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Structural evolutions in electroactive poly(VDF-co-TrFE) copolymers for organic electronics
François Bargain, Sylvie Tencé-Girault, Fabrice Domingues Dos Santos, Michel Cloitre
Soft Matter and Chemistry Laboratory
10/03/16 – New-Orleans-USA
PVDF-based semi-crystalline polymers 2/16
Fluoropolymer 2016 10/03/16 BARGAIN François
VDF
H
F
F
H
PVDF
PVDF-based semi-crystalline polymers 2/16
Fluoropolymer 2016 10/03/16 BARGAIN François
VDF
H
F
F
H
α phase PVDF
β phaseStretching
TGTG TTTT
PVDF-based semi-crystalline polymers
P(VDF-co-TrFE)
2/16
Fluoropolymer 2016 10/03/16 BARGAIN François
VDF
H
F
F
H
F
F
H
FH
F
F
H+
VDF TrFE
α phase PVDF
β phaseStretching
TGTG TTTT
PVDF-based semi-crystalline polymers
P(VDF-co-TrFE)
2/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Ferroelectric (FE) Phase
VDF
H
F
F
H
F
F
H
FH
F
F
H+
VDF TrFE
α phase PVDF
β phaseStretching
μ
c
b
TGTG TTTT
PVDF-based semi-crystalline polymers
P(VDF-co-TrFE)
2/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Ferroelectric (FE) Phase
VDF
H
F
F
H
F
F
H
FH
F
F
H+
VDF TrFE
α phase
Ferroelectricity
PVDFβ phase
Stretching
μ
c
b
Piezoelectricity
d33 = - 20 pC/N
Pr = 60 mC/m2
Ec = 50 V/µm
TGTG TTTT
Polarization displacement
PVDF-based semi-crystalline polymers
P(VDF-co-TrFE)
2/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Ferroelectric (FE) Phase
VDF
H
F
F
H
F
F
H
FH
F
F
H+
VDF TrFE
α phase
Ferroelectricity
PVDFβ phase
Stretching
Paraelectric (PE) Phase
μ
c
Curie Transition
b
Piezoelectricity
d33 = - 20 pC/N
Pr = 60 mC/m2
Ec = 50 V/µm
TGTG TTTT
Polarization displacement
Applications in printed organic electronics 3/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Ferroelectric
Direct piezoelectric
Inverse piezoelectric
Ferroelectric memories
Sensors
Actuators
Manufacturing thin, light and flexible devices… …using ink-jet printing, press-printing…
keyboards
speakers
smart labels
From polymer solution to electroactive film 4/16
Fluoropolymer 2016 10/03/16 BARGAIN François
T (°C)
TCurie
80
130
TMelting
25
Melt
Paraelectric (PE) Phase
Ferroelectric (FE) Phase
From polymer solution to electroactive film 4/16
Fluoropolymer 2016 10/03/16 BARGAIN François
1 Spreading
T (°C)
TCurie
80
130
TMelting
25
Melt
Paraelectric (PE) Phase
Ferroelectric (FE) Phase
1
From polymer solution to electroactive film 4/16
Fluoropolymer 2016 10/03/16 BARGAIN François
1 2 EvaporationSpreading
T (°C)
TCurie
80
130
TMelting
25
Melt
Paraelectric (PE) Phase
Ferroelectric (FE) Phase
1 2
From polymer solution to electroactive film 4/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Annealing1 2 3EvaporationSpreading
T (°C)
TCurie
80
130
TMelting
25
Melt
Paraelectric (PE) Phase
Ferroelectric (FE) Phase
1 32
From polymer solution to electroactive film 4/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Annealing Poling1 2 3 4EvaporationSpreading
E
E = 150 V/µm
T (°C)
TCurie
80
130
TMelting
25
Melt
Paraelectric (PE) Phase
Ferroelectric (FE) Phase
1 32 4
From polymer solution to electroactive film 4/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Annealing Poling1 2 3 4EvaporationSpreading
E
E = 150 V/µm
Applications
T (°C)
TCurie
80
130
TMelting
25
Melt
Paraelectric (PE) Phase
Ferroelectric (FE) Phase
1 32 4
Motivations for organic electronics 5/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Lot of studies have been done on annealed andstretched films obtained from solvent or from themelt.
An intermediate phase with a tilt has also beenobserved for 50-60 VDF mol %
Tashiro et al, Polymer, 1986
FE CL PE
Motivations for organic electronics 5/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Lot of studies have been done on annealed andstretched films obtained from solvent or from themelt.
An intermediate phase with a tilt has also beenobserved for 50-60 VDF mol %
Tashiro et al, Polymer, 1986
FE CL PE
Our work focuses specifically on isotropicsolvent-cast samples to be close to printed organic electronics applications
Motivations for organic electronics 5/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Lot of studies have been done on annealed andstretched films obtained from solvent or from themelt.
An intermediate phase with a tilt has also beenobserved for 50-60 VDF mol %
Tashiro et al, Polymer, 1986
FE CL PE
Understanding the crystalline and morphological changes upon annealing andpoling steps
Our work focuses specifically on isotropicsolvent-cast samples to be close to printed organic electronics applications
5 µm
Morphology and crystalline organization 6/16
1-10 m
0.1-1 nm
SpherulitesSEM
Crystalline lamellaeSAXS
Crystalline cellWAXS
Fluoropolymer 2016 10/03/16 BARGAIN François
Spherulite size Inter-planar distances dhkl
Crystallinity χc
Long period LP
Electronic contrast
LP = 2π/q 2dhklsinθ = λ
10 nm
5 µm
Morphology and crystalline organization 6/16
1-10 m
0.1-1 nm
SpherulitesSEM
Crystalline lamellaeSAXS
Crystalline cellWAXS
Fluoropolymer 2016 10/03/16 BARGAIN François
Spherulite size Inter-planar distances dhkl
Crystallinity χc
Long period LP
Electronic contrast
LP = 2π/q 2dhklsinθ = λ
10 nm
5 µm
Morphology and crystalline organization 6/16
1-10 m
0.1-1 nm
SpherulitesSEM
Crystalline lamellaeSAXS
Crystalline cellWAXS
Fluoropolymer 2016 10/03/16 BARGAIN François
Spherulite size Inter-planar distances dhkl
Crystallinity χc
Long period LP
Electronic contrast
LP = 2π/q 2dhklsinθ = λ
10 nm
Simultaneous SAXS-WAXS experiments
Pierre PanineGrenoble, FRANCE
7/16
Solvent-cast samples of 20 µm thickness poly(VDF-co-TrFE) 70/30 mol %
Collaboration with:
Fluoropolymer 2016 10/03/16 BARGAIN François
Simultaneous SAXS-WAXS experiments
Pierre PanineGrenoble, FRANCE
7/16
Solvent-cast samples of 20 µm thickness poly(VDF-co-TrFE) 70/30 mol %
Collaboration with:
Fluoropolymer 2016 10/03/16 BARGAIN François
Simultaneous SAXS-WAXS experiments
Pierre PanineGrenoble, FRANCE
7/16
Solvent-cast samples of 20 µm thickness poly(VDF-co-TrFE) 70/30 mol %
Collaboration with:
Fluoropolymer 2016 10/03/16 BARGAIN François
25
130
T(°C)
Time
1°C/min
hot stage
Simultaneous SAXS-WAXS experiments
Pierre PanineGrenoble, FRANCE
DSAXS 1-2 m
DWAXS 10 cm
1 SAXS and 1 WAXS image /min
7/16
Solvent-cast samples of 20 µm thickness poly(VDF-co-TrFE) 70/30 mol %
Collaboration with:
Fluoropolymer 2016 10/03/16 BARGAIN François
25
130
T(°C)
Time
1°C/min
hot stage
Simultaneous acquisition
SAXS on solvent-cast sample 8/16
Fluoropolymer 2016 10/03/16 BARGAIN François
0.1 0.2 0.40.3 0.5 0.80.70.6q (nm-1)
Heating
Cooling
T(°C)
ANNEALING 10 min
SAXS on solvent-cast sample 8/16
Fluoropolymer 2016 10/03/16 BARGAIN François
0.1 0.2 0.40.3 0.5 0.80.70.6q (nm-1)
Heating
Cooling
T(°C)
LP = 38 nm
LP = 15 nm
LP = 30 nm
ANNEALING 10 min
SAXS on solvent-cast sample 8/16
Fluoropolymer 2016 10/03/16 BARGAIN François
0.1 0.2 0.40.3 0.5 0.80.70.6q (nm-1)
Heating
Cooling
T(°C)
LP = 38 nm
LP = 15 nm
LP = 30 nm
Increase of the long period from 15 nm to 30 nm
ANNEALING 10 min
WAXS on solvent-cast sample 9/16
Fluoropolymer 2016 10/03/16 BARGAIN François
T(°C)
Heating
Cooling
ANNEALING 10 min
WAXS on solvent-cast sample 9/16
Fluoropolymer 2016 10/03/16 BARGAIN François
T(°C)
FE
PE
FE + DFE
Heating
Cooling
FE Phase
PE Phase
FE
DFE
ANNEALING 10 min
PE
TC
TC
Orthorhombic symmetry
Hexagonal symmetry
WAXS on solvent-cast sample 9/16
Fluoropolymer 2016 10/03/16 BARGAIN François
T(°C)
FE
PE
FE + DFE
Heating
Cooling
FE Phase
PE Phase
FE
DFE
ANNEALING 10 min
PE
TC
TC
Orthorhombic symmetry
Hexagonal symmetry
Appearance of a second crystalline phase after an annealing step in the PE phase. It coexists with the FE phase at RT and we named it DFE (Defective Ferroelectric) phase
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
25 %
45 %
Curie transition
Curie transition
Time
30 °C 130 °C 30 °C
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
25 %
45 %
Curie transition
Time
30 °C 130 °C 30 °C
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
25 %
45 %
Curie transition
Curie transition
Time
30 °C 130 °C 30 °C
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
25 %
45 %
Curie transition
Time
30 °C 130 °C 30 °C
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
25 %
45 %
Curie transition
Curie transition
Time
30 °C 130 °C 30 °C
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
Curie transition
Curie transition
Time
30 °C 130 °C 30 °C
Evolution upon temperature cycle (WAXS & DSC) 10/16
Fluoropolymer 2016 10/03/16 BARGAIN François
χC (%)
Heat Flow
Inter-planar distance (nm)
Area peaksratio
An
ne
alin
g 1
0 m
in 1
30
°C
HEATING COOLING
130 T (°C)
FEFE
PE PEDFE
25 %
45 %
Curie transition
Curie transition
Time
30 °C 130 °C 30 °C
Model 11/16
Two main conclusions : - crystallisation in the PE phase upon heating- appareance of the DFE phase upon cooling
Fluoropolymer 2016 10/03/16 BARGAIN François
Model 11/16
Two main conclusions : - crystallisation in the PE phase upon heating- appareance of the DFE phase upon cooling
Fluoropolymer 2016 10/03/16 BARGAIN François
Formation of FE crystals duringsolvent evaporation
Part of chains with gauchechemical defects are expelledfrom the FE crystals and stayed atthe interface crystal/amorphous
Model 11/16
Two main conclusions : - crystallisation in the PE phase upon heating- appareance of the DFE phase upon cooling
Fluoropolymer 2016 10/03/16 BARGAIN François
Formation of FE crystals duringsolvent evaporation
Part of chains with gauchechemical defects are expelledfrom the FE crystals and stayed atthe interface crystal/amorphous
Trans and gauche conformationsare allowed in conformationnalydisorder PE phase
Crystallization of defective partof chains at the border of PEcrystals
Model 11/16
Two main conclusions : - crystallisation in the PE phase upon heating- appareance of the DFE phase upon cooling
Fluoropolymer 2016 10/03/16 BARGAIN François
Formation of FE crystals duringsolvent evaporation
Part of chains with gauchechemical defects are expelledfrom the FE crystals and stayed atthe interface crystal/amorphous
Trans and gauche conformationsare allowed in conformationnalydisorder PE phase
Crystallization of defective partof chains at the border of PEcrystals
Part of PE phase transitsdiscontinuously to FE phaseat TC
Part of PE phase transistscontinuously to DFE phase
Influence of poling on annealed sample 12/16
Fluoropolymer 2016 10/03/16 BARGAIN François
70 %FE
Annealed sample
Annealed and poled sample
5 %DFE
95 %FE
30 %DFE
WAXS (25 °C)
Influence of poling on annealed sample 12/16
Fluoropolymer 2016 10/03/16 BARGAIN François
ΔHC : 17 J/g 25 J/g ΔHm : 30 J/g constant
Increase of the FE phase content No change in the PE phase content
FE + DFETC
PE Melt
FE
Tm
70 %FE
Annealed sample
Annealed and poled sample
5 %DFE
95 %FE
30 %DFE
WAXS (25 °C) DSC (10 °C/min)
PE Melt
Influence of poling on annealed sample 12/16
Fluoropolymer 2016 10/03/16 BARGAIN François
ΔHC : 17 J/g 25 J/gΔHm : 30 J/g constant
Increase of the FE phase content No change in the PE phase content
FE + DFETC
PE Melt
FE
Tm
Poling treatment induces the transition of the DFE phase to the FE phase
70 %FE
Annealed sample
Annealed and poled sample
5 %DFE
95 %FE
30 %DFE
WAXS (25 °C) DSC (10 °C/min)
PE Melt
14/16
Fluoropolymer 2016 10/03/16 BARGAIN François
The DFE PE phase transition
The phase transition between the DFE phase and the PE phase has also been studied:
14/16
Fluoropolymer 2016 10/03/16 BARGAIN François
The DFE PE phase transition
The phase transition between the DFE phase and the PE phase has also been studied:
Evolution of orthorhombic symmetry (DFE) to hexagonal symmetry (PE)
Continuous evolution of inter-reticular distance (a and b cell parameters) withtemperature due to the progressive change of trans in gauche conformations
Correlated behavior between DFE peak’s position and peak’s width
14/16
Fluoropolymer 2016 10/03/16 BARGAIN François
The DFE PE phase transition
The phase transition between the DFE phase and the PE phase has also been studied:
Evolution of orthorhombic symmetry (DFE) to hexagonal symmetry (PE)
Continuous evolution of inter-reticular distance (a and b cell parameters) withtemperature due to the progressive change of trans in gauche conformations
Correlated behavior between DFE peak’s position and peak’s width
Modulation of the temperature range of the transition according to annealing procedure.
The phase transition can occur before or during the Curie transition (FE to PE)
Good correlation between different experiments: WAXS, SAXS, DSC, FTIR and DMA
14/16
Fluoropolymer 2016 10/03/16 BARGAIN François
The DFE PE phase transition
The phase transition between the DFE phase and the PE phase has also been studied:
Evolution of orthorhombic symmetry (DFE) to hexagonal symmetry (PE)
Continuous evolution of inter-reticular distance (a and b cell parameters) withtemperature due to the progressive change of trans in gauche conformations
Correlated behavior between DFE peak’s position and peak’s width
Modulation of the temperature range of the transition according to annealing procedure.
The phase transition can occur before or during the Curie transition (FE to PE)
Good correlation between different experiments: WAXS, SAXS, DSC, FTIR and DMA
Article in reviewBargain François, Panine Pierre, Domingues Dos Santos Fabrice, Tencé-Girault Sylvie. Polymer.
Conclusion and perspectives 15/16
Fluoropolymer 2016 10/03/16 BARGAIN François
Understanding changes occuring during annealing and poling steps to improveelectroactive properties of poly(VDF-co-TRFE) films for organic electronicsapplications
Studying the thermal phase transition between the orthorhombic DefectiveFerroelectric (DFE) phase and the hexagonal Paraelectric (PE) phase
Understanding the role of defects in PVDF-based copolymers to developmaterials with interesting electro-active properties