Mechanical Strength of Carbon Nanotubes

提出了一种制备石英包裹碳纳米管束的新方法。制造原始碳纤维的初始阶段包括K.Tohji等人开发的水热提纯工艺。这个原始样品被真空密封在石英管中，然后将碳样品加热到大约1250℃，直到石英变白，碳也变白并软化。此时，石英管被拿到空气中，碳被淬火和拉伸，直到它凝固。通过一种简单的加载测试技术，我们可以发现碳纳米管束的临界张力可以承受40吨W/mm^2的临界张力，从束直径100微米左右估计。因此，由于纳米管的单晶性，这种石英包层碳纤维可以承受高温和酸性环境。

A new method has been developed for fabricating quartz-clad carbon nanotube bundles. The initial stage of making an original carbon fiber consists of hydrothermal purifying process developed by K. Tohji et al. This original sample is vacuum-sealed in a quartz tube, Then the carbon sample is heated up to about 1250 ℃ until the quartz becomes incandescent and so does the carbon and soften. At the moment, quartz tube is taken out in the air and the carbon is quenched and stretched until it solidifies. Then the fiber becomes a thin thread of about 100 nm in diameter.Through a simple technique of loading test, we may find that the carbon nanotube bundles may stand the critical tension of 40 tonsW/mm^2 as estimated from the bundle diameter of 100 microns or so. Thus, this quartz-clad carbon fiber stands high temperature and acid environment because of the single crystalline character of nanotube.