Preparation Of Crosslinked Sulfonated Polysulfone Cation Exchange Membrane

Electrodialysis（ED）is an electro-driven membrane process that can separate charged species across ion-exchange membranes（IEMs）.Nowadays,because of its high efficiency and sustainability,ED has been widely used in many application areas.As the key component of ED,ion-exchange membranes should not only have a high ion permselectivity and low electrical resistance,but also a good mechanical and chemical stability.However,high IEC often leads to membrane swelling,and even dissolution in water,which can further result in a significant loss of mechanical stability.Cross-linking is a well-established method to make the balance between a high ionic conductivity and a good dimensional stability.In this work,two crosslinking methods were uesed to prepare crosslinked sulfonated polysulfone（SPSU）.For thermal crosslinking treatment,-SO₃ H was supposed to be the reactive site,polyvinyl alcohol（PVA）was used as crosslinker.After crosslink,the water uptake and swelling ratio was reduce,but still in a high range.And the crosslinked membrane has better mechanical and thermal properties but low IEC.For the UV crosslinking treatment,-CH₃ was supposed to be the reactive site,2,4,6-trimethylbenzoyldiphenyl-phosphine oxide（TPO）was used as photoinitiator,and trimethylolpropane tri-acrylate（TMPTA）as crosslinker.Compared with the pristine membranes,the crosslinked membranes exhibited an enhanced dimensional stability,better mechanical and thermal properties and better ion permselectivity.When applied in ED process,the crosslinked membranes,especially SPSU-60 were found to be more efficient and lower energy comsumption than commercial membranes.These improvements showed the crosslinked membranes can be a promising candidate for industrialization of water desalination.