yellow curve in the chart is polypropylene (PP) nanofiber. We can see that it absorbs low frequencies well. The other materials show comparable sound absorption at half the density of glass wool (GW) (30 kg/cm3 compared to 64 kg/cm3 for GW), which is shown in red.
In addition, nanofibers have excellent heat insulation properties due to the large amount of empty space.
The nano-size effect can prevent heat conduction and convection.
Using nanofibers as a heat insulator and sound absorber can be used for
And many others applications
A vacuum membrane is generated by blowing nanofibers onto a material; at 1 atm and 0 degree C, the size of air molecules is Φ5-6 nm, but the average process is Φ68 nm. When nanofibers with a diameter of Φ50nm form a layer of fibers, no air molecules can enter the layer, and the resulting vacuum layer is a “vacuum membrane”.
Since the vacuum creates heat insulation and sound absorption effects, for example, spraying nanofibers on wallpaper may make it possible in the future to build a house without the need for heat insulation or sound absorption materials.
What do you think? This article introduced the functions of nanofibers as seen through the “nano-size effect”. These functions are just one of the many possibilities of nanofibers. If you would like to know more about nanofibers, please take a look at the other articles on our website!