Carbon nanotubes are a substance in which carbon molecules are linked in a cylindrical shape. They have a number of properties that make them promising as a material for the future, including strength several hundred times higher than that of iron, the ability to be used as semiconductors, and high electrical conductivity.
By themselves carbon nanotubes have a cotton-like configuration, so they must be added to a base material for practical use. Paper is such a candidate material, but when CNTs are immersed in water it forms clumps rather than distributing evenly. Since water is used to embed things in paper, embedding CNTs has posed a technical challenge. Tokushu Paper has overcome this difficulty with a new distribution method that successfully embeds CNTs in paper in a uniform manner.
A major feature of CNT paper is its high electrical conductivity. Paper with CNT content of 3% by weight exhibits conductivity 10 trillion times greater than that of paper without CNTs. This is equivalent to several tenths the conductivity of copper wire.
Paper with high conductivity can also be obtained by embedding carbon fibers or powdered carbon black in paper, but a considerable amount of these substances must to be embedded to achieve such conductivity, significantly reducing the strength of the paper. By contrast, CNT paper is slightly stronger than normal paper, and this is another advantage of CNT paper.
Substances with high conductivity are capable of absorbing electromagnetic waves, and Tokushu Paper hopes to take advantage of this property to use CNT paper as an electromagnetic shielding material. Most electronic devices give off electromagnetic waves, which become noise for other devices, and material to shield such waves is necessary.
Making Paper with Carbon Nanotubes
