Characterization and Membrane Stability Study for the Switchable Polarity Solvent N,N-Dimethylcyclohexylamine as a Draw Solute in Forward Osmosis

摘要: Abstract Commercially available reverse osmosis and forward thin-film composite membranes were assessed for long-term chemical stability when immersed in 10 molal N,N -dimethylcyclohexylammonium hydrogen carbonate draw solution, a model switchable polarity solvent solute osmosis. Membrane performance was monitored with testing, including rejection of 2000 ppm sodium chloride (NaCl), three commercial membranes—Dow BW30, SW30HR, SW30HR polyester backing layer removed—and membrane (HTI TFC). The RO observed to be largely unaffected by exposures up 90 days while the HTI TFC suffered sharp increase both water permeance permeability, manifesting itself as reduction intrinsic NaCl from 95% 82%. as-received characterized osmotic flux, where it found flux very insensitive concentration pressure-retarded operating modes. Reverse permeation highly variable, despite lower variability flux. Forward desalination 0.5 feed solution indicated higher (ca. 98.7) than under albeit presence solute. overall results imply that acceptable tolerance solutions can developed within existing framework polyamide-on-polysulfone chemistry.