From Bird feathers To Fruit skins, There are two main ways to show color in the natural world: by Pigment products They provide selective color absorption, or by Structure color – The use of microscopic structures to control light reflection.
Now scientists have developed a computer model that explains why nature’s bright matte texture colors are always blue and green: because they are the limits of the structural color within the visible spectrum of light.
Research is important to give us a better understanding of how bright blues and greens are created in the natural world, and to create vibrant, eco-friendly paints and coatings that do not fade over time or release toxic chemicals.
“Apart from their intensity and resistance to fading, a matte paint that uses texture color is more environmentally friendly because it does not require toxic dyes and pigments.” Says physicist Gianni Jacuzzi From the University of Cambridge in the UK.
“However, we must first understand the limitations of recreating these types of colors before any commercial applications are possible.”
Along with the texture color, the nano-sized structure on the surface dictates the true color.
Sometimes – like peacock feathers, for example – that color can be different and switch between different shades at different angles and under different lights. These are made of ordered crystal systems.
Peacock feathers are a great example of structural color. (Tj Holowaychuk / Unsplash)
With other textures, you will get a matte color that does not arise from irregular textures; In nature it is found only in the formation of blue and green colors. The motivation of the new study is to know that this is the inherent limitation of the stated structures.
The new computer model, based on synthetics called photonic mirrors, shows that red does not really exist outside the range of scattering techniques behind matte texture colors: these microscopic surface structures cannot easily reflect the long wavelength of the visible spectrum.
“Because of the complex gap between single scatter and multiple scatter and the contributions of related scatter, we found that nothing other than red, yellow and orange could be achieved.” Says chemist Sylvia Vignolini, From the University of Cambridge.
Plum-throat coatings show clear texture matte blues. (redabbott / iNaturalist / CC-BY-NC)
This is why bright matte reds are made using pigments in nature rather than textured color. The team believes that the evolution of nature has led to the creation of red in various ways because of the limitations of the basic structures.
Learning more about how these matte texture paints are created will take us closer to creating paints free from pigments and dyes — a significant step in long-lasting, eco-friendly products for many uses.
It still exists in some ways, and seems to require a different approach to reds and oranges – other types of nanostructures can do that job after extensive research into them, but for now material scientists have problems similar to the natural world.
“When we try to artificially recreate the matte texture color for red or orange, we end up with poor-quality results in terms of concentration and color purity.” Says chemist Lucas Sherdell, From the University of Cambridge.
Research has been published PNAS.
