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Open Porosity and Pore Size Distribution of Mesoporous Silica Films Investigated by Positron Annihilation Lifetime Spectroscopy and Ellipsometric Porosimetry
- Source :
- Materials, Vol 14, Iss 12, p 3371 (2021)
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- Tunable mesoporous silica films were prepared though a sol-gel process directed by the self-assembly of various triblock copolymers. Positron annihilation γ-ray energy spectroscopy and positron annihilation lifetime spectroscopy (PALS) based on intense pulsed slow positron beams as well as ellipsometric porosimetry (EP) combined with heptane adsorption were utilized to characterize the open porosity/interconnectivity and pore size distribution for the prepared films. The consistency between the open porosities was examined by the variations of orthopositronium (o-Ps) 3γ annihilation fractions and the total adsorbed volumes of heptane. The average pore sizes deduced by PALS from the longest-lived o-Ps lifetimes are in good agreement with those by EP on the basis of the Barrett–Joyner–Halenda model, as indicated by a well fitted line of slope k = 1. The results indicate that the EP combined with heptane adsorption is a useful method with high sensitivity for calibrating the mesopore size in highly interconnected mesoporous films, whereas PALS is a novel, complementary tool for characterizing both closed and open pores in them.
- Subjects :
- open porosity
mesopore size
orthopositronium lifetime
positron annihilation lifetime spectroscopy
ellipsometric porosimetry
Technology
Electrical engineering. Electronics. Nuclear engineering
TK1-9971
Engineering (General). Civil engineering (General)
TA1-2040
Microscopy
QH201-278.5
Descriptive and experimental mechanics
QC120-168.85
Subjects
Details
- Language :
- English
- ISSN :
- 14123371 and 19961944
- Volume :
- 14
- Issue :
- 12
- Database :
- Directory of Open Access Journals
- Journal :
- Materials
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.6eed941d6fe34292a5b6f4506961507f
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/ma14123371