With hydroxyl multi-walled carbon nanotubes(MWCNTs-OH) as carbonous fillers the high performance PVDF hollow fiber ultrafiltration membranes modified by MWCNTs-OH were prepared by the nonsolvent induced phase inversion process.Adding MWCNTs-OH into N

N-dimethyl acetamide (DMAC) solvent with ultrasonic treatment could strengthen their dispersion

and produce uniform casting membrane solution.The morphology and performances of modified membranes were characterized by scanning electron microscopy (SEM)

Fourier transform infrared spectroscopy (FTIR)

X-ray diffraction (XRD)

dynamic contact angle (DCA) and mechanical properties tests.The effects of MWCNTs-OH on the water flux and rejection as well as mechanical properties of the resulted hollow fiber membranes were investigated.The results showed that the water flux increased from 376.4 L/m2h to 510.9 L/m2h

while the rejection stabilized around 95.0% as the MWCNTs-OH loading increased from 0 to 0.09 wt%.The tensile strength and elongation at break increased from 1.68 to 2.42 MPa and 44.18% to 79.18%

respectively.The SEM and TEM images indicated that MWCNTs-OH were easy to reunite in the matrix along with the increase of contents of MWCNTs over 0.09 wt%

resulting in the decrease of the membrane tensile strength and water flux.The crystal form of the hollow fiber membranes changed little with the addition of MWCNTs-OH which was evidenced by the analysis of Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction.