A single carbon nanotube has excellent power, electricity and performance. The development of super-strong multifunctional carbon nanotube macroscopic materials has always been one of the research hotspots in the field of materials. However, due to the limitations of traditional carbon nanotube dispersion and orientation technology, the excellent properties of carbon nanotubes have not been fully utilized in materials so far.

The research group of Li Qingwen of Suzhou Institute of Nanotechnology and Nano-Bionics, Chinese Academy of Sciences, based on spinnable carbon nanotube arrays, developed a dry method to prepare high-performance carbon nanotube functional composite materials. High load, high orientation and directional electron transfer explore new preparation ideas. The main research results include: 1) High-strength, high-conductivity and foldable carbon nanotube films were prepared by layer-layer solid-state assembly of oriented carbon nanotube films. The preparation process is simple, and it only needs to continuously pull the carbon nanotube film out of the array and then wind it, without going through the complicated solution treatment process of the traditional carbon nanotube bucky paper. The tensile strength of the carbon nanotube paper is as high as 2 GPa, and the modulus is as high as 90 GPa. The mechanical properties are far better than those of carbon nanotubes, graphene and other nano-carbon films reported in the literature (Figure 1). In addition, due to the high aspect ratio and orientation of the carbon nanotube film, it has very good flexibility and high conductivity, and the resistance does not change significantly after thousands of times of bending with a small radius of curvature. Related work was published in the recent ACS Nano (2012, 6, 5457–5464). 2) In cooperation with the research group of Professor YT Zhu from North Carolina State University in the United States, during the winding process of carbon nanotube films, the polymer was introduced by spraying to obtain polymer composites with high carbon nanotube content. The composite material exhibits better mechanical and electrical conductivity than the carbon fiber composite material, as shown in Figure 2. Related work has been published in Carbon (2011, 49, 4786–4791), Material Research Letters (2013, Accepted) and Composites Science and Technology (2012, 72, 1402–1407) and other magazines. 3) Taking advantage of the oriented electron transport characteristics of oriented carbon nanotube films, a carbon nanotube/tungsten oxide composite flexible film with gradient discoloration is reported for the first time. Related work was published in the recent Chem. Commun. (2012, 48, 8252-8254).

The above work was supported by 973, National Natural Science Foundation of China, Ministry of Science and Technology and other projects.

Figure 1 Preparation process and mechanical properties of super strong carbon nano paper

Figure 2 Carbon nanotube/polymer composite material (a) and its electrical properties (b)