The Secrets of Abalone

[button_man]

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I just stumbled across this NYT article from 1999 on the amazing strength of abalone.
In case other folks with abalone-handled switchblades might be interested, I'm posting
the entire article here with no permission whatsoever.....


https://www.nytimes.com/1999/06/29/scie ... found.html


Secret of Abalone's Remarkable Strength Is Found

By Henry Fountain June 29, 1999


The world is awash in space-age materials, from the graphite panels of an airplane wing to the honeycomb sandwich of a skateboard. To the list can be added the shell of an abalone, that rock-dwelling creature, about the size of a steam iron, that lives in shallow waters off the West Coast and elsewhere
in the Pacific.

Abalone shell is prized for the iridescent beauty of its mother-of-pearl interior. But scientists admire it for something else: its toughness.
The shell is composed almost entirely of calcium carbonate, yet it is 3,000 times more fracture resistant than a crystal of the pure mineral alone.
Now, scientists at the University of California at Santa Barbara have uncovered the secret to abalone's remarkable strength, and the findings
may help in the development of a new class of strong, lightweight materials.

Mother of pearl, or nacre, is a composite material, one that any chemical engineer would be proud to have invented.
Electron microscopy has revealed its structure: tiny tablets of calcium carbonate held together in a protein matrix, like bricks in mortar.

''We first thought that the key to its strength was how the tablets were stacked,'' said Dr. Bettye L. Smith, the lead author of a paper
describing the abalone research in the current issue of Nature.

But a brick wall will crumble when hit by a sledgehammer. The researchers realized that there must be something about the proteins
in abalone that act like an adhesive, keeping the tablets together even when subject to strong forces.

For their investigations, the researchers had the ideal tool: an atomic force microscope, which can measure the force required to break bonds.
A.F.M.'s, as they are known, are relatively new, and Santa Barbara has a leading A.F.M. expert, Paul K. Hansma, on its faculty.

Using an atomic force microscope is something like pulling taffy, but on a molecular level. A tiny cantilever tip is stuck to the material
and pulls on it, measuring the minuscule forces exerted as the material stretches and eventually breaks.

With other materials, force steadily increases until a catastrophic break occurs. But the abalone proteins broke in fits and starts,
with force building up and then releasing, building up again and releasing again, continuing until finally a permanent break occurred.

The researchers realized that the proteins have what they call ''sacrificial'' bonds that break before the entire molecule does.
Dr. Smith compared it to a sticky string that has been clumped together in various spots along its length. ''When you pull on the string, the first thing
that happens is one of those knots is going to break,'' she said. ''But you haven't broken the backbone -- you can keep pulling and pulling on it.''

Large amounts of energy can be dissipated with this arrangement, so that it takes cumulatively more force to fracture the shell.
The abalone proteins have a further advantage in that these sacrificial bonds can re-form after they are broken.

The researchers are now investigating ways to create similar materials in the laboratory, ones that might eventually have commercial applications.
Such new materials might also be easier to manufacture. While many composite materials require high temperature or pressure or both in the manufacturing process, abalone makes its shell while sitting on a rock, getting the calcium carbonate from sea water and secreting the protein adhesive. For all the space-age qualities of the material, the process is decidedly down to earth.

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[jim d,]

Thanks for sharing the article, button_man. I found it quite interesting, but then I admit to being a bit of a nerd about this kind of stuff.

Jim

[john]

Interesting article, I wonder if scientists/engineers have been able to replicate the properties of the calcium carbonate and the protein that give abalone its strength and if so what products have been made from the discovery made back in back 1999.

[NorthCarolinaDude]

Thanks for posting the article brother.

Abalone is my word of the month. For some reason I never picked up a knife scaled in it. I had decided it was "too fancy" for the Italian stilettos I collect, and didn't fit my "vision." Well, heck, for some reason I reached out and picked up one of the newer 9 inch Frank B models with the larger spines, 4mm versus 3.5, I think...and in doing so I thought I'd finally break with my "ideals" and get one scaled in abalone. Well, to illustrate the fickleness of taste, my second Frank B in abalone showed up today! That didn't take long. And, of course, I'm already considering my next! So goes this addiction, er hobby!

Peace.

[button_man]

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Glad to see that a few other folks found this to be of interest....!

This is my prized 'Superior' abalone -- the scales look terrible in the photo,
but in real life they are just beautiful. I feel very fortunate to own this knife.

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[john]

Abalone of any color, white or black lip mop are very difficult to photograph. Your knife looks fabulous!