crystallization, liquid–liquid phase separation, hydrogen bonding, and entanglements. Small angle neutron scattering is used to follow the cryotropic gelation of
PVA/water solutions and detailed information is extracted concerning the gelation
mechanism and kinetic parameters related to the formation of these complex
systems.
Keywords Cryotropic gelation • Poly(vinyl alcohol) hydrogels • Time-resolving
small angle neutron scattering • Ostwald stage-rule • Confined polymer
crystallization
Abbreviations
a-PS
Atactic polystyrene
BP
Berghmans point
CLSM
Confocal laser scanning microscopy
C p
Polymer concentration
dσ
dΩ
=
Scattering cross-section
d s
Surface fractal dimension
DSC
Differential scanning calorimetry
F
Free energy
hΦi
Order parameter
f c (DSC)
Fractions of crystalline phase from DSC analysis
f c (NMR)
Fraction of rigid protons from NMR measurements
f c (XR)
Crystallinity index from WAXS analysis
LL
Liquid–liquid phase separation
NMR
Nuclear magnetic resonance
PEG
Poly(ethylene glycol)
PVA
Poly(vinyl alcohol)
q
Scattering vector
SANS
Small angle neutron scattering
SEM
Scanning electronic microscopy
TEM
Transmission electron microscopy
T g
Glass transition temperature
T m
Melting temperature
TR-SANS Time resolving-SANS
UCST
Upper critical solution temperature
WAXS
Wide angle X-ray scattering
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C. De Rosa et al.