Method and apparatus for preparing boron nitride nanotubes by heat treating boron precursor prepared by using air-jet

A method of preparing boron nitride nanotubes (BNNTs), the method comprising steps of:

• providing a first powder by mixing boron and a catalyst powder;
• forming a second powder comprising a boron precursor by nano-sizing the first powder;
• forming a precursor disk having a thickness of 100 μm to 1000 μm by mixing 100 wt % of a precursor powder with 5 to 50 wt % of a binder including at least one of sugar, syrup, grain syrup, polypropylene carbonate, polyvinyl alcohol, polyvinyl butyral, and ethylcellulose;
• and
• growing BNNTs on the precursor disk;
• wherein the growing of the BNNTs on the precursor disk comprises steps of:
• locating the precursor disk in a heating zone of a reaction chamber;
• heating the heating zone;
• and
• applying a reactive gas to the heating zone to thereby grow the BNNTs by forming pores on the precursor disk as the binder is sublimated and removed;
• and
• wherein the nano-sizing of the first powder comprises steps of:
• applying first air in a direction inclined to a perpendicular direction of a round nano-sizing area;
• applying the first powder to the nano-sizing area to form an acute angle towards a flow direction of the first air;
• and
• forming the second powder by using the first air in the nano-sizing area.