Fujita Shohei, Xu Huaizhong, Dong Yubing, Okahisa Yoko
Department of Biobased Materials Science, Kyoto Institute of Technology, Sakyoku, Kyoto 606-8585, Japan.
School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Polymers (Basel). 2021 Dec 23;14(1):43. doi: 10.3390/polym14010043.
Fibroin nanofibers (FNFs) achieved from physical treated silk can keep its original crystal structure, showing excellent mechanical properties, however, processing the FNFs into fibers is still a challenge. Herein, a brand-new environmentally friendly approach is proposed to manufacture FNFs-based composite nanofibers. The water-soluble polymer, poly(vinyl alcohol) PVA, was applied to increase the viscoelasticity of the spinning dope, and the content of FNFs can reach up to 20 wt%. The established phase image of spinning suggested that the concentrations ranging from 6 wt% to 8 wt% are premium to achieving relatively homogenous FNFs/PVA nanofibers. Random fibers were deposited on a fixed collector, while the fiber orientation intensity increased with the rotational speed of drum and started decreasing after 12 m/s. The mechanical properties of the composite nanofibers showed the similar tendency of variation of fiber orientation. In addition, chemical changes, crystallinity, and thermal properties of the composite nanofibers were further clarified by means of FTIR, DSC, and TG. As a result, high FNFs contained nanofibers with excellent thermal properties were created from an aqueous solution. This study is the first original work to realize the spinnability of FNFs, which provides a new insight of the FNFs.
通过物理处理丝绸得到的丝素蛋白纳米纤维（FNFs）能够保持其原始晶体结构，展现出优异的机械性能，然而，将FNFs加工成纤维仍然是一项挑战。在此，提出了一种全新的环保方法来制造基于FNFs的复合纳米纤维。应用水溶性聚合物聚乙烯醇（PVA）来提高纺丝原液的粘弹性，FNFs的含量可达20 wt%。所建立的纺丝相图表明，6 wt%至8 wt%的浓度范围有利于制备相对均匀的FNFs/PVA纳米纤维。无规纤维沉积在固定收集器上，而纤维取向强度随着滚筒转速的增加而增大，并在12 m/s后开始减小。复合纳米纤维的机械性能呈现出与纤维取向相似的变化趋势。此外，通过傅里叶变换红外光谱（FTIR）、差示扫描量热法（DSC）和热重分析法（TG）进一步阐明了复合纳米纤维的化学变化、结晶度和热性能。结果，从水溶液中制备出了具有优异热性能的高含量FNFs纳米纤维。本研究是实现FNFs可纺性的首个原创性工作，为FNFs提供了新的见解。
