Positron Annihilation Lifetime Spectroscopy on Controlled Pore Glass – Porosimetry and Phase Transition of Gas in Confined Matter

摘要

Positron Annihilation Lifetime Spectroscopy (PALS) is used to investigate Controlled Pore Glasses (CPG) [1]. A common PALS spectrum of controlled pore glass consists of four different lifetime components which have its origin in the annihilation of the p-Ps (τ1=0.125 ns), the annihilation of free positrons (τ2=0.5 ns), the annihilation of the o-Ps in the amorphous region of the glass (τ3=1.5 ns) and the annihilation of o-Ps in the pores of the glass (τ4=1.5 ns to 142 ns). So τ4 contains information about the pore size which can be extracted by utilising approved models like the extended Tao-Eldrup model [2].