Functionalized Molybdenum Disulfide Membranes For Water Filtration

SUMMARY

• The invention is a method to fabricate membranes made from exfoliated molybdenum disulfide (MoS2) for improved separation performance and membrane stability. Reverse osmosis (RO) membranes are undergoing widespread adoption in desalination applications as global water supplies are becoming increasingly stressed, forcing consumers to turn to more challenged water sources—brackish- and seawaters, for example—to meet demand.  RO membranes require significant energy inputs to remove the salt entrained in these source waters, however, rendering the technology economical unattractive in some applications.
• This technology reduces the input energy required to remove dissolved solids from source water, extending the attractiveness of RO membrane separations to applications or regions that may have been previously economically unviable.  
• By increasing membrane water permeability to near thermodynamic entitlement limits while keeping the salt rejection constant, the energy requirements for filtration of seawater and brackish water decrease by approximately 15% and 50%, respectively.  The membrane further exhibits increased selectivity, especially towards smaller components such as boron, which would obviate the need for the multi-pass RO systems that are necessary for wastewater treatment and desalination of water for irrigation.
• Membranes are fabricated using by stacking exfoliated two-dimensional samples with precise, uniform, and optimal interlayer spacing through a novel drying and rewetting method enabled by covalent surface functionalization. Membranes fabricated using this approach demonstrate high separation performance without having to store the material in a hydrated condition, which contrasts starkly to existing fabrication methods, requiring precise control over the degree of hydration of the membrane (which must be stored in water for the entirety of their lifetime, limiting commercial viability).  

FIGURE

ADVANTAGES

ADVANTAGES

• Improved separation performance
• Enhanced membrane stability
• Precise control over membrane pore size
• Reduced energy consumption

APPLICATIONS

• Membrane separations
• Water purification / desalination

December 16, 2021

Proof of concept

Patent Pending

Licensing,Co-development

Chong Liu