Metal organic framework membranes for ion transport and separation

Background

Ion-selective separation membranes play a critical role in applications such as water purification, energy storage, and chemical processing. These tech­nologies are essential for tackling global challenges like clean water scarcity, efficient energy utilization, and sustainable industrial processes. Traditional ion separation methods, including reverse osmosis and electro­dialysis, have notable limitations in selectivity and energy efficiency. As industrial demands and population growth accelerate, the need for more effective and selective ion separation technologies is becoming increasingly critical.
Commercial ion-selective separation methods encounter significant challenges. For example, reverse osmosis membranes are prone to fouling and require high pressure, which raises operational costs. Furthermore, electro­dialysis is hindered by the selectivity limitations of ion exchange membranes, resulting in low separation efficiencies. Additionally, many existing membranes face a trade-off between permeability and selectivity, making it difficult to achieve high throughput without sacrificing the purity of the separated ions.
These challenges highlight the need for innovative material designs that can provide more efficient, selective, and cost-effective solutions for ion separation.

Technology overview

The ion selective separation membrane features a metal-organic framework (MOF) layer integrated with a substrate. This MOF layer possesses a unique crystal structure comprising a first and second surface, interconnected by ion transport channels. These channels are delineated by pore windows, which are meticulously designed to have a pore size smaller than the hydrated diameter of the target ion.
By applying a potential difference across the membrane using first and second electrodes, the membrane can effectively control ion transport, making it highly selective for specific ions. This precise selectivity is facilitated by the size-exclusion mechanism of the pore windows, ensuring that only ions of a certain size can pass through. Moreover, this technology achieves exceptional selectivity and ion separation efficiency due to the novel MOF layer and pore window design.
The ability to form the MOF layer on, in, and around a substrate provides versatility in application, allowing it to be tailored for various industrial and environmental uses. Additionally, the incorporation of a potential difference to drive ion transport adds a layer of control that is not commonly found in traditional separation methods.
This combination of precise size-exclusion, structural versatility, and electrochemical control makes this membrane a significant advancement for highly selective and efficient ion separation.

Figure 1: a) Schematic of a biological fluoride (F−) ion channel with an angstrom-sized region as F− selectivity filter and nanometer-sized vestibule and outlet for selective, ultrafast F− transport. b) Schematics of bioinspired artificial zirconium-based UiO-66-X (X = H, NH2, and N+(CH3)3) MOF channels with sub-1-nanometer crystalline pores for selective and ultrafast F− transport. Sub-1-nanometer MOF channels consist of angstrom-sized triangular windows (~6 Å in diameter) for ion sieving and nanometer-sized octahedral cavities (~11 Å in diameter) for ultrafast ion conduction.

Benefits

  • The novel metal-organic framework (MOF) architecture provides highly selective ion separation due to its precisely designed pore windows, which allow only target ions to pass through.
  • The integration of the MOF layer with the substrate and the use of a potential difference to drive ion transport result in higher separation efficiencies compared to traditional methods like reverse osmosis and electrodialysis.
  • By achieving high selectivity at lower pressures and minimizing fouling, this technology can reduce the operational costs associated with ion separation processes.
  • The structural integrity and stability of the MOF layer ensures a longer lifespan for the membranes, reducing the need for frequent replacements and maintenance.

Applications

  • Membrane manufacturing
  • Battery recycling equipment manufacturing
  • Water treatment facilities
  • Lithium-ion battery recycling

Opportunity

  • This novel membrane technology addresses critical challenges in water purification, offering higher selectivity and efficiency in removing contaminants and ions.
  • The high selectivity and efficiency of these membranes make them ideal for recovering valuable ions from spent lithium-ion batteries, contributing to the sustainability of battery materials.
  • This advanced MOF membrane is available for exclusive license.

Publication

“Fast and selective fluoride ion conduction in sub-1-nanometer metal-organic framework channels” (https://www.nature.com/articles/s41467-019-10420-9)

Patent

Patent Information:
Title App Type Country Serial No. Patent No. File Date Issued Date Expire Date
METAL ORGANIC FRAMEWORK MEMBRANES US National United States 16/771,324 11,471,874 6/10/2020 10/18/2022 12/20/2038
Direct Link:
https://canberra-ip.technologypublisher.com/tech/Metal_organic_framework_memb ranes_for_ion_transport_and_separation
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For Information, Contact:
Andrei Zorilescu
Sr. Licensing Specialist
University of Texas at Austin
andrei.zorilescu@austin.utexas.edu