Eng8450 + MWNT Sample annealed 15 minutes in the press (140 C) Around 30 minutes between put the...
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Transcript of Eng8450 + MWNT Sample annealed 15 minutes in the press (140 C) Around 30 minutes between put the...
Eng8450 + MWNTEng8450 + MWNTSample annealed Sample annealed 15 minutes15 minutes in the press (140 C) in the press (140 C)
Around Around 30 minutes30 minutes between put the sample in the between put the sample in the equipment and to start the experimentequipment and to start the experiment
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-11
10-9
10-7
10-5
10-3
Eng Eng + 0,05 MWNT Eng + 0,1 MWNT Eng + 0,5 MWNT Eng + 1,0 MWNT Eng + 3,0 MWNT Eng + 6,0 MWNT Eng + 12,0 MWNT
S (S
/cm
)
Freq. [Hz]
Dielectric regionDielectric regionDC regionDC region
DCDC decrease with decrease with low amount of CNT!!!!!low amount of CNT!!!!!
How we can understand this “rare” behavior?How we can understand this “rare” behavior?
)exp(0 E
Symmetric Hopping ModelSymmetric Hopping Model
1 tACDC c
Based on the study of the displacement of a charge carrier from one position to another close by
The nearest-neighbor jump rate (frequency) is:
It is possible to show that the transition from DC to AC is determined by the smallest jump rate (c) , and the transition will be given by:
So, it is possible to think that the presence of nanotubes increase theactivation energy for the jump-rate of charge carriers or decrease its diffusion
processes. At higher amount the last is compensated by the percolation process.
dtetvvD
DTkqn
t
B
0
2
)()0()(
)()(
TkB
1
From this model is showed that:
Another approach based on the same arguments define the probabilityAnother approach based on the same arguments define the probabilityfor a electron (“hole”) transition from state “a” to “b”, as:for a electron (“hole”) transition from state “a” to “b”, as:
)exp()2exp()exp(Tk
WRqpB
abababababab
)(4/)()( 2bababaab EEW
’s are the reorganization energy
It is showed that the response of the system to an alternating field is:
)],,([12
)( 222
baabB
s qqRPRTkNe
ab
baab qq 2ln
The major contribution to the conductivity comes from polymerThe major contribution to the conductivity comes from polymerpair elements satisfying the last assumptionpair elements satisfying the last assumption!!! !!!
The response at The response at very low frequenciesvery low frequencies involve pair states with very low involve pair states with very low transition rates. As a consequence the rare transition rates. As a consequence the rare transitions from pair transitions from pair
states into new states become more significantstates into new states become more significant..
Again, the presence of nanotubes could Again, the presence of nanotubes could change the dynamic change the dynamic of charge carriersof charge carriers, decreasing the conductivity, decreasing the conductivity
Another theory is based on the equivalent circuit concept:Another theory is based on the equivalent circuit concept:
At high frequencies the conductive regions are important and at low frequencies the isolated areas limit the charge carrier motion.
Any solid with spatially varying free Any solid with spatially varying free charge conductivity and uniformcharge conductivity and uniform charge dielectric constantcharge dielectric constant
)('')(')( iUnder AC conditions, it is defined:Under AC conditions, it is defined:
Resistor contribution
Conductancecontribution
10-2 10-1 100 101 102 103 104 105 106 107
10-11
10-9
10-7
10-5
10-3
10-1
Eng Eng + 0,05 MWNT Eng + 0,1 MWNT Eng + 0,5 MWNT Eng + 1,0 MWNT Eng + 3,0 MWNT Eng + 6,0 MWNT Eng + 12,0 MWNT
S' (
S/c
m)
Freq. [Hz]
Eng8450 + MWNTEng8450 + MWNT
10-2 10-1 100 101 102 103 104 105 106 10710-14
10-12
10-10
10-8
10-6
10-4
10-2 Eng Eng 0,05 MWNT Eng 0,1 MWNT Eng 0,5 MWNT Eng 1,0 MWNT Eng 3 MWNT Eng 6 MWNT Eng 12MWNT
S''
(S/c
m)
Freq. [Hz]
’ is related with the current through the resistors
’’ is related with the current through the capacitors
Below the percolation point, the high frequency area is influenced by the CNT (conductive)At low frequency, the isolated-region (bulk polymer) make the greater contributions
The presence of CNT does not affectthe conductance of the sample below
the percolation point
Eng8450 + SWNTEng8450 + SWNT
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
Eng Eng + 0,05 SWNT Eng + 0,1 SWNT Eng + 1,0 SWNT
S''
(S/c
m)
Freq. [Hz]
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
Eng Eng + 0,05 SWNT Eng + 0,1 SWNT Eng + 1,0 SWWT
S' (
S/c
m)
Freq. [Hz]
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5 Eng Eng + 0,05 SWNT Eng + 0,1 SWNT Eng + 1,0 SWWT
S (S
/cm
)
Freq. [Hz]
Same behavior!!!Same behavior!!!
CNTs affect the resistor contribution of the composite, andat low frequencies changes in the dynamic of the polymers due to CNT decrease their conductivity
The effect of the dynamic of the polymer on the conductivity The effect of the dynamic of the polymer on the conductivity is confirmed by the is confirmed by the relaxation processrelaxation process observed in some composites observed in some composites
10-2 10-1 100 101 102 103 104 105 1061E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5
S (S
/cm
)
Freq. [Hz]
10-2 10-1 100 101 102 103 104 105 1061E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5
S (S
/cm
)
Freq. [Hz]
Eng + 1.0 SWNTEng + 1.0 SWNT
Eng + 0.05 SWNTEng + 0.05 SWNT
3 hrs annealing3 hrs annealing 140 C140 C
3 hrs annealing3 hrs annealing 140 C140 C
10-2 10-1 100 101 102 103 104 105 106 1071E-14
1E-12
1E-10
1E-8
1E-6
1E-4 Eng + 1,0 SWNT original Eng + 1,0 SWNT ann 3 hrs
S''
(S/c
m)
Freq. [Hz]
10-2 10-1 100 101 102 103 104 105 106 1071E-13
1E-11
1E-9
1E-7 Eng + 1,0 SWNT original Eng + 1,0 SWNT ann 3 hrs
S' (
S/c
m)
Freq. [Hz]
10-2 10-1 100 101 102 103 104 105 106 1071E-11
1E-10
1E-9
1E-8
1E-7
1E-6 120 C 140 C 190 C
S (S
/cm
)
Frequency (Hz)
Eng8450Eng8450Effect of the temperatureEffect of the temperature
Annealing Studies for some Eng/MWNT samplesAnnealing Studies for some Eng/MWNT samples
10-2 10-1 100 101 102 103 104 105 10610-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5 |Sig| [S/cm] 1% MWNT before annealing |Sig| [S/cm] 1% MWNT after annealing
Sig
ma
(S/c
m)
Frequency (Hz)
1% MWNT1% MWNT
12% MWNT12% MWNT
10-2 10-1 100 101 102 103 104 105 106 1071E-6
1E-5
1E-4
1E-3 |Sig| [S/cm] before annealing 12WNT |Sig| [S/cm] after annealing 12WNT
Sig
ma
(S/c
m)
Frequency (Hz)
1Hz
0 5000 10000 150001,0x10-6
1,0x10-5
1,0x10-4
|Sig
| [S
/cm
]
Time [s]
Effect of the amount of fillerEffect of the amount of filler
0 5000 10000 150001,0x10-12
1,0x10-11
1,0x10-10
|Sig
| [S
/cm
]
Time [s]
Pure EngPure Eng
Annealing Studies for some Eng samplesAnnealing Studies for some Eng samplesEffect of the kind of fillerEffect of the kind of filler
10-2 10-1 100 101 102 103 104 105 106 10710-1310-1210-1110-1010-910-810-710-610-510-4
|Sig| [S/cm] before annealing 1% SWNT |Sig| [S/cm] after annealing 1% SWNT
Sig
ma
(S/c
m)
Frequency (Hz)
0 5000 10000 15000
1,0x10-11
1,0x10-10
1,0x10-9
|Sig
| [S
/cm
]
Time [s]
1% SWNT1% SWNT
10-2 10-1 100 101 102 103 104 105 10610-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5 |Sig| [S/cm] 1% MWNT before annealing |Sig| [S/cm] 1% MWNT after annealing
Sig
ma
(S/c
m)
Frequency (Hz)
1% MWNT1% MWNT
0 5000 10000 150001,0x10-12
1,0x10-11
1,0x10-10
|Sig
| [S
/cm
]
Time [s]
Annealing Studies for some Eng samplesAnnealing Studies for some Eng samplesEffect of the kind of matrixEffect of the kind of matrix
10-2 10-1 100 101 102 103 104 105 10610-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
|Sig| [S/cm] before annealing 1WNT |Sig| [S/cm] after annealing 1WNT
Sig
ma
(S/c
m)
Frequency (Hz)
10-2 10-1 100 101 102 103 104 105 10610-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5 |Sig| [S/cm] 1% MWNT before annealing |Sig| [S/cm] 1% MWNT after annealing
Sig
ma
(S/c
m)
Frequency (Hz)
EngEng1% MWNT1% MWNT
0 5000 10000 150001,0x10-13
1,0x10-12
1,0x10-11
|Sig
| [S
/cm
]
Time [s]
PE3732CPE3732C1% MWNT1% MWNT
0 5000 10000 150001,0x10-13
1,0x10-12
1,0x10-11
|Sig
| [S
/cm
]
Time [s]
Annealing Studies for some Eng samplesAnnealing Studies for some Eng samplesEffect of the kind of matrixEffect of the kind of matrix
EngEng12% MWNT12% MWNT
10-2 10-1 100 101 102 103 104 105 106 1071E-6
1E-5
1E-4
1E-3 |Sig| [S/cm] before annealing 12WNT |Sig| [S/cm] after annealing 12WNT
Sig
ma
(S/c
m)
Frequency (Hz)
1Hz
0 5000 10000 150001,0x10-6
1,0x10-5
1,0x10-4
1,0x10-3
|Sig
| [S
/cm
]
Time [s]
10-2 10-1 100 101 102 103 104 105 1061E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5 |Sig| [S/cm] before annealing PE 12% MWNT |Sig| [S/cm] after annealing PE 12% MWNT
Sig
ma
(S/c
m)
Frequency (Hz)
0 5000 10000 150001,0x10-10
1,0x10-9
1,0x10-8
1,0x10-7
|Sig
| [S
/cm
]
Time [s]
PE3732CPE3732C12% MWNT12% MWNT
Annealing Studies for some Eng samplesAnnealing Studies for some Eng samplesEffect of the kind of matrixEffect of the kind of matrix
10-2 10-1 100 101 102 103 104 105 106 10710-1410-1310-1210-1110-1010-910-810-710-610-5
Sig
ma
(S/c
m)
Frequency (Hz)10-2 10-1 100 101 102 103 104 105 106 107
10-1310-1210-1110-1010-910-810-710-610-510-4
Sig
ma
(S/c
m)
Frequency (Hz)
0 5000 10000 15000
1,0x10-11
1,0x10-10
1,0x10-9
|Sig
| [S
/cm
]
Time [s]
EngEng1% SWNT1% SWNT
0 5000 10000 150001,0x10-13
1,0x10-12
1,0x10-11
|Sig
| [S
/cm
]
Time [s]
PE3732CPE3732C1% SWNT1% SWNT
Eng8450 + MWNTEng8450 + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
0 1000 2000 30008E-13
1E-12
1,2E-12
1,4E-12
1,6E-12
S (S
/cm
)
Time [s]
Shear strain 10%
Shear strain 100%stop strain
0 1000 2000 30008E-13
1E-12
1,2E-12
1,4E-12
1,6E-12
S (S
/cm
)
Time [s]
Stop strain
300% strain
1% MWNT1% MWNT
0 500 1000 15001,5E-12
1,6E-12
1,7E-12
1,8E-12
1,9E-12
2E-12
S (S
/cm
)
Time [s]
Shear strain 100%
Stop Shear strain
1 Hz
0.5 % MWNT0.5 % MWNT
1 Hz
1 Hz
The system is not able to relax during the shear-strain of 300%
Small relaxation during shear-strain of 100%
Eng8450 + MWNTEng8450 + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
3% MWNT3% MWNT
0 1500 3000 4500 60001E-9
1E-8
1E-7
1E-6
S (S
/cm
)
Time [s]
Stop shear strain
Shear strain 100%
100 Hz
0 1500 3000 4500 6000 75001E-9
1E-8
1E-7
1E-6
S (S
/cm
)
Time [s]
Stop shear strain
Shear strain 300%
10-2 10-1 100 101 102 103 104 105 1061E-9
1E-8
1E-7
1E-6
1E-5
1E-4 Original 2 hrs and strain 100% 2 hrs and strain 300
S (S
/cm
)
Freq. [Hz]
The shear-strain disrupt the conductivitybut only in the beginning, after that the
system relax independent of the strain!!!!
At this condition the kinetic of the relaxation is modified by the external forces
The location of this peak is shear-strain dependent!!!
Eng8450 + MWNTEng8450 + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
6% MWNT6% MWNT
0 1500 3000 4500 600010-8
10-7
10-6
10-5
S (S
/cm
)
Time [s]
Shear strain 100%
Stop Shear strain
100 Hz
0 1500 3000 450010-8
10-7
10-6
10-5
S (S
/cm
)
Time [s]
100 Hz
300% shear strain
Stop shear strain
10-2 10-1 100 101 102 103 104 105 106 1071E-7
1E-6
1E-5
1E-4
1E-3 original strain 100, 3 hrs strain 300, 3 hrs
S (S
/cm
)
Freq. [Hz]
It is clear that the drop in conductivity depends of the shear-strain, and again the system is able to relax independent of the
shear-strain!!!!
Eng8450 + MWNTEng8450 + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
12% MWNT12% MWNT
0 1000 2000 3000 4000 50001E-5
1E-4
Stop Shear-strain
S (S
/cm
)
Time [s]
Shear-strain 5%
0 1000 2000 3000 4000 50001E-5
1E-4
Stop Shear-strainS (S
/cm
)
Time [s]
Shear-strain 10%
0 1000 2000 3000 4000 50001E-5
1E-4
Stop Shear-strain
S (S
/cm
)
Time [s]
Shear-strain 50%
0 1000 2000 3000 4000 50001E-5
1E-4
Stop Shear-strain
S (S
/cm
)
Time [s]
Shear-strain 100%
0 1000 2000 3000 4000 50001E-5
1E-4
Stop Shear-strain
S (S
/cm
)
Time [s]
Shear-strain 300%
Eng8450 + MWNTEng8450 + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
12% MWNT12% MWNT
10-2 10-1 100 101 102 103 104 105 10610-6
10-5
10-4
10-3
10-2
original 6 hrs annealing and shear strain
S (S
/cm
)
Freq. [Hz]
0 1000 2000 3000 4000 50000,1
1
5 strain 10 strain 50 strain 100 strain 300 strain
Nor
mal
ized
con
duct
ivity
Time [s]0 5000 10000 15000 20000 25000
1E-5
1E-4 50% 300%100%
10%
S (S
/cm
)
Time [s]
5%
10 Hz
Eng8450 + SWNTEng8450 + SWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
0.05% SWNT0.05% SWNT
0 200 400 600 800 1000 1200
1,12E-011
1,16E-011
1,20E-011
1,24E-011
1,28E-011
S (S
/cm
)
Time [s]
Shear strain 100%
Stop shear strain
10 Hz
10-2 10-1 100 101 102 103 104 105 1061E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5 original Annealing 3 hrs and strain
S (S
/cm
)
Freq. [Hz]
1.0% SWNT1.0% SWNT
0 2000 4000 6000 80001E-12
1E-11
1E-10
1E-9
S (S
/cm
)
Time [s]
Shear strain 100%
Stop shear strain
1 Hz
10-2 10-1 100 101 102 103 104 105 1061E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5
original annealing 3 hrs and strain
S (S
/cm
)
Frequency (Hz)
PE3732C + MWNTPE3732C + MWNTSample annealed Sample annealed 15 minutes15 minutes in the press (140 C) in the press (140 C)
Around Around 30 minutes30 minutes between put the sample in the between put the sample in the equipment and to start the experimentequipment and to start the experiment
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
PE PE + 0,05% MWNT PE + 0,1% MWNT PE + 0,5% MWNT PE + 1,0% MWNT PE + 3,0% MWNT PE + 6,0% MWNT PE + 12,0% MWNT
S (S
/cm
)
Frequency (Hz)
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
PE PE + 0,05WNT PE + 0,1% MWNT PE + 0,5% MWNT PE + 1,0% MWNT PE + 3,0% MWNT PE + 6,0% MWNT PE + 12,0% MWNT
S' (
S/c
m)
Frequency (Hz)10-2 10-1 100 101 102 103 104 105 106 107
10-1410-1310-1210-1110-1010-910-810-710-610-5
PE PE + 0,05% MWNT PE + 0,1% MWNT PE + 0,5% MWNT PE + 1,0% MWNT PE + 3,0% MWNT PE + 6,0% MWNT PE + 12,0% MWNT
S''
(S/c
m)
Frequency (Hz)
Same behavior than Eng Same behavior than Eng sample, the changes are related sample, the changes are related
with the with the resistor contributionresistor contribution
PE3732C + SWNTPE3732C + SWNTSample annealed Sample annealed 15 minutes15 minutes in the press (140 C) in the press (140 C)
Around Around 30 minutes30 minutes between put the sample in the between put the sample in the equipment and to start the experimentequipment and to start the experiment
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
PE PE + 0,05% SWNT PE + 0,1% SWNT PE + 0,5% SWNT PE + 1,0% SWNT
S (S
/cm
)
Frequency (Hz)
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9 PE PE + 0,05% SWNT PE + 0,1% SWNT PE + 0,5% SWNT PE + 1,0% SWNT
S' (
S/c
m)
Frequency (Hz)10-2 10-1 100 101 102 103 104 105 106 107
10-1410-1310-1210-1110-1010-910-810-710-610-5
PE PE + 0,05% SWNT PE + 0,1% SWNT PE + 0,5% SWNT PE + 1,0% SWNT
S''
(S/c
m)
Frequency (Hz)
PE3732C + MWNTPE3732C + MWNTEffect of the processing on the composite dynamicEffect of the processing on the composite dynamic
6% MWNT6% MWNT
10-2 10-1 100 101 102 103 104 105 106 10710-13
10-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
PE original PE + 6,0% MWNT original PE + 6,0% MWNT no-aligned
S (S
/cm
)
Frequency (Hz)
This plot shows that the decrease in the conductivity is associated with the This plot shows that the decrease in the conductivity is associated with the morphology of CNTsmorphology of CNTs in the polymeric matrix in the polymeric matrix
PE3732C + MWNTPE3732C + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
1% MWNT1% MWNT
0 1000 2000 3000 40008E-13
9E-13
1E-12
1,1E-12
1,2E-12 |Sig| [S/cm] strain 10 and 100% |Sig| [S/cm] strain 200
S (S
/cm
)
Time [s]
0 1000 2000 30005E-13
6E-13
7E-13
8E-13
9E-131E-12
1,1E-121,2E-12
|Sig| [S/cm] 1WNT 10 and 100% strain |Sig| [S/cm] strain 200% 1WNT
S (S
/cm
)
Time [s]
1% SWNT1% SWNT
0 1000 2000 30002,0x10-11
4,0x10-11
6,0x10-11
10% strain 100% strain 200% strain
S(S
/cm
)
Time [s]
6% MWNT6% MWNT
0.05% SWNT0.05% SWNT
0 1000 2000 30006,9E-12
6,93E-12
6,96E-12
6,99E-12
S (S
/cm
)
Time [s]
Shear strain 50%
Stop Shear strain10 Hz
10-2 10-1 100 101 102 103 104 105 10610-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5 |Sig| [S/cm] PE 6% MWNT antes ann |Sig| [S/cm] PE 6WNT after strain
Sig
ma
(S/c
m)
Frequency (Hz)0 1000 2000 3000 4000 5000 6000
2,0x10-11
4,0x10-11
6,0x10-11
|Sig| [S/cm] PE 6WNT ann 1
S(S
/cm
)
Time [s]
PE3732C + MWNTPE3732C + MWNT6% MWNT6% MWNT
0 1000 2000 3000 40001E-7
2E-7
3E-7
4E-7
5E-7
Stop shear strain
S (S
/cm
)
Time [s]
shear strain 10%
Stop shear strain
shear strain 50%
1000 Hz
PE3732C + MWNTPE3732C + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
12% MWNT12% MWNT
PE3732C + MWNTPE3732C + MWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
12% MWNT12% MWNT
10-2 10-1 100 101 102 103 104 105 10610-9
10-8
10-7
10-6
10-5
|Sig| [S/cm] after ann 12WNT |Sig| [S/cm] after strain 10% 12WNT |Sig| [S/cm] after strain 100% 12WNT
Sig
ma
(S/c
m)
Frequency (Hz)0 1000 2000 3000
1,0x10-11
1,0x10-10
1,0x10-9
1,0x10-8
1,0x10-7
|Sig| [S/cm] strain 10% 12WNT |Sig| [S/cm] strain 100% 12WNT
S(S
/cm
)
Time [s]Strain-induced insulation!!!Strain-induced insulation!!!
0 1000 2000 3000 4000 5000 60001,0x10-11
1,0x10-10
1,0x10-9
1,0x10-8
1,0x10-7
S(S
/cm
)
Time [s]
100% strain, 1 min100% strain, 1 min
100% strain, 20 min100% strain, 20 min
10% strain10% strain
100% strain100% strain
Effect of timeEffect of time
PE3732C + SWNTPE3732C + SWNTEffect of the strain on the composite dynamicEffect of the strain on the composite dynamic
0.05% SWNT0.05% SWNT
0 1000 2000 30006,9E-12
6,93E-12
6,96E-12
6,99E-12
S (S
/cm
)
Time [s]
Shear strain 50%
Stop Shear strain10 Hz
10-2 10-1 100 101 102 103 104 105 1061E-13
1E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6 original annealing 1 hr and strain
S (S
/cm
)
Frequency (Hz)