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Large Sheets of Carbon Nanotubes Produced
StCredZero brings news that scientists have developed sheets of nanotubes that measure up to three feet by six feet, and they promise "slabs 100 square feet in area as soon as this summer." The developers see uses for the sheets in electromagnetic shields and airplane construction, and according to the Next Big Future blog, the sheets could also impact the development of solar sails.
"The sheets, which the company can produce on its single machine at a rate of one per day, are composed of a series of nanotubes each about a millimeter long, overlapping each other randomly to form a thin mat. The tensile strength of the mat ranges from 200 to 500 megapascals--a measure of how tough it is to break. A sheet of aluminum of equivalent thickness, for comparison, has a strength of 500 megapascals. If Nanocomp takes further steps to align the nanotubes, the strength jumps to 1,200 megapascals."
Probably much lighter than aluminum, for the same strength.
The question I have is, how strong could it be for the same weight? Off to rtfa...
Link about the marbles/pegs/bell curve:
http://www.mapageweb.umontreal.ca/cousined/lego/5-Machines/Galton/Galton.html
Ballistic electrons in graphene:
http://www.nanowerk.com/spotlight/spotid=2340.php
Besides having very different properties from aluminum, and besides the last sentence stating that they can be upped to 1,200 megapascals; this could be considered a proof of concept. Excuse the tautology, but: as technologies develop, they improve.
One good reason is that aluminum is a limited resource. Although there's lots of it around, current estimates show that it will only last for about 200 more years ( source). That may seem like quite a long time, but it probably wouldn't hurt to start investigating alternatives before we run out.
Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
One good reason is that aluminum is a limited resource. Although there's lots of it around, current estimates show that it will only last for about 200 more years ( source).
I don't have a copy of that book, so can't read it in context, but I still have to call bullshit on this.
Aluminum (Aluminium for you Brits) is the most abundant metal in the Earth's crust. While smelting it is energy intensive, recycling it is significantly less so. There is so much that has already been used, and available for recycling, I can't see us running out in the next couple of centuries, if ever.
Learning HOW to think is more important than learning WHAT to think.
The property mentioned in the article is only covers one property of the material. Different types of Carbon Fiber are already being used for sports car bodies, bicycles and countless other things. In the case of bicycles, yes carbon fiber allows you to create a light frame, but from what I understand, aluminum frames are still stiffer, more shock absorbent, more durable and most importantly, more cost effective. Until carbon materials can match aluminum in these properties, and in cost effectiveness, aluminum isn't going anywhere.
For bikes, aluminum frames are certainly stiffer, but they're substantially less shock absorbing.
One of the reasons carbon fiber is used is the ability to choose different properties on different axes. Many cyclists want a frame that absorbs road vibration (longitudinally flexible) while being as stiff as possible laterally to transmit pedaling force efficiently and maneuver aggressively.
Pure aluminum is soft, aircraft grade aluminum (and virtually all aluminum used in the real world) is alloyed with other elements, greatly increasing its strength.
Here's a breakdown of the composition of Aluminum Alloy 6061 to give you an idea...
"Be light, stinging, insolent and melancholy"
First off, they don't explode all at once, they explode tube by tube and the explosions are very small. It takes a fairly powerful direct laser strike to cause this to happen. I.E. a hand-held laser pointed at a plane will be about as useful as shooting a BB gun at it.
Second... I guess you've never heard of... paint.
And finally... not all carbon nanotubes are created equally.
FUD.
I do not respond to cowards. Especially anonymous ones.
Aluminium for you Brits
Yes, sadly we weren't subjected to the spelling errors of a certain Mr Hall...
tensile strength != toughness. And, unfortunately, aluminum is not particularly ductile. At least, not when compared to, say, steel.
But aluminum does have a very good strength to weight ratio. Also, it doesn't rust. Instead it forms an oxide layer which prevents further oxidation.
Can you be Even More Awesome?!
So this is 1-2GPa tensile strength. We need about 60-100GPa tensile strength for a space elevator.