posted on 2023-01-04, 13:07authored byLina Nie, Kunli Goh, Yu Wang, Sadiye Velioğlu, Yinjuan Huang, Shuo Dou, Yan Wan, Kun Zhou, Tae-Hyun Bae, Jong-Min Lee
Membrane technology is a key enabler for a circular pharmaceutical
industry, but chemically resistant polymeric membranes for organic
solvent nanofiltration (OSN) often suffer from lower-than-required
performances. Recently, graphene-based laminated membranes using small-flake
graphene oxide (SFGO) nanosheets open up new avenues for high-performance
OSN, but their permeance toward high viscosity solvents is below expectation.
To address this issue, we design hyperlooping channels using multiwalled
carbon nanotubes (MWCNTs) intercalated within lanthanum(III) (La3+)-cross-linked SFGO nanochannels to form a ternary nanoarchitecture
for low-resistant transport toward high viscosity solvents. At optimized
MWCNT loading, the defect-free membrane exhibits 138 L m–2 h–1 bar–1 ethanol permeance
at >99% rejections toward organic dyes, outperforming state-of-the-art
graphene oxide (GO)-based membranes to date. Even butanolwith
twice the viscosity of ethanolexhibits a permeance no less
than 60 L m–2 h–1 bar–1 at comparable rejection rates. Theoretical simulation suggests that
La3+ cross-linking is critical and can create an intact
architecture that brings size exclusion into play as the dominant
separation mechanism. Also, MWCNT nanochannel offers at least 1.5-fold
lower ethanol transport resistance than that of the GO nanochannel,
owing to greater bulk freedom in orientating ethanol molecules. Overall,
the hyperlooping architecture demonstrates ∼3-fold higher permeance
than neat SFGO membrane for elevating OSN performances.