Lasers used to make nanotube yarn
Not satisfied with your Kevlar body armor? Well, you may be in luck. American researchers have used lasers to create the world’s first practical macroscopic yarns from boron nitride fibers. The development could unlock the potential of the material for a wide variety of applications, including radiation-shielding for spacecraft, solar energy collection, and stronger body armor. If the supplied photo is anything to go by, it also does a great job at holding up a quarter.
The research was conducted by NASA’s Langley Research Center, the Department of Energy’s Thomas Jefferson National Accelerator Facility, and the National Institute of Aerospace. The result was a new technique to synthesize high-quality boron-nitride nanotubes (BNNT’s). Unlike the tubes produced with previous techniques, these ones are very long and contain few interior layers, which is apparently what you want.
"Before, labs could make really good nanotubes that are are short or really crummy ones that are long. We've developed a technique that makes really good ones that are really long," said Mike Smith, a staff scientist at NASA's Langley Research Center.
The technique is called the pressurized vapor/condenser (PVC) method. To quote the press release, “In this technique, the laser beam strikes a target inside a chamber filled with nitrogen gas. The beam vaporizes the target, forming a plume of boron gas. A condenser, a cooled metal wire, is inserted into the boron plume. The condenser cools the boron vapor as it passes by, causing liquid boron droplets to form. These droplets combine with the nitrogen to self-assemble into BNNTs.” The BNNT’s were then twisted by hand into strands of cotton-like yarn, which could one day be processed by traditional textile-manufacturing equipment.
The researchers are now working on ramping up production, and determining potential uses for the yarn. And just to put everything in context, these “really long” BNNT’s are a few microns across, and approximately one millimeter long. It makes you wonder how long the short ones were.
Via Jefferson Labs.