Mother of pearls mass-produced

Cyril Roger Brossard

Well-known member
Aug 30, 2012
This is an old article (2010) and I remember reading a thread mentioning the idea.

Nacre, or mother of pearl, is one of the toughest and most beautiful natural materials on Earth. Now scientists can make it -- cheaply.


Artificial nacre, or mother of pearl, can now be mass-produced.
The material is flameproof, super strong and as cheap as paper to make.
It could be used to fireproof homes and to make cars more fuel efficient.

A natural pearl is a rare treasure, but new mass-produced mother of pearl could soon be as cheap and versatile as paper.

Flameproof yet flexible, thinner than office paper but 20 times as strong, the new material could eventually make aircraft lighter and comfortably protect police from bullets.

"Natural nacre is this perfect marriage of stiffness, strength and toughness," said Andreas Walther, a researcher at the Helsinki University of Technology and a co-author of a recent paper in the journal Nano Letters.

"Our artificial nacre compares very well to the natural material."

Synthetic nacre has long been a goal for both material scientists and biologists. For material scientists man-made nacre could provide strong, lightweight, cheap and environmentally-friendly material for a huge variety of products.

For biologists, synthetic nacre would provide a new way to study the complex mesh of soft protein and hard calcium carbonate that mollusks use as protection and women as decoration.


Artificial nacre has been produced before, but in small, labor-intensive amounts, said Walther. "To get even a few microns you had to dip a glass slide 1,800 times into various glass beakers," said Walther. The entire process could take anywhere from days to weeks to complete.

Walther and his other colleagues in Finland and Sweden aimed to reduce those hundreds of steps down to one. Drawing on the Scandinavian nations' experience in the wood processing and paper making industry, the scientists mixed hard clay particles and a soft, binding synthetic polymer.

The two materials are attracted to each other and arrange themselves in alternating layers. When drawn out like paper, square feet of artificial nacre emerges in minutes.

One layer of the new nacre looks like paper but is thinner, stronger, and stiffer than paper. One quality the new nacre lacks is toughness; it tears more readily than paper, said Walter.

The new nacre, however, is impervious to heat.

"The material doesn't burn," said Walther. "We placed a silk cocoon five millimeters behind the material and heated it to 2,000 degrees [Celsius]. The material acted like a shield," said Walter, leaving the delicate silk unharmed.

Synthetic nacre could be glued to a surface, or even painted on a wall, to make it flameproof. As if a cheap, strong, elastic and flameproof coating weren't enough, the new nacre also blocks oxygen, making it ideal for use in electronics.

"The area of applications for this materials is quite large," said Nicholas Kotov, a scientist from the University of Michigan who makes artificial nacre with the same base materials. Body armor for soldiers or police, fireproof coatings for buildings, casings for electronics and lightweight materials for more fuel efficient cars and aircraft are just a few of the research's potential applications.

Before synthetic nacre appears in consumer products a few kinks in the research need to be ironed out, said Kotov, including the appearance of some imperfections in the material. But the fact that the scientists can cheaply and easily produce synthetic nacre on this large of a scale is, according to Kotov, "quite amazing."

mentioned also was the discovery made in 2009 by two Japanese scientists.

Aug. 14, 2009 -- The iridescent beauty of pearl and nacre, the material found inside the shells of clams, oysters and other mollusks, would likely be impossible without two new proteins recently discovered by Japanese scientists.
The discovery could allow for the production of larger pearls in less time.
Pearl and nacre, also known as mother of pearl, have been used as decorations for millennia. In recent years, scientists have discovered the physical structure responsible for their valuable iridescence, the minerals that make up those structures, and the proteins that hold those minerals together.
What science has failed to find, however, are the proteins that actually produce pearls. The Japanese researchers set out to find those missing proteins.
By infecting Japanese pearl oysters with an engineered virus specifically designed to reduce the amount of the newly discovered proteins, the scientists essentially stopped pearls from forming.
"This is really fundamental research," said Nils Kroger, a scientist at the University of Georgia who wrote an accompanying article in the journal Science. "The mollusk shells looked much more disorganized, not the nice structured layers you would normally expect."By washing nacre with distilled water and using gold nanoparticles tipped with antibodies, the Japanese scientists discovered two new proteins, Pif 80 and Pif 97, which appeared to be crucial for building nacre.
Pif 97, the scientists suspect, creates a basic template of what the nacre should look like using chitin, the same material lobsters and crayfish use to build their exoskeleton. Pif 80 binds calcium and bicarbonate to the chitin, finishing the nacre.
To test this theory that these proteins actually produced pearls, the Japanese scientists tried to eliminate the two proteins from Japanese pearl oysters. Using a genetically engineered virus, the scientists were able to reduce the amount of Pif 80 and Pif 97 by about 40 percent when compared with control oysters.
Six days later, the oysters had produced virtually no new nacre. The nacre that they did manage to develop was abnormal and misshapen on a microscopic level. To the human eye, the lackluster structure wouldn't have been apparent.
"If we rear the oyster for a longer period, the luster of the nacreous layer might be decreased, because the surface of the nacreous layer becomes more irregular," said Hiromichi Nagasawa, a scientist at the University of Tokyo and co-author of the Science paper.
Although discovering the proteins responsible for producing pearls is a good start, more work needs the work can be applied. If eliminating Pif 80 and Pif 97 stopped nacre formation, then increasing the amount of the two proteins should speed up pearl production -- a possibility the Japanese scientists are currently exploring.

Note Gold nanoparticles are apparently used for cancer treatment, the scientists started with nanospheres made from cobalt, then replaced the cobalt atoms with gold atoms, using the same process that turns the calcium in dinosaur bones into fossils.
The gold nanospheres are then coated in antibodies that detect, and then latch onto, cancer cells. Then a laser would be used to sear the cancerous cells.
To test their idea, scientists intravenously injected skin cancer-ridden mice with a solution of the gold nanoparticles. After four hours the gold nanospheres had used their antibody-antigen to latch onto the harmful cells. Scientists shined a laser beam onto the mice, killing the cancer cells.