Rufan Zhang

What is the strongest material in the world? Stainless steel? Carbon fiber? or Titanium alloys? The answer is: NONE of the above. With the density of 1/6 the density of stainless steel, carbon nanotubes (CNTs) can reach a tensile strength that is 100 times stronger than stainless steel. CNTs are the strongest materials known to human beings and are considered to be the only possible candidate for manufacturing space elevators. Being the key to future super-strong materials, CNTs can be used to make a long list of products that humans have only dreamt about: space infrastructure, super buildings, high-performance bulletproof vests, transparent monitors…

However, CNT's may be theoretically strong, but the length of an individual single-walled CNTs must reach macroscale – centimeters, decimeters, and even meters – to make CNT bundles as strong as individual CNTs. Since the diameters of CNTs are only 1-2 nanometers, which is 10,000 times thinner than a human hair follicle, it is extremely difficult to synthesize macroscale long CNTs with perfect structures and extraordinary mechanical properties.

Rufan Zhang, who has been working on the synthesis and property study of ultra-long CNTs for more than ten years, discovered the key to unlocking the material’s tremendous potential. With in-depth research about the nature of CNT growth, he demonstrated the successful fabrication of ultra-long CNT fibers with a tensile strength of more than 80 GPa, ten times higher than other fibers. Rodney S. Ruoff, one of the most famous experts in the field, said that Prof. Zhang’s work bridges the gap between what is known about the ideal ultimate strength of individual single-walled CNTs and these new macroscale CNT bundles. Professor Zhang also actualized that the defect-free growth of ultra-long CNTs with perfect structures and successfully synthesized the longest CNTs in the world, which are more than half a meter and 2.75 times longer than the previously reported values. Also for the first time, Zhang observed that macroscale superlubricity behaviors could exist between ultra-long CNT shells due to their perfect structures. The superlubricity scale was three orders larger than the previously reported values. These advanced works marked an impactful milestone in the research of CNTs and the future of manufacturing.