Rice flour-based nanostructures via a water-based system: transformation from powder to electrospun nanofibers under hydrogen-bonding induced viscosity, crystallinity and improved mechanical property

Abstract

Rice flour is a naturally abundant and renewable biodegradable and biocompatible material. Nevertheless, fabrication of rice flour-based functional nanostructures has been challenging due to the difficulties in fine-tuning solution parameters. The present work shows a successful synthesis of rice-flour based nanofibers containing PVA by simply allowing rice flour and PVA to solubilize in alkaline conditions prior to electrospinning. Rice flour/PVA blend nanofibers at the rice flour weight content of 25% led to an optimal condition with reinforced hydrogen bonding between the two polymers. The interaction induced good processability and fiber formation with well-defined morphology. In addition, rice flour functioning as a nucleating agent promoted the crystallization of small PVA crystals resulting in an improvement of tensile strength and Young's modulus with respect to PVA nanofibers. This is for the first time showing not only the transformation of rice flour via a water-based system into mechanically robust nanofibers, but also the role of rice flour in inducing crystalline phase in semi-crystalline polymers in blends. The finding is important to bring in unprecedented practical applications for rice flour such as disposable nanofilters, tissue engineering scaffolds, wound dressings, etc.