Preparation of a highly permeable ordered porous microfiltration membrane of brominated poly(phenylene oxide) on an ice substrate by the breath figure method

A highly permeable ordered porous microfiltration membrane of brominated poly(phenylene oxide) (BPPO) was prepared successfully on an ice substrate using the breath figure method. The effects of polymer concentration and substrate material on the formed porous structures were studied. As the polymer concentration in the casting solution increased, the pore size in the formed membrane decreased. The permeability of the membrane cast on the ice substrate was much higher than that of the membrane cast on a glass substrate, because the formed ice/water interface not only sped up condensation of water droplets, but also helped the water droplets run through the BPPO casting solution under gravity. The ordered porous BPPO membrane with high permeability was not only used for microfiltration, but also used for fabrication of functional microstructures.