The Story of YInMn Blue
YInMn Blue, or “MasBlue” as it is commonly referred to at Oregon State University (“OSU”), is a serendipitous discovery of a bright blue pigment by scientists led by Mas Subramanian at OSU while researching materials for electronics applications. YInMn refers to the elements yttrium, indium and manganese, which along with oxygen comprise the vibrant pigment.
In 2009, graduate student Andrew Smith was exploring the electronic properties of manganese oxide by heating it to approximately 1200 °C (~2000 °F). Instead of a new, high-efficiency electronic material, what emerged from the furnace was a brilliant blue compound – a blue that Subramanian knew immediately was a research breakthrough. “If I hadn’t come from an industry research background – DuPont has a division that developed pigments and obviously they are used in paint and many other things – I would not have known this was highly unusual, a discovery with strong commercial potential,” he says.
Blue pigments dating back to ancient times have been notoriously unstable – many fade easily and contain toxic materials. The fact that this pigment was synthesized at such high temperatures signaled to Subramanian that this new compound was extremely stable, a property long sought in a blue pigment, he says. To read further about the historical context of this discovery, see here.
THE CHEMISTRY BEHIND THE BLUE
The chemical formula of YInMn Blue is YIn1-xMnxO3. These compositions adopt a crystal structure in which the chromophore responsible for the intense blue color (Mn3+) resides in the trigonal bipyramidal site (shown in blue). The intensity of the color can be systematically tuned by adjusting the In:Mn ratio, as shown below.
By measuring the spectral properties of this series (shown in the figure below), it was found that YIn1-xMnxO3 exhibits high absorbance in the UV region and high reflectivity in the near-infrared region when compared to currently-used Cobalt Blue pigments. To read further about the physical properties of this pigment, see here.
APPLICATIONS AND COMMERCIALIZATION
In May 2012, the Subramanian team received a patent with the U.S. Patent Office for the new pigment (US82822728). Shepherd Color Co. subsequently entered into a non-disclosure agreement with OSU and began rigorous testing of the pigment. They concluded that the increased UV absorbance and stability in outdoor weathering and heat buildup tests demonstrate that YInMn blue is superior to Cobalt Blue (CoAl2O4). In addition, the high solar reflectance (compared to similarly colored pigments) indicates that this ‘cool pigment’ can find use in a variety of exterior applications by reducing surface temperatures, cooling costs, and energy consumption. As a result of this testing, Shepherd Color Co. has licensed the patent for commercialization efforts.
YInMn BLUE IN ART
LOOKING BEYOND THE BLUE
The excitement of discovering a brilliant blue, heat reflecting, thermally stable, and UV absorbing pigment did not stop them from exploring beyond the blues. Since then, Subramanian and his team have expanded their research and have made a range of new pigments to include almost every color, from bright oranges to shades of purple, turquoise and green.
They continue to search for a new stable, heat reflecting, and brilliant red, the most elusive color to synthesize.
A contest to find a name for the new Blue
Now the blue pigment discovered at Oregon State University is the inspiration for Crayola’s new crayon color.
Crayola made the announcement at The Colorful World of Pigments, an OSU-hosted celebration of YInMn blue and its impact on art, culture and industry.
Subramanian, noting that people love the color blue for a wide variety of reasons, called it “truly an honor” that his discovery has led to a new crayon color.
“Blue is associated with open spaces, freedom, intuition, imagination, expansiveness, inspiration and sensitivity,” said Subramanian, the Milton Harris Chair of Materials Science. “Blue also represents meanings of depth, trust, loyalty, sincerity, wisdom, confidence, stability, faith, heaven and intelligence. We could not imagine a better partner than Crayola, a brand synonymous with color and creativity, to help us share this discovery with the world.”
Crayola is inviting the public to help name the color of its new blue with a contest on Crayola.com/NewColor and running through June 2. Those who submit name ideas will be entered for a chance to win one of four weekly prizes.
Crayola will unveil the new name and announce six grand prize winners in early September, and the new blue crayon will begin appearing in Crayola products in late 2017.
“We are a company all about kids, creativity and color, so we strive to keep our color palette innovative and on trend, which is why we’re excited to introduce a new blue crayon color inspired by the YInMn pigment,” said Smith Holland, CEO and president of Crayola. “The new blue crayon color will help Crayola to continue to inspire kids and kids at heart, to create everything imaginable.”
YInMn blue was discovered by accident in 2009 when Subramanian and his team were experimenting with new materials that could be used in electronics applications.
The researchers mixed manganese oxide – which is black in color – with other chemicals and heated them in a furnace to nearly 2,000 degrees Fahrenheit. One of their samples turned out to be a vivid blue. Oregon State graduate student Andrew Smith initially made these samples to study their electrical properties.
“This was a serendipitous discovery, a happy accident,” Subramanian said. “But in fact, many breakthrough discoveries in science happen when one is not looking for it. As Louis Pasteur famously said, ‘In the fields of observation, chance favors only the prepared mind.’
“Most pigments are discovered by chance,” Subramanian added. “The reason is because the origin of the color of a material depends not only on the chemical composition, but also on the intricate arrangement of atoms in the crystal structure. So someone has to make the material first, then study its crystal structure thoroughly to explain the color.”
YInMn blue features a unique structure that allows the manganese ions to absorb red and green wavelengths of light while only reflecting blue. The vibrant blue is so durable, and its compounds are so stable – even in oil and water – that the color does not fade.
These characteristics, as well as its non-toxicity, make the new pigment versatile for a variety of commercial products. Used in paints, for example, they can help keep buildings cool by reflecting infrared light.
“What is amazing is that through much of human history, civilizations around the world have sought inorganic compounds that could be used to paint things blue but often had limited success,” Subramanian said. “Most had environmental and/or durability issues. The YInMn blue pigment is very stable/durable. There is no change in the color when exposed to high temperatures, water, and mildly acidic and alkali conditions.”
The Colorful World of Pigments event is part of a series known as SPARK: The Year of Arts and Science at OSU. The series explores the places where art and science intersect.
Hosted by the College of Science, the event included a discussion of color by a panel that included Subramanian; Holland; Christopher Manning of the Shepherd Color Company, OSU’s licensing partner for the pigment; and the curator of Harvard University’s 2,500-specimen Forbes Pigment Collection, a scientific catalog of color that includes YInMn blue.
“We are very excited about our part in bringing YInMn blue to market for this and other industries,” Manning said. “We pride ourselves on being at the leading edge of inorganic color and pigment technology.”
Also at the event, Subramanian led tours of the lab where YInMn blue was discovered, and demonstrated how it was discovered.