Performance of PDMS membranes in pervaporation: Effect of silicalite fillers and comparison with SBS membranes

• Published in: Journal of colloid and interface science 2010-06, Vol.346 (1), p.254-264
• Main Authors: Dobrak, A., Figoli, A., Chovau, S., Galiano, F., Simone, S., Vankelecom, I.F.J., Drioli, E., Van der Bruggen, B.
• Format: Article
• Language: English
• Subjects: Butadienes - chemistry; Chemistry; Colloidal state and disperse state; Colloids; Dimethylpolysiloxanes - chemistry; Ethanol; Ethyl alcohol; Exact sciences and technology; Fillers; General and physical chemistry; Ion-exchange; Mathematical models; Membrane performance; Membranes; Membranes, Artificial; Nylons - chemistry; Particle Size; PDMS membranes; Pervaporation; Porous materials; Silicalite; Silicates - chemistry; Silicone resins; Solution-diffusion model; Styrene - chemistry; Surface physical chemistry; Surface Properties; Temperature; Temperature effect; Time Factors; Volatilization; Zeolites: preparations and properties
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2010.02.023

Incorporation of silicalites into PDMS network improved selectivity due to reduction of swelling. Performance of novel dense SBS membranes was found to be promising in alcohol/water separations. Laboratory-made silicalite filled PDMS membranes were tested by means of concentration and temperature influence on the membrane performance in removal of ethanol from ethanol/water mixtures. This allowed studying the applicability of solution-diffusion model in the transport mechanism description. Experiments were performed by varying the ethanol concentration in the feed and temperature. Two types of fillers were incorporated into the PDMS network: commercial zeolite silicalite (CBV 3002) and laboratory-made colloidal silicalite-1. Obtained results were then compared with data gathered for unfilled PDMS membranes to examine the effect of fillers incorporation. Moreover, the comparison with novel block co-polymer based porous and dense SBS membranes was done. It was found that the solution-diffusion model was a good representation of ethanol transport through both filled and unfilled PDMS membranes, whereas the water flux did not obey this model due to the swelling effects. Incorporation of the fillers increased membrane stability and improved the selectivity. Performance of the SBS membranes characterized by a dense structure was found to be similar to the performance of filled PDMS membranes.