Surface modification of membranes for the separation of volatile organic compounds from water by pervaporation

摘要

Surface modifying macromolecules (SMMs) are oligomeric fluoropolymers synthesized by urethane chemistry and tailored with fluorinated endgroups. The novel SMM formulations were blended into polyvinylidene fluoride (PVDF) casting solutions containing N,N-dimethylacetamide. Based on the advancing and the receding contact angle measurements, it was found that the SMM modified membranes exhibited higher surface hydrophobicity than the unmodified membranes. The effect of solvent evaporation time and SMM concentration in the PVDF casting solution has been investigated. The membranes were characterized by scanning electron microscopy. Pervaporation experiments were carried out for dilute chloroform/water binary mixtures and the relationship between the membrane characteristics and the pervaporative performance of the membranes is discussed.