Method for preparing super long Nano SiC fibers

Abstract

This invention relates to a method for preparing ultra-long SiC nanofibers, which can solve the problems of low nanofibers purity, low yield, ununiformity of nanofibers thickness and short nanofibers (on micrometer scale only) faced by previous techniques. The method comprises: (1) loading SiC gel powder containing C into a graphite crucible; (2) placing the graphite crucible into an atmospheric sintering furnace, and vacuumizing; (3) introducing Ar into the atmospheric sintering furnace to 0.1-2.0 MPa; (4) heating and keeping the temperature; (5) cooling the room temperature to obtain ultra-long SiC nanofibers. The SiC nanofibers prepared by this method are monocrystalline, and have high purity and uniform thickness. The diameters are within 30-300 nm, mainly within 50-150 nm, and the lengths can reach millimeter scale.

Description

technical field

[0001] The invention relates to a preparation method of nanofibers. Background technique

[0002] Among the many preparation methods of SiC nanowires, chemical vapor deposition (CVD) is a widely used method. During the growth of nanowires, not only the presence of drainage carriers (such as hydrogen and other reducing gases) and catalysts are required, but also It is also difficult to obtain nanofibers with larger sizes, and the obtained SiC nanowires generally only reach tens of microns. The reason is that during the growth of the nanowires, SiO molecules and CO molecules will be taken away by the airflow, and cannot be replenished in the preferential growth direction of the nanowires in time, which will cause many defects and irregularities in the thickness of the nanowires during the growth process. Uniformity, low yield and other shortcomings, of course, it is difficult to prepare very long nanofibers. Contents of the invention

[0003] The invention ...