Electrospun polymethyl methacrylate fibers-based membrane with heterogeneous structure achieving a full-particle size separation of oil-water emulsion

There is an urgent requirement of developing new technology with low energy consumption to separate oil-water emulsion, especially when the emulsion is stabilized using surfactants. Electrospun fiber membranes (EFM) may be favorable for oil/water emulsion separation due to its high permeability resulting from its high porosity. However, high porosity in EFM restricts the separation of water droplets under 200 nm from emulsion. Here, we prepared a heterogeneous EFM through self-assembly of Ethyl cellulose (EC) colloid and Polyfluortetraethylene (PTFE) nanoparticles and subsequent self-organization on polymethyl methacrylate (PMMA) EFM to attain the separation of small particle size water droplets from oil/water emulsion. The preparation mechanism, oil/water emulsion separation effect and mechanism were disclosed by the morphology, water absorption, particle size distribution, TG, BET, Karl Fischer testing and surface tension characterization. The results showed that the prepared heterogeneous structure EFM could remove full particle size water droplets especially the water droplets below 200 nm from oil/water emulsion during membrane separation process. Hydroxyl groups, hydrophobic PTFE nanoparticles and hydrophobic PMMA formed the heterogeneous structure which exerted different directions force on water droplets. The size separation and water absorption were the main action in oil/water emulsion separation.