Systematic investigation on the influence of solutes on the separation behavior of a PDMS membrane in organic solvent nanofiltration

Organic solvent nanofiltration with a Poly(dimethylsiloxane) membrane: Parameters affecting its sieving properties

“… Molecular reactivity: sorption of the solvent into the membrane and consequent membrane swelling, molecular motion, and flexibility Physical considerations: polymer stiffness (sensitivity to compaction) …”

“…Furthermore, several studies have shown that the balance between convective and diffusive transports would be mainly directed toward convective transport, especially when the solute size is much lower than the volume depicted by the interchain spaces in a polymer matrix. Zeidler et al showed that solute transfer through the membrane can be described using either the solution‐diffusion model or the pore flow model, depending on the affinity between functional groups of the solute and the membrane. Given the variability in valid available models which can be used to describe solute transport through SRNF membranes, further investigations are needed to better understand the SRNF process and predict its performances.…”

Predictive membrane transport models for Organic Solvent Nanofiltration: How complex do we need to be?

“…The different chain flexibility compared to glassy polyimide/polyamide and rubbery silicone-coated membranes results in different sorption and swelling properties, which in turn results in different rejection profiles in OSN [21]. For both glassy and rubbery membranes, negative rejection has been demonstrated to be non-negligible under certain operating conditions, and the number of publications reporting negative rejection in non-aqueous nanofiltration has increased in recent years [16,21,[23][24][25][26][27]. However, the data on negative rejection available in the literature are mostly reported as observed data.…”

Solvent permeation behavior of PDMS grafted γ-alumina membranes

“…This finding was later confirmed by Robinson et al [20], who successfully used a pore-flow model to describe the transport behavior of PDMS membranes for nonpolar solvents based on the reasoning that the swollen PDMS layer may form a pore-like structure in the presence of nonpolar solvents. Meanwhile, Zeidler et al [21] found that a viscous flow behavior was observed for PDMS membranes in the presence of swelling solvents like n-heptane and THF. On the other hand, in the presence of nonswelling solvents, like ethanol, it was proposed that the rejection of PDMS might be closer to that of the solution-diffusion mechanism.…”