Press Release: William & Mary Purification Method Reveals the Next Generation of Cooling Material for Electronic Devices
Improved High Yield Purification Method of BNNTs
Researchers at William & Mary propose a mild, high-yield method that removes >99% of the h-BN impurities without any apparent loss or damage to the BNNTs, as described in a new article in peer reviewed Royal Society of Chemistry journal Chmistry of Materials (download).
Achievement of the next-generation electronic devices which are smaller, lighter, and of higher performance requires a new cooling technology that is more advanced than what is available today. This may seem easy but virtually all materials such as copper that are excellent thermal conductors also conduct electricity which makes this task challenging. Recently a major advance in developing a useable material was made by researchers at William and Mary. Working with a material initially developed two decades ago at NASA Langley, boron nitride nanotubes (BNNT) have been shown to be an electrical insulator with a projected thermal conductivity over ten times that of copper. A current challenge is producing high purity BNNT in useful amounts for industrial and defense applications. Companies in Canada and now in Newport News, Virginia are each developing manufacturing methods to produce useful amounts of BNNT. Unfortunately, the as-produced BNNT is of varying purity from 30% to 70%.
Previously researchers at NASA Langley and Rice University established a method to purify BNNT by heating the material to a very high temperature of 1400 °F which damaged the BNNT and resulted in a very low yield. At William and Mary, Prof. Schniepp, Prof. Kranbuehl, and graduate student Amin succeeded in developing a unique method using a modest temperature, below boiling water, and a mild hydrocarbon similar to gasoline, heptane. It is readily scalable for industrial quantities, does not damage the nanotubes, and has a yield of greater than 90%. Support from Virginia’s Center of Innovative Technology and the National Science Foundation enabled the researchers to create the purest BNNT ever made. The new virtually free of impurities BNNT has the potential for countless technologies such as more efficient solar cells, faster, smaller electronics and lighter, more powerful devices for defense-aerospace applications. The work is described in a recent article in the American Chemical Society’s Chemistry of Materials.