PALS and DSC study of nanopores partially filled by hexadecane

16th International Conference on Positron Annihilation

Šaua, O.^1 ; Illeková, E.^1 ; Kritiak, J.^1 ; Berek, D.^2 ; MacOvá, E.^2

Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 11 Bratislava, Slovakia^1

Polymer Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia^2

关键词: Controlled porosity;    Differential scanning calorimetry methods;    DSC measurements;    DSC studies;    Hexadecane;    Large pores;    o-Ps lifetime;    Positron annihilation lifetime spectroscopy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012059/pdf
DOI  :  10.1088/1742-6596/443/1/012059

来源: IOP

【 摘 要 】

The controlled porosity glasses (CPG) filled with various amount of hexadecane (HXD) in nanopores were studied both by the positron annihilation lifetime spectroscopy (PALS) and the differential scanning calorimetry (DSC) methods. Two types of CPG matrices were used with average pore sizes 12.6 and 22.2 nm. The PALS measurements showed, that when the process of large pores filling by HXD has started, the long o-Ps lifetime went down to HXD o-Ps lifetime about 3ns [1]. DSC measurements at partially filled nanopores showed always two crystallization peaks [2]. Their positions depended on average pore size of matrix. Third crystallization peak was identified in overfilled samples (only short o-Ps lifetimes were present) and their position in temperature scale was the same as for the bulk HXD peak. The latter peak was independent of the average pore size of matrices. This fact confirms the assumption that processes studied by PALS with the samples that contained smaller amount of HXD in CPG occured inside of nanopores of the matrix.