Proceedings of 2nd International Symposium for Color Science and Art 2020

Development of Structural Color Material Contributing toMaintenance Management of Social Infrastructure and its
Application in the Civil Engineering and Architecture Fields.
Toshihiro Hiejima, Hiroshi Jinnai, Tsuyoshi Moriyama, Rika Matsumoto,
Mitsutoshi Okano, Noritoshi Nambu and Kazuyuki Hiraoka
Tokyo Polytechnic Univ., 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan
from Toyo Aluminiums K. K., called “Chromashine”. The
silicon, urethane and epoxy resins was used as the main
ingredient. The weight ratios of pigment and synthetic
resin were 1:10 and 1:20. In this project, the structural
color paints were directly applied to the concrete surface
without using additives or primers.

ABSTRACTThis project constitute of the two independent themes
related with the structural color materials. (1) The one is todevelop the structural color materials detecting the aging
degradation of building material as the change of color.
(2) The other one is to develop the educational tool madeit possible to visualize and colorize the sounds. At first, we
succeeded in directly applying a structural color pigmenton the rough surface of concrete without primer coating.
Secondary, we demonstrate the visualization andcolorization of Chladni patterns created by the structural
color materials.

3. Results and Discussion
As show in Figure 1, all of pigment exhibit to retain theclear metallic color despite the roughness of concretesurface, and their color change depending on the view
angle. Urethane and silicon resins could be successfully
applied the pigment n the concrete surface, whereas theepoxy resin was repelled on the concrete surface, causing
the color unevenness.
Figure 2 shows the typical reflectance spectra of SCP
applied on the surface of concrete. The absorption bands
were observed at the identical wavelength regardless ofthe differences of the resin. However, the maximum
reflectivity strongly depends on the resins, increasing inorder of urethane > silicon > epoxy resins.

1. INTRODUCTION
Structural colors are responsible for many of the brilliant
colors we see in nature. The blue of the sky, the rainbow ofcolors in an oil slick, the bright colors of peacock feathers,
the brilliant blue of a Blue Morpho butterfly, the metallic
colors of certain beetles, and the glimmering colors ofsome fish, are all due to structural color. This project
constitute of the two independent themes related with thestructural color materials. (1) The one is to develop thestructural color materials detecting the aging degradationof building material as the change of color. (2) The otherone is to develop the educational tool made it possible tovisualize and colorize the sounds.

(A) Urethane resin

I. Development of Structural Color Material
Contributing to Maintenance Management of Social
Infrastructure and its Application in the Civil
Engineering and Architecture Fields.
1 Introduction
A fifty or more years has passed since the last Tokyo
Olympics. Most of the social infrastructures built at thattime are rapidly progressing their deterioration. It is very
important issues in Japan to construct the maintenancesystems for easily diagnosing the deterioration of social
infrastructures. We focus on the point that the structural
color materials exhibit the remarkably change of colors by
the structural damage and distortion, which cause withapplying a slight external stimulus such as pressure,temperature and vibration. In this study, we tried todevelop the structural color paint to diagnose the aging
deterioration of buildings as the change of color.

(B) Silicone resin

2. Experimental
The structural color pigments (SCP) were obtained

Figure 1. Photographs of SCPs on the concretesurfaces, (A) Urethane and (B) Silicon resins.

19Proceedings of 2nd International Symposium for Color Science and Art 2020

Reflectance (Arb. Units)

In particular, it should be noted that the silicon resin retain
the high transparency, indicating to be a candidate for thetransparent dispersant in Section II.

Figure 4. Chladni figures in the various frequencies [1].

400600
Wavelength / nm

2. Experimental
The sand art powder were obtained from Koeido Hobby
Ltd. SCP was also used “Chromaschine®”. Silicon oil (350cp) was used as the dispersion matrix for the SCP. The
weight ratios of SCP and silicon oil were 1:20. Chladni
figures were drawn on the iron plate equipped with thevibration generator and function generator.

800

Fig. 2 Typical reflectance spectra of the SCP-urethane
paint applying on the concrete surface.

3. Result and Discussion
As shown in Fig. 5, we succeeded in drawing thecolor-coded Chladni figures by using the difference ofdensity of the sand art powder.

Figure 3 shows the comparison of colors of SCP-urethane
paints before and after destruction of concrete.
Unfortunately, we could not observed the color change of
pigments with generating the cracks on the concrete.
II Development for Coloring of the Mysterious
Geometric Pattern "Chladni Figure" Made by Sound
with Using the Structural Color Materials
1. Introduction
Structural color is one of the interference of light; itarises through the reflection of light from complex
nanostructures found in the feathers of birds or the hardouter shell of beetles. These multi-layered structures
produce iridescence, whereby the color appears tochange depending on the angle of view. In contrast,
Chladni figures are one of the resonance phenomena ofsounds; it reveals the various shapes or patterns
characteristic of the vibrational mode of sounds, as shownin Figure 4.
If we can make Chladni figures colorized by using thestructural color materials, it could be an extremely
effective educational tool not only in experiencing scientificinterest but also on understanding in both of theinterference of light and the resonance of sounds forJapanese high school students. In this study, we wish to
demonstrate the Chladni figures changing optical patterns
according to the frequency of sound and the angle of view.

Figure 5. Photographs of Chladni figures drawn by using
the sand art powders.
Applying the vibration to SCP dispersed in Silicon oil,
we found to change the color tone of the optical texture
with elevating the frequency, although it is notnecessarily so clear (See Figure 6). In order to draw theclearer optical texture, it would be necessary to optimize
the viscosity of silicone oil and concentration of SCP.

Figure 6. The variation of optical texture of SCP dispersed
in Silicon oil as a function of the vibrational frequency.
4. REFERENCES
https://dailynewsagency.com/2013/06/10/amazing-resona
nce-experiment-g7j/

Figure 3. Comparison of colors in SCP-urethane paint before and after destruction of concrete.

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