Electrospinning Superhydrophobic and Antibacterial PS/MWNT Nanofibers onto Multilayer Gas Barrier Films

In this work, we demonstrate the non-synthetic surface modification of a co-extruded multilayer poly(methyl methacrylate) (PMMA)/poly(ϵ-caprolactone) (PCL) film with gas barrier properties through electrospinning of polystyrene (PS)/multi-walled carbon nanotube (MWNT) nanofibers. As produced by forced assembly layer multiplying co-extrusion, the heterogeneous nucleating crystallization of PCL was induced using the glassy confinement of the amorphous PMMA thus creating in-plane lamellae crystallization, which is impermeable to most gas molecules. To complement these intrinsic gas barrier properties of the multilayer film, electrospun PS/MWNT nanofibers were deposited onto the surface of the PMMA/PCL film, which increased the surface roughness and resulted in superhydrophobic behavior (water contact angles>150°). Furthermore, the inclusion of the MWNT in the matrix caused an increasing antibacterial efficacy, which was determined to reach 97% inactivation against gram-positive bacteria Bacillus subtilis. The fiber mats were further characterized using scanning electron microscopy (SEM), Raman spectroscopy, and thermogravimetric analysis (TGA).