Subnanometer hole properties of CO2-exposed polysulfone studied by positron annihilation lifetime spectroscopy

✍ Scribed by J.-P. Yuan; H. Cao; E. W. Hellmuth; Y. C. Jean

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 199 KB
• Volume: 36
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199812)36:17<3049::aid-polb5>3.0.co;2-o

✦ Synopsis

Positron annihilation lifetime (PAL) spectroscopy has been employed to study subnanometer hole properties in polysulfone (PSF). In this study, hole properties of size, fraction, and distribution of PSF exposed to CO 2 are reported. In the PSF/CO 2 system, the hole size and fraction significantly increase and the free-volume distribution broadens as a function of CO 2 pressure in the range of 0 -1000 psi. Hysteresis in hole properties is observed during CO 2 sorption/desorption cycle. The high sensitivity of PAL results due to CO 2 exposure in PSF is explained in terms of the microstructural changes in the polymer matrix, i.e., filling penetrant and plasticization, gas hydrostatic pressure effect, and creation of free volumes and holes.