In this study, tetraethyl orthosilicate-derived (TEOS-derived) siloxanes were successfully incorporated into chitosan (CS) membranes to form siloxane/CS mixed-matrix membranes (MMMs) via a drying-free and one-step process. Compared with the two-step process for the formation of MMMs in the previous literature, the one-step process of membrane preparation has the advantages of a decrease in the membrane formation time and the prevention of particle aggregation to form uniform and smooth MMMs. The siloxane/CS MMMs were used to separate a mixture of ethanol/water in the pervaporation process at 25 degrees C. MMMs with different siloxane concentrations, such as 0.025, 0.05, 0.15, 0.3 and 0.5 wt%, have been investigated, and MMMs with 0.05 wt% siloxanes (0.05 wt% MMMs) have the best pervaporation performance, with flux, separation factor and pervaporation separation index (PSI) values of 468 g/m(2)h, 2182 and 1021 kg/m(2)h, respectively. The pervaporation performance of 0.05 wt% siloxane/CS MMMs is better than that of CS-based membranes and other MMMs, as reported in the previous literature. As a result, the as-prepared siloxane/CS MMMs with 0.05 wt% siloxane loading show great potential for future industrial pervaporation applications.