Temperature and time dependence of free volume in bisphenol A polycarbonate studied by positron lifetime spectroscopy

1992 ◽  
Vol 25 (19) ◽  
pp. 5089-5093 ◽  
Author(s):  
J. E. Kluin ◽  
Z. Yu ◽  
S. Vleeshouwers ◽  
J. D. McGervey ◽  
A. M. Jamieson ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Time Dependence ◽  
Free Volume ◽  
Positron Lifetime ◽  
Bisphenol A Polycarbonate ◽  
Positron Lifetime Spectroscopy

A Positron-Annihilation-Lifetime study of Polymer Blends

1993 ◽  
Vol 321 ◽  
Author(s):  
J. Liu ◽  
Y. C. Jean ◽  
H. Yang
Keyword(s):  
Bisphenol A ◽  
Polymer Blends ◽  
Positron Annihilation ◽  
Free Volume ◽  
Weight Fraction ◽  
Bisphenol A Polycarbonate ◽  
Positron Annihilation Lifetime ◽  
Miscible Blend ◽  
Immiscible Blend ◽  
Free Volume Hole

ABSTRACTPositron-annihilation-lifetime (PAL) spectroscopy has been utilized to investigate the free-volume properties of two types of polymer blends, a miscible blend of bisphenol-A polycarbonate (PC) and tetramethyl bisphenol-A polycarbonate (TMPC), and an immiscible blend of PC and polystyrene (PS). In the miscible blend, the free-volume hole size and its fraction follow a linear relationship with respect to the weight fraction while in the immiscible blend, the relationship is not linearly additive. The free-volume hole distributions in the immiscible blend are found to be significantly broader than those in the pure polymers. The difference is thought to be a result of the free volume formed and associated with the conformation and interchain packing between the dissimilar chains in incompatible polymers.

scholarly journals Temperature dependence of free volume distributions in polymers studied by positron lifetime spectroscopy

1993 ◽  
Vol 03 (C4) ◽  
pp. 265-270 ◽  
Author(s):  
J. KRIŠTIAK ◽  
K. KRIŠTIAKOVÁ ◽  
O. ŠAUŠA ◽  
P. BANDŽUCH ◽  
J. BARTOŠ
Keyword(s):  
Temperature Dependence ◽  
Free Volume ◽  
Positron Lifetime ◽  
Positron Lifetime Spectroscopy

Effect of Water on the Size Distribution of Free-Volume Holes in Nafion Membrane

2012 ◽  
Vol 733 ◽  
pp. 49-52 ◽  
Author(s):  
Jakub Čížek ◽  
Zuzana Barnovská ◽  
Michal Šourek ◽  
Ivan Procházka
Keyword(s):  
Size Distribution ◽  
Free Volume ◽  
Water Uptake ◽  
Positron Lifetime ◽  
Ionic Clusters ◽  
Mean Size ◽  
Positron Lifetime Spectroscopy ◽  
The Mean ◽  
Kinetics Of

Positron lifetime spectroscopy was employed for investigation of the size distribution of free volume holes in Nafion N-1110 membrane. Size distribution of free volume holes was determined in the as-received and dried membrane and in the membrane immersed in water at various temperatures. It was found that absorbed water causes reduction of the mean size of free volume holes and increase of their dispersion and concentration. This indicates that free volumes are split by swollen ionic clusters absorbing water. The kinetics of water uptake and the amount of absorbed solvent was determined by in-situ measurement of the weight increase.

scholarly journals Free-Volume Studies in Polycaprolactone/Poly(propylene oxide) Urethane/Urea Membranes by Positron Lifetime Spectroscopy

2008 ◽  
Vol 113 (5) ◽  
pp. 1359-1364 ◽  
Author(s):  
M.F. Ferreira Marques ◽  
P.M. Gordo ◽  
A.P. de Lima ◽  
D.P. Queiroz ◽  
M. Norberta de Pinho ◽  
...  
Keyword(s):  
Free Volume ◽  
Propylene Oxide ◽  
Positron Lifetime ◽  
Positron Lifetime Spectroscopy ◽  
Poly Propylene

Water in Montmorillonites

2010 ◽  
Vol 666 ◽  
pp. 119-122 ◽  
Author(s):  
Barbora Sláviková ◽  
Martina Iskrová ◽  
Viktor Majerník ◽  
Ondrej Šauša ◽  
Jozef Krištiak ◽  
...  
Keyword(s):  
Time Dependence ◽  
Water Content ◽  
Free Volume ◽  
Room Temperature ◽  
Positron Lifetime ◽  
Bulk Water ◽  
X Ray Diffraction ◽  
Mass Percentage ◽  
X Ray ◽  
Different Content

Positron lifetime was measured for pure and water filled montmorillonites (MMT) at room temperature. The size of free volume was correlated with interlayer distances from X-ray diffraction for different content of water in MMT. Free volume in samples with water content above 10 % (mass percentage) is smaller in comparison with bulk water. Time dependence of release of water from MMT under vacuum will be discussed.

Monitoring the Crystallization Stages of Silicalite by Positron Lifetime Spectroscopy

2008 ◽  
Vol 607 ◽  
pp. 173-176 ◽  
Author(s):  
Z. Kajcsos ◽  
C. Kosanovic ◽  
S. Bosnar ◽  
B. Subotic ◽  
P. Major ◽  
...  
Keyword(s):  
Porous Media ◽  
Positron Annihilation ◽  
Free Volume ◽  
Positron Lifetime ◽  
Large Change ◽  
Zeolite Framework ◽  
Positron Lifetime Spectroscopy

In porous media, positron annihilation techniques (PAT) revealed the existence of annihilation modi with long lifetimes connected to structural and extrastructural free volumes acting as trapping centres for o-Ps. Our aim in this work was to study the influence of the synthesis applied for the production of the zeolite framework and the correlation between the trapping pattern and crystallization progress. PAT lifetime (LT) measurements were performed in silicalite-1 samples in various stages of crystallization and a large change was observed in the long components. The results are discussed in connection to the crystallization and the availability of free volume.

Free volume and phase transitions of 1-butyl-3-methylimidazolium based ionic liquids from positron lifetime spectroscopy

2012 ◽  
Vol 14 (19) ◽  
pp. 6856 ◽  
Author(s):  
Yang Yu ◽  
Witali Beichel ◽  
Günter Dlubek ◽  
Reinhard Krause-Rehberg ◽  
Marian Paluch ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Phase Transitions ◽  
Free Volume ◽  
Positron Lifetime ◽  
Positron Lifetime Spectroscopy
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