General model for prediction of solvent permeation through organic and inorganic solvent resistant nanofiltration membranes

The convective-diffusive nature of the transport mechanism through solvent resistant nanofiltration (SRNF) has already been demonstrated extensively. A new semi-empirical model based on the traditional solution diffusion with imperfection model has been developed. In the newly developed model solvent permeability was found to be dependent on viscosity, and two new defined non-dimensional parameters. These parameters reflect the surface tension and dielectric constant. The permeation of a homologous series of six primary alcohols through hydrophobic polymeric membrane (Solsep-030505) has been measured. The experimental results have been used to validate the new model. The result of the model fitting was well satisfactory. The model was also validated for a broad range of solvents using additional filtration experiments. The permeation of various solvents from different chemical families through a hydrophobic polymeric membrane (MPF 50) and a hydrophilic ceramic membrane (HITK 275) has been measured. The permeability values calculated with the new model showed a very high correlation over the entire range of solvents used. The modelling results confirm the assumption of convective-diffusive transport in SRNF.