Electrospun konjac glucomannan-gelatin/polycaprolactone bilayer nanofibrous films with improved hydrophobicity and mechanical properties for food packaging

Konjac glucomannan-gelatin (KGM-GEL) based electrospun nanofibrous films are promising materials for food packaging but suffer from high hydrophilicity and weak mechanical properties. To overcome these limitations, KGM-GEL-based nanofibrous films were reinforced using polycaprolactone (PCL) nanofibers as a crosslinking layer via two-step electrospinning technique. The results show that the bilayer nanofibrous films composed of PCL nanofibers and KGM-GEL nanofibers display a homogenous morphology. Additionally, FTIR and X-ray diffraction analysis shows that physicochemical properties of each biopolymer are preserved in bilayer nanofibrous films. The hydrophobicity of KGM-GEL-based nanofibers is improved dramatically with PCL nanofibers as indicated by water contact angle (WCA) and WVP measurement. All bilayer nanofibrous films have achieved improvements in mechanical properties and thermal stability. It can be concluded that crosslinking with biocompatible synthetic polymers PCL nanofibrous films is an effective pathway for the preparation of natural biopolymers-based nanofibrous films with improved properties, which may be a promising material for food packaging.