Yang Jinhong, Sun Na, Xie Xuelai, Feng Zhangyu, Liu Na, Wang Kai, Lin Min
State Key Laboratory of Bio-Fibers and Eco-Textiles, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China.
College of Textiles and Clothing, Qingdao University, Qingdao 266071, China.
Materials (Basel). 2025 Jun 3;18(11):2619. doi: 10.3390/ma18112619.
The brittleness of alginate fibers has limited their biological applications. Enhancing fiber toughness without sacrificing fracture tensile strength is challenging. Herein, an acidity-triggered helical conformational change in alginate is demonstrated to improve fiber toughness. During fiber formation by Ca crosslinking, HCl triggers 2-helical and antiparallel twofold helical conformational changes in sodium alginate. The helical structures were confirmed using circular dichroism and X-ray diffraction. Rheological analysis revealed that the helical conformation was flexible and could extend fiber elongation from 9.4 ± 0.6 to 15.3 ± 2.2%, while the fracture tensile strength was slightly enhanced by 12.4%, reaching 308 MPa. Thus, toughness was enhanced by 74%, reaching 35.5 ± 2.1 MJ m, thereby reducing brittleness. The introduction of helical structures required no significant changes to the wet-spinning process and exhibited good processability. The improved elongation and toughness will broaden the biomedical applications of alginate fibers.
藻酸盐纤维的脆性限制了它们的生物应用。在不牺牲断裂拉伸强度的情况下提高纤维韧性具有挑战性。在此，证明了藻酸盐中由酸度引发的螺旋构象变化可改善纤维韧性。在通过钙交联形成纤维的过程中，盐酸会引发海藻酸钠中2-螺旋和反平行双螺旋构象变化。使用圆二色性和X射线衍射确认了螺旋结构。流变学分析表明，螺旋构象具有柔韧性，可将纤维伸长率从9.4±0.6%提高到15.3±2.2%，而断裂拉伸强度略有提高12.4%，达到308MPa。因此，韧性提高了74%，达到35.5±2.1MJ/m，从而降低了脆性。螺旋结构的引入不需要对湿纺工艺进行重大改变，并且具有良好的加工性能。伸长率和韧性的提高将拓宽藻酸盐纤维的生物医学应用。
