Layer-by-Layer Structured Nanofiber Membranes with Photoinduced Self-Cleaning Functions

A series of organic chemicals capable of generating radicals under photoexposure, such as 2-anthraquinone sulfonate (2-AQS), 2,6-AQS, and 2,7-AQS, have been layer-by-layer (LBL) assembled onto the hydrophilic poly(vinyl alcohol- co -ethylene) (PVA- co -PE) nanofiber composite membranes. The composite nanofiber membranes assembled with AQS chemicals have demonstrated excellent photoinduced self-cleaning properties by decolorizing colorants and killing bacteria. Scanning electron microscopy (SEM) images showed that the nanofibrous membranes maintained the well-defined fiber morphology and large specific surface area after LBL assembly. The effects of AQS types, the compositions of PVA- co -PE, as well as the number of AQS layers on the decolorization property were studied. The PVA- co -PE (44% ethylene unit) nanofiber membrane assembled with one layer of 2,6-AQS was able to provide expected photoinduced self-cleaning properties, and the system could be a promising candidate of self-cleaning protective clothing materials.