Active layers enhance or enable the function of membranes. For example, thin film polyamide active layersenable ultrafiltration membranes to function as reverse osmosis membranes do to the poor solubility of salt inthe polyamide active layer. In biology, the cell uses molecular bilayers comprised of lipids to separate solutesinside and outside of the cell. Lipid only mimics of the cellular membrane have demonstrated three orders ofmagnitude higher permeability and six orders of magnitude higher salt rejection than current forward osmosismembranes.Here we present the properties of active layers for ultrafiltration and microfiltration membranes containing lipidinspired active layers. In addition, these membranes can be used in forward osmosis applications. These activelayers are comprised of a z-dimensional structure of alternating lamella of silica and surfactants. The nativelyhydrophilic silica and polar surfactant surface demonstrate >50% increase in wetting in comparison to polysulfone and poly ethersulfone membranes. The charge of the surfactants can be non-ionic, cationic, anionic, orzwitterionic. Additionally, the in plane surface charge density of the surfactant lamella is calculated to be ashigh as +1e or -1e per 45 amu versus -1e per 426 amu for amorphous polysulfone. Surfactant based membranescan be cationic, anionic, zwitterionic or non-ionic, a desirable feature for the development of process specificmembranes. When the active layer is applied to an ultrafiltration membrane, the layer is pore spanning asobserved as a measurable decrease in molecular weight cutoff. When the active layer is applied to amicrofiltration membrane, the layer is conformal as observed as no change in the molecular weight cutoff.As an example application, we demonstrate how the lipid inspired active layer improves membraneperformance when filtering waste laundry water. The active layer increase flux of an ultrafiltration membraneflux by 1.54x, COD removal by 2.50x, and calcium removal by 11.6% compared to the control ultrafiltrationmembrane. Similarly, the active layer improves microfiltration flux by 1.44x, has comparable COD removal,and calcium removal by 15.3% compared to the control ultrafiltration membrane. Data detailing theperformance of membranes containing the active layer for when filtering emulsions will also be presented.Forward osmosis (FO) is used as a pretreatment to minimize reverse osmosis (RO) membrane fouling in shortand long term spacecraft wastewater treatment processes 1 . Presented here is data characterizing theperformance of an unsupported forward osmosis zNANO ML-1 membrane in terms of water flux rates andcontaminant rejection. Testing results indicated that the unsupported forward osmosis zNANO ML-1 membranehas a 12 times greater flux rate than that of commercially available forward osmosis membrane with deionizedwater as the feed water and with 2.0 mol/l sodium chloride as the osmotic agent. When secondary wastewaterwas used as the feed water, the unsupported forward osmosis zNANO ML-1 membrane had 4.4 times the flux rate vs. the commercially available forward osmosis membrane when using 2.0 mol/l sodium chloride as theosmotic agent. In addition, the unsupported forward osmosis zNANO ML-1 membrane rejects 82±14%,90±7%, 92±4%, 92±3%, 88±3%, and 86±17% of ammonium, potassium, magnesium, calcium, nitrate, sulfate,and total organic carbon respectively. The ion specific rejection suggests an electrostatic mechanism, not asolubility diffusion mechanism.
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