This document summarizes research on how adding inorganic nanoparticles affects the structure, morphology, and crystallization behavior of poly(ethylene oxide) (PEO). The researchers investigated PEO mixed with montmorillonite clay nanoparticles (Na+-MMT), silica nanoparticles of different sizes, and their combinations using X-ray diffraction and differential scanning calorimetry. They found that smaller silica nanoparticles induced more confinement, causing double melting peaks and preventing crystallization at high loadings. Larger nanoparticles and clay induced less severe confinement, allowing crystallization but changing the behavior. By using mixtures of nanoparticle sizes, they could reach lower polymer contents and tune the crystallinity more effectively than single nanoparticles alone.

1. 0 10 20 30 40 50 60 70 80 90 100 110
0
20
40
60
80
100
Crystallinity%
PEO content wt%
ls (r=7nm)
zl (r=70nm)
Na
+
-MMT
Elena Perivolari1,2, Hellen Papananou1,2, Kiriaki Chrissopoulou1, and Spiros H. Anastasiadis1,2
1Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, Heraklion Crete, Greece
2 Department of Chemistry, University of Crete, Heraklion Crete, Greece
The addition of inorganic nanomaterials in a polymer matrix has been
widely used to optimize the polymer mechanical and thermal properties. Nevertheless, although in certain cases
improved properties have been obtained, the mechanism behind their optimization as well as their correlation with structure and morphology
has not been fully understood. Moreover, in the case of semi-crystalline polymers, the influence of the addition and the state of dispersion of the nanofillers on
the crystallinity and the crystallization characteristics has been largely overlooked. In this work, the structure, morphology and crystallization behavior of a semi-
crystalline polymer, poly(ethylene oxide), PEO, when mixed with a) natural montmorillonite (Na+-MMT) and b) silica nanoparticles of different sizes and c)mixtures of
nanoparticles are investigated through X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). In all cases, the nanohybrids were synthesized
through solution intercalation in water in a broad range of compositions never the less the crystalline behavior showed distinct differences
depending on the induced confinement
LUDOX LS
R =7nm
ΡΕΟ
Rh =12nm
Acknowledgements
This work was performed in the framework of
PROENYL research project, Action KRIPIS, 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
No Confinement
Polymer Crystallizes normally
-80 -60 -40 -20 0 20 40 60 80
PEO content
%w %v
Cp
(calg
-1o
C
-1
)
PEO-SiO2
(R=70nm)
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%
67
o
C
-80 -60 -40 -20 0 20 40 60 80
Cp
(calg
-1o
C
-1
)
PEO-SiO2
(R=7nm)
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%
Confinement
Effect:
● Double Melting
Larger confinement for
the 3-component systems
In 3 component
systems we are able to:
Reach lower Tune the
polymer contents crystallinity
This geometry allows us
to reach polymer contents
that were previously
forbidden.
-80 -60 -40 -20 0 20 40 60 80 100
PEO-Na
+
MMT
Cp
(calg
-1o
C
-1
)
5
10
20
30
40
50
60
65
70
80
90
95
98
Temperature (
o
C)
100
wt%
PEO endo
SNOWTEX ZL
R =70nm
ΡΕΟ
Rh =12nm
ΡΕΟ
Rh =12nm
D =1nm
Medium Confinement
Polymer Crystallizes differently
Severe Confinement
Polymer Cannot Crystallize
Filling the gap
How?
Reaching lower polymer contents Tuning the crystallinity
-80 -60 -40 -20 0 20 40 60 80
100-0-0
Temperature (
o
C)
Cp
(calg
-1o
C
-1
)
15-50-35
19-50-31
33-50-17
37-50-13
vol %
22-50-28
50-50-0
10-50-40
20-50-30
25-50-25
30-50-20
40-50-10
PEO-70nm-7nm
0 10 20 30 40 50 60 70 80 90 100
0
20
40
60
80
100
peo-ls
peo-zl
peo-50% zl-ls
Crystallinity%
PEO content (vol%)
5 10 15 20 25
100-0-0
30-0-70
Intensity(a.u.)
30-60-10
30-70-0
30-50-20
 (
o
)
vol%
30-40-30
PEO-70nm-7nm
30-30-40
0 10 20 30 40 50 60 70 80 90 100
0
20
40
60
80
100
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
Crystallinity%
PEO content (vol%)
increase LS content
3-component system
Amorphous
Nanohybrids
Tuning of crystallinity for
constant polymer content
Severe
Confinement
Effect:
● Amorphous Polymer
L~μm
L~μm
Tuning the crystallinity of Poly(ethylene oxide)
in PEO-SiO2 nanocomposites