Positron annihilation lifetime spectroscopy studies of irradiated poly(propylene-co-ethylene)/poly(ethylene-co-vinyl acetate) blends

Positron annihilation lifetime study of organic-inorganic hybrid materials prepared by irradiation

“…From SANS results, when Zr is added a serious doubt appear if segregation does not occur [18]. In case of polymer blends PAL spectrometry has proved to be very sensitive for studying miscibility for example [23,24]. It has been determined, that if systems are miscible, there is a negative deviation in the free volume as a function of concentration, which is ascribed to close packing of the polymeric components.…”

Microstructure studies of isotactic polypropylene under natural weathering by positron annihilation lifetime spectroscopy

“…Therefore, it is correct to attribute the decrease in I 3 to the increase in crystallinity. In many PALS studies [20,21,39,42,49] on polymer degradation, it has been argued that natural weathering of polymer seemed to cause the higher ordering of the molecules so as to decrease the free volume of the amorphous regions. However, the effect of carbonyl groups on positronium formation has not been taken into account.…”

Nanocharacterization of Lyotropic Liquid Crystalline Systems

“…PALS is a well -established technique used for investigating chain packing and nanostructure in polymer (Ata et al, 2009 ;Misheva et al, 2000 ) high -viscosity liquid (Jain, 1995 ) and recently lyotropic liquid crystals (Dong et al, 2009 ). It is used to provide an atomic -scale probe of the dimensions of free volume within materials, based on the lifetime of orthopositronimum (oPs) localized in inter -and intramolecular spaces.…”