Combining aggregation-induced emission and instinct high-performance of polyarylene ether nitriles via end-capping with tetraphenylethene

•Polyarylene ether nitriles (PEN) end-capped by AIEgen were obtained by one-pot synthesis strategy via stepwise polymerization.•Average molecular weight has effects on thermal resistance, processability and AIE performance.•PEN processed into flexible casting films and electrospun membranes with efficient blue emitting.•Electrospun membranes exhibited much efficient AIE effect than that of casting films, which is probably associated to the oriented and aligned chains.