Organic-inorganic　nanohybrids　are　believed　to　be　one　of　the　most　promising　new　membrane　materials　for　separation　applications.　In　this　study,　a　new　nanohybrid　membrane　was　prepared　by　incorporating　graphene　oxide　(GO)　into　polyelectrolyte　complexes　(PECs).　Poly(ethyleneimine)-modified　GO　and　polyacrylic　acid　were　sequentially　assembled　onto　a　hydrolyzed　polyacrylonitrile　ultrafiltration　supporting　membrane.　The　nanohybrid　membranes　were　subsequently　immersed　in　polyvinyl　alcohol　solutions　and　cross-linked　by　glutaraldehyde.　The　assembly　process　was　systematically　investigated　by　scanning　electron　microscopy,　fourier　transform　infrared　analysis,　an　electrokinetic　analyzer,　a　nano-indenter　and　thermogravimetric　analyzer.　The　nanoindentation　and　thermogravimetric　experiments　in　particular　indicated　that　the　GO　incorporation　greatly　improved　the　Young＇s　modulus,　hardness　and　thermal　stability　of　the　membranes.　It　was　found　that　the　resulting　membranes　had　excellent　dye　removal　capacity.　The　retention　of　Congo　red　could　reach　99.5%　with　the　permeance　of　8.4　kg/m(2)　h　MPa.　In　the　case　of　the　separation　of　monovalent　and　divalent　ions,　such　membranes　show　good　nanofiltration　properties.　The　retention　of　Mg2+　and　Na+　were　92.6%　and　43.2%,　respectively.　Additionally,　it　was　demonstrated　that　this　GO/PECs　nanohybrid　membrane　is　also　a　good　candidate　for　the　pervaporation　dehydration　of　different　solvent-water　mixtures.　The　water　content　could　be　enriched　from　5.0　wt.%　(in　the　feed)　to　95.4　wt.%　(in　the　permeate)　with　the　permeate　flux　of　268　g/m(2)h　in　the　pervaporation　of　ethanol/water　mixture　(50　degrees　C).　(C)　2012　Elsevier　B.V.　All　rights　reserved.