Separation properties of supported ionic liquid–polydimethylsiloxane membrane in pervaporation process

Pervaporation separation properties of water–butan-1-ol binary mixtures were measured with the use of three supported liquid membranes at 37°C, namely PDMS, 1-ethenyl-3-ethyl-imidazolium hexafluorophosphate–PDMS, and tetrapropyl-ammonium tetracyanoborate–PDMS membranes. An ultrafiltration ceramic module from TiO2 with 60 nm pore size was used as a support. The diffusion coefficients of butan-1-ol in IL-PDMS were much higher than in PDMS only. However, the sorption isotherms were identical for all three measured membranes. Higher permeation flux and enrichment factors of butan-1-ol in IL-PDMS membrane were probably caused by higher diffusion coefficient. The supported ionic liquid membranes were stable during all measurements.