Ortho-positronium migration in mesopores of MCM-41, MSF and SBA-3

摘要: Recent studies prove that positron annihilation lifetime spectroscopy (PALS) can be successfully used as a porosimetric technique [8, 11, 26–28]. PALS has several advantages over the standard sorption techniques, i.e., range of PALS’s sensitivity spreads mesopores and micropores (reaching even intermolecular free spaces angstroms [26]). It allows characterization closed pores [15, 20, 22] measurements performed in ambient temperatures or any temperature from 0 K to hundred Kelvin [4, 12, 18, 30] situ (e.g. at various mechanical pressures [24] presence pore filling gas [6, 21, 23]). Such features are impossible obtain by most popular methods. However, limitations less known than Therefore investigating porosity materials is required verify porosimetry reliability. A comparison results with findings other methods gives ability find phenomena influencing spectra, which have taken into account order correct their proper interpretation. One such positronium migration. Positron consists measurement lifetime. Positronium hydrogen-like bound state an electron, formed randomly sample volume result interaction between emitted radioactive source one electrons present sample. Ortho-positronium migration MCM-41, MSF SBA-3 Radoslaw Zaleski, Artur Blazewicz, Agnieszka Kierys