In　this　article,　an　organic-inorganic　nanohybrid　multilayer　membranes　have　been　developed　by　incorporating　zirconium　dioxide　(ZrO2)　and　alumina　oxide　(Al2O3)　nanoparticles　into　polyelectrolyte　complexes　such　as　poly(diallyldimethyl　ammonium　chloride)/poly(sodium　styrene　sulfonate)　and　poly(ethyleneimine)/polyacrylic　acid.　These　nanohybrid　multilayers　were　successfully　formed　on　to　both　flat　sheets　and　hollow　fiber　polyacrylonitrile　ultrafiltration　support　membranes　by　layer-by-layer　(LbL)　assembly　of　polycation-　and　polyanion-coated　nanoparticles　and　used　for　pervaporation　dehydration　of　an　acetone-water　mixture.　We　show　that　the　matching　between　the　size　of　the　NPs　and　the　supporting　membrane　pore　size　strongly　influences　the　morphologies　and　performance　of　the　multilayer　membranes.　SEM-EDX　and　AFM　analyses　suggest　that　the　ZrO2　NPs　are　mostly　distributed　on　the　substrate　surface　while　the　Al2O3　NPs　are　able　to　migrate　into　the　substrate　membrane　pores.　This　is　due　to　the　differences　between　the　sizes　of　the　two　NPs　and　results　in　an　increase　of　the　surface　roughness　of　the　ZrO2　nanohybrid　multilayer　membrane　while　that　oft　he　Al2O3　nanohybrid　multilayer　membrane　decreased.　The　ZrO2　nanohybrid　multilayer　membrane　was　able　to　overcome　the　trade-off　phenomenon,　which　enabled　both　higher　flux　and　larger　separation　factor.　However,　for　the　Al2O3　nanohybrid　multilayer　membrane,　the　separation　factor　increased　while　the　corresponding　flux　values　were　somewhat　lower　than　those　observed　for　pristine　polymeric　membranes.　(c)　2012　Elsevier　B.V.　All　rights　reserved.