A series of cation exchange membranes based on multiblock suflonated poly(arylene ether sulfone)s (bSPAES) were prepared successfully and used as the separators in the microbial fuel cell (MFC) systems.The properties of the membranes relative to the MFC applications were investigated in details.After introduction of the rigid fluorenyl in the hydrophilic moieties of bSPAES

the corresponding membranes exhibited much better dimensional stability and hydrolytic stability.bSPAES showed isotropic performance in a range of 10%~20% in size change and 81~140 mS/cm of proton conductivity

which were much higher than those of commercial product of ULTREX CMI-7000.After 1000 h MFC operation

almost no changes were observed for the proton conductivity of bSPAES membranes.Hydrolytic stability test in 100 ℃ water for 24 h showed that the weight loss was between 1.5% and 6.3%.The maximum power density of MFC increased with the block length increasing.Comparing with the ULTREX CMI-7000 membrane

the bSPAES membranes exhibited much higher MFC performances

and the maximum power density for bSPAES(30/30) reached to 705 mW/m2.