Addition of nanosized inorganic materials in a polymeric matrix results to nanohybrids with optimized properties with respect to the initial components. On the other hand, the behavior of polymers when they are restricted in space or when they are close to surfaces can be very different from that in the bulk. In this work, we attempt to modify the crystallinity of poly(ethylene oxide) / silica, PEO/SiO2, nanohybrids utilizing two kinds of silica nanoparticles with different sizes in an attempt to bridge the case of severely confined polymers within the galleries of layered silicates with that of polymer/single-nanoparticle hybrids. The two kinds of nanoparticles vary by an order of magnitude in radius as verified by Dynamic Light Scattering (DLS). Hybrids with different ratio between the two silica nanoparticles were prepared in order to achieve the highest confinement. The good dispersion of the nanoparticles was verified by Scanning Electron Microscopy (SEM), (Figure 1) whereas the morphology and crystallization behavior of the hybrids were investigated with X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Polarized Optical Microscopy (POM). Polymer crystallinity in single nanoparticle hybrids decrease with increasing silica content whereas the behavior in the three component systems is found indeed intermediate between the cases of PEO/Na+-MMT and PEO/SiO2 and can be tuned by varying the ratio of the large vs small nanoparticles.

1. PEO-SiO2 nanocomposites:
Tuning of crystallinity
H. Papananou,1,2 E. Perivolari,1,2 , K. Chrissopoulou 1 and S. H. Anastasiadis1,2
1 Institute of Electronic Structure and Laser, Foundation for Research and Technology
Hellas, Heraklion Crete, Greece
2 Department of Chemistry, University of Crete, Heraklion Crete, Greece

2. Unit Cell(XRD)
Lamella
(SAXS)
Spherulite
(POM)
DSC
Crystallization
Å nm μm

3. Crystallization in thin films
DIFFERENT
MORPHOLOGY
DSC
ORIENTATION
KINETICS

4. Confinement

5. PURPOSE
Understanding Crystallization
under Confinement

6. Previous Work
MOTIVE
• Flat Geometry
• Confinement within 1nm walls
• Polymer could NOT crystallize
• We need CONTROL of the
confining length
0 5 10 15 20 25 30
100
98
95
90
80
70
50
30
20
10
5
Intensity(a.u.)
2 (
o
)
0
PEO wt%

7. 4
4
SiO2 Nanoparticles
CHANGING:
Size Concentration

8. The Φ of the polymer
Surface Area
Interparticle distance
Curvature

9. Nanohybrid Materials ΡΕΟ-SiO2
ΡΕΟ
Rh =12nm
LUDOX LS
R =7nm
LUDOX AS40
R =15nm
SNOWTEX ZL
R =70nm

10. 10
-5
10
-4
10
-3
10
-2
10
-1
0.00
0.05
0.10
0.15
0.20
0.25
0.30
150
o
130
o
110
o
90
o
70
o
50
o
<[C(q,t)]>
2
t (sec)
Ludox LS
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
10
1
10
2
0.00
0.05
0.10
0.15
0.20
0.25
150
o
130
o
110
o
90
o
70
o
50
o
30
o
t (sec)
Ludox AS40
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
0.00
0.05
0.10
0.15
0.20
0.25
0.30
Snowtex ZL
150
o
130
o
90
o
70
o
30
o
t (sec)
SiO2 Nanoparticles
LS
R =7nm
AS40
R =15nm
ZL
R =70nm

11. 99,5% PEO (VOL)
LUDOX LS
R =7nm
86% PEO (VOL) 43% PEO (VOL)
Nanohybrid Materials
Cryomicrotomed at University of Ioannina

12. DSC
Melting curves
Crystallinity gradually
decreases
Τm remains the same
SNOWTEX ZL
R =70nm
-80 -60 -40 -20 0 20 40 60 80
Cp
(calg
-1o
C
-1
)
PEO-ZL
92.5%
90%
Temperature (
o
C)
100%
96%
95%
80%
70%
37%
50%
30%
20%
100%
98%
97.5%
96%
89%
82.5%
54.5%
67%
46.5%
95%
34%
w% vol%
67
o
C

13. DSC
LUDOX LS
R =7nm
Crystallinity gradually
decreases
Second Melting peak appears
Reduction of Τm
-80 -60 -40 -20 0 20 40 60 80
Cp
(calg
-1o
C
-1
)
PEO-LS
PEO content
%w %v
97% 98.5%
93% 96.5%
90% 95%
Temperature (
o
C)
27% 43%
28% 44%
30% 47%
100%
35% 52%
34% 51%
55% 71.5%
64% 78%
18% 31%
44% 62%
75% 86%
86.5% 93%

14. 0 10 20 30 40 50 60 70 80 90 100 110
0
20
40
60
80
100
Crystallinity%
PEO content %
ls (r=7nm)
as40 (r=15nm)
zl (r=70nm)
Na
+
-MMT
Crystallinity

15. Crystallinity
𝑖𝑑 = 𝑑(
𝜑 𝑚𝑎𝑥
𝜑 𝑛𝑝
1
3
− 1)
1 10 100
20
30
40
50
60
70
80
90
peo-ls
peo-zl
peo-as40
Crystallinity%
Interparticle distance (nm)

16. 10
6
10
7
10
8
10
9
-10
0
10
20
30
40
50
60
70
80
90
100
peo-ls
peo-zl
peo-as40
CLAYS
Crystallinity%
E/Vpeo
(1/m)
Crystallinity

17. Mixture of Nanoparticles

18. 80%PEO+20%LS
35%PEO+65%LS
25%PEO+62.5%ZL+12.5%LS
5%PEO+52%ZL+43%LS
Mixture of Nanoparticles ZL-LS

19. -80 -60 -40 -20 0 20 40 60 80
50-50-0
Cp
(calg
-1o
C
-1
)
PEO-50%ZL-LS
Temperature (
o
C)
15-50-35
19-50-31
33-50-17
37-50-13
22-50-28
100-0-0
10-50-40
20-50-30
25-50-25
30-50-20
40-50-10
PEO-ZL-LS
vol%
Constant ZL Volume 50%
Mixture of Nanoparticles ZL-LS
5 10 15 20 25
PEO-50%ZL-LS
Intensity(a.u.)
100-0-0
15-50-35
19-50-31
33-50-17
37-50-13
PEO-ZL-LS
2 (
o
)
vol%
22-50-28
50-50-0
10-50-40
20-50-30
25-50-25
30-50-20
40-50-10

20. Constant PEO Volume 30%
Mixture of Nanoparticles ZL-LS
5 10 15 20 25
30% PEO -ZL - LS
100-0-0
30-0-70
Intensity(a.u.)
30-60-10
30-70-0
30-50-20
 (
o
)
vol%
30-40-30
30-30-40
-50 0 50 100
Cp
(calg
-1o
C
-1
)
30% PEO -ZL - LS
100-0-0
30-0-70 24
o
C
Temperature (
o
C)
30-60-10
30-50-20
PEO-ZL-LS
vol%
30-30-40
34-66-0
30-40-30
67
o
C

21. Constant PEO Volume 40%
Mixture of Nanoparticles ZL-LS
5 10 15 20 25
40-0-60
Intensity(a.u.)
40-10-50
40-20-40
40-30-30
40-40-20
40-50-10
100-00-0
2 (
o
)
Content vol%
40-60-0
PEO-ZL-LS
-50 0 50 100
Cp
(calg
-1o
C
-1
)
33
o
C
40-0-60
100%
Temperature (
o
C)
40-60-0
40-40-20
40-30-30
PEO-ZL-LS
vol%
40-10-50
40-50-10
40-20-40
67
o
C

22. ‘Tuning’ the crystallinity
0 10 20 30 40 50 60 70 80 90 100
0
20
40
60
80
100
PEO
peo-ls
peo-zl
peo-50% zl-ls
clay
Crystallinity%
increase ls content

23. ‘Tuning’ the crystallinity
0 10 20 30 40 50 60 70 80 90 100
0
20
40
60
80
100
PEO
peo-ls
peo-zl
peo-50% zl-ls
60% peo-zl-ls
50% peo-zl-ls
40% peo-zl-ls
30% peo-zl-ls
20% peo-zl-ls
clay
Crystallinity%
increase ls content

24. 10
6
10
7
10
8
10
9
-10
0
10
20
30
40
50
60
70
80
90
peo-ls
peo-zl
peo-50% zl-ls
60% peo-zl-ls
50% peo-zl-ls
40% peo-zl-ls
30% peo-zl-ls
CLAYS
Crystallinity%
E/Vpeo
(1/m)
‘Tuning’ the crystallinity

25. Conclusions
Preparation of ΡΕΟ-SiO2
nanocomposites with
different sizes of
nanoparticles
Degree of crystalinity
drops as the polymer
gets more confined
Confined Polymer
crystallizes differently
than the bulk
Control of crystallinity by
using two sizes of
nanoparticles

26. 1000 1200 1400 1600 1800
0
10
20
HeatFlow(mcal/s)
time (s)
43
o
C
44
o
C
45
o
C
46
o
C
47
o
C
48
o
C
49
o
C
50
o
C
51
o
C
52
o
C
53
o
C
54
o
C
55
o
C
60
o
C
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amet
Chain Conformation
1200 1250 1300 1350 1400
Wavenumbers (cm
-1
)
T=120
o
C
100% PEOTm
=68.5
o
C
T=40
o
C
T=110
o
C
T=100
o
C
T=90
o
C
T=50
o
C
T=60
o
C
T=80
o
C
T=70
o
C
T=22
o
C
1300 1320 1340 1360 1380 1400
Wavenumbers (cm
-1
)
T=120
o
C
T=100
o
C
T=90
o
C
T=30
o
C
T=70
o
C
T=60
o
C
T=58
o
C
T=54
o
C
T=50
o
C
T=34
o
C
T=38
o
C
T=44
o
C
T=48
o
C
T=40
o
C
maximum=49
o
C
30% PEO (wt)
44% PEO (vol)Tm2
=38.7
o
C
Tm1
=55.4
o
C
T=27
o
C
3.6 4.0 4.4 4.8 5.2 5.6 6.0 6.4 6.8 7.2
-4
-3
-2
-1
0
1
2
3
4
5
6
7
100% PEO
80% PEO
35% PEO
30% PEO
20% PEO
logfmax
1000/T
Chain Dynamics
Kinetics of crystallization

28. • NFFA Europe project of the European Union (grant agreement No.
654360)
• Action KRIPIS, PROENYL research project, MIS-448305
(2013SE01380034), funded by the General Secretariat for Research
and Technology, Ministry of Education, Greece and the European
Regional Development Fund (Sectoral Operational Programme:
Competitiveness and Entrepreneurship, NSRF 2007-2013)/ European
Commission
• COST Action MP0902-COINAPO (STSM-MP0902-14971).
Acknowledgements

29. Acknowledgements

30. Acknowledgements

31. Thank you for
watching