Mix-charged nanofiltration membrane: Engineering charge spatial distribution for highly selective separation

Luo, Jianquan; Wan, Yinhua

doi:10.1016/j.cej.2023.142689

“…As such, Mg 2 + are repulsed by the bottom part of MÀ E 1 , despite the negatively charged top surface. Recently, mixed-charged membranes were prepared by sequential coating and layer-by-layer assembly, [20] which is beneficial for cation selectivity though their permeance is lower (< 16 LMH/bar).…”

Section: Methodsmentioning

confidence: 99%

Advanced Lithium Extraction Membranes Derived from Tagged‐Modification of Polyamide Networks

Peng,

Liu,

Su

et al. 2023

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Efficient Mg2+/Li+ separation is crucial to combating the lithium shortage worldwide, yet current nanofiltration membranes suffer from low efficacy and/or poor scalability, because desirable properties of membranes are entangled and trade‐off. This work reported a “tagged‐modification” chemistry to tackle the challenge. A mixture of 3‐bromo‐trimethylpropan‐1‐aminium bromide (E1) and 3‐aminopropyl‐trimethylazanium (E2) was designed to modify polyethylenimine – trimesoyl chloride (PEI‐TMC) membranes. E1 and E2 reacted with the PEI and TMC, respectively, and thus, membrane properties (hydrophilicity, pore sizes, charge) were untangled and intensified simultaneously. Permeance (34.3 L m‐2 h‐1 bar‐1) and Mg2+/Li+ selectivity (23.2) of modified membranes are ~4 times and ~2 times higher than the pristine membrane, and remain stable in a 30‐days test. The permeance is the highest among all analogous nanofiltration membranes. The tagged‐modification method enables the preparation of large‐area membranes and modules that produce high‐purity Lithium carbonate (Li2CO3) from simulated brine.

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Low‐Friction Graphene Oxide‐Based Ion Selective Membrane for High‐Efficiency Osmotic Energy Harvesting

Wang,

Chen

et al. 2023

Advanced Energy Materials

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Graphene‐based laminate membranes with selective ion‐transport capability show great potential in renewable osmotic energy harvesting. One of the great challenges is to reduce the overall energy barriers while remain the high ion selectivity in the transmembrane ion transport process. Here, a strategy is proposed to break the trade‐off between ion selectivity and permeability in laminar nanochannels using amphiphilic molecules as modifier, which enhances the surface charge density of nanochannel by loading more ion polymer with polar head and lows the frictional force of ion transport with hydrophobic tail. The conversion efficiency can reach to 32% in osmotic energy harvesting (0.5 m/0.01 m concentration gradient) after adopting this modifier. During the process of mixing real river water and seawater, the maximum power density can reach to 13.38 W m−2. The amphiphilic molecules also bind adjacent nanosheets, endowing the membrane's strong mechanical strength and high stability in aqueous solution. This work can open up a new way to regulate the transmembrane ion transport in 2D laminate membranes.

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Advanced Lithium Extraction Membranes Derived from Tagged‐Modification of Polyamide Networks

Peng,

Liu,

Su

et al. 2023

Angewandte Chemie

2

0

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Efficient Mg2+/Li+ separation is crucial to combating the lithium shortage worldwide, yet current nanofiltration membranes suffer from low efficacy and/or poor scalability, because desirable properties of membranes are entangled and trade‐off. This work reported a “tagged‐modification” chemistry to tackle the challenge. A mixture of 3‐bromo‐trimethylpropan‐1‐aminium bromide (E1) and 3‐aminopropyl‐trimethylazanium (E2) was designed to modify polyethylenimine – trimesoyl chloride (PEI‐TMC) membranes. E1 and E2 reacted with the PEI and TMC, respectively, and thus, membrane properties (hydrophilicity, pore sizes, charge) were untangled and intensified simultaneously. Permeance (34.3 L m‐2 h‐1 bar‐1) and Mg2+/Li+ selectivity (23.2) of modified membranes are ~4 times and ~2 times higher than the pristine membrane, and remain stable in a 30‐days test. The permeance is the highest among all analogous nanofiltration membranes. The tagged‐modification method enables the preparation of large‐area membranes and modules that produce high‐purity Lithium carbonate (Li2CO3) from simulated brine.

show abstract

Mix-charged nanofiltration membrane: Engineering charge spatial distribution for highly selective separation

Cited by 48 publications

References 72 publications

Advanced Lithium Extraction Membranes Derived from Tagged‐Modification of Polyamide Networks

Advanced Lithium Extraction Membranes Derived from Tagged‐Modification of Polyamide Networks

Low‐Friction Graphene Oxide‐Based Ion Selective Membrane for High‐Efficiency Osmotic Energy Harvesting

Advanced Lithium Extraction Membranes Derived from Tagged‐Modification of Polyamide Networks

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