Observations on solvent flux and solute rejection across solvent resistant nanofiltration membranes

Non-aqueous nanofiltration: solute rejection in low-polarity binary systems

“…The data in Figures 3-6, and other data 7,10 , suggest viscous solvent transport to an extent dependent on the degree of swelling induced porosity. Increasing solute rejection with molecular weight has previously been reported by Gibbins et al 9 for an MPF-50 membrane where solute molecular weights ranged from 250 to 400 g mol -1 . A size-exclusion mechanism seems unlikely for dense membranes like PDMS as solute (and solvent) transport is intuitively diffusive.…”

“…Interestingly, the rejection in low-polarity solvents was found to be reduced when compared with that observed with polar solvents. Gibbins et al 9 showed solute rejection in methanol to increase with both pressure and solute molecular weight, and estimated an effective pore diameter of ~1.2 nm for the MPF-50 membrane based on available pore models. Bhanushali et al 6,10 studied a range of solvents and solutes with both hydrophilic and hydrophobic membranes; the latter comprised PDMS composites at least superficially similar to the membranes used in the current study.…”

Cellulose nanopapers as tight aqueous ultra-filtration membranes

“…This is attributed to nanopaper compaction due to the applied pressure [34]. The compaction of the nanopapers is shown exemplarily in Fig.…”

Solvent flux through dense polymeric nanofiltration membranes

“…Scarpello et al [22] studied solvent flux through a range of organic nanofiltration membranes at pressures of 1000-4000 kPa and reported a zero intercept. In a further experiment by the authors, a sample of the membrane with an identical PAN substrate and a 10 μm thick PDMS layer was obtained from GKSS.…”