Size and Shape Exclusion in 2D Silicon Dioxide Membranes
Abstract
2D membranes such as artificially perforated graphene are deemed to bring great advantages for molecular separation. However, there is a lack of structure‐property correlations in graphene membranes as neither the atomic configurations nor the number of introduced sub‐nanometer defects are known precisely. Recently, bilayer silica has emerged as an inherent 2D membrane with an unprecedentedly high areal density of well‐defined pores. Mass transfer experiments with free‐standing SiO2 bilayers demonstrated a strong preference for condensable fluids over inert species, and the measured membrane selectivity revealed a key role of intermolecular forces in ångstrom‐scale openings. In this study, vapor permeation measurements are combined with quantitative adsorption experiments and density functional theory (DFT) calculations to get insights into the mechanism of surface‐mediated transport in vitreous 2D silicon dioxide. The membranes are shown to exhibit molecular sieving performance when exposed to vaporous methanol, ethanol, isopropanol, and tert‐butanol. The results are normalized to the coverage of physisorbed molecules and agree well with the calculated energy barriers.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 15, 2022
- Source ID
- 10.1002/smll.202205602
Entities
People
- Anjana Devi
- David Zanders
- Eric I Altman
- Inga Ennen
- Neita Khayya
- Petr Dementyev
Organizations
- Army Research Office
- Bielefeld University
- German Research Foundation
- Ruhr University Bochum
- Yale University