(695e) Nanofibers in Osmotic Membranes for Sustainable Water and Energy

Nanofibers in Osmotic Membranes for Sustainable
Water and Energy

Ngoc Bui, Lawrence
Livermore National Laboratory, Livermore, CA

Jeffrey R.
McCutcheon, University of Connecticut, Chemical and Biomolecular Engineering
Department, Storrs, CT

To address global problems
associated with water scarcity, new effective methods of producing water at low
energetic and environmental costs are essential. Forward osmosis has recently gained
increasing attention due to its various advantages in sustainable water, resource
and energy production. Developing robust membranes with effective and
controlled structures for osmotic transport is imperative for widespread
adoption of this technology platform. Here we report a scalable approach to
fabricate osmotic thin-film composite membranes with high permselectivity based
on nanofibers and nanocomposite thereof. Nanofiber has recently emerged as an
exciting platform for forward osmosis membranes. Possessing a high porosity,
low tortuosity and an interconnected porous structure, nanofibrous mats exhibit
exceptionally low structural parameters. This work highlights recent efforts to develop nanofiber-related
materials for use in forward osmosis and pressure-retarded osmosis. Our
best membranes showed an outstanding permselectivity, exceeding those reported
in academic literature. Specifically, these membranes show a remarkable 7-fold
and 3.5-fold enhancements in osmotic water permeability and water/sodium
chloride selectivity, respectively, compared to standard commercial forward
osmosis membranes. These new membranes, if tuned appropriately to further
increase mechanical integrity, may help enable forward osmosis to effectively
function in processes related to water treatment, desalination and power
production.