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A new long-distance and dynamic low-temperature plasma (LDDLTP) setup for modification of PE hollow fiber membranes in a module scale was proposed.The Ar plasma conditions of external pressure type were optimized by contact angle measurements.Changes in morphology and chemical composition of the surfaces were determined by scanning electron microscopy,attenuated total reflection-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.Contact angle variations along with fiber axial distance from plasma inlet revealed that there was an effective treatment distance.At this effective distance,almost all contact angles for outside membrane surfaces were close to 60°,far less than that of the virgin membrane (about 120°).To minimize the structural damage and maximize the effective distance,a RF power of 60W,a pressure of 20±2Pa and an exposure time of 120s were selected.Under these conditions,the effective distance can reach 10.5cm and no physical damage was observed.The changes in the surface hydrophilicity were mainly as a result of implantation of a large amount of polar C–O,C=O/O–C-O or COOH/COOR groups onto the outside membrane surface.Due to aging,there was some hydrophobic recovery,but the contact angle values of aged membranes (1 month) were still in the effective area (<70°).Moreover,the effective distance was easily upgraded to over 20cm after plasma treatment from the double inlets.And the plasma-treated PE hollow fiber membranes significantly reduced protein fouling and increased water flux.However,the plasma treatment in module scale is not uniform and the modules used in this work were still at a relative small size.Fortunately,the new LDDLTP set-up used can be easily upgraded to larger dimensions.These problems are exactly our interests and motions for further investigation.