Performance of solvent-resistant membranes for non-aqueous systems: solvent permeation results and modeling

Solvent flux through dense polymeric nanofiltration membranes

“…Solvents and polymers with a similar value of Hildebrand parameter would be expected to interact strongly, whilst those with dissimilar values would not. Such an approach has been verified by Bhanushali et al [9], in a study of the sorption behaviour of a range of solvents in PDMS.…”

“…Permeation through the membrane pores is only possible when the difference in surface energy can be overcome by the applied pressure. Bhanushali et al [9] have shown that solvent surface tension is inversely proportional to flux for hydrophobic membranes, as polarity of organic solvents is strongly related to surface tension.…”

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

“…This relatively robust polymer is stable in the presence of many organic solvents, although the passage of solvent(s) induces physical, but reversible, swelling. The Hildebrand solubility parameter, δ, is reported to be a good indictor of the extent of swelling to be expected for a particular solvent/PDMS membrane combination 6,7 , solvents with a solubility parameter similar to that of PDMS (i.e. δ =15.5 MPa 0.5 ) induce more swelling.…”

“…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. Through experimental observations and the application of existing models, the authors concluded that convective transport can be significant and coupling of solvent and solute flows may take place.…”

The influence of polarity on flux and rejection behaviour in solvent resistant nanofiltration—Experimental observations

“…Although the literature is by no means extensive, a number of researchers have investigated the nanofiltration of organic feeds containing alcohol. The majority have determined flux and/or rejection performance at the laboratory scale with relatively simple deadend permeation or stirred cell apparati in order to establish fundamental data, membrane stability and/or an insight into transport mechanisms [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Much of the work has focussed on the behaviour of pure components and whilst some workers have identified membrane swelling as an important Recent work by the authors in SRNF examined the flux behaviour of low polarity alkyl and aromatic solvents with radiation crosslinked polydimethylsiloxane (PDMS) membranes.…”