Investigation of PCM microcapsules at various temperatures and pressures by PALS method

11th International Workshop on Positron and Positronium Chemistry

物理学;化学

Zgardziska, B.^1 ; Tydda, M.^1 ; Blazewicz, A.^1

Institute of Physics, Maria Curie-Sklodowska University, Lublin

20-031, Poland^1

关键词: Destructive effects;    Irradiation time;    Liquid Phase;    Microcapsules;    Polymer capsules;    Positron annihilation lifetime spectroscopy;    Temperature dependence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/618/1/012028/pdf
DOI  :  10.1088/1742-6596/618/1/012028

来源: IOP

【 摘 要 】

The positron annihilation lifetime spectroscopy (PALS) was used to investigate the properties of Phase Change Material (PCM): the Micronal® DS 5001 X microcapsules. The microcapsules are composed of a polymer capsule shell and a paraffin core. Two groups of free volumes were observed: those producing the long-lived component can be ascribed to the polymer, the other to the mixed alkanes. Both o-Ps components show the known effect of the intensity rise with positron irradiation time. At temperatures below-3°C we have observed the short lifetime as for alkane rigid phase, then the rotator-like phase preceded liquid phase. This form of temperature dependence of PAL spectra is discussed. There was no destructive effect of temperature. The PALS results were compared with those obtained by scanning electron microscopy.