High-performance polyamide thin-film composite membranes were successfully prepared using interfacial polymerization of triethylenetetramine (TETA) and trimesoyl chloride (TMC) on the surface of a modified polyacrylonitrile (mPAN) membrane for alcohol dehydration by pervaporation. Attenuated total reflection infrared spectroscopy (FTIR-ATR), scanning electron microscope (SEM), atomic force microscope (AFM) and the contact angle were used to characterize the chemical structures, morphologies and hydrophilicity of the composite membrane active layers. The best pervaporation performance was achieved by using the TETA-TMC/mPAN composite membrane that is prepared by immersing mPAN in 0.1 wt.% aqueous TETA solution for 5 s and then contact with 0.05 wt.% organic TMC solution for 10 s. The pervaporation separation of a 70 wt.% isopropanol-water mixture through the composite membrane with the ultra thin polyamide layer at 70 degrees C, the permeation rate and water concentration in permeate were 3.4 kg/m(2) h and higher than 99 wt.%, respectively. It was also found that TETA-TMC/mPAN exhibited superior performance to the composite membranes discussed in the literature. (C) 2008 Elsevier B.V. All rights reserved.