No. 426: Using carbon dioxide laser to produce nanocarbon fibers (February 2, 2012)

Technology

Electrospinning is the most widespread method to produce nanofibers at present, but it has problems with safety because raw fibers have to be dissolved by solvent and with the condition that the raw materials should be polymer soluble in solvent. A University of Yamanashi professor Akihiro Suzuki successfully developed a technology to produce nanofibers, each of which is 100 nanometers in diameter on average, using carbon dioxide laser and utilizing air current. The newly developed technology does not need solvent to dissolve raw materials, nor does it allow nanofibers to fly apart thanks to the closed production system. The new technology uses fibers with 100-200 micrometers in diameter as raw materials, and they are dissolved by carbon dioxide laser with a maximum output of 40 watts.

The dissolved raw materials pass through the air current where ultrasonic air flows, and are stretched by dint of air. Because strength does not concentrate in one point, it is possible to make the fiber thinner and hard-to-cut. The width of the fiber can be made from 100 nanometers to several micrometers by changing the degree of decompression and output of carbon dioxide laser. Finished fibers fall on the wire mesh chain conveyor, and are collected as nonwoven fabrics. Theoretically, it is possible to extend the fiber without any limit. In the experiment, the research team produced a nanofiber sheet of 1-2 meters long. The nanofiber produced by this method can be applied to the separator of lithium-ion battery and used for raw materials of medical purposes.