A novel composite microfiltration membrane: Structure and performance

A dilute PVDF solution with concentration lower than 8 wt% was investigated using the Loeb–Sourirajan process to produce an asymmetric microporous membrane. The parameters such as polymer concentration and solution composition were optimized and a type of asymmetric microporous membrane with high porosity, thin barrier layer, narrow pore size distribution, short pore flow distance and self-similar structure was obtained. A composite microfiltration membrane, consisting of an asymmetric microporous membrane, ultrathin nanofibers and non-woven PET fabric was constructed and evaluated in the filtration test. In comparison to the commercial microfiltration membrane and raw electrospun nanofibrous membrane, the novel composite microfiltration membrane exhibited a much better performance: dramatically high water flux, high selectivity, low fouling tendency and excellent flux recovery property.