March 5, 2024
Japan Atomic Energy Agency (JAEA)
J-PARC
Meiji University
Discovery of a mystery in “absolute darkness” with quantum beams
— A “lacquer technique” born in the Jomon era is used for cutting-edge technologies —
- [Summary of announcement]
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- Lacquer is an ancient super paint whose stability is so high that it is sometimes found in ruins of the Jomon era without decomposition. Black lacquer is widely known in Japan as a traditional craft due to its deep and gorgeous black color obtained by adding iron powder to lacquer. Scientifically, coating films of lacquer are known to cure rapidly due to iron ion effect, while it has been found recently that it has a catalyst function of accelerating the decomposition of harmful substances.
- However, it is difficult to analyze black lacquer, because black color is stable and absorbs visible lights. Therefore, the mechanism and internal structures of how black color is formed has been a mystery until the present day. Unraveling the mystery of black lacquer is helpful to further analyze historical materials and develop new functional materials containing lacquer.
- We succeeded for the first time in observing iron ions and special nanostructures inside black lacquer by utilizing X-ray and neutron rays that have excellent permeability of materials and can detect a very small quantity of components inside. Moreover, it was revealed that iron ions act on the structurization of urushiol, an organic component of lacquer, and that its array structure produces beautiful black color.
- The finding discovered for the first time in this research indicates the possibility of applying the ancient lacquer technique to cutting-edge catalyst technology and related fields by controlling the type and quantity of metal ions added to lacquer. Furthermore, the analytical method established as a result of this research will be used for non-destructive analysis of historical materials.
- [Information on article]
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Name of journal: Langmuir Title of article: Effects of Fe ions, UV irradiation, and heating on microscopic structures of black lacquer films Names of authors: Takuya Nankawa1*, Yurina Sekine2*, Daiju Matsumura2, Kosuke Hiroi2,3, Shin-ichi Takata2,3, Yoshimi Kamiya4, Takayuki Honda4 Organizations of affiliation: - 1
- Policy Planning and Administration Department, Japan Atomic Energy Agency
- 2
- Materials Sciences Research Center, Japan Atomic Energy Agency
- 3
- J-PARC Center, Japan Atomic Energy Agency
- 4
- Meiji University