Carbon Nanotube dan Pedang Salahuddin Al-Ayyubi

[Yasin]

Artikel lama, cuma lumayan bagus di ulang lagi.  

Carbon nanotubes: Saladin's secret weapon

15 November 2006

Carbon nanotubes are no longer the proud boast of 21st century materials scientists. It appears their discovery was unwittingly pre-empted by mediaeval Muslim sword-smiths whose tough Damascus blades taught the Crusaders the true meaning of cold steel when they fought over the Holy Land.

Peter Paufler and colleagues at Dresden's Technical University discovered carbon nanotubes in the microstructure of a 17th century Damascus sabre. Intriguingly, the nanotubes could have encapsulated iron-carbide nanowires that might give clues to the mechanical strength and sharpness of these swords.

Damascus sabre
Mediaeval nanotubes, a cut above the rest


© Nature

To Europeans, Damascus steel blades seemed magical. Not only could they cut a piece of silk in half as it fell to the floor, they could cleave rocks and their own swords without losing sharpness. The problem facing sword smiths was how to produce steel that was both hard and malleable. Too much carbon and the steel is hard and brittle; too little and it is too soft and malleable to hold an edge when sharpened. Damascus steel blades were forged out of small pure cakes of steel containing around 1.6-1.7 per cent carbon, called wootz. Produced in India, wootz cakes were shipped to Damascus where expert sword smiths fashioned them into blades.

Steel that contains this amount of carbon forms plates of cementite (Fe3C) which, on its own, makes the steel brittle. However, during the forging process at around 800oC, small amounts of 'impurities' were added containing many first-row transition elements (such as V, Cr, Mn, Co, and Ni), tungsten, and some rare-earths. which together had the effect of forming the cementite into bands. This gave the blades great strength, malleability, and a distinctive wavy-band pattern known as a damask. The skill had been lost by the 18th century,   when supplies of these ores and impurities ran out.

Micro-structural examination of the bands had previously shown they contained nanowires of Fe3C. Now, Paufler's team has uncovered the presence of carbon nanotubes by exposing a small piece of a blade to corrosion by hydrofluoric acid, and examining the effects under a high resolution scanning electron microscope. In some remnants the researchers saw evidence of incompletely dissolved Fe3C nanowires, suggesting the nanotubes could have encapsulated the nanowires. This would not only have given the blades their renowned strength and sharpness, but also their characteristic banding pattern. 'The nanotubes probably came from the addition of mandatory organic ingredients we know were added during wootz production, such as wood from the tree Cassia auriculata and leaves from Coltropis gigantean,' said Paufler.   'So, by empirically optimising their blade-treatment procedures, these craftsmen made nanotubes more than 400 years ago.'

Lionel Milgrom

http://www.rsc.org/chemistryworld/News/2006/November/15110602.asp

Legendary Swords' Sharpness, Strength From Nanotubes, Study Says
Mason Inman
for National Geographic News
November 16, 2006

New studies of Damascus swords are revealing that the legendary blades contain nanowires, carbon nanotubes, and other extremely small, intricate structures that might explain their unique features.

Damascus swords, first made in the eighth century A.D., are renowned for their complex surface patterns and sharpness. According to legend, the blades can cut a piece of silk in half as it falls to the ground and maintain their edge after cleaving through stone, metal, or even other swords.

But since the techniques for making these swords have been lost for hundreds of years, no one is sure exactly why these swords are so exceptional.

Now studies of the swords' molecular structure are uncovering the tiny structures that may explain these properties.

Peter Paufler, a crystallographer at Technical University in Dresden, Germany, and his colleagues had previously found tiny nanowires and nanotubes when they used an electron microscope to examine samples from a Damascus blade made in the 17th century.

Today in the journal Nature, the teams reports that it has also discovered carbon nanotubes in the sword—the first nanotubes ever found in steel, Paufler says.

The nanotubes, which are remarkably strong, run through the blade's softer steel, likely making it more resilient. (Related: "Nano-Switches Could Yield Even Smaller Gadgets" [August 16, 2005].)

"It is a general principle of nature," Paufler said. "Materials that are softer, you can strengthen by including harder wires."

Secret Techniques


Some of the nanowires Paufler and his team had previously found were made of an extremely hard iron-based mineral called cementite.

In the new research, the team discovered that carbon nanotubes encase some cementite nanowires, protecting them.

These nanotube-nanowire bundles may give the swords their special properties, Paufler says.

selengkapnya...

http://news.nationalgeographic.com/news/2006/11/061116-nanotech-swords.html
http://news.nationalgeographic.com/news/2006/11/061116-nanotech-swords_2.html

===============


Selama ini nano teknologi merupakan kebanggan ilmuwan barat abad 21, namun semua itu terpatahkan, karena orang-orang Islam dan di Damaskus sudah mengenal teknik membuat pedang yang mengandung Carbon nanotube pada abad 11-an, dengan menggunakan teknik pembuatan pedang metode Damaskus abad 8.

[Yasin]

Reserved,  PERTAMAX habissss


Sedikit informasi tentang Carbon Nanotube (CNT)

Carbon nanotubes are molecular-scale tubes of graphitic carbon with outstanding properties. They are among the stiffest and strongest fibres known, and have remarkable electronic properties and many other unique characteristics. For these reasons they have attracted huge academic and industrial interest, with thousands of papers on nanotubes being published every year. Commercial applications have been rather slow to develop, however, primarily because of the high production costs of the best quality nanotubes.






selengkapnya..


http://www.personal.reading.ac.uk/~scsharip/tubes.htm


-----------------------------------------------------------------------------


Nano Technology

A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced.

The Meaning of Nanotechnology

When K. Eric Drexler (right) popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nanometers wide—motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nanometer-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nanotech: their definition includes anything smaller than 100 nanometers with novel properties.

selengkapnya

http://www.crnano.org/whatis.htm

[ady_husein]

Oiyyy Cek bahasa Indonesia ke.... supaya yang laen ngerti.... (taula kami...)

[d4vid_r5]

buseeet mantap gan!