کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5180226 | 1502546 | 2015 | 7 صفحه PDF | دانلود رایگان |
- Positron annihilation study of the edible polymer inulin as a non-destructive, in-situ probe is reported for the first time.
- It reveals important structural characteristics of Inulin.
- Non-monotonous temperature variations of the structure are important for shelf food storage.
- Temperature dependent free volume analysis depicts a thermotropic transition â¼320-330Â K, and loss of structure beyond 330Â K.
Inulins are nano-meter size semi-crystalline particles, composed of oligomeric fructose units. This bio-macromolecular material has been subjected to fine micro-structural analysis under temperature variations using mainly positron annihilation spectroscopy for the first time. The results show a non-monotonous temperature sensitive behavior of the positron parameters that help to understand the molecular stacking pattern. Considerable variation of its free volume size has been observed through the ortho-positronium pick-off component annihilation results. The material shows a major thermotropic transition at â¼320Â K and further a structure loss due to glass transition. Differential Scanning Calorimetry confirms the onset of the major molecular transition around the same temperature with an enthalpy change of ÎH â¼379Â J/gm and thermo-gravimetric analysis shows a â¼7.5% mass loss in the said transition.
Journal: Polymer - Volume 60, 9 March 2015, Pages 137-143