Mechanically-robust electrospun nanocomposite fiber membranes for oil and water separation

Mechanically-robust nanocomposite membranes have been developed via crosslinking chemistry and electro-spinning technique based on the rational selection of dispersed phase materials with high Young's modulus (i.e., graphene and multiwalled carbon nanotubes) and Cassie-Baxter design and used for oil and water separation. Proper selection of dispersed phase materials can enhance the stiffness of nanocomposite fiber membranes while their length has to be larger than their critical length. Chemical modification of the dispersed phase materials with fluorochemcials and their induced roughness were critical to achieve superhydrophobocity. Surface analytic tools including goniometer, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spec-troscopy, Raman spectroscopy, atomic force microscopy (AFM) and scanning electron microscope (SEM) were applied to characterize the superhydrophobic nanocomposite membranes. An AFM-based nanoindentation technique was used to measure quantitativly the stiffness of the nanocomposite membranes for local region and whole composites, compared with the results by a tensile test technique. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques were used to confirm composition and formation of nano-composite membranes. These membranes demonstrated excellent oil/water separation. This work has potential application in the field of water purification and remediation.

Automated summary

Mechanically-robust nanocomposite membranes for oil and water separation were developed through crosslinking chemistry and electro-spinning technique. The dispersed phase materials with high Young's modulus, such as graphene and multiwalled carbon nanotubes, were selected to enhance the stiffness of the membranes. Chemical modification and induced roughness of the dispersed phase materials were critical for achieving superhydrophobicity. Surface analytic tools were used to characterize the membranes, and AFM-based nanoindentation and TGA/DSC techniques were employed for stiffness measurement and confirmation of composition and formation, respectively. These membranes showed excellent oil/water separation and have potential application in water purification and remediation.