基于赖斯大学的新发现，以及前一个，氮化硼纳米管已被启动成为下一代复合材料和聚合物材料的有效构件。
已知米饭的科学家找到了一种使用大学开创性的化学过程增强独特的纳米管的方法。化学家安吉尔·马蒂（AngelMartí）的稻米实验室利用了Billups-Birch反应过程，以增强硝酸硼纳米管。
这项工作在《美国化学学会杂志》中描述ACS Applied Nano Materials.
Boron nitride nanotubes, like their carbon cousins, are rolled sheets of hexagonal arrays. Unlike carbon nanotubes, they’re electrically insulating hybrids made of alternating boron and nitrogen atoms.
Insulating nanotubes that can be functionalized will be a valuable building block for nanoengineering projects, Martí said. “Carbon nanotubes have outstanding properties, but you can only get them in semiconducting or metallic conducting types,” he said. “Boron nitride nanotubes are complementary materials that can fill that gap.”
Until now, these nanotubes have steadfastly resisted functionalization, the “decorating” of structures with chemical additives that allows them to be customized for applications. The very properties that give boron nitride nanotubes strength and stability, especially at high temperatures, also make them hard to modify for their use in the production of advanced materials.
But the Billups-Birch reaction developed by Rice Professor Emeritus of Chemistry Edward Billups, which frees electrons to bind with other atoms, allowed Martí and lead author Carlos de los Reyes to give the electrically inert boron nitride nanotubes a negative charge.
反过来，这使它们与其他小分子（包括脂族碳链）打开了功能化。
马蒂说：“使纳米管功能化会修饰或调整其特性。”“当它们是原始的时，它们在水中散发，但是一旦我们连接这些烷基链，它们就会极为疏水（避开水）。然后，如果将它们放入非常疏水的溶剂中，例如具有长链烃的溶剂，它们比原始形式更具分散性。
他说：“这使我们能够调整纳米管的特性，并使下一步迈向复合材料变得更加容易。”“为此，材料需要兼容。”
After he discovered the phenomenon, de los Reyes spent months trying to reproduce it reliably. “There was a period where I had to do a reaction every day to achieve reproducibility,” he said. But that turned out to be an advantage, as the process only required about a day from start to finish. “That’s the advantage over other processes to functionalize carbon nanotubes. There are some that are very effective, but they may take a few days.”
该过程始于向纳米管中添加纯氨气，并将其冷却至-70°C（-94°F）。马蒂说：“当它与钠，锂或钾（我们使用锂）结合使用时，它会产生一大堆电子。”“当锂溶解在氨中时，它会排出电子。”
释放的电子迅速与纳米管结合，并为其他分子提供钩子。当德洛斯·雷耶斯（De Los Reyes）发现慢慢地添加烷基链而不是一次性，从而增强了比利布斯 - 比尔奇（Billups-Birch）提高了它们的结合能力。
The researchers also discovered the process is reversible. Unlike carbon nanotubes that burn away, boron nitride nanotubes can stand the heat. Placing functionalized boron nitride tubes into a furnace at 600°C (1,112°F) stripped them of the added molecules and returned them to their nearly pristine state.
“We call it defunctionalization,” Martí said. “You can functionalize them for an application and then remove the chemical groups to regain the pristine material. That’s something else the material brings that is a little different.”
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