The overall objective of this EArly-concept Grants for Exploratory Research (EAGER) project is to develop low-pressure (0.2-3.0 bar) ion absorbing microfiltration membranes that can reversibly bind and release dissolved anions/cations by intermittently backwashing the membrane hollow fibers with acidic/basic solutions. This new filtration technology would replace current water treatment/desalination technologies utilizing reverse osmosis (RO), which is energy-intensive due to the large pressure (40-70 bar) needed to force water to flow against the natural osmotic pressure of saline water while overcoming the hydraulic resistance of an RO membrane. In addition, ion absorbing microfiltration membranes would permit the selective removal of specific ions with high water recovery and much reduced waste volumes.
To achieve this objective, we propose to exploit recent advances in nanomaterial synthesis, characterization and modeling to: 1. Design and synthesize low-cost hyperbranched macromolecules with high molar mass (10-100 nm) that can be used as high capacity, selective and recyclable ligands for cations and anions in aqueous solutions; 2. Develop a new generation of low-pressure filtration membranes for water treatment and desalination by embedding and/or covalently attaching these ion-absorbing hyperbranched macromolecules onto hollow polymeric fibers.
This exploratory research project will require 12 months for its completion. It will consist of proof-of-concept experiments to synthesize ion-absorbing hollow-fibers (IAHF) that can bind and release cations (Na+, Ca2+and Mg2+) and anions (Cl- and SO4 2-) by washing the fibers with acidic/basic solutions. These IAHF will serve as the building blocks for the low-pressure ion absorbing microfiltration membranes. We will initially use (i) low-cost hyperbranched macromolecules and (ii) poly(vinylidene) fluoride (PVDF) as building blocks for the IAHF. The proposed research activities will be structured around two tasks: 1. Task 1: Synthesis and Characterization of Ion-Selective Hyperbranched (ISH) Macromolecules 2. Task 2: Synthesis and Characterization of Hollow-Fibers with Embedded ISH Macromolecules
We anticipate the successful completion of this project to provide the proof-of-concept data needed to design and fabricate low-pressure membranes for water treatment and desalination. The development and commercialization of such membranes would have a transformative impact on water treatment and desalination. This project will also provide training opportunities to a post-doctoral research fellow.
