Effective preparation of superhydrophilic-underwater superoleophobic nanoparticles/polymeric sponges for oil-water separation

Abstract The hierarchically-micro/nanoscale rough surface structure and the high surface hydrophilicity are two necessary factors to construct the superhydrophilic-underwater superoleophobic materials for oil-water separation. In this work, an effective method on the fabrication of the superhydrophilic-underwater superoleophobic sponges was developed, in which the mixture of the Fe 3 O 4 nanoparticles or (and) the SiO 2 nanoparticles, the chitosan, the polyvinyl alcohol, and the glutaraldehyde was coated on the polymeric sponge by dip-coating to obtain the surface-modified sponges possessing the rough superhydrophilic-underwater superoleophobic surface. The structure of the surface-modified sponges were investigated by TGA, FTIR, WAXD, XPS, SEM, two-dimensional EDS element mapping as well as VSM, and the underwater superoleophobicity of the surface-modified sponges was proved by CH 2 Cl 2 contact angle measurement. Furthermore, the resultant surface-modified sponges exhibited good oil-water separation ability by adsorption and filtration.