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Abstract 2D layered nanomaterials have attracted considerable attention for their potential for highly efficient separations, among other applications. Here, a 2D lamellar membrane synthesized using hexagonal boron nitride nanoflakes (h‐BNF) for highly efficient ion separation is reported. The ion‐rejection performance and the water permeance of the membrane as a function of the ionic radius, ion valance, and solution pH are investigated. The nonfunctionalized h‐BNF membranes show excellent ion rejection for small sized salt ions as well as for anionic dyes (>97%) while maintaining a high water permeability, ≈1.0 × 10−3L m m−2h−1bar−1). Experiments show that the ion‐rejection performance of the membrane can be tuned by changing the solution pH. The results also suggest that the rejection is influenced by the ionic size and the electrostatic repulsion between fixed negative charges on the BN surface and the mobile ions, and is consistent with the Donnan equilibrium model. These simple‐to‐fabricate h‐BNF membranes show a unique combination of excellent ion selectivity and high permeability compared to other 2D membranes.
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Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics
Abstract Xe is only produced by cryogenic distillation of air, and its availability is limited by the extremely low abundance. Therefore, Xe recovery after usage is the only way to guarantee sufficient supply and broad application. Herein we demonstrate DD3R zeolite as a benchmark membrane material for CO2/Xe separation. The CO2permeance after an optimized membrane synthesis is one order magnitude higher than for conventional membranes and is less susceptible to water vapour. The overall membrane performance is dominated by diffusivity selectivity of CO2over Xe in DD3R zeolite membranes, whereby rigidity of the zeolite structure plays a key role. For relevant anaesthetic composition (<5 % CO2) and condition (humid), CO2permeance and CO2/Xe selectivity stabilized at 2.0×10−8 mol m−2 s−1 Pa−1and 67, respectively, during long‐term operation (>320 h). This endows DD3R zeolite membranes great potential for on‐stream CO2removal from the Xe‐based closed‐circuit anesthesia system. The large cost reduction of up to 4 orders of magnitude by membrane Xe‐recycling (>99+%) allows the use of the precious Xe as anaesthetics gas a viable general option in surgery.
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- Award ID(s):
- 1545560
- PAR ID:
- 10130268
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie
- Volume:
- 131
- Issue:
- 43
- ISSN:
- 0044-8249
- Page Range / eLocation ID:
- p. 15664-15671
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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