Liu Jiliang, Sixta Herbert, Ogawa Yu, Hummel Michael, Sztucki Michael, Nishiyama Yoshiharu, Burghammer Manfred
European Synchrotron Radiation Facility, ESRF, 38000 Grenoble, France.
Department of Bioproducts and Biosystem, Aalto University, Finland.
Carbohydr Polym. 2024 Jan 15;324:121512. doi: 10.1016/j.carbpol.2023.121512. Epub 2023 Oct 19.
Cellulose in solution can be assembled into textile fibers by wet-spinning (Viscose etc.) or dry-jet wet spinning (Lyocell, Ioncell etc.), which leads to significant differences in the mechanical properties of fibers. We use scanning X-ray microdiffraction (SXM) to reveal regenerated fibers having a "skin-core" morphology. The "core" region comprises microfibrils (MFs) with ~100 nm in diameter. The cellulose forms elementary fibrils having a ribbon-like cross sectional shape of about 6 × 2 nm, which are packed into MFs. Our SXM studies demonstrate that MFs within Ioncell fibers are composed of elementary fibrils with homogeneous morphologies. Furthermore, the stacking of cellulose molecular sheets within elementary fibrils of Viscose fibers is preferentially along the 010 direction, while those of Ioncell fibers preferably stack in the 1-10 direction. The better structural regularities and distinct morphologies of elementary fibrils give Ioncell fibers enhanced mechanical properties and a wet strength far superior to those of Viscose fibers.
溶液中的纤维素可通过湿法纺丝（粘胶纤维等）或干喷湿纺（莱赛尔纤维、离子纤维素等）组装成纺织纤维，这导致纤维的机械性能存在显著差异。我们使用扫描X射线微衍射（SXM）来揭示具有“皮芯”形态的再生纤维。“芯”区域由直径约为100纳米的微纤丝（MFs）组成。纤维素形成具有约6×2纳米带状横截面形状的基本原纤，这些基本原纤堆积成微纤丝。我们的SXM研究表明，离子纤维素纤维中的微纤丝由形态均匀的基本原纤组成。此外，粘胶纤维基本原纤内纤维素分子片层的堆积优先沿010方向，而离子纤维素纤维的分子片层则优选沿1-10方向堆积。基本原纤更好的结构规整性和独特形态赋予离子纤维素纤维增强的机械性能，其湿强度远优于粘胶纤维。
