Determination of Free-Volume and Hole Number Density in Polycarbonates by Positron Lifetime Spectroscopy

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.

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

Acta Physica Polonica A ◽

10.12693/aphyspola.113.1359 ◽

2008 ◽

Vol 113 (5) ◽

pp. 1359-1364 ◽

Cited By ~ 3

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

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

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:1993441 ◽

1993 ◽

Vol 03 (C4) ◽

pp. 265-270 ◽

Cited By ~ 5

Author(s):

J. KRIŠTIAK ◽

K. KRIŠTIAKOVÁ ◽

O. ŠAUŠA ◽

P. BANDŽUCH ◽

J. BARTOŠ

Keyword(s):

Temperature Dependence ◽

Free Volume ◽

Positron Lifetime ◽

Positron Lifetime Spectroscopy

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Free Volume Determination of Azobenzene−PMMA Copolymer by a Pulsed Low-Energy Positron Lifetime Beam with in-Situ UV Illumination

Macromolecules ◽

10.1021/ma0486086 ◽

2004 ◽

Vol 37 (21) ◽

pp. 8035-8042 ◽

Cited By ~ 14

Author(s):

John Algers ◽

Peter Sperr ◽

Werner Egger ◽

Laszlo Liszkay ◽

Gottfried Kögel ◽

...

Keyword(s):

Free Volume ◽

Positron Lifetime ◽

Low Energy ◽

Volume Determination ◽

Uv Illumination

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Monitoring the Crystallization Stages of Silicalite by Positron Lifetime Spectroscopy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.607.173 ◽

2008 ◽

Vol 607 ◽

pp. 173-176 ◽

Cited By ~ 6

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.

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