posted on 2020-03-10, 15:36authored byYanlei Hu, Liang Liu, Juan Yu, Zhiguo Wang, Yimin Fan
Natural
silk fibers consist of well-organized, sophisticated hierarchical
architectures that contribute to the robust mechanical performance
and functions of the fibers; thus, the direct extraction of silk nanofibers
(SNFs) at a single level is a major challenge. Herein, a novel simple,
environmentally friendly, and recyclable route was developed to directly
downsize natural silks into SNFs via a green deep eutectic solvent
(DES) system assisted by mild mechanical disintegration. SNFs with
diameters ranging from 2.3 to 28 nm and lengths of 598 ± 308
nm were isolated at a high yield (over 70%) under optimal DES pretreatment
conditions. On the basis of the inherent amphoteric properties of
SNFs, the pH sensitivity and reversibility were explored to lighten
the weight of SNF dispersions for storage and transport, and furthermore,
the double adsorption properties of the SNFs might functionalize them
for transparent anticounterfeiting devices. In addition, the nanodispersibility
of the SNFs in organic solvents and the subsequent nanofiber-containing
composite materials with hydrophobic polymer matrixes provide new
prospects for wound dressing and porous scaffold materials in biomedical
applications.