Solvent-Induced Programable Wettability/Transparency Transition of Electrospun Colloidal Fibers with Embedded Polymer Nanospheres for Oil Adsorption and Plastic Remediation

The wettability of fiber membranes is very important in sewage treatment. This paper presents an interesting solvent-induced programable wettability/transparency transition of electrospun colloidal fibers from superhydrophilic to hydrophobic/highly hydrophobic depending on different solvent properties. There appeared three wettability transitions (from superhydrophilic to hydrophobic and then to hydrophilic and hydrophobic) during the solvent treatment process, accompanied by a program change of transparency from opaque to transparent and then to opaque states. This change can be attributed to the combined change in the surface chemical composition and the surface morphology during the solvent immersion process. These specific changes are due to the distinct dissolution effects of solvents toward poly(vinyl alcohol) (PVA) and poly(styrene-methyl methacrylate-acrylic acid) [P(St-MMA-AA)] latex, resulting in partial melting out of the hydrophobic latex particles, a residue of latex particles on the fiber surface, and a dynamic change of the intra-/intermolecular hydrogen bonding of the PVA surface, as could be confirmed from Fourier transform infrared and X-ray photoelectron spectroscopy data. The as-prepared porous fiber presents applications in oil absorption and catching plastic particles. This work is of significance for the development of advanced function porous fibers.