The search for the “blackest black” has fascinated artists and scientists alike for centuries. From developing ever darker pigments to engineering light-absorbing nanomaterials, the quest continues to create a black that absorbs nearly all light, creating the illusion of staring into a void. But what is the blackest black possible? And what unique properties allow certain materials to capture and contain light so efficiently? In this article, we’ll explore the science behind some of the blackest materials created to date and what makes them so dark.
What Makes a Material Appear Black?
For a material to appear black, it must absorb most visible light wavelengths while reflecting very little back to the eye. The more light a material can “trap,” the darker it will appear. Here are some key reasons why certain materials are extremely black:
| Property | Description |
|---|---|
| Light absorption | Materials with high light absorption have properties that capture and contain light particles (photons) rather than reflecting them. |
| Nanostructures | Microscopic and nanoscale surface structures can “trap” light through multiple internal reflections. |
| Carbon content | Carbon is very effective at absorbing light, so carbon-based black pigments are common. |
The most black materials maximize light absorption and retention using various combinations of these properties.
Traditional Black Pigments
For centuries, black paints and dyes were produced using carbon-based pigments mixed with liquids like oils or inks. Common traditional black pigments include:
– Lamp black – Soot deposited from burning oils, fats or resins.
– Vine black – Charcoal pigment made by burning sticks or residues of grape vines.
– Ivory black – Charred animal bones or ivory.
The carbon particles in these pigments absorb light efficiently, creating very dark blacks. However, traditional carbon blacks still reflect about 3-5% of light. So there was room for improvement.
Super-Black Nanomaterial Coatings
In the past few decades, nanotechnology has allowed the engineering of microscopic surface structures and coatings that are far blacker than traditional pigments. Two leaders in this field are:
Vantablack – This carbon nanotube coating, developed by Surrey NanoSystems, contains tiny nanotube structures packed tightly together. Light enters the spaces between the tubes but is essentially “trapped” after bouncing around between the tubes multiple times. Vantablack absorbs up to 99.965% of visible light, outperforming any traditional black pigments.
Black 3.0 – A nickel and phosphorus alloy coating developed by Stuart Semple, Black 3.0 also utilizes nanoscale surface structures to capture and absorb light. It absorbs up to 99.4% of visible light and holds the Guinness World Record for “blackest acrylic paint.”
Both Vantablack and Black 3.0 rely on microscopic light-trapping architectures to absorb nearly all light that strikes them. This creates the illusion of a flat, shadowless black void.
Properties of Super-Black Materials
Let’s look at why Vantablack and Black 3.0 are able to absorb virtually all visible light:
| Property | Vantablack | Black 3.0 |
|---|---|---|
| Composition | Carbon nanotubes grown on surface | Nickel-phosphorus alloy powder |
| Surface structure | Densely packed nanotubes | Microscopic tooth-like ridges |
| Light absorption | Up to 99.965% | Up to 99.4% |
The combination of composition and nano/micro-scale surface structures allows both materials to capture light extremely efficiently through multiple internal reflections and absorption events. This results in virtually no light being reflected back to the eye.
Blackest Natural Materials
Though synthetic nano-engineered coatings hold the record for blackest blacks, some natural materials also absorb over 99% of visible light by combining carbon content with microscopic structures:
Butterfly wings – The wings of some species like the Papilio ulysses butterfly have evolved ultra-black pigmentation to increase heat absorption. The wing scales contain microscopic ribs that “trap” light through many internal reflections.
Bird of paradise feathers – These feathers contain tiny microscopic barbules that capture and absorb light. This results in incredibly rich, deep blacks that help attract mates.
By mimicking nano-architectures found in nature, material scientists continue to develop ever blacker synthetic coatings and pigments.
Blackest Natural Substances
In terms of natural substances, here are some of the blackest materials found in nature:
| Substance | Light Absorption |
|---|---|
| Coal | Up to 98% |
| Black oak wood | Up to 95% |
| Dragonfish skin | Up to 99.5% |
Coal and black-stained wood absorb light efficiently due to high carbon content. And the dragonfish skin achieves near total light absorption using black pigment packed into microscopic structures.
Applications of Super-Black Materials
What are these ultra-black materials useful for? Some key applications include:
– Camouflage – Vantablack coating can hide military equipment against the night sky.
– Space instrumentation – Black coatings improve calibration of sensitive optical devices by reducing stray reflections.
– Radiators – Maximizing light absorption allows radiators coated in Black 3.0 to efficiently convert light to heat.
– Art and design – Sculptures and installations using super-blacks create unique visual effects playing with viewers’ perception of light and space.
So while aesthetically striking, these ultra-blacks also have many practical uses for decoration, military, science and engineering.
Blackest Known Material in Universe
What is considered the blackest known substance in the universe? That title goes to the material at the center of black holes. The immense gravity of a black hole pulls in surrounding matter and light, compressing it into an infinitesimally tiny point with nearly infinite density and darkness.
No light can escape a black hole once it crosses the boundary known as the event horizon. This makes the material inside the ultimate black, absorbing 100% of any light it intakes. Yet the true “surface” of the black hole singularity remains unknown, making its blackness theoretical. But research indicates black holes are the closest known approximation to being pure black.
Conclusion
From sooty lamp blacks to ultra-black carbon nanotubes and nickel-phosphorus coatings, the quest for the “blackest black” continues to push scientific boundaries. By maximizing light absorption, reflection-minimizing nanostructures, and carbon composition, the blackest synthetics and natural materials achieve light absorption rates over 99%. But aspiring to the infinite darkness of black holes, the search for an ideal full-spectrum black that reflects no light may literally continue forever. Yet this challenge also promises advancements in nanomaterials, biomimetics, and optical engineering that could broaden practical applications.