Oil/water separation using a lauric acid-modified, superhydrophobic cellulose composite membrane

To achieve cheap and highly efficient separation of oil/water mixtures, a superhydrophobic ployvinylidene fluoride (PVDF) and microcrystalline cellulose (MCC) composite membrane was prepared by a two-step method, in which MCC and PVDF were directly mixed to form the membrane at 25 ?C, then lauric acid was induced on surface of the membrane using grafting method. Then membranes were characterized using field emission scanning electron microscope (SEM) Attenuated total reflection infrared spectra (FTIR-ATR). Thermogravimetric analysis (TGA), water contact angle (WCA). The water contact angle of the superhydrophobic membrane in air is 153? ? 2? and the separation efficiency for different immiscible oil/water mixtures is above 99%. The superhydrophobic membrane (119.6 mg/g loading amount of lauric acid) has a high flux of 8800 L m- 2 h-1 for nhexane-water mixture and stable separation performance to kerosene-water mixture, which can be reused 20 times without decreasing the separation efficiency. Meanwhile, surfactant-stabilized emulsions can be effectively separated using the superhydrophobic membrane under gravity. Besides, the superhydrophobic film can be degraded in soil.

Automated summary

The study demonstrates a cost-effective and efficient method for separating oil/water mixtures using a superhydrophobic PVDF and MCC composite membrane. This membrane shows high separation efficiency for different immiscible oil/water mixtures, with the capability of multiple reuse.