A FACILE WAY TO PREPARE A SPONGE/CELLULOSE FIBER COMPOSITE AND ITS APPLICATION IN OIL/WATER SEPARATION

Developing efficient filtering materials, with both high permeation flux and rejection, by a low-cost and facile way, for oil/water separation has been the goal that mankind pursues. In this paper, we report a porous poly(melamine formaldehyde) (PMF) sponge with superwettability and controlled pore size obtained simply, by introducing hydrophilic fibers, i.e. cellulose fibers. Driven by concentration or pressure difference, the fibers diffuse into the sponge body, and the pore size of the sponge can be regulated by changing only the fiber content. These hydrophilic fibers endow the sponge with inherent superhydrophilicity and underwater superoleophobicity. The resulting modified sponges, with varied pore sizes, can effectively separate a wide range of oil/water mixtures (including layered oil/water mixtures, surfactant-free oil/water emulsion and the surfactant-stabilized emulsion) solely by gravity, with high permeation flux and satisfactory oil rejection. It is expected that such a facile way will provide a low-cost and easily scaled-up method to construct a series of filtering materials for highly efficient separation of target oil/water mixtures.