Description:
Project #D2019-22
Background
Reverse osmosis is a common technique used in desalination; it utilizes high pressure to separate water from salt. Although this separation technique is widely used for desalination, it would be advantageous to use a membrane that allows for selective transport of salt relative to water.
Charge mosaic (CM) membranes are parallel arrays of ion-exchange elements. They can remove salt from water using piezodialysis, which uses hydrostatic pressure to push a solution of high salinity through a membrane. CM membranes offer the ability to permeate salt ions from a low concentration solution to a higher concentration by convective flow. Alternating charges within the membrane allow anions and cations to flow in parallel through their appropriate channels, providing a continuous pathway from feed to permeate.
Although they offer some advantages over reverse osmosis, known CM membranes have been fabricated out of ion exchange resins, block co-polymers, polymer blends, and stacked ion-exchange membranes that lack mechanical strength, have low enrichment, and low flux. In order for CM membrane advantages to be realized, a solution is needed to provide more durability for desalination requirements.
Invention Description
Researchers at the University of Toledo have developed a technique to produce a charge mosaic membrane within a porous support. The support can be made out of a limited variety of materials, including polyacrylyonitrile (PAN). Membranes are formed via counter-diffusion and ionic crosslinking inside pores within the support.
Applications
- Desalination
Advantages
- Simple to produce with short formation time
- Possesses hydraulic stability
- Higher salt enrichment, even at lower feed concentration
- Tight network structures reduce water permeation
IP Status: Patent Pending