Research On Multi-functional Magnetic Membrane Based On Bacterial Cellulose

Bacterial cellulose (BC) is a new kind of biological nanomaterials. BC can serve as the template to synthesize magnetic materials with specific shape and size of nanoparticles by in situ synthesis, due to its ultrafine network architecture with a distinct tunnel and pore structure, higher specific surface area with a great deal of hydroxyl groups. The magnetic membrane based on BC inherits the flexibility of BC, overcoming the brittleness of inorganic fibrous mats. It also combines the superparamagnetic ability of Fe3O4 nanoparticles, improving the comprehensive performance of the magnetic membrane.The magnetic nanoparticles aggregation and single function of magnetic material not only cause dimensional instability but also limit the application of the materials. So it's important to inhibit magnetic nanoparticles aggregation and to possess multifunction, without compromising the mechanical properties of the materials.In this paper, BC is used as the nano-reactor to fabricate flexible magnetic nanohybrid membrane and multi-functional magnetic membrane with amphiphobic surface.1. Preparation of flexible magnetic nanohybrid membraneFlexible magnetic membrane based on BC was successfully prepared by in-situ synthesis of the Fe3O4 nanoparticles coated with poly(ethylene glycol) (PEG) into BC membrane matrix under ultrasonic irradiation. The flexible magnetic nanohybrid membrane is made in the condition of Fe2+ ion of 0.05mol/L with PEG 4000 under the ultrasonic irradiation. The field emission scanning electron microscopy revealed that the Fe3O4 nanoparticles coated with PEG were well homogeneously dispersed in the BC matrix under ultrasonic irradiation. The magnetometric measurements revealed that the membrane possessed extremely superparamagnetic behaviour at room temperature with the saturation magnetization of 40.58 emu/g.2. Preparation of multi-functional magnetic membrane with amphiphobic surfaceMulti-functional magnetic membranes based on BC with amphiphobicity were prepared by in-situ synthesis of the Fe3O4 nanoparticles into BC membrane and the surface modification of fluoroalkyl silane (FAS). The fluorinated membrane made by Fe2+ ion of 0.05mol/L and FAS modification in 10mins showed the highest water contact angle (WCA) of 130°and oil contact angle (OCA) of 112°. Additionally, the magnetometric measurements revealed that the membranes exhibited the superparamagnetic behavior and can be magnetically actuated.