Alcohol　permselective　pervaporation　is　a　promising　technology　for　bio-alcohol　production.　In　this　study,　a　multiple　spray　technique　has　been　developed　to　prepare　hydrophobic　composite　membranes　for　alcohol　permselective　pervaporation.　A　defect-free　permselective　layer　was　successfully　obtained　by　repeated　alternate　spraying　of　dihydroxypolydimethylsiloxane　(PDMS)　and　tetraethylorthosilicate　with　the　addition　of　dibutyltin　dilaurate　on　to　a　polysulfone　ultrafiltration　membrane　using　an　automatic　spray　system.　The　effects　of　PDMS　molecular　weight　and　concentration,　number　of　spraying　cycles,　spraying　time　and　standing　interval　on　the　membrane　performance　were　intensively　investigated.　Experiments　proved　that,　compared　with　the　dip-coated　membrane,　the　membrane　flux　obtained　in　this　way　showed　a　dramatically　increase　while　the　selectivity　remained　at　a　comparable　level.　It　was　found　that　the　multiple　spray　technique　can　ensure　that　there　are　no　defects　in　the　separation　layer,　by　repeated　adjustment　of　the　number　of　spraying　cycles,　and　can　also　greatly　reduce　the　thickness　of　a　selective　layer.　In　addition,　the　automatic　spray　technology　removes　the　inherent　unreliability　of　manual　techniques,　so　is　beneficial　for　large-scale　rapid　preparation　of　composite　membranes.　(C)　2013　Elsevier　B.V.　All　rights　reserved.