Preparation and performances research of Al_2O_3/TiO_2/PVDF hybrid ultrafiltration membrane

The polymer polyvinylidene fluoride(PVDF) membranes were modified by blending with nanometer particles to improve its hydrophilic property and anti-fouling performances in water treatment.The organic macromolecule blended ultrafiltration(UF) membranes modified by the inorganic nanometer TiO2 and Al2O3 were prepared by the phase inversion process.The cup ultrafiltration set was employed to study the effects of nanometer particles addition on the permeation performances of hybrid membrane.The experimental results showed that the hybrid membrane water flux increased with 79.5% than that of organic membrane with 3% nanometer particles addition and the proportion of TiO2 and Al2O3 was 1∶1,but its rejection rate did not change.The tensile strength of the hybrid membrane increased 41.6%;pure water contact angle of hybrid membrane dropped from78.68° to 50.54°,which improved the hybrid membranes hydrophilic.The hybrid membrane average pore size was larger than that of organic membrane and the pore size distribution was more uniform.The pore density of the membrane surface was increased due to nanometer particles addition,but without changing the membrane's microscopic cross section structure.The hybrid UF membrane not only maintained PVDF membrane's favorable performances but also improved its intensity,hydrophilic and anti-fouling performances.