Utilizing the elementary building blocks of plant cell walls, cellulose nanofibrils (CNFs), can give final materials excellent mechanical properties. For instance, CNF-based wet-spun fibers exhibit superior mechanical properties, surpassing their source materials, plant fibers. Such high mechanical performance is closely related to CNFs’ orientation; thus, most previous research has focused on optimizing spinning rates or introducing post-stretching to enhance this parameter. In this study, the effects of the CNF surface properties on CNF orientation were investigated, which are often neglected in the literature: 1) during extrusion, the CNF surface properties affect the rheological behaviors of the spinning suspension, which in turn influences CNFs’ orientation potential; 2) during coagulation, they govern the affinity between CNFs and antisolvents, thereby determining the shrinkage of CNF gels; 3) during drying, they directly impact capillary forces induced by the evaporation of antisolvents, which significantly determine the CNF orientation in the end products. Overall, this fundamental study provides deeper insights into the assembling behavior of colloidal nanoparticles such as CNFs, which can advance the development of high-performance man-made fibers.

中文翻译：

---

纳米纤维素表面特性对人造纤维相应湿法纺丝工艺的影响：挤出、凝结和干燥


利用植物细胞壁的基本组成部分纤维素纳米原纤维 （CNF），可以赋予最终材料优异的机械性能。例如，基于 CNF 的湿纺纤维表现出卓越的机械性能，超过了其来源材料植物纤维。如此高的机械性能与 CNF 的取向密切相关;因此，以前的大多数研究都集中在优化纺纱速率或引入后拉伸以提高该参数。在这项研究中，研究了 CNF 表面特性对 CNF 取向的影响，这在文献中经常被忽视：1） 在挤出过程中，CNF 表面特性会影响纺丝悬浮液的流变行为，进而影响 CNF 的取向电位;2） 在凝结过程中，它们控制 CNF 和反溶剂之间的亲和力，从而决定 CNF 凝胶的收缩率;3） 在干燥过程中，它们直接影响抗溶剂蒸发引起的毛细管力，这在很大程度上决定了最终产品中的 CNF 取向。总体而言，这项基础研究为胶体纳米颗粒（如 CNF）的组装行为提供了更深入的见解，这可以推动高性能人造纤维的开发。