Atom efficient thermal and photocuring combined treatments for the synthesis of novel eco-friendly grid-like zein nanofibres

Abstract

We report herein for the first time a novel crosslinking approach for the synthesis of grid-like zein nanofibres with SbQ (styrylpyridinequaternary) realized by a simple electrospinning process followed by thermal treatment and/or UV illumination. The properties of the electrospinning solution, such as viscosity, conductivity, and surface tension, were tested to evaluate the effect of SbQ addition (0 wt%, 10 wt%, 20 wt%) on the electrospinnability of glacial acetic acid solution of zein (25 wt%). The incorporation of SbQ resulted in bead-free nanofibre structures with increased diameter compared to pure zein nanofibres. The FT-IR results indicated that the zein-glacial acidic acid protein solution crosslinked, a phenomenon that can be characterized by two discrete, temporally distinct events: inter-molecular solution crosslinking and intra-fiber crosslinking from the SbQ throughout the nanofibrous mat following photocuring. The SbQ can form intra-fiber bridges, as confirmed by the SEM images; on a macroscopic (gross) scale, the crosslinking manifests itself by the formation of grid-like structures. The thermal properties of the zein nanofibres, however, were minimally improved after the incorporation of SbQ, whereas the cured composite nanofibres demonstrated significantly improved tensile and elongation properties.