Research Highlights, Electromagnetic Wave Shielding by Paint Using Carbon Nanotubes

Seisuke Ata CNT-Application Research Center


We have developed aqueous paint capable of forming a flexible electromagnetic wave shielding film having high heat resistance (180 °C) on various base materials using long single-wall carbon nanotubes (SGCNTs).

Photo:Film deposition on polyimide sheet using SGCNT-based aqueous paint
Film deposition on polyimide sheet using SGCNT-based aqueous paint
Photo:SGCNT-based aqueous paint
SGCNT-based aqueous paint
  Figure:Coating speed dependence of viscosity
Coating speed dependence of viscosity


Due to the recent explosive spread of electrical equipment, electronic equipment, mobile phones, etc., our living environment is covered with electromagnetic waves emitted from such equipment. At the same time, in order to prevent health disorders, device malfunctions, radio wave terrorism, etc., the needs for electromagnetic wave shielding materials are increasing dramatically.

There are various types of electromagnetic wave shielding materials depending on applications. Among them, an electromagnetic wave shielding film formed using a paint containing metal particles on a base material is capable of providing electromagnetic wave shielding characteristics to the base material by post-processing and has, therefore, a certain need. However, environmental affinity is low, because an organic solvent is used. Also, it has various problems such as dripping and a reduction in shield-ability due to oxidation of metal particles at high temperature. In order to solve such problems of the paint serving as a source of electromagnetic wave shielding materials, AIST has developed aqueous paint using CNTs developed by AIST.

Outcomes and Methods

Using long single-wall carbon nanotubes (SGCNTs) developed by AIST, we have developed aqueous paint capable of forming a high-performance electromagnetic wave shielding material on the surface of various base materials. Since the paint uses water as a solvent, it is high in environmental affinity and can be handled safely. The developed paint is capable of being finely deposited not only on a flat surface but on a curved surface etc. using the unique viscoelastic behavior of the SGCNT solution. In addition, the formed electromagnetic wave shielding film has flexibility and even when bending the base material, cracks and the like never occur. Further, we have confirmed that electromagnetic wave shielding characteristics can be kept at 180 °C for a long period of time, since SGCNTs having high heat resistance are used as a base.

Future Plan

We will put the paint into practical use by providing samples and improve the paint on the basis of received needs. 



Photo:Seisuke Ata  
Seisuke Ata
Senior Researcher
CNT Application Development Team, CNT-Application Research Center

AIST Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 Japan

TEL: +81-29-861-4551
WEB: http://www.nanocarbon.jp/en/

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