Study of the influence of graphite content on polysulfone-graphite composite membrane properties

techniques such as plasma treatment and electrophilic aromatic substitution are strategies commonly used to increase membrane hydrophilicity. we here suggest the addition of graphite (the contents of 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mass%) in the system composed of polysulfone/n-methyl-2-pyrrolidone/water and, consequently, the formation of a composite membrane as a method to increase membrane hydrophilicity. polysulfone-graphite membranes were prepared by wet-phase inversion method and were compared to that of pristine polysulfone membrane. from x-ray diffraction and fourier transform infrared spectroscopy, it was observed that the structures of both starting materials were maintained. scanning electron microscopy images revealed a cellular morphology of both membranes and the presence of graphite particles in the cross-sectional area. contact angle measurements showed that lewis acid-base interactions were favored by graphite addition and membrane hydrophilicity increased by increasing the graphite content except for the membrane prepared from a dispersion containing 3.0 mass% graphite. by increasing the graphite content, the onset temperature of degradation was increased and mass loss was decreased whereas only the membranes with low graphite content presented an increase in glass transition temperature. finally, from tensile tests, it was noted that the presence of graphite particles resulted in the brittleness of the composite membranes.