Polydimethylsiloxane (PDMS) membrane has attracted increasing attention due to its potential application in separating organic-organic liquid mixtures and removing volatile organic compounds from water and soil. However, solvents like n-hexane, n-heptane and others are generally used in large amounts during its traditional preparation process. This study aimed to provide a low-pollution and highefficiency preparation method using water as a solvent in the presence of surfactant (dodecylbenzene sulfonic acid, DBSA). Comparisons between the membranes prepared separately with the traditional method and the green method were conducted by scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (FTIR-ATR) spectroscopy and pervaporation (PV) experiments. The results showed that they performed basically the same in the first three aspects but displayed markedly different characteristics in the PV experiments. The separation factors of the PDMS membranes prepared using the green method for separating 1.5 wt% n-butanol aqueous solution at 55 °C increased by 30-53% relative to those of membranes prepared using the traditional method, while the total flux only decreased by 7-10%. These performance improvements resulted from the shortening of evaporation time induced by the decrease of n-hexane content. Further, this hypothesis was confirmed by the performance of membranes prepared using the green method, from angles of crosslinking density, water contact angle and swelling degree (SD). Comparison with previous reports on PV performance of PDMS membranes implied that the green method was not only environmentfriendly and economically competitive but also led to enhanced PV performance.

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Furfural is an important platform chemical with a wide range of applications. However, due to the low concentration of furfural in the hydrolysate, the conventional methods for furfural recovery are energy-intensive and environmentally unfriendly. Considering the disadvantages of pervaporation (PV) and distillation in furfural separation, a novel energy-efficient ‘green technique’, gas stripping assisted vapor permeation (GSVP), was introduced in this work. In this process, the polydimethylsiloxane (PDMS) membrane was prepared by employing water as solvent. Coking in pipe and membrane fouling was virtually non-existent in this new process. In addition, GSVP was found to achieve the highest pervaporation separation index of 216200 (permeate concentration of 71.1 wt% and furfural flux of 4.09 kgm−2h−1) so far, which was approximately 2.5 times higher than that found in pervaporation at 95°C for recovering 6.0 wt% furfural from water. Moreover, the evaporation energy required for GSVP decreased by 35% to 44% relative to that of PV process. Finally, GSVP also displayed more promising potential in industrial application than PV, especially when coupled with the hydrolysis process or fermentation in biorefinery industry.