Background

There is an increased need for filtration methods for obtaining fresh water due to a depleting supply. Typically, technologies such as nanofiltration, ultrafiltration, and reverse osmosis have been used to treat water. Conventional membranes for water filtration have top layer coatings made through interfacial polymerization. The membranes that are currently commercially available have been effective in treating water, but have several drawbacks, including low flux and clogged membrane pores. Clogging of membrane pores causes the flux rate to decrease over time, making the membrane increasingly less effective. Nanofibrous supports have been studied for applications in water treatment, since they improve flux rates significantly; they lack the top layer coating that conventional filtration methods have.

Technology

This technology is a fibrous support (with a thickness of 5 to about 50 ¼m) comprising nanofibers, and an interfacially polymerized polymer layer positioned on the surface of the support. The fibrous support can be in the form of a sheet with a top layer and a bottom layer. The top layer lies between the polymer layer and the bottom layer. In a different form, the polymer layer is disposed on the surface of the fibrous support and the polymer layer comprises a nanoparticulate filter. The fibrous support is dampened with a solution of a polyfunctional monomer; a second solution with a second polyfunctional monomer is dissolved into the support, so that the monomers react. This reaction forms an interfacially polymerized polymer layer, removing the excess monomers and solvents.

Advantages

- Improved filtration performance  - High flux rates - Excellent permeation rejection ratio - Reduced clogging of membrane pores

Application

- Fluid separation; water filtration - Ultrafiltration membranes - Filtration membranes - Reverse osmosis membranes - Forward osmosis membranes - Oil/water emulsion separation - Water desalination