Effect of surface functionalization on the moisture stability and sorption properties of porous boron nitride
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Porous boron nitride (BN) is a promising adsorbent owing to its high surface area and porosity, as well as thermal and oxidative stability. It has been explored in the past decade for applications in gas and liquid separations, such as CO2 capture and water cleaning. However, the material has displayed hydrolytic instability. Owing to the presence of moisture in most industrial settings, whether it is for storage or cyclic adsorption processes, ensuring the moisture stability of an adsorbent is crucial. While this topic has been researched for other adsorbents such as zeolites and metal organic frameworks (MOFs), little is known on controlling the hydrolytic stability of porous BN. In this study, we propose a method to enhance porous BN's hydrolytic stability via surface functionalization using a fluoroalkylsilane. We explored two different routes of functionalization: (i) functionalization of porous BN powder followed by pelletization (route 1) and (ii) coating of porous BN pellets with fluoroalkylsilane (route 2). Spectroscopic, analytical and imaging techniques confirmed the functionalization process qualitatively and quantitatively. We subjected the functionalized samples to moisture exposure at 54% RH (similar to common storage conditions) and 92% RH (similar to flue gas stream conditions with high moisture content), and characterized them to probe their resistance to moisture. We also investigated their equilibrium and kinetic sorption properties in the context of CO2/N2 separation. Both routes produced materials with enhanced moisture stability. However, we noted differences between both functionalization routes. Route 2 produced a sample with a higher grafting yield and hydrophobic nature, and therefore better resistance to moisture exposure than route 1. From a sorption point of view, despite reduced porosity, the functionalized samples maintain reasonable CO2 uptakes. The functionalization led to changes in the textural features of the samples, which caused differences in the mass transfer. This work shows that functionalization could be used to protect porous BN upon moisture exposure.
Date Issued
2023-03-15
Date Acceptance
2023-02-02
Citation
Microporous and Mesoporous Materials, 2023, 352, pp.1-13
ISSN
1387-1811
Publisher
Elsevier
Start Page
1
End Page
13
Journal / Book Title
Microporous and Mesoporous Materials
Volume
352
Copyright Statement
© 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000948577800001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Subjects
Adsorption
ADSORPTION
Boron nitride
Chemistry
Chemistry, Applied
Chemistry, Physical
Hydrolytic stability
HYDROLYTIC STABILITY
HYDROPHOBIC ZEOLITES
LIQUID
Materials Science
Materials Science, Multidisciplinary
Nanoscience & Nanotechnology
Physical Sciences
Porosity
POROSITY
Science & Technology
Science & Technology - Other Topics
Surface functionalization
Technology
Publication Status
Published
Article Number
ARTN 112478
Date Publish Online
2023-02-13