From bird feathers to fruit skins, there are two main ways to display color in the natural world: by pigment substances that provide selective color absorption, or by structural color – using microscopic compositions to control light reflection.
Now scientists have created a computer model that explains why the brightest matte structural color in nature is always blue and green: because it is the limit of structural color within the visible spectrum of light.
In addition to giving us a better understanding of how bright blues and greens are made in the natural world, research can also be important for developing vibrant, eco-friendly paints and coatings that do not fade over time or release toxic chemicals.
“In addition to their intensity and fading resistance, a matte paint that uses structural dyes will also be more environmentally friendly, as no toxic dyes and pigments are required,” says Ginny Jacuzzi, a physicist at Cambridge University in the UK. .
“However, we need to understand what the limitations are for recreating these types of colors before any commercial applications are possible.”
Along with structural color, the nanoscale structure on the surface is what indicates the actual color itself.
Sometimes – such as on peacock feathers, for example – the color may be obese, and the color may vary between colors at different angles and under different lights. These are made by order crystal structures.
As with other compositions, you get a matte color that doesn’t change arising from the messy texture; In nature this is only seen in blue and green colored products. The thrust of the new study was to see if this is an internal limitation of the said structures.
A new computer model based on synthetic objects known as photonic glasses shows that red is actually beyond the scope of the scattering techniques behind matte structural colors: the visible spectrum cannot be easily reflected using long-wavelength field techniques. The microscopic surface structures.
“Because of the complex interplay between scattering alone and multiple scattering and the contribution of correlated scattering, we find that red, yellow and orange are rarely reached,” says Sylvia Vigolini, a chemist at Cambridge University. “
Instead of structural color, bright matte reds have been produced using pigments in nature. The team thinks that evolution in nature led to different ways of producing red, due to the limitations of the underlying structures.
More information on how these matte structural paints are made will take us closer to producing paints free of pigments and paints – a significant step into a long lasting, environmentally friendly material for many applications.
It is still closed in some ways, and it seems that red and orange will require a different approach – other types of nanostructures, after more detailed research, may work, but for now the material scientists natural The world has the same problems.
“When we try to artificially recreate a matte structural color for red or orange, we end up with poor-quality results in terms of saturation and color refinement,” says Lucas Schertel, a chemist at Cambridge University. .
Research has been published in P.N.A.S..