Percolation Threshold in carbon nanotube polymer composites

1
Percolation Threshold in carbon nanotubepolymer
composites

• ???????? K??sta?t????
• Seµ?????? F?s????
• 8? e??µ???
• S???? ?.?.F.?.
• ?pe?????? ?a????t?? ?. ??ss??

2
?e??e??µe?a

• ??sa???? st??? ?a??s????e? ????a?a CNT
• ??sa???? st? fa???µe?? d????s?? (percolation)
• ?e????af? ep?d?as?? t?? ?a??s?????? st??
  µa???s??p???? ?d??t?te? t?? p???µe???
• ?fa?µ???? ?p?te?esµ?t??

3
?a??s????e? ????a?a

• CNT carbon nanotubes
• 2 e?d?
• MWNT multiwalled nanotubes
• SWNT singlewalled nanotubes

4
???p?? pa?a?????

• ? ßas??? ?d?a e??a? ap?? t??????µe ??a
• f???? ??afe???? ?ste ?a s??µat?ste? ?
• s????a?.

5
???p?? pa?a?????

• ?p?????? d??f???? µ???d?? p?? ???s?µ?p?????ta?
  s?µe?a.
• ???t?? ? ?p???? ?ft?a?e , t??a?a, ?a??s????e?
  ?ta?e ? Iijima t? 1991.
• ? Smalley t? 1996 e?s??a?e ??a µ???d? ??????
  ap?d?t???t?ta? (laser ablation).

6
Chemical Vapor Deposition

• ????d?? p?? a?apt?????e t? 1996.
• ? a??pt??? ???eta? p??? se ?p?st??µa
  ( p???t??, ??a??, a???µ????).
• ?? CNT p????pt??? ap? t?? ap?s???es?
  ?d?????a???????.
• ????? ???s?µ?p????µe?? µ???d?? ???? p?????
  p?e??e?t?µ?t??.

7
(No Transcript)
8
?d??t?te? CNT

• ???a?????
• ??a??et??? a??e?t???? (100 f???? pe??ss?te?? ap?
  t? ats???).
• ??a??et??? e?????st?? (epa??????ta? se ?a??????
  ??s? a??µa ?a? ap? ?aµp???s? 120?) .

 
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?d??t?te? CNT

• Te?µ????
• ????? s?µe?a ?e????saµe t?? ad?µa?ta ?? t??
  ?a??te?? a???? ?e?µ?t?ta?, ?? CNT ?µ?? ?de??a?
  d?p??s?a ?e?µ??? a????µ?t?ta
• ?fe??eta? ?????? st?? d?e???se?? t?? f??????? t??
  p???µat??

10
?d??t?te? CNT

• ??e?t?????
• ????? e?a??et??? ????? a????µ?t?ta p?? ?fe??eta?
  st?? s?ed?? µ???d??stat? f?s? t???.
• ???a? ta ????? p?? µp????? ?a f????? t??
  µe?a??te?? p????t?ta ?e?µat?? ap? ?p???d?p?te
  ???? (109 A/cm2).

11
Percolation Threshold

• ?at?f?? ??af????.
• ?µfa??st??e sa? stat?st??? p??ß??µa.
• ?f??? t? p?s?st? e??? s?st?µat?? p?? p??pe? ?a
  ep??easte? ?ste ?a a??????? ?? ?d??t?te? t??.
• Ge????te?a ß???? st?? p??s????s? ???s?µ?? t?µ??
  ???? p??? ? µet? ap? t? ?at?f?? e??? ?e????t??.

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?a??de??µa
St?? t?e?? d?ast?se?? p??? e??a? t? p?s?st??

• ??a ???stas?

• ??? ??ast?se??

100
50
13
Percolation Threshold in carbon nanotubepolymer
composites

• St??e???µe st?? s??e??as?a t?? ?a??s?????? µe
  ???a ?????.
• ?a p???µe?? ap?te???? ??a t?p? ?????? e?????
  ???s?µ?p????µe??.
• ??a µa? apas???e? t? p?s?st? t?? ?a??s?????? p??
  p??pe? ?a e?s????µe se µ?a p???µe???? µ?t?a ?ste
  ?a ap???µ?s??µe t?? ep???µ?t?? ?d??t?te?.

14
?????e? ap? µ????s??p??
15
S??µat???
16
??a p??t? ?d?a

• ??d?afe??µaste ep?µ???? ?a ß???µe t?? ???s?µ?
  pe??e?t???t?ta t?? s???et?? ?????? se CNT ?ste ?a
  e??a? a????µ?.

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??????a t?? µ?t?a

• ?a pe???µata ?de??a? ?t? t? ?at?f?? a?t? e??a?
  µetaß??t? a?????a µe t? ????? p?? ???s?µ?p????µe
  sa? µ?t?a.
• Polyamide 6 1.7 vol
• Polypropylene 2.2 wt
• Polyimide 1.1 wt
• Epoxy matrices 0.0025 wt ( ??a 2 wt
  eµfa?????? a????µ?t?ta 2 S/m)

18
Percolation Threshold in carbon nanotubepolymer
composites

• ?? pe??aµat???? d?ad??as?e? ?de??a? ep?µ???? ?t?
  µ???? ??a p??? µ???? p?s?st? CNT a??e? ?ste t?
  p???µe??? ?a eµfa??se? ??e?t???? a????µ?t?ta.

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?et? t? ?at?f??

• ?et? t? ?at?f?? a????µ?t?ta? ?p???e? a???s? t??
  a????µ?t?ta? a??? µe ?aµ???te?? ???µ?
  (percolation threshold 1.7 vol).

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??af??et??? ?e??e?t???t?ta

• ??? s???e???µ??a , a??????ta? t?? s?????t??s? t??
  CNT µ?sa st? p???µe??? ?a? µe?et??ta? ta
  ap?te??sµata pa?at????µe

21
Percolation Threshold in carbon nanotubepolymer
composites

• ?? fa???µe?? e?a?t?ta? e??s?? ap? t? e?d??? t??
  p???µe???? p?? ???s?µ?p??e?ta? sa? µ?t?a.

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???e? ep?pt?se??

• ???a ap? t?? ??e?t???? a????µ?t?ta ? p??s?es? CNT
  se p???µe????? µ?t?e? ??e? ep?pt?s? ?a? st??
  µ??a????? ?d??t?te? a?t??.
• ????s? t?? a?t???? t?? ?????? (??a p?s?st? 1 wt
  se p???a???????? a??e? ??a a???s? a?t???? µ????
  ?a? 150).
• Se ??e? polyacrylonitrile p?? pe??e??a? MWNT
  pa?at??????e a???s? t?? e????e?a? ??a?s?? ??? ?a?
  80.

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???e? ep?pt?se??

• ?p?s?? ?p???e? µetaß??? st?? µetaß?se?? t??
  d??f???? f?se?? t?? p???µe???? (p.?.a????e? t??
  ???sta?????t?ta t?? p???µe????).

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??????s?

• ?? ?a??s????e? ????a?a , f????ta? t?? ??µ??? ?a?
  ??e?t????a?? p??f?? t?? ????a?a, de?????? se
  µe????? pe??pt?se?? ?a s??e??????ta? d?s???a µe
  t?? p???µe????? µ?t?e?.
• ?a p??ß??µata ?fe????ta? ?????? st??
  ?d?a?te??t?ta t?? ep?f??e?a? a????ep?d?as??
  (interface)

??? ?a µp???s??µe ?a ße?t??s??µe t?? s??e??as?a
µ?t?a? ?a? ?a??s?????? µe?????ta? ta p??ß??µata???
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?fa?µ????

• ?atas?e?ast??? ?????
• ????t???? asp?de? ??e?t??sµ?? ?a? ?e?µ?t?ta?
• ??ast??? µe a????µe? ?d??t?te?
• ?????a????e?t??

26
?????

• The Physics Of Amorphous Solids
• (Richard Zallen)
• Carbon Nanotube Based Composites- A Review
• (Rupesh Khare, Suryasarathi Bose)
• Thermal and Electrical Characterization of
  Polypropylene/Carbon Nanotube Nanocomposites
• Thermal and electrical properties of
  Polyamide/Multi-Walled Carbon Nanotubes
  nanocomposites
• (E. Logakis, Ch. Pandis, V. Peoglos, P. Pissis,
  A. Kanapitsas,J. Pionteck, P. Pötschke, M.
  Micušík and M. Omastová)
• www.nanohub.org/