on the coarsening of cocontinuous polymer blends€¦ · laser scanning confocal microscopy (lscm):...
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On the Coarsening of Cocontinuous Polymer Blends
Carlos R. López Barrón
Ph.D. Thesis DefenseNov. 18th, 2009
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Cocontinuous Structures
2
Applications
Conductive blends for controlled dissipation of static charges
3
Applications
Membranes and porous media for separation and filtration
Jacoby, 2006
4
Applications
Washburn et al., J Biomed Mater Res, 2002
Tissue engineered scaffolds
5
Desiccant entrained polymers
US Pat. No. 5,911,937 ‐ Base Polymer (PE, PP, Nylon, etc)‐ Channeling Agent (EVOH, PVOH)‐ Desiccant
Mixing
Phase Separation
Applications
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‐ Base Polymer (PE, PP, Nylon, etc)‐ Channeling Agent (EVOH, PVOH)‐ Desiccant
Mixing
Phase Separation
Container Liner
http://www.csptechnologies.com/
Aluminum Pouch Inserts
Films
Applications
Desiccant entrained polymers
US Pat. No. 5,911,937
7
20 m
20/80 PS/SAN Blend
50 m
50/50 PS/SAN Blend
Cocontinuous blends are
not in thermodynamic
equilibrium
50 m 20 m
Annealing for 20 min at 200 °C Annealing for 45 min at 200 °C
The Coarsening Problem
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Outline
1. Coarsening dynamics• 3D imaging +Image analysis
2. Morphology control• Addition of block copolymer
3. Rheological response• Non‐Compatibilized and compatibilized blends
• Relate Morphology‐Rheology9
Olympus Fluoview 1000
Drawbacks:
1. Visible depth depends on sample transparency
PMMA/SAN20nPMMA‐nSAN =0.1
PS/SAN20nPS‐nSAN =0.02
System: PS(n = 1.59)/SAN(n = 1.57)
Laser Scanning Confocal Microscopy (LSCM):
3D Imaging
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Olympus Fluoview 1000
Drawbacks:
1. Visible depth depends on sample transparency
2. Need fluorescently labeled blends
System: PS(n = 1.59)/SAN(n = 1.57)
Fluorescent dye
Laser Scanning Confocal Microscopy (LSCM):
3D Imaging
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Fluorescent‐Dye Monomer (AMMA) Synthesis:
FL‐Polystyrene synthesis (by radical polymerization):
FL‐PS Synthesis
12
FL‐ PS SAN
Blends:
Polymer AN‐content(% mole)
MW (Kg/mol)
η(Pa‐s)
FL‐PS 40K ‐‐‐ 40 80
FL‐PS 120K ‐‐‐ 120 1500
FL‐PS 200K ‐‐‐ 200 6900
SAN10 9.5 135 2100
SAN20 19.3 115 2350
SAN 30 28.9 100 2500
Materials
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200 °C
‐Daca Micro‐Compounder‐Vertical TSE w/recirculation
‐ 4g batches
‐mixing for 10 min at 100 rpm and 180 °C
‐ Blends with 50/50, 35/65, 20/80 w/w
‐Annealing: ‐ Quiescent annealing @ 200 °C
‐ Quenched after different times
Pellets
Blend Preparation
14
Laser Scanning Confocal Microscopy (LSCM):
Olympus Fluoview 1000
Stack of images:
3D Imaging
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ThresholdedDeconvoluted 3D ImageOriginal from LSCM
Image Processing:
3D Reconstruction
Why 3D images?
3D Imaging
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50 m 17
18
19
20
21
Lopez‐Barron and Macosko, Langmuir 2009 22
23
24
25
Outline
1. Coarsening dynamics• 3D imaging +Image analysis
2. Morphology control• Addition of block copolymer
3. Rheological response• Non‐Compatibilized and compatibilized blends
• Relate Morphology‐Rheology26
PS/SAN20 50/50 Blend
5 min 10 min 20 min
50 m 50 m 50 m
Coarsening
27
0 50 100 150
0
20
40
60
80
1/Q
, m
time, min
Q Interfacial area p.u.v. Siggia, 1979
Pin
PP
2a
PS/SAN20 50/50
1ddz a
P
Coarsening
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PS/SAN20 50/50
Q Interfacial area p.u.v.
0 50 100 150
0
20
40
60
80
1/Q
, m
time, min
1ddz a
P
Pin
PP
2a
Siggia, 1979
Pin
PP
2a
2
:8 8a d aPoiseuille v
dz
P
: ,Assumptions a v d dt
Coarsening
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Pin
PP
2a
0 50 100 150
0
20
40
60
80
1/Q
, m
time, min
1 ~Avg
c tQ
Siggia, 1979
Pin
PP
2a
PS/SAN20 50/50
~ 0.1 t
Q Interfacial area p.u.v.
Coarsening
1ddz a
P
30
1dz a
Hd
P
Pin
PP
2a
Siggia, 1979
Pin
PP
2a
PS/SAN20 50/50
~ 0.1 t
Q Interfacial area p.u.v.
0 50 100 150
0
20
40
60
80
1/Q
, m
time, min
Late coarsening:
~ 0.1 t
Coarsening
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~ 0.1 t 0 50 100 150
0
20
40
60
80
1/Q
, m
time, min
Late coarsening:Siggia, 1979
1adz
Hd
P
Q Interfacial area p.u.v.
PS/SAN20 50/50
Pin2a
PP
~ 0.1 t
Coarsening
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0 50 100 150
0
20
40
60
80
1/Q
, m
time, min
Late coarsening:Siggia, 1979
1adz
Hd
P
Q Interfacial area p.u.v.
PS/SAN20 50/50
Pin2a
PP
8d Hdt
Coarsening
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34
Excess free energy localized at the interface.
1 2
2H
Mean Curvature
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ˆinterfacedU H A dn
int ;ˆ
erfacedU dAdA HAdn
1 2
2H Excess free energy localized at
the interface.
Mean Curvature
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Mean Curvature DistributionPS/SAN20 50/50 Blend
-2 -1 0 1 2
0.01
0.1
1
10
5 min 10 min 30 min 60 min
PH,
m
H, m-1
[ | / 2 / 2]( )
( ) 1
jj
Hj
j
H
A j H H H H HP H
H A
P H H
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Mean CurvaturePS/SAN20 50/50 Blend
-4 -2 0 2 4
0.01
0.1
1
5 min 10 min 30 min 60 min
Q P
H
H/Q-2 -1 0 1 2
0.01
0.1
1
10
5 min 10 min 30 min 60 min
PH,
m
H, m-1
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-4 -2 0 2 4
0.01
0.1
1
5 min 10 min 30 min 60 min
Q P
H
H/Q
-4 -2 0 2 41E-3
0.01
0.1
1
60 min 90 min 120 min 150 min
Q P
H
H/Q
Mean Curvature
38
0 50 100 150
0
20
40
60
1/Q
, m
time, min
-4 -2 0 2 4
0.01
0.1
1
5 min 10 min 30 min 60 min
Q P
H
H/Q
-4 -2 0 2 41E-3
0.01
0.1
1
60 min 90 min 120 min 150 min
Q P
H
H/Q
Mean Curvature & Coarsening
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2 21 2C
2A
Curvedness:
ˆinterfacedU H A dn
0 60 120 1800
30
60
1/Q
, m
time, min
0.1
0.2
0.3
C, m
-1
Mean Curvature & Coarsening
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0 60 120 180
time, min
0.1
0.2
0.3
C, m
-1
C tn
Curvedness:2 2
1 2C2
A
Mean Curvature & Coarsening
8d Hdt
Pin2a
PP
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8d Hdt
Pin2a
PP
2 2
~ exp
C 2H K
Hdt
0 60 120 180
time, min
0.1
0.2
0.3
C, m
-1
C tn
Mean Curvature & Coarsening
Curvedness:2 2
1 2C2
A
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0 60 120 180
time, min
0.1
0.2
0.3
C, m
-1
C tn
8d Hdt
Pin2a
PP
Mean Curvature & Coarsening
42 3exp cc c t
~ exp Cdt
Mean Curvature & Coarsening
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1c t
Early coarsening:
Mean Curvature & Coarsening
=
1/Q
, m
0
20
40
60
80FLPS/SAN20
FLPS/SAN30
FLPS/SAN10
0 25 50 75 100 125 150
time, min44
42 3exp cc c t
1c t
Early coarsening:
Early and late coarsening:
Mean Curvature & Coarsening
=
1/Q
, m
0
20
40
60
80FLPS/SAN20
FLPS/SAN30
FLPS/SAN10
0 25 50 75 100 125 150
time, min45
1 2K
K<0 K>0 K=0, H0 K=0, H=0
Hyperbolic PlanarParabolicElliptic
Gaussian Curvature
46
K<0 K>0 K=0, H0 K=0, H=0
Hyperbolic PlanarParabolicElliptic
-0.4 -0.2 0.0 0.2
1
10
100
5 min 10 min 30 min 60 min
PK,
m2
K, m-2
[ | / 2 / 2]( )
jj
Kj
j
A j K K K K KP K
K A
1 2K PS/SAN20 50/50
Gaussian Curvature
47
Sphere Torus Double torus . . . Bicontinuous
. . .
g=0 g=1 g=2 . . . g=
2 (2 2 )Kda g Gauss-Bonnet Theorem:
1 2K
Gaussian Curvature
48
Interface Topology
10 100101
102
103
104
35/65 50/50
g/V
, mm
-3
time, min
-1.7
5 min 10 min 20 min
G=g/V (1/Q)1.7
50 m 50 m50 m
FLPS/SAN20 50/50
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Interface Topology
10 100
0.1
1
35/65 50/50
G/G
0
time, min
G=g/V (1/Q)1.7
5 min 40 min
FLPS/SAN20 35/65
50
• Visualized and quantify 3D microstructure of cocontinuous blends
•In 50/50 blends we identified two regimes of coarsening:
o Early: linear self‐similar growth of =1/Q (Siggia, 1979).o Late: slowing down due to decrease in H.
• New criterion for pinch‐off based on topological (genus) evolution.
López‐Barrón & Macosko, Langmuir, 2009López‐Barrón & Macosko, Soft Matter, In Preparation
Summary
51
Outline
1. Coarsening dynamics• 3D imaging +Image analysis
2. Morphology control• Addition of block copolymer
3. Rheological response• Non‐Compatibilized and compatibilized blends
• Relate Morphology‐Rheology52
Batchlor, J. Fluid.Mech., 1970Interface tensor
Onuki, Phys.Rev. A, 1987
Vinckier And Laun, J. Rheol., 2001.
Rheology of 2-phase liquids
• Oldroyd (1953,1955)Dilute emulsions of Newtonian liquids
• Choi‐Schowalter (1975)Semidilute emulsions of Newtonian liquids
• Palierne (1990)Emulsions of viscoelastic components
Droplet‐matrix morphologies
• Doi‐Ohta (1991)
Complex interfacesCocontinuous?
Rheology Modeling
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13
1ij i j ijq dS n n
V
PDMS/PB
Almusallam et al., 2003
AnisotropySurface tensor:
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Questions:1‐What is qij of non sheared blends?
|qij |~ 10‐5 m‐1 ~ 0
Anisotropy
55
single strain step
Questions:1‐What is qij of non sheared blends?2‐What is the maximum qij during SAOS experiments?
|qij |~ 10‐4 m‐1
~ 10‐3 N/mqij ~ 0.1 Pa
|qij |~ 10‐5 m‐1 ~ 0
Anisotropy
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For oscillatory flow:
Experimental fact: max degree of anisotropy qij /Q ~ 3 10‐4
Modeling
Char. Length: =1/Q
• Doi‐Ohta (1991)
57
0ji
ij ij ijj i
vv q px x
0 sin
ij,int
xy
ijq
t
q S t
Modeling
• Doi‐Ohta (1991)
58
0ji
ij ij ijj i
vv q px x
0 sin
ij,int
xy
ijq
t
q S t
Modeling
• Doi‐Ohta (1991)
0.01 0.1 1 10 100
10-1
100
101
102
103
104
105
G''
PS120K/SAN20
shea
r mod
uli,
Pa
, rad/s
G'Components
Blend
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sin( )ij,int xy
tt q
t
Modeling
• Doi‐Ohta (1991)
0,int 1int
0
( )'
tG t
10t s
60
Modeling
• Doi‐Ohta (1991)
0,int 1int
0
( )'
tG t
Simplification for small amplitudes:
1 tQ
(1)
(2)
≡ Characteristic length
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0 50 100 150
0
20
40
60
80
100
PS200K-SAN30
PS120K-SAN30
=1/
Q,
m
time, min
PS40K-SAN30
0 50 100 150
0
20
40
60
80
100
PS200K-SAN10
PS120K-SAN10
=1
/Q,
m
time, min
PS40K-SAN10
Characteristic Length, :
= 0.29 ± 0.07 = 1.1 ± 0.2
Q ≡ Interfacial area per unit volume
Coarsening Morphology
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ªAE
BDF
CG
1 tQ
Coarsening Morphology
63
0.01 0.1 1 10 100
10-1
100
101
102
103
104
105
G''
PS120K/SAN20
shea
r mod
uli,
Pa
, rad/s
G'
Measured at 200 °C with strain =20%
Frequency Sweep
Components
Blend
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Measured at 200 °C with 0 =20% and = 0.1 rad/s
0 100 200 300
1
10SAN30
SAN20SAN10
PS200K
PS120K
G',
Pa
time, min
PS40K
Time Sweep
65
0 50 100 150
0
20
40
60
PS200-SAN10 PS115-SAN10 PS40-SAN10
G' in
t
time, min0 50 100 150
0
20
40
60
PS200-SAN30 PS115-SAN30 PS40-SAN30
G' in
t
time, min
' ' 'blend comp intG G G
= 0.29 ± 0.07 = 1.1 ± 0.2
Time Sweep
66
0 50 100 150
0
20
40
60
PS200-SAN30 PS115-SAN30 PS40-SAN30
G' in
t
time, min0 50 100 150
0
20
40
60
PS200-SAN10 PS115-SAN10 PS40-SAN10
G' in
t
time, min
0 50 100 150
0.00
0.05
0.10
0.15
PS200K-SAN30 PS120K-SAN30 PS40K-SAN30
Q,
m-1
time, min0 50 100 150
0.0
0.2
0.4
0.6
0.8
PS200K-SAN10 PS120K-SAN10 PS40K-SAN10
Q,
m-1
time, min
Time Sweep
= 0.29 ± 0.07 = 1.1 ± 0.2
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• Doi‐Ohta (1991) 10int
0
( )' tG t
1 10 1000.1
1
10
PS200K-SAN10 PS120K-SAN10 PS40K-SAN10
G' in
t
time, min1 10 100
1
10
100
PS200-SAN30 PS115-SAN30 PS40K-SAN30
G' in
t
time, min
= 0.29 ± 0.07 = 1.1 ± 0.2
Model vs. Exp. Data
68
• Doi‐Ohta (1991) 10int
0
( )' tG t
1 10 1000.1
1
10
PS200K-SAN10 PS120K-SAN10 PS40K-SAN10
G' in
t
time, min1 10 100
1
10
100
PS200-SAN30 PS115-SAN30 PS40K-SAN30
G' in
t
time, min
= 0.29 ± 0.07 = 1.1 ± 0.2
Model vs. Exp. Data
69
• Identified 2 regimes of elasticity decrease during coarsening,described by
•Developed new method to compute qij from 3D images.
• Proposed simplification to Doi‐Ohta’s model for smalldeformations: ª
Need Improvements
Summary
int' bG t
70
• NSF DMS‐0352143 with J. Lowengrub, UC Irvine
• NSF MRSEC Program (University of Minnesota) under
Awards Number :
– DMR‐0212302
– DMR‐0819885
Funding
71
• Advisor: Chris Macosko
• Committee Members: Tim Lodge, Satish Kumar, Kevin Dorfman
• Research:
– Joel Bell – discussions on cocontinuous blends
– Yutaka Miura – synthesis of fluorescent monomer
– Jerry Sedgewick – confocal microscopes
– Ravi Chityala – 3D reconstruction
– David Morse and Kwanho Chang – block copolymer theory
– Randy Ewoldt ‐ LAOS
• Macosko Group
– Hyunwoo Kim, Luca Martinelli, Aaron Hedegaard, Dawud Tan, Zhengzi Zhu, Suqin Tan, Jing Han,
Kirby Liao, Chunfeng Zhou, Jaesoo Yang, Jie Song, Adam Wohl, Shingo Kobayashi, …
• Undergrads: Kate Dennehy, Yessica Lie
• Friends/Family: Parents, Yeny, Cristobal and Sofia
Acknowledgements
72