Free volume dilatation in polymers by ortho-positronium.
(2012) In Journal of Chemical Physics 136(24).- Abstract
- The possibility of positronium induced free volume cavity expansion in some polymers above the glass transition temperature was investigated using experimental positron annihilation lifetime data from the literature for polydimethylsiloxane, polyisobutylene, and polybutadiene as function of temperature. The results suggest that free volume sites can expand towards an equilibrium size, determined as the equilibrium Ps-bubble size defined earlier for low-molecular-weight liquids. The expansion can be explained by the increase of molecular mobility and hence decrease of relaxation times, which at the higher temperatures approach the o-Ps lifetimes. Nanoscale viscosities were estimated using Navier-Stokes equation and were found to be several... (More)
- The possibility of positronium induced free volume cavity expansion in some polymers above the glass transition temperature was investigated using experimental positron annihilation lifetime data from the literature for polydimethylsiloxane, polyisobutylene, and polybutadiene as function of temperature. The results suggest that free volume sites can expand towards an equilibrium size, determined as the equilibrium Ps-bubble size defined earlier for low-molecular-weight liquids. The expansion can be explained by the increase of molecular mobility and hence decrease of relaxation times, which at the higher temperatures approach the o-Ps lifetimes. Nanoscale viscosities were estimated using Navier-Stokes equation and were found to be several orders of magnitude lower than the macroscopic viscosity at the same temperature. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2967561
- author
- Winberg, Petra LU ; Eldrup, Morten LU and Maurer, Frans LU
- organization
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Chemical Physics
- volume
- 136
- issue
- 24
- article number
- 244902
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- wos:000305881100042
- pmid:22755598
- scopus:84863508975
- ISSN
- 0021-9606
- DOI
- 10.1063/1.4729561
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Polymer and Materials Chemistry (LTH) (011001041)
- id
- 19fe243d-c949-49a6-84cc-2610629033a0 (old id 2967561)
- date added to LUP
- 2016-04-01 09:52:08
- date last changed
- 2022-01-25 17:24:26
@article{19fe243d-c949-49a6-84cc-2610629033a0,
abstract = {{The possibility of positronium induced free volume cavity expansion in some polymers above the glass transition temperature was investigated using experimental positron annihilation lifetime data from the literature for polydimethylsiloxane, polyisobutylene, and polybutadiene as function of temperature. The results suggest that free volume sites can expand towards an equilibrium size, determined as the equilibrium Ps-bubble size defined earlier for low-molecular-weight liquids. The expansion can be explained by the increase of molecular mobility and hence decrease of relaxation times, which at the higher temperatures approach the o-Ps lifetimes. Nanoscale viscosities were estimated using Navier-Stokes equation and were found to be several orders of magnitude lower than the macroscopic viscosity at the same temperature.}},
author = {{Winberg, Petra and Eldrup, Morten and Maurer, Frans}},
issn = {{0021-9606}},
language = {{eng}},
number = {{24}},
publisher = {{American Institute of Physics (AIP)}},
series = {{Journal of Chemical Physics}},
title = {{Free volume dilatation in polymers by ortho-positronium.}},
url = {{http://dx.doi.org/10.1063/1.4729561}},
doi = {{10.1063/1.4729561}},
volume = {{136}},
year = {{2012}},
}