Boosting the pervaporation performance of PDMS membrane for 1-butanol by MAF-6

To meet the increasing requirements toward biobutanol, pervaporation membrane with high separation performance needs to be developed. In this work, a hydrophobic MAF-6 (RHO-[Zn(eim)2]) was synthesized and its adsorption properties for 1-butanol was systematically studied, which are supposed to benefit the separation performance of polydimethylsiloxane (PDMS) membrane. The hydrophobic MAF-6 particles were therefore doped into PDMS to fabricate mixed matrix membrane. The morphology, chemical structure, and other properties of particles and hybrid membrane were fully studied by SEM, PXRD, FT-IR, TGA, and BET. Results demonstrate that the hydrophobicity of PDMS membrane is improved with the water contact angle increasing from 112.7° to 118.1° after being doped with MAF-6, as well as enhanced adsorption ability toward 1-butanol. More importantly, when doping MAF-6 into PDMS layer, the enhancements of 23.30% and 41.93% are separately observed in the separation factor and total flux to separate 1.5 wt% 1-butanol solution, compared with the PDMS membrane. In addition, the heat energy consumption of pervaporation process is decreased from 4.27 to 3.71 kJ g−1 via the doping of MAF-6. Overall, this work confirms that the hydrophobic particle such as MAF-6 is not only conductive to enhance the separation performance of PDMS membrane but also helpful to decrease the energy consumption.