Carbon nanotube [Archive] - Physics Forums

Dirk Bruere at Neopax

Sep16-04, 07:09 AM

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nrecord length etc\nhttp://www.physorg.com/news1157.html\n\nHow much force does it take to break a single walled nanotube ie how much weight\nwill one support?\n\n--\nDirk\n\nThe Consensus:-\nThe political party for the new millenium\nhttp://www.theconsensus.org\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>record length etc
http://www.physorg.com/news1157.html

How much force does it take to break a single walled nanotube ie how much weight
will one support?

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org

Douglas Natelson

Sep17-04, 05:32 AM

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nDirk Bruere at Neopax wrote:\n>\n> How much force does it take to break a single walled nanotube ie how much weight\n> will one support?\n\nWell, the tensile strength for a perfect SWNT is often quoted as\nbeing on the order of 1 TPa, which is basically the elastic\nmodulus of one, also. (That\'s been determined by a couple\nof techniques, the coolest of which is the observation of\nthermally driven oscillations of a cantilevered tube via\ntransmission electron microscopy.)\n\nSo, a typical tube cross-section is something like 10^-18 m^2,\nimplying a tensile force at failure of something like 10^-6\nNewtons. So, one could imagine hanging ~10^-7 kg off of a\nsingle tube (or 0.1 mg).\n\nIt\'s important to note that no nanotube fiber (i.e. bundle\nof tubes or composite of tubes and polymer epoxy) has come\nremotely close to this. Basically the problem becomes, how\ndo you transfer the load within such a fiber to the tubes.\n\nDN\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>Dirk Bruere at Neopax wrote:
>
> How much force does it take to break a single walled nanotube ie how much weight
> will one support?

Well, the tensile strength for a perfect SWNT is often quoted as
being on the order of 1 TPa, which is basically the elastic
modulus of one, also. (That's been determined by a couple
of techniques, the coolest of which is the observation of
thermally driven oscillations of a cantilevered tube via
transmission electron microscopy.)

So, a typical tube cross-section is something like 10^-18 m^2,
implying a tensile force at failure of something like 10^-6
Newtons. So, one could imagine hanging ~10^-7 kg off of a
single tube (or .1 mg).

It's important to note that no nanotube fiber (i.e. bundle
of tubes or composite of tubes and polymer epoxy) has come
remotely close to this. Basically the problem becomes, how
do you transfer the load within such a fiber to the tubes.

DN

Dirk Bruere at Neopax

Sep20-04, 03:38 AM

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nDouglas Natelson wrote:\n\n> Dirk Bruere at Neopax wrote:\n>\n>>How much force does it take to break a single walled nanotube ie how much weight\n>>will one support?\n>\n>\n> Well, the tensile strength for a perfect SWNT is often quoted as\n> being on the order of 1 TPa, which is basically the elastic\n> modulus of one, also. (That\'s been determined by a couple\n> of techniques, the coolest of which is the observation of\n> thermally driven oscillations of a cantilevered tube via\n> transmission electron microscopy.)\n>\n> So, a typical tube cross-section is something like 10^-18 m^2,\n> implying a tensile force at failure of something like 10^-6\n> Newtons. So, one could imagine hanging ~10^-7 kg off of a\n> single tube (or 0.1 mg).\n>\n> It\'s important to note that no nanotube fiber (i.e. bundle\n> of tubes or composite of tubes and polymer epoxy) has come\n> remotely close to this. Basically the problem becomes, how\n> do you transfer the load within such a fiber to the tubes.\n\nI believe that the problem has been partially solved by making imperfections in\nthe tubes and bonding to these. Questions as to the strength of such imperfect\ntubes is even more interesting.\n\nIIRC there was an SF story once called \'The Thing Edge\' that featured a material\nvery similar. A composite strand of nanotubes capable of taking kg of force and\nstill being invisible (cross section 10^-2 mm sq) would make quite a blade.\n\nDirk\n\nThe Consensus:-\nThe political party for the new millenium\nhttp://www.theconsensus.org\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>Douglas Natelson wrote:

> Dirk Bruere at Neopax wrote:
>
>>How much force does it take to break a single walled nanotube ie how much weight
>>will one support?
>
>
> Well, the tensile strength for a perfect SWNT is often quoted as
> being on the order of 1 TPa, which is basically the elastic
> modulus of one, also. (That's been determined by a couple
> of techniques, the coolest of which is the observation of
> thermally driven oscillations of a cantilevered tube via
> transmission electron microscopy.)
>
> So, a typical tube cross-section is something like 10^-18 m^2,
> implying a tensile force at failure of something like 10^-6
> Newtons. So, one could imagine hanging ~10^-7 kg off of a
> single tube (or .1 mg).
>
> It's important to note that no nanotube fiber (i.e. bundle
> of tubes or composite of tubes and polymer epoxy) has come
> remotely close to this. Basically the problem becomes, how
> do you transfer the load within such a fiber to the tubes.

I believe that the problem has been partially solved by making imperfections in
the tubes and bonding to these. Questions as to the strength of such imperfect
tubes is even more interesting.

IIRC there was an SF story once called 'The Thing Edge' that featured a material
very similar. A composite strand of nanotubes capable of taking kg of force and
still being invisible (cross section 10^-2 mm sq) would make quite a blade.

Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org